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1 /* | |
2 ** 2005 May 25 | |
3 ** | |
4 ** The author disclaims copyright to this source code. In place of | |
5 ** a legal notice, here is a blessing: | |
6 ** | |
7 ** May you do good and not evil. | |
8 ** May you find forgiveness for yourself and forgive others. | |
9 ** May you share freely, never taking more than you give. | |
10 ** | |
11 ************************************************************************* | |
12 ** This file contains the implementation of the sqlite3_prepare() | |
13 ** interface, and routines that contribute to loading the database schema | |
14 ** from disk. | |
15 */ | |
16 #include "sqliteInt.h" | |
17 | |
18 /* | |
19 ** Fill the InitData structure with an error message that indicates | |
20 ** that the database is corrupt. | |
21 */ | |
22 static void corruptSchema( | |
23 InitData *pData, /* Initialization context */ | |
24 const char *zObj, /* Object being parsed at the point of error */ | |
25 const char *zExtra /* Error information */ | |
26 ){ | |
27 sqlite3 *db = pData->db; | |
28 if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){ | |
29 char *z; | |
30 if( zObj==0 ) zObj = "?"; | |
31 z = sqlite3_mprintf("malformed database schema (%s)", zObj); | |
32 if( z && zExtra ) z = sqlite3_mprintf("%z - %s", z, zExtra); | |
33 sqlite3DbFree(db, *pData->pzErrMsg); | |
34 *pData->pzErrMsg = z; | |
35 if( z==0 ) db->mallocFailed = 1; | |
36 } | |
37 pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT; | |
38 } | |
39 | |
40 /* | |
41 ** This is the callback routine for the code that initializes the | |
42 ** database. See sqlite3Init() below for additional information. | |
43 ** This routine is also called from the OP_ParseSchema opcode of the VDBE. | |
44 ** | |
45 ** Each callback contains the following information: | |
46 ** | |
47 ** argv[0] = name of thing being created | |
48 ** argv[1] = root page number for table or index. 0 for trigger or view. | |
49 ** argv[2] = SQL text for the CREATE statement. | |
50 ** | |
51 */ | |
52 int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){ | |
53 InitData *pData = (InitData*)pInit; | |
54 sqlite3 *db = pData->db; | |
55 int iDb = pData->iDb; | |
56 | |
57 assert( argc==3 ); | |
58 UNUSED_PARAMETER2(NotUsed, argc); | |
59 assert( sqlite3_mutex_held(db->mutex) ); | |
60 DbClearProperty(db, iDb, DB_Empty); | |
61 if( db->mallocFailed ){ | |
62 corruptSchema(pData, argv[0], 0); | |
63 return 1; | |
64 } | |
65 | |
66 assert( iDb>=0 && iDb<db->nDb ); | |
67 if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */ | |
68 if( argv[1]==0 ){ | |
69 corruptSchema(pData, argv[0], 0); | |
70 }else if( sqlite3_strnicmp(argv[2],"create ",7)==0 ){ | |
71 /* Call the parser to process a CREATE TABLE, INDEX or VIEW. | |
72 ** But because db->init.busy is set to 1, no VDBE code is generated | |
73 ** or executed. All the parser does is build the internal data | |
74 ** structures that describe the table, index, or view. | |
75 */ | |
76 int rc; | |
77 sqlite3_stmt *pStmt; | |
78 TESTONLY(int rcp); /* Return code from sqlite3_prepare() */ | |
79 | |
80 assert( db->init.busy ); | |
81 db->init.iDb = iDb; | |
82 db->init.newTnum = sqlite3Atoi(argv[1]); | |
83 db->init.orphanTrigger = 0; | |
84 TESTONLY(rcp = ) sqlite3_prepare(db, argv[2], -1, &pStmt, 0); | |
85 rc = db->errCode; | |
86 assert( (rc&0xFF)==(rcp&0xFF) ); | |
87 db->init.iDb = 0; | |
88 if( SQLITE_OK!=rc ){ | |
89 if( db->init.orphanTrigger ){ | |
90 assert( iDb==1 ); | |
91 }else{ | |
92 pData->rc = rc; | |
93 if( rc==SQLITE_NOMEM ){ | |
94 db->mallocFailed = 1; | |
95 }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){ | |
96 corruptSchema(pData, argv[0], sqlite3_errmsg(db)); | |
97 } | |
98 } | |
99 } | |
100 sqlite3_finalize(pStmt); | |
101 }else if( argv[0]==0 || (argv[2]!=0 && argv[2][0]!=0) ){ | |
102 corruptSchema(pData, argv[0], 0); | |
103 }else{ | |
104 /* If the SQL column is blank it means this is an index that | |
105 ** was created to be the PRIMARY KEY or to fulfill a UNIQUE | |
106 ** constraint for a CREATE TABLE. The index should have already | |
107 ** been created when we processed the CREATE TABLE. All we have | |
108 ** to do here is record the root page number for that index. | |
109 */ | |
110 Index *pIndex; | |
111 pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName); | |
112 if( pIndex==0 ){ | |
113 /* This can occur if there exists an index on a TEMP table which | |
114 ** has the same name as another index on a permanent index. Since | |
115 ** the permanent table is hidden by the TEMP table, we can also | |
116 ** safely ignore the index on the permanent table. | |
117 */ | |
118 /* Do Nothing */; | |
119 }else if( sqlite3GetInt32(argv[1], &pIndex->tnum)==0 ){ | |
120 corruptSchema(pData, argv[0], "invalid rootpage"); | |
121 } | |
122 } | |
123 return 0; | |
124 } | |
125 | |
126 /* | |
127 ** Attempt to read the database schema and initialize internal | |
128 ** data structures for a single database file. The index of the | |
129 ** database file is given by iDb. iDb==0 is used for the main | |
130 ** database. iDb==1 should never be used. iDb>=2 is used for | |
131 ** auxiliary databases. Return one of the SQLITE_ error codes to | |
132 ** indicate success or failure. | |
133 */ | |
134 static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){ | |
135 int rc; | |
136 int i; | |
137 #ifndef SQLITE_OMIT_DEPRECATED | |
138 int size; | |
139 #endif | |
140 Table *pTab; | |
141 Db *pDb; | |
142 char const *azArg[4]; | |
143 int meta[5]; | |
144 InitData initData; | |
145 char const *zMasterSchema; | |
146 char const *zMasterName; | |
147 int openedTransaction = 0; | |
148 | |
149 /* | |
150 ** The master database table has a structure like this | |
151 */ | |
152 static const char master_schema[] = | |
153 "CREATE TABLE sqlite_master(\n" | |
154 " type text,\n" | |
155 " name text,\n" | |
156 " tbl_name text,\n" | |
157 " rootpage integer,\n" | |
158 " sql text\n" | |
159 ")" | |
160 ; | |
161 #ifndef SQLITE_OMIT_TEMPDB | |
162 static const char temp_master_schema[] = | |
163 "CREATE TEMP TABLE sqlite_temp_master(\n" | |
164 " type text,\n" | |
165 " name text,\n" | |
166 " tbl_name text,\n" | |
167 " rootpage integer,\n" | |
168 " sql text\n" | |
169 ")" | |
170 ; | |
171 #else | |
172 #define temp_master_schema 0 | |
173 #endif | |
174 | |
175 assert( iDb>=0 && iDb<db->nDb ); | |
176 assert( db->aDb[iDb].pSchema ); | |
177 assert( sqlite3_mutex_held(db->mutex) ); | |
178 assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) ); | |
179 | |
180 /* zMasterSchema and zInitScript are set to point at the master schema | |
181 ** and initialisation script appropriate for the database being | |
182 ** initialized. zMasterName is the name of the master table. | |
183 */ | |
184 if( !OMIT_TEMPDB && iDb==1 ){ | |
185 zMasterSchema = temp_master_schema; | |
186 }else{ | |
187 zMasterSchema = master_schema; | |
188 } | |
189 zMasterName = SCHEMA_TABLE(iDb); | |
190 | |
191 /* Construct the schema tables. */ | |
192 azArg[0] = zMasterName; | |
193 azArg[1] = "1"; | |
194 azArg[2] = zMasterSchema; | |
195 azArg[3] = 0; | |
196 initData.db = db; | |
197 initData.iDb = iDb; | |
198 initData.rc = SQLITE_OK; | |
199 initData.pzErrMsg = pzErrMsg; | |
200 sqlite3InitCallback(&initData, 3, (char **)azArg, 0); | |
201 if( initData.rc ){ | |
202 rc = initData.rc; | |
203 goto error_out; | |
204 } | |
205 pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName); | |
206 if( ALWAYS(pTab) ){ | |
207 pTab->tabFlags |= TF_Readonly; | |
208 } | |
209 | |
210 /* Create a cursor to hold the database open | |
211 */ | |
212 pDb = &db->aDb[iDb]; | |
213 if( pDb->pBt==0 ){ | |
214 if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){ | |
215 DbSetProperty(db, 1, DB_SchemaLoaded); | |
216 } | |
217 return SQLITE_OK; | |
218 } | |
219 | |
220 /* If there is not already a read-only (or read-write) transaction opened | |
221 ** on the b-tree database, open one now. If a transaction is opened, it | |
222 ** will be closed before this function returns. */ | |
223 sqlite3BtreeEnter(pDb->pBt); | |
224 if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){ | |
225 rc = sqlite3BtreeBeginTrans(pDb->pBt, 0); | |
226 if( rc!=SQLITE_OK ){ | |
227 sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc)); | |
228 goto initone_error_out; | |
229 } | |
230 openedTransaction = 1; | |
231 } | |
232 | |
233 /* Get the database meta information. | |
234 ** | |
235 ** Meta values are as follows: | |
236 ** meta[0] Schema cookie. Changes with each schema change. | |
237 ** meta[1] File format of schema layer. | |
238 ** meta[2] Size of the page cache. | |
239 ** meta[3] Largest rootpage (auto/incr_vacuum mode) | |
240 ** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE | |
241 ** meta[5] User version | |
242 ** meta[6] Incremental vacuum mode | |
243 ** meta[7] unused | |
244 ** meta[8] unused | |
245 ** meta[9] unused | |
246 ** | |
247 ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to | |
248 ** the possible values of meta[4]. | |
249 */ | |
250 for(i=0; i<ArraySize(meta); i++){ | |
251 sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]); | |
252 } | |
253 pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1]; | |
254 | |
255 /* If opening a non-empty database, check the text encoding. For the | |
256 ** main database, set sqlite3.enc to the encoding of the main database. | |
257 ** For an attached db, it is an error if the encoding is not the same | |
258 ** as sqlite3.enc. | |
259 */ | |
260 if( meta[BTREE_TEXT_ENCODING-1] ){ /* text encoding */ | |
261 if( iDb==0 ){ | |
262 #ifndef SQLITE_OMIT_UTF16 | |
263 u8 encoding; | |
264 /* If opening the main database, set ENC(db). */ | |
265 encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3; | |
266 if( encoding==0 ) encoding = SQLITE_UTF8; | |
267 ENC(db) = encoding; | |
268 #else | |
269 ENC(db) = SQLITE_UTF8; | |
270 #endif | |
271 }else{ | |
272 /* If opening an attached database, the encoding much match ENC(db) */ | |
273 if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){ | |
274 sqlite3SetString(pzErrMsg, db, "attached databases must use the same" | |
275 " text encoding as main database"); | |
276 rc = SQLITE_ERROR; | |
277 goto initone_error_out; | |
278 } | |
279 } | |
280 }else{ | |
281 DbSetProperty(db, iDb, DB_Empty); | |
282 } | |
283 pDb->pSchema->enc = ENC(db); | |
284 | |
285 if( pDb->pSchema->cache_size==0 ){ | |
286 #ifndef SQLITE_OMIT_DEPRECATED | |
287 size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]); | |
288 if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; } | |
289 pDb->pSchema->cache_size = size; | |
290 #else | |
291 pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE; | |
292 #endif | |
293 sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size); | |
294 } | |
295 | |
296 /* | |
297 ** file_format==1 Version 3.0.0. | |
298 ** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN | |
299 ** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults | |
300 ** file_format==4 Version 3.3.0. // DESC indices. Boolean constants | |
301 */ | |
302 pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1]; | |
303 if( pDb->pSchema->file_format==0 ){ | |
304 pDb->pSchema->file_format = 1; | |
305 } | |
306 if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){ | |
307 sqlite3SetString(pzErrMsg, db, "unsupported file format"); | |
308 rc = SQLITE_ERROR; | |
309 goto initone_error_out; | |
310 } | |
311 | |
312 /* Ticket #2804: When we open a database in the newer file format, | |
313 ** clear the legacy_file_format pragma flag so that a VACUUM will | |
314 ** not downgrade the database and thus invalidate any descending | |
315 ** indices that the user might have created. | |
316 */ | |
317 if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){ | |
318 db->flags &= ~SQLITE_LegacyFileFmt; | |
319 } | |
320 | |
321 /* Read the schema information out of the schema tables | |
322 */ | |
323 assert( db->init.busy ); | |
324 { | |
325 char *zSql; | |
326 zSql = sqlite3MPrintf(db, | |
327 "SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid", | |
328 db->aDb[iDb].zName, zMasterName); | |
329 #ifndef SQLITE_OMIT_AUTHORIZATION | |
330 { | |
331 sqlite3_xauth xAuth; | |
332 xAuth = db->xAuth; | |
333 db->xAuth = 0; | |
334 #endif | |
335 rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0); | |
336 #ifndef SQLITE_OMIT_AUTHORIZATION | |
337 db->xAuth = xAuth; | |
338 } | |
339 #endif | |
340 if( rc==SQLITE_OK ) rc = initData.rc; | |
341 sqlite3DbFree(db, zSql); | |
342 #ifndef SQLITE_OMIT_ANALYZE | |
343 if( rc==SQLITE_OK ){ | |
344 sqlite3AnalysisLoad(db, iDb); | |
345 } | |
346 #endif | |
347 } | |
348 if( db->mallocFailed ){ | |
349 rc = SQLITE_NOMEM; | |
350 sqlite3ResetAllSchemasOfConnection(db); | |
351 } | |
352 if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){ | |
353 /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider | |
354 ** the schema loaded, even if errors occurred. In this situation the | |
355 ** current sqlite3_prepare() operation will fail, but the following one | |
356 ** will attempt to compile the supplied statement against whatever subset | |
357 ** of the schema was loaded before the error occurred. The primary | |
358 ** purpose of this is to allow access to the sqlite_master table | |
359 ** even when its contents have been corrupted. | |
360 */ | |
361 DbSetProperty(db, iDb, DB_SchemaLoaded); | |
362 rc = SQLITE_OK; | |
363 } | |
364 | |
365 /* Jump here for an error that occurs after successfully allocating | |
366 ** curMain and calling sqlite3BtreeEnter(). For an error that occurs | |
367 ** before that point, jump to error_out. | |
368 */ | |
369 initone_error_out: | |
370 if( openedTransaction ){ | |
371 sqlite3BtreeCommit(pDb->pBt); | |
372 } | |
373 sqlite3BtreeLeave(pDb->pBt); | |
374 | |
375 error_out: | |
376 if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ | |
377 db->mallocFailed = 1; | |
378 } | |
379 return rc; | |
380 } | |
381 | |
382 /* | |
383 ** Initialize all database files - the main database file, the file | |
384 ** used to store temporary tables, and any additional database files | |
385 ** created using ATTACH statements. Return a success code. If an | |
386 ** error occurs, write an error message into *pzErrMsg. | |
387 ** | |
388 ** After a database is initialized, the DB_SchemaLoaded bit is set | |
389 ** bit is set in the flags field of the Db structure. If the database | |
390 ** file was of zero-length, then the DB_Empty flag is also set. | |
391 */ | |
392 int sqlite3Init(sqlite3 *db, char **pzErrMsg){ | |
393 int i, rc; | |
394 int commit_internal = !(db->flags&SQLITE_InternChanges); | |
395 | |
396 assert( sqlite3_mutex_held(db->mutex) ); | |
397 assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) ); | |
398 assert( db->init.busy==0 ); | |
399 rc = SQLITE_OK; | |
400 db->init.busy = 1; | |
401 ENC(db) = SCHEMA_ENC(db); | |
402 for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ | |
403 if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue; | |
404 rc = sqlite3InitOne(db, i, pzErrMsg); | |
405 if( rc ){ | |
406 sqlite3ResetOneSchema(db, i); | |
407 } | |
408 } | |
409 | |
410 /* Once all the other databases have been initialized, load the schema | |
411 ** for the TEMP database. This is loaded last, as the TEMP database | |
412 ** schema may contain references to objects in other databases. | |
413 */ | |
414 #ifndef SQLITE_OMIT_TEMPDB | |
415 assert( db->nDb>1 ); | |
416 if( rc==SQLITE_OK && !DbHasProperty(db, 1, DB_SchemaLoaded) ){ | |
417 rc = sqlite3InitOne(db, 1, pzErrMsg); | |
418 if( rc ){ | |
419 sqlite3ResetOneSchema(db, 1); | |
420 } | |
421 } | |
422 #endif | |
423 | |
424 db->init.busy = 0; | |
425 if( rc==SQLITE_OK && commit_internal ){ | |
426 sqlite3CommitInternalChanges(db); | |
427 } | |
428 | |
429 return rc; | |
430 } | |
431 | |
432 /* | |
433 ** This routine is a no-op if the database schema is already initialized. | |
434 ** Otherwise, the schema is loaded. An error code is returned. | |
435 */ | |
436 int sqlite3ReadSchema(Parse *pParse){ | |
437 int rc = SQLITE_OK; | |
438 sqlite3 *db = pParse->db; | |
439 assert( sqlite3_mutex_held(db->mutex) ); | |
440 if( !db->init.busy ){ | |
441 rc = sqlite3Init(db, &pParse->zErrMsg); | |
442 } | |
443 if( rc!=SQLITE_OK ){ | |
444 pParse->rc = rc; | |
445 pParse->nErr++; | |
446 } | |
447 return rc; | |
448 } | |
449 | |
450 | |
451 /* | |
452 ** Check schema cookies in all databases. If any cookie is out | |
453 ** of date set pParse->rc to SQLITE_SCHEMA. If all schema cookies | |
454 ** make no changes to pParse->rc. | |
455 */ | |
456 static void schemaIsValid(Parse *pParse){ | |
457 sqlite3 *db = pParse->db; | |
458 int iDb; | |
459 int rc; | |
460 int cookie; | |
461 | |
462 assert( pParse->checkSchema ); | |
463 assert( sqlite3_mutex_held(db->mutex) ); | |
464 for(iDb=0; iDb<db->nDb; iDb++){ | |
465 int openedTransaction = 0; /* True if a transaction is opened */ | |
466 Btree *pBt = db->aDb[iDb].pBt; /* Btree database to read cookie from */ | |
467 if( pBt==0 ) continue; | |
468 | |
469 /* If there is not already a read-only (or read-write) transaction opened | |
470 ** on the b-tree database, open one now. If a transaction is opened, it | |
471 ** will be closed immediately after reading the meta-value. */ | |
472 if( !sqlite3BtreeIsInReadTrans(pBt) ){ | |
473 rc = sqlite3BtreeBeginTrans(pBt, 0); | |
474 if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ | |
475 db->mallocFailed = 1; | |
476 } | |
477 if( rc!=SQLITE_OK ) return; | |
478 openedTransaction = 1; | |
479 } | |
480 | |
481 /* Read the schema cookie from the database. If it does not match the | |
482 ** value stored as part of the in-memory schema representation, | |
483 ** set Parse.rc to SQLITE_SCHEMA. */ | |
484 sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie); | |
485 assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); | |
486 if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){ | |
487 sqlite3ResetOneSchema(db, iDb); | |
488 pParse->rc = SQLITE_SCHEMA; | |
489 } | |
490 | |
491 /* Close the transaction, if one was opened. */ | |
492 if( openedTransaction ){ | |
493 sqlite3BtreeCommit(pBt); | |
494 } | |
495 } | |
496 } | |
497 | |
498 /* | |
499 ** Convert a schema pointer into the iDb index that indicates | |
500 ** which database file in db->aDb[] the schema refers to. | |
501 ** | |
502 ** If the same database is attached more than once, the first | |
503 ** attached database is returned. | |
504 */ | |
505 int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){ | |
506 int i = -1000000; | |
507 | |
508 /* If pSchema is NULL, then return -1000000. This happens when code in | |
509 ** expr.c is trying to resolve a reference to a transient table (i.e. one | |
510 ** created by a sub-select). In this case the return value of this | |
511 ** function should never be used. | |
512 ** | |
513 ** We return -1000000 instead of the more usual -1 simply because using | |
514 ** -1000000 as the incorrect index into db->aDb[] is much | |
515 ** more likely to cause a segfault than -1 (of course there are assert() | |
516 ** statements too, but it never hurts to play the odds). | |
517 */ | |
518 assert( sqlite3_mutex_held(db->mutex) ); | |
519 if( pSchema ){ | |
520 for(i=0; ALWAYS(i<db->nDb); i++){ | |
521 if( db->aDb[i].pSchema==pSchema ){ | |
522 break; | |
523 } | |
524 } | |
525 assert( i>=0 && i<db->nDb ); | |
526 } | |
527 return i; | |
528 } | |
529 | |
530 /* | |
531 ** Free all memory allocations in the pParse object | |
532 */ | |
533 void sqlite3ParserReset(Parse *pParse){ | |
534 if( pParse ){ | |
535 sqlite3 *db = pParse->db; | |
536 sqlite3DbFree(db, pParse->aLabel); | |
537 sqlite3ExprListDelete(db, pParse->pConstExpr); | |
538 } | |
539 } | |
540 | |
541 /* | |
542 ** Compile the UTF-8 encoded SQL statement zSql into a statement handle. | |
543 */ | |
544 static int sqlite3Prepare( | |
545 sqlite3 *db, /* Database handle. */ | |
546 const char *zSql, /* UTF-8 encoded SQL statement. */ | |
547 int nBytes, /* Length of zSql in bytes. */ | |
548 int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */ | |
549 Vdbe *pReprepare, /* VM being reprepared */ | |
550 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
551 const char **pzTail /* OUT: End of parsed string */ | |
552 ){ | |
553 Parse *pParse; /* Parsing context */ | |
554 char *zErrMsg = 0; /* Error message */ | |
555 int rc = SQLITE_OK; /* Result code */ | |
556 int i; /* Loop counter */ | |
557 | |
558 /* Allocate the parsing context */ | |
559 pParse = sqlite3StackAllocZero(db, sizeof(*pParse)); | |
560 if( pParse==0 ){ | |
561 rc = SQLITE_NOMEM; | |
562 goto end_prepare; | |
563 } | |
564 pParse->pReprepare = pReprepare; | |
565 assert( ppStmt && *ppStmt==0 ); | |
566 assert( !db->mallocFailed ); | |
567 assert( sqlite3_mutex_held(db->mutex) ); | |
568 | |
569 /* Check to verify that it is possible to get a read lock on all | |
570 ** database schemas. The inability to get a read lock indicates that | |
571 ** some other database connection is holding a write-lock, which in | |
572 ** turn means that the other connection has made uncommitted changes | |
573 ** to the schema. | |
574 ** | |
575 ** Were we to proceed and prepare the statement against the uncommitted | |
576 ** schema changes and if those schema changes are subsequently rolled | |
577 ** back and different changes are made in their place, then when this | |
578 ** prepared statement goes to run the schema cookie would fail to detect | |
579 ** the schema change. Disaster would follow. | |
580 ** | |
581 ** This thread is currently holding mutexes on all Btrees (because | |
582 ** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it | |
583 ** is not possible for another thread to start a new schema change | |
584 ** while this routine is running. Hence, we do not need to hold | |
585 ** locks on the schema, we just need to make sure nobody else is | |
586 ** holding them. | |
587 ** | |
588 ** Note that setting READ_UNCOMMITTED overrides most lock detection, | |
589 ** but it does *not* override schema lock detection, so this all still | |
590 ** works even if READ_UNCOMMITTED is set. | |
591 */ | |
592 for(i=0; i<db->nDb; i++) { | |
593 Btree *pBt = db->aDb[i].pBt; | |
594 if( pBt ){ | |
595 assert( sqlite3BtreeHoldsMutex(pBt) ); | |
596 rc = sqlite3BtreeSchemaLocked(pBt); | |
597 if( rc ){ | |
598 const char *zDb = db->aDb[i].zName; | |
599 sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb); | |
600 testcase( db->flags & SQLITE_ReadUncommitted ); | |
601 goto end_prepare; | |
602 } | |
603 } | |
604 } | |
605 | |
606 sqlite3VtabUnlockList(db); | |
607 | |
608 pParse->db = db; | |
609 pParse->nQueryLoop = 0; /* Logarithmic, so 0 really means 1 */ | |
610 if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){ | |
611 char *zSqlCopy; | |
612 int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH]; | |
613 testcase( nBytes==mxLen ); | |
614 testcase( nBytes==mxLen+1 ); | |
615 if( nBytes>mxLen ){ | |
616 sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long"); | |
617 rc = sqlite3ApiExit(db, SQLITE_TOOBIG); | |
618 goto end_prepare; | |
619 } | |
620 zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes); | |
621 if( zSqlCopy ){ | |
622 sqlite3RunParser(pParse, zSqlCopy, &zErrMsg); | |
623 sqlite3DbFree(db, zSqlCopy); | |
624 pParse->zTail = &zSql[pParse->zTail-zSqlCopy]; | |
625 }else{ | |
626 pParse->zTail = &zSql[nBytes]; | |
627 } | |
628 }else{ | |
629 sqlite3RunParser(pParse, zSql, &zErrMsg); | |
630 } | |
631 assert( 0==pParse->nQueryLoop ); | |
632 | |
633 if( db->mallocFailed ){ | |
634 pParse->rc = SQLITE_NOMEM; | |
635 } | |
636 if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK; | |
637 if( pParse->checkSchema ){ | |
638 schemaIsValid(pParse); | |
639 } | |
640 if( db->mallocFailed ){ | |
641 pParse->rc = SQLITE_NOMEM; | |
642 } | |
643 if( pzTail ){ | |
644 *pzTail = pParse->zTail; | |
645 } | |
646 rc = pParse->rc; | |
647 | |
648 #ifndef SQLITE_OMIT_EXPLAIN | |
649 if( rc==SQLITE_OK && pParse->pVdbe && pParse->explain ){ | |
650 static const char * const azColName[] = { | |
651 "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment", | |
652 "selectid", "order", "from", "detail" | |
653 }; | |
654 int iFirst, mx; | |
655 if( pParse->explain==2 ){ | |
656 sqlite3VdbeSetNumCols(pParse->pVdbe, 4); | |
657 iFirst = 8; | |
658 mx = 12; | |
659 }else{ | |
660 sqlite3VdbeSetNumCols(pParse->pVdbe, 8); | |
661 iFirst = 0; | |
662 mx = 8; | |
663 } | |
664 for(i=iFirst; i<mx; i++){ | |
665 sqlite3VdbeSetColName(pParse->pVdbe, i-iFirst, COLNAME_NAME, | |
666 azColName[i], SQLITE_STATIC); | |
667 } | |
668 } | |
669 #endif | |
670 | |
671 if( db->init.busy==0 ){ | |
672 Vdbe *pVdbe = pParse->pVdbe; | |
673 sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag); | |
674 } | |
675 if( pParse->pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){ | |
676 sqlite3VdbeFinalize(pParse->pVdbe); | |
677 assert(!(*ppStmt)); | |
678 }else{ | |
679 *ppStmt = (sqlite3_stmt*)pParse->pVdbe; | |
680 } | |
681 | |
682 if( zErrMsg ){ | |
683 sqlite3ErrorWithMsg(db, rc, "%s", zErrMsg); | |
684 sqlite3DbFree(db, zErrMsg); | |
685 }else{ | |
686 sqlite3Error(db, rc); | |
687 } | |
688 | |
689 /* Delete any TriggerPrg structures allocated while parsing this statement. */ | |
690 while( pParse->pTriggerPrg ){ | |
691 TriggerPrg *pT = pParse->pTriggerPrg; | |
692 pParse->pTriggerPrg = pT->pNext; | |
693 sqlite3DbFree(db, pT); | |
694 } | |
695 | |
696 end_prepare: | |
697 | |
698 sqlite3ParserReset(pParse); | |
699 sqlite3StackFree(db, pParse); | |
700 rc = sqlite3ApiExit(db, rc); | |
701 assert( (rc&db->errMask)==rc ); | |
702 return rc; | |
703 } | |
704 static int sqlite3LockAndPrepare( | |
705 sqlite3 *db, /* Database handle. */ | |
706 const char *zSql, /* UTF-8 encoded SQL statement. */ | |
707 int nBytes, /* Length of zSql in bytes. */ | |
708 int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */ | |
709 Vdbe *pOld, /* VM being reprepared */ | |
710 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
711 const char **pzTail /* OUT: End of parsed string */ | |
712 ){ | |
713 int rc; | |
714 | |
715 #ifdef SQLITE_ENABLE_API_ARMOR | |
716 if( ppStmt==0 ) return SQLITE_MISUSE_BKPT; | |
717 #endif | |
718 *ppStmt = 0; | |
719 if( !sqlite3SafetyCheckOk(db)||zSql==0 ){ | |
720 return SQLITE_MISUSE_BKPT; | |
721 } | |
722 sqlite3_mutex_enter(db->mutex); | |
723 sqlite3BtreeEnterAll(db); | |
724 rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail); | |
725 if( rc==SQLITE_SCHEMA ){ | |
726 sqlite3_finalize(*ppStmt); | |
727 rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, pOld, ppStmt, pzTail); | |
728 } | |
729 sqlite3BtreeLeaveAll(db); | |
730 sqlite3_mutex_leave(db->mutex); | |
731 assert( rc==SQLITE_OK || *ppStmt==0 ); | |
732 return rc; | |
733 } | |
734 | |
735 /* | |
736 ** Rerun the compilation of a statement after a schema change. | |
737 ** | |
738 ** If the statement is successfully recompiled, return SQLITE_OK. Otherwise, | |
739 ** if the statement cannot be recompiled because another connection has | |
740 ** locked the sqlite3_master table, return SQLITE_LOCKED. If any other error | |
741 ** occurs, return SQLITE_SCHEMA. | |
742 */ | |
743 int sqlite3Reprepare(Vdbe *p){ | |
744 int rc; | |
745 sqlite3_stmt *pNew; | |
746 const char *zSql; | |
747 sqlite3 *db; | |
748 | |
749 assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) ); | |
750 zSql = sqlite3_sql((sqlite3_stmt *)p); | |
751 assert( zSql!=0 ); /* Reprepare only called for prepare_v2() statements */ | |
752 db = sqlite3VdbeDb(p); | |
753 assert( sqlite3_mutex_held(db->mutex) ); | |
754 rc = sqlite3LockAndPrepare(db, zSql, -1, 0, p, &pNew, 0); | |
755 if( rc ){ | |
756 if( rc==SQLITE_NOMEM ){ | |
757 db->mallocFailed = 1; | |
758 } | |
759 assert( pNew==0 ); | |
760 return rc; | |
761 }else{ | |
762 assert( pNew!=0 ); | |
763 } | |
764 sqlite3VdbeSwap((Vdbe*)pNew, p); | |
765 sqlite3TransferBindings(pNew, (sqlite3_stmt*)p); | |
766 sqlite3VdbeResetStepResult((Vdbe*)pNew); | |
767 sqlite3VdbeFinalize((Vdbe*)pNew); | |
768 return SQLITE_OK; | |
769 } | |
770 | |
771 | |
772 /* | |
773 ** Two versions of the official API. Legacy and new use. In the legacy | |
774 ** version, the original SQL text is not saved in the prepared statement | |
775 ** and so if a schema change occurs, SQLITE_SCHEMA is returned by | |
776 ** sqlite3_step(). In the new version, the original SQL text is retained | |
777 ** and the statement is automatically recompiled if an schema change | |
778 ** occurs. | |
779 */ | |
780 int sqlite3_prepare( | |
781 sqlite3 *db, /* Database handle. */ | |
782 const char *zSql, /* UTF-8 encoded SQL statement. */ | |
783 int nBytes, /* Length of zSql in bytes. */ | |
784 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
785 const char **pzTail /* OUT: End of parsed string */ | |
786 ){ | |
787 int rc; | |
788 rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,0,ppStmt,pzTail); | |
789 assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ | |
790 return rc; | |
791 } | |
792 int sqlite3_prepare_v2( | |
793 sqlite3 *db, /* Database handle. */ | |
794 const char *zSql, /* UTF-8 encoded SQL statement. */ | |
795 int nBytes, /* Length of zSql in bytes. */ | |
796 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
797 const char **pzTail /* OUT: End of parsed string */ | |
798 ){ | |
799 int rc; | |
800 rc = sqlite3LockAndPrepare(db,zSql,nBytes,1,0,ppStmt,pzTail); | |
801 assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ | |
802 return rc; | |
803 } | |
804 | |
805 | |
806 #ifndef SQLITE_OMIT_UTF16 | |
807 /* | |
808 ** Compile the UTF-16 encoded SQL statement zSql into a statement handle. | |
809 */ | |
810 static int sqlite3Prepare16( | |
811 sqlite3 *db, /* Database handle. */ | |
812 const void *zSql, /* UTF-16 encoded SQL statement. */ | |
813 int nBytes, /* Length of zSql in bytes. */ | |
814 int saveSqlFlag, /* True to save SQL text into the sqlite3_stmt */ | |
815 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
816 const void **pzTail /* OUT: End of parsed string */ | |
817 ){ | |
818 /* This function currently works by first transforming the UTF-16 | |
819 ** encoded string to UTF-8, then invoking sqlite3_prepare(). The | |
820 ** tricky bit is figuring out the pointer to return in *pzTail. | |
821 */ | |
822 char *zSql8; | |
823 const char *zTail8 = 0; | |
824 int rc = SQLITE_OK; | |
825 | |
826 #ifdef SQLITE_ENABLE_API_ARMOR | |
827 if( ppStmt==0 ) return SQLITE_MISUSE_BKPT; | |
828 #endif | |
829 *ppStmt = 0; | |
830 if( !sqlite3SafetyCheckOk(db)||zSql==0 ){ | |
831 return SQLITE_MISUSE_BKPT; | |
832 } | |
833 if( nBytes>=0 ){ | |
834 int sz; | |
835 const char *z = (const char*)zSql; | |
836 for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){} | |
837 nBytes = sz; | |
838 } | |
839 sqlite3_mutex_enter(db->mutex); | |
840 zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE); | |
841 if( zSql8 ){ | |
842 rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, 0, ppStmt, &zTail8); | |
843 } | |
844 | |
845 if( zTail8 && pzTail ){ | |
846 /* If sqlite3_prepare returns a tail pointer, we calculate the | |
847 ** equivalent pointer into the UTF-16 string by counting the unicode | |
848 ** characters between zSql8 and zTail8, and then returning a pointer | |
849 ** the same number of characters into the UTF-16 string. | |
850 */ | |
851 int chars_parsed = sqlite3Utf8CharLen(zSql8, (int)(zTail8-zSql8)); | |
852 *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed); | |
853 } | |
854 sqlite3DbFree(db, zSql8); | |
855 rc = sqlite3ApiExit(db, rc); | |
856 sqlite3_mutex_leave(db->mutex); | |
857 return rc; | |
858 } | |
859 | |
860 /* | |
861 ** Two versions of the official API. Legacy and new use. In the legacy | |
862 ** version, the original SQL text is not saved in the prepared statement | |
863 ** and so if a schema change occurs, SQLITE_SCHEMA is returned by | |
864 ** sqlite3_step(). In the new version, the original SQL text is retained | |
865 ** and the statement is automatically recompiled if an schema change | |
866 ** occurs. | |
867 */ | |
868 int sqlite3_prepare16( | |
869 sqlite3 *db, /* Database handle. */ | |
870 const void *zSql, /* UTF-16 encoded SQL statement. */ | |
871 int nBytes, /* Length of zSql in bytes. */ | |
872 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
873 const void **pzTail /* OUT: End of parsed string */ | |
874 ){ | |
875 int rc; | |
876 rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail); | |
877 assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ | |
878 return rc; | |
879 } | |
880 int sqlite3_prepare16_v2( | |
881 sqlite3 *db, /* Database handle. */ | |
882 const void *zSql, /* UTF-16 encoded SQL statement. */ | |
883 int nBytes, /* Length of zSql in bytes. */ | |
884 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
885 const void **pzTail /* OUT: End of parsed string */ | |
886 ){ | |
887 int rc; | |
888 rc = sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail); | |
889 assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ | |
890 return rc; | |
891 } | |
892 | |
893 #endif /* SQLITE_OMIT_UTF16 */ | |
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