GeezerVisonThe World Wide Web, restored to 800 pixels of glory. |
| Home|About|Gaming cabinet|Archives|How it works|Starter sites |
GeezerVison is showing github.com — sqlcipher/src/prepare.c at master · securitykernel/sqlcipher Expand file tree/ Copy pathprepare.cMore file actions 929 lines (871 loc) · 31 KB / Copy pathprepare.cFile metadata and controls929 lines (871 loc) · 31 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 /* ** 2005 May 25 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the implementation of the sqlite3_prepare() ** interface, and routines that contribute to loading the database schema ** from disk. */ #include "sqliteInt.h" /* ** Fill the InitData structure with an error message that indicates ** that the database is corrupt. */ static void corruptSchema( InitData *pData, /* Initialization context */ const char *zObj, /* Object being parsed at the point of error */ const char *zExtra /* Error information */ ){ sqlite3 *db = pData->db; if( db->mallocFailed ){ pData->rc = SQLITE_NOMEM_BKPT; }else if( pData->pzErrMsg[0]!=0 ){ /* A error message has already been generated. Do not overwrite it */ }else if( pData->mInitFlags & INITFLAG_AlterTable ){ *pData->pzErrMsg = sqlite3DbStrDup(db, zExtra); pData->rc = SQLITE_ERROR; }else if( db->flags & SQLITE_WriteSchema ){ pData->rc = SQLITE_CORRUPT_BKPT; }else{ char *z; if( zObj==0 ) zObj = "?"; z = sqlite3MPrintf(db, "malformed database schema (%s)", zObj); if( zExtra && zExtra[0] ) z = sqlite3MPrintf(db, "%z - %s", z, zExtra); *pData->pzErrMsg = z; pData->rc = SQLITE_CORRUPT_BKPT; } } /* ** Check to see if any sibling index (another index on the same table) ** of pIndex has the same root page number, and if it does, return true. ** This would indicate a corrupt schema. */ int sqlite3IndexHasDuplicateRootPage(Index *pIndex){ Index *p; for(p=pIndex->pTable->pIndex; p; p=p->pNext){ if( p->tnum==pIndex->tnum && p!=pIndex ) return 1; } return 0; } /* forward declaration */ static int sqlite3Prepare( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */ Vdbe *pReprepare, /* VM being reprepared */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ); /* ** This is the callback routine for the code that initializes the ** database. See sqlite3Init() below for additional information. ** This routine is also called from the OP_ParseSchema opcode of the VDBE. ** ** Each callback contains the following information: ** ** argv[0] = type of object: "table", "index", "trigger", or "view". ** argv[1] = name of thing being created ** argv[2] = associated table if an index or trigger ** argv[3] = root page number for table or index. 0 for trigger or view. ** argv[4] = SQL text for the CREATE statement. ** */ int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){ InitData *pData = (InitData*)pInit; sqlite3 *db = pData->db; int iDb = pData->iDb; assert( argc==5 ); UNUSED_PARAMETER2(NotUsed, argc); assert( sqlite3_mutex_held(db->mutex) ); DbClearProperty(db, iDb, DB_Empty); pData->nInitRow++; if( db->mallocFailed ){ corruptSchema(pData, argv[1], 0); return 1; } assert( iDb>=0 && iDb<db->nDb ); if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */ if( argv[3]==0 ){ corruptSchema(pData, argv[1], 0); }else if( sqlite3_strnicmp(argv[4],"create ",7)==0 ){ /* Call the parser to process a CREATE TABLE, INDEX or VIEW. ** But because db->init.busy is set to 1, no VDBE code is generated ** or executed. All the parser does is build the internal data ** structures that describe the table, index, or view. */ int rc; u8 saved_iDb = db->init.iDb; sqlite3_stmt *pStmt; TESTONLY(int rcp); /* Return code from sqlite3_prepare() */ assert( db->init.busy ); db->init.iDb = iDb; db->init.newTnum = sqlite3Atoi(argv[3]); db->init.orphanTrigger = 0; db->init.azInit = argv; pStmt = 0; TESTONLY(rcp = ) sqlite3Prepare(db, argv[4], -1, 0, 0, &pStmt, 0); rc = db->errCode; assert( (rc&0xFF)==(rcp&0xFF) ); db->init.iDb = saved_iDb; /* assert( saved_iDb==0 || (db->mDbFlags & DBFLAG_Vacuum)!=0 ); */ if( SQLITE_OK!=rc ){ if( db->init.orphanTrigger ){ assert( iDb==1 ); }else{ if( rc > pData->rc ) pData->rc = rc; if( rc==SQLITE_NOMEM ){ sqlite3OomFault(db); }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){ corruptSchema(pData, argv[1], sqlite3_errmsg(db)); } } } sqlite3_finalize(pStmt); }else if( argv[1]==0 || (argv[4]!=0 && argv[4][0]!=0) ){ corruptSchema(pData, argv[1], 0); }else{ /* If the SQL column is blank it means this is an index that ** was created to be the PRIMARY KEY or to fulfill a UNIQUE ** constraint for a CREATE TABLE. The index should have already ** been created when we processed the CREATE TABLE. All we have ** to do here is record the root page number for that index. */ Index *pIndex; pIndex = sqlite3FindIndex(db, argv[1], db->aDb[iDb].zDbSName); if( pIndex==0 || sqlite3GetInt32(argv[3],&pIndex->tnum)==0 || pIndex->tnum<2 || sqlite3IndexHasDuplicateRootPage(pIndex) ){ corruptSchema(pData, argv[1], pIndex?"invalid rootpage":"orphan index"); } } return 0; } /* ** Attempt to read the database schema and initialize internal ** data structures for a single database file. The index of the ** database file is given by iDb. iDb==0 is used for the main ** database. iDb==1 should never be used. iDb>=2 is used for ** auxiliary databases. Return one of the SQLITE_ error codes to ** indicate success or failure. */ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){ int rc; int i; #ifndef SQLITE_OMIT_DEPRECATED int size; #endif Db *pDb; char const *azArg[6]; int meta[5]; InitData initData; const char *zMasterName; int openedTransaction = 0; assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 ); assert( iDb>=0 && iDb<db->nDb ); assert( db->aDb[iDb].pSchema ); assert( sqlite3_mutex_held(db->mutex) ); assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) ); db->init.busy = 1; /* Construct the in-memory representation schema tables (sqlite_master or ** sqlite_temp_master) by invoking the parser directly. The appropriate ** table name will be inserted automatically by the parser so we can just ** use the abbreviation "x" here. The parser will also automatically tag ** the schema table as read-only. */ azArg[0] = "table"; azArg[1] = zMasterName = SCHEMA_TABLE(iDb); azArg[2] = azArg[1]; azArg[3] = "1"; azArg[4] = "CREATE TABLE x(type text,name text,tbl_name text," "rootpage int,sql text)"; azArg[5] = 0; initData.db = db; initData.iDb = iDb; initData.rc = SQLITE_OK; initData.pzErrMsg = pzErrMsg; initData.mInitFlags = mFlags; initData.nInitRow = 0; sqlite3InitCallback(&initData, 5, (char **)azArg, 0); if( initData.rc ){ rc = initData.rc; goto error_out; } /* Create a cursor to hold the database open */ pDb = &db->aDb[iDb]; if( pDb->pBt==0 ){ assert( iDb==1 ); DbSetProperty(db, 1, DB_SchemaLoaded); rc = SQLITE_OK; goto error_out; } /* If there is not already a read-only (or read-write) transaction opened ** on the b-tree database, open one now. If a transaction is opened, it ** will be closed before this function returns. */ sqlite3BtreeEnter(pDb->pBt); if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){ rc = sqlite3BtreeBeginTrans(pDb->pBt, 0, 0); if( rc!=SQLITE_OK ){ sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc)); goto initone_error_out; } openedTransaction = 1; } /* Get the database meta information. ** ** Meta values are as follows: ** meta[0] Schema cookie. Changes with each schema change. ** meta[1] File format of schema layer. ** meta[2] Size of the page cache. ** meta[3] Largest rootpage (auto/incr_vacuum mode) ** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE ** meta[5] User version ** meta[6] Incremental vacuum mode ** meta[7] unused ** meta[8] unused ** meta[9] unused ** ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to ** the possible values of meta[4]. */ for(i=0; i<ArraySize(meta); i++){ sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]); } if( (db->flags & SQLITE_ResetDatabase)!=0 ){ memset(meta, 0, sizeof(meta)); } pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1]; /* If opening a non-empty database, check the text encoding. For the ** main database, set sqlite3.enc to the encoding of the main database. ** For an attached db, it is an error if the encoding is not the same ** as sqlite3.enc. */ if( meta[BTREE_TEXT_ENCODING-1] ){ /* text encoding */ if( iDb==0 ){ #ifndef SQLITE_OMIT_UTF16 u8 encoding; /* If opening the main database, set ENC(db). */ encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3; if( encoding==0 ) encoding = SQLITE_UTF8; ENC(db) = encoding; #else ENC(db) = SQLITE_UTF8; #endif }else{ /* If opening an attached database, the encoding much match ENC(db) */ if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){ sqlite3SetString(pzErrMsg, db, "attached databases must use the same" " text encoding as main database"); rc = SQLITE_ERROR; goto initone_error_out; } } }else{ DbSetProperty(db, iDb, DB_Empty); } pDb->pSchema->enc = ENC(db); if( pDb->pSchema->cache_size==0 ){ #ifndef SQLITE_OMIT_DEPRECATED size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]); if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; } pDb->pSchema->cache_size = size; #else pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE; #endif sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size); } /* ** file_format==1 Version 3.0.0. ** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN ** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults ** file_format==4 Version 3.3.0. // DESC indices. Boolean constants */ pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1]; if( pDb->pSchema->file_format==0 ){ pDb->pSchema->file_format = 1; } if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){ sqlite3SetString(pzErrMsg, db, "unsupported file format"); rc = SQLITE_ERROR; goto initone_error_out; } /* Ticket #2804: When we open a database in the newer file format, ** clear the legacy_file_format pragma flag so that a VACUUM will ** not downgrade the database and thus invalidate any descending ** indices that the user might have created. */ if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){ db->flags &= ~(u64)SQLITE_LegacyFileFmt; } /* Read the schema information out of the schema tables */ assert( db->init.busy ); { char *zSql; zSql = sqlite3MPrintf(db, "SELECT*FROM\"%w\".%s ORDER BY rowid", db->aDb[iDb].zDbSName, zMasterName); #ifndef SQLITE_OMIT_AUTHORIZATION { sqlite3_xauth xAuth; xAuth = db->xAuth; db->xAuth = 0; #endif rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0); #ifndef SQLITE_OMIT_AUTHORIZATION db->xAuth = xAuth; } #endif if( rc==SQLITE_OK ) rc = initData.rc; sqlite3DbFree(db, zSql); #ifndef SQLITE_OMIT_ANALYZE if( rc==SQLITE_OK ){ sqlite3AnalysisLoad(db, iDb); } #endif } if( db->mallocFailed ){ rc = SQLITE_NOMEM_BKPT; sqlite3ResetAllSchemasOfConnection(db); } if( rc==SQLITE_OK || (db->flags&SQLITE_NoSchemaError)){ /* Black magic: If the SQLITE_NoSchemaError flag is set, then consider ** the schema loaded, even if errors occurred. In this situation the ** current sqlite3_prepare() operation will fail, but the following one ** will attempt to compile the supplied statement against whatever subset ** of the schema was loaded before the error occurred. The primary ** purpose of this is to allow access to the sqlite_master table ** even when its contents have been corrupted. */ DbSetProperty(db, iDb, DB_SchemaLoaded); rc = SQLITE_OK; } /* Jump here for an error that occurs after successfully allocating ** curMain and calling sqlite3BtreeEnter(). For an error that occurs ** before that point, jump to error_out. */ initone_error_out: if( openedTransaction ){ sqlite3BtreeCommit(pDb->pBt); } sqlite3BtreeLeave(pDb->pBt); error_out: if( rc ){ if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ sqlite3OomFault(db); } sqlite3ResetOneSchema(db, iDb); } db->init.busy = 0; return rc; } /* ** Initialize all database files - the main database file, the file ** used to store temporary tables, and any additional database files ** created using ATTACH statements. Return a success code. If an ** error occurs, write an error message into *pzErrMsg. ** ** After a database is initialized, the DB_SchemaLoaded bit is set ** bit is set in the flags field of the Db structure. If the database ** file was of zero-length, then the DB_Empty flag is also set. */ int sqlite3Init(sqlite3 *db, char **pzErrMsg){ int i, rc; int commit_internal = !(db->mDbFlags&DBFLAG_SchemaChange); assert( sqlite3_mutex_held(db->mutex) ); assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) ); assert( db->init.busy==0 ); ENC(db) = SCHEMA_ENC(db); assert( db->nDb>0 ); /* Do the main schema first */ if( !DbHasProperty(db, 0, DB_SchemaLoaded) ){ rc = sqlite3InitOne(db, 0, pzErrMsg, 0); if( rc ) return rc; } /* All other schemas after the main schema. The "temp" schema must be last */ for(i=db->nDb-1; i>0; i--){ assert( i==1 || sqlite3BtreeHoldsMutex(db->aDb[i].pBt) ); if( !DbHasProperty(db, i, DB_SchemaLoaded) ){ rc = sqlite3InitOne(db, i, pzErrMsg, 0); if( rc ) return rc; } } if( commit_internal ){ sqlite3CommitInternalChanges(db); } return SQLITE_OK; } /* ** This routine is a no-op if the database schema is already initialized. ** Otherwise, the schema is loaded. An error code is returned. */ int sqlite3ReadSchema(Parse *pParse){ int rc = SQLITE_OK; sqlite3 *db = pParse->db; assert( sqlite3_mutex_held(db->mutex) ); if( !db->init.busy ){ rc = sqlite3Init(db, &pParse->zErrMsg); if( rc!=SQLITE_OK ){ pParse->rc = rc; pParse->nErr++; }else if( db->noSharedCache ){ db->mDbFlags |= DBFLAG_SchemaKnownOk; } } return rc; } /* ** Check schema cookies in all databases. If any cookie is out ** of date set pParse->rc to SQLITE_SCHEMA. If all schema cookies ** make no changes to pParse->rc. */ static void schemaIsValid(Parse *pParse){ sqlite3 *db = pParse->db; int iDb; int rc; int cookie; assert( pParse->checkSchema ); assert( sqlite3_mutex_held(db->mutex) ); for(iDb=0; iDb<db->nDb; iDb++){ int openedTransaction = 0; /* True if a transaction is opened */ Btree *pBt = db->aDb[iDb].pBt; /* Btree database to read cookie from */ if( pBt==0 ) continue; /* If there is not already a read-only (or read-write) transaction opened ** on the b-tree database, open one now. If a transaction is opened, it ** will be closed immediately after reading the meta-value. */ if( !sqlite3BtreeIsInReadTrans(pBt) ){ rc = sqlite3BtreeBeginTrans(pBt, 0, 0); if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ sqlite3OomFault(db); } if( rc!=SQLITE_OK ) return; openedTransaction = 1; } /* Read the schema cookie from the database. If it does not match the ** value stored as part of the in-memory schema representation, ** set Parse.rc to SQLITE_SCHEMA. */ sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie); assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){ sqlite3ResetOneSchema(db, iDb); pParse->rc = SQLITE_SCHEMA; } /* Close the transaction, if one was opened. */ if( openedTransaction ){ sqlite3BtreeCommit(pBt); } } } /* ** Convert a schema pointer into the iDb index that indicates ** which database file in db->aDb[] the schema refers to. ** ** If the same database is attached more than once, the first ** attached database is returned. */ int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){ int i = -1000000; /* If pSchema is NULL, then return -1000000. This happens when code in ** expr.c is trying to resolve a reference to a transient table (i.e. one ** created by a sub-select). In this case the return value of this ** function should never be used. ** ** We return -1000000 instead of the more usual -1 simply because using ** -1000000 as the incorrect index into db->aDb[] is much ** more likely to cause a segfault than -1 (of course there are assert() ** statements too, but it never hurts to play the odds). */ assert( sqlite3_mutex_held(db->mutex) ); if( pSchema ){ for(i=0; 1; i++){ assert( i<db->nDb ); if( db->aDb[i].pSchema==pSchema ){ break; } } assert( i>=0 && i<db->nDb ); } return i; } /* ** Free all memory allocations in the pParse object */ void sqlite3ParserReset(Parse *pParse){ sqlite3 *db = pParse->db; sqlite3DbFree(db, pParse->aLabel); sqlite3ExprListDelete(db, pParse->pConstExpr); if( db ){ assert( db->lookaside.bDisable >= pParse->disableLookaside ); db->lookaside.bDisable -= pParse->disableLookaside; db->lookaside.sz = db->lookaside.bDisable ? 0 : db->lookaside.szTrue; } pParse->disableLookaside = 0; } /* ** Compile the UTF-8 encoded SQL statement zSql into a statement handle. */ static int sqlite3Prepare( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */ Vdbe *pReprepare, /* VM being reprepared */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ char *zErrMsg = 0; /* Error message */ int rc = SQLITE_OK; /* Result code */ int i; /* Loop counter */ Parse sParse; /* Parsing context */ memset(&sParse, 0, PARSE_HDR_SZ); memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ); sParse.pReprepare = pReprepare; assert( ppStmt && *ppStmt==0 ); /* assert( !db->mallocFailed ); // not true with SQLITE_USE_ALLOCA */ assert( sqlite3_mutex_held(db->mutex) ); /* For a long-term use prepared statement avoid the use of ** lookaside memory. */ if( prepFlags & SQLITE_PREPARE_PERSISTENT ){ sParse.disableLookaside++; DisableLookaside; } sParse.disableVtab = (prepFlags & SQLITE_PREPARE_NO_VTAB)!=0; /* Check to verify that it is possible to get a read lock on all ** database schemas. The inability to get a read lock indicates that ** some other database connection is holding a write-lock, which in ** turn means that the other connection has made uncommitted changes ** to the schema. ** ** Were we to proceed and prepare the statement against the uncommitted ** schema changes and if those schema changes are subsequently rolled ** back and different changes are made in their place, then when this ** prepared statement goes to run the schema cookie would fail to detect ** the schema change. Disaster would follow. ** ** This thread is currently holding mutexes on all Btrees (because ** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it ** is not possible for another thread to start a new schema change ** while this routine is running. Hence, we do not need to hold ** locks on the schema, we just need to make sure nobody else is ** holding them. ** ** Note that setting READ_UNCOMMITTED overrides most lock detection, ** but it does *not* override schema lock detection, so this all still ** works even if READ_UNCOMMITTED is set. */ if( !db->noSharedCache ){ for(i=0; i<db->nDb; i++) { Btree *pBt = db->aDb[i].pBt; if( pBt ){ assert( sqlite3BtreeHoldsMutex(pBt) ); rc = sqlite3BtreeSchemaLocked(pBt); if( rc ){ const char *zDb = db->aDb[i].zDbSName; sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb); testcase( db->flags & SQLITE_ReadUncommit ); goto end_prepare; } } } } sqlite3VtabUnlockList(db); sParse.db = db; if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){ char *zSqlCopy; int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH]; testcase( nBytes==mxLen ); testcase( nBytes==mxLen+1 ); if( nBytes>mxLen ){ sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long"); rc = sqlite3ApiExit(db, SQLITE_TOOBIG); goto end_prepare; } zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes); if( zSqlCopy ){ sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg); sParse.zTail = &zSql[sParse.zTail-zSqlCopy]; sqlite3DbFree(db, zSqlCopy); }else{ sParse.zTail = &zSql[nBytes]; } }else{ sqlite3RunParser(&sParse, zSql, &zErrMsg); } assert( 0==sParse.nQueryLoop ); if( sParse.rc==SQLITE_DONE ){ sParse.rc = SQLITE_OK; } if( sParse.checkSchema ){ schemaIsValid(&sParse); } if( pzTail ){ *pzTail = sParse.zTail; } if( db->init.busy==0 ){ sqlite3VdbeSetSql(sParse.pVdbe, zSql, (int)(sParse.zTail-zSql), prepFlags); } if( db->mallocFailed ){ sParse.rc = SQLITE_NOMEM_BKPT; } rc = sParse.rc; if( rc!=SQLITE_OK ){ if( sParse.pVdbe ) sqlite3VdbeFinalize(sParse.pVdbe); assert(!(*ppStmt)); }else{ *ppStmt = (sqlite3_stmt*)sParse.pVdbe; } if( zErrMsg ){ sqlite3ErrorWithMsg(db, rc, "%s", zErrMsg); sqlite3DbFree(db, zErrMsg); }else{ sqlite3Error(db, rc); } /* Delete any TriggerPrg structures allocated while parsing this statement. */ while( sParse.pTriggerPrg ){ TriggerPrg *pT = sParse.pTriggerPrg; sParse.pTriggerPrg = pT->pNext; sqlite3DbFree(db, pT); } end_prepare: sqlite3ParserReset(&sParse); return rc; } static int sqlite3LockAndPrepare( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */ Vdbe *pOld, /* VM being reprepared */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ int rc; int cnt = 0; #ifdef SQLITE_ENABLE_API_ARMOR if( ppStmt==0 ) return SQLITE_MISUSE_BKPT; #endif *ppStmt = 0; if( !sqlite3SafetyCheckOk(db)||zSql==0 ){ return SQLITE_MISUSE_BKPT; } sqlite3_mutex_enter(db->mutex); sqlite3BtreeEnterAll(db); do{ /* Make multiple attempts to compile the SQL, until it either succeeds ** or encounters a permanent error. A schema problem after one schema ** reset is considered a permanent error. */ rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail); assert( rc==SQLITE_OK || *ppStmt==0 ); }while( rc==SQLITE_ERROR_RETRY || (rc==SQLITE_SCHEMA && (sqlite3ResetOneSchema(db,-1), cnt++)==0) ); sqlite3BtreeLeaveAll(db); rc = sqlite3ApiExit(db, rc); assert( (rc&db->errMask)==rc ); sqlite3_mutex_leave(db->mutex); return rc; } /* ** Rerun the compilation of a statement after a schema change. ** ** If the statement is successfully recompiled, return SQLITE_OK. Otherwise, ** if the statement cannot be recompiled because another connection has ** locked the sqlite3_master table, return SQLITE_LOCKED. If any other error ** occurs, return SQLITE_SCHEMA. */ int sqlite3Reprepare(Vdbe *p){ int rc; sqlite3_stmt *pNew; const char *zSql; sqlite3 *db; u8 prepFlags; assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) ); zSql = sqlite3_sql((sqlite3_stmt *)p); assert( zSql!=0 ); /* Reprepare only called for prepare_v2() statements */ db = sqlite3VdbeDb(p); assert( sqlite3_mutex_held(db->mutex) ); prepFlags = sqlite3VdbePrepareFlags(p); rc = sqlite3LockAndPrepare(db, zSql, -1, prepFlags, p, &pNew, 0); if( rc ){ if( rc==SQLITE_NOMEM ){ sqlite3OomFault(db); } assert( pNew==0 ); return rc; }else{ assert( pNew!=0 ); } sqlite3VdbeSwap((Vdbe*)pNew, p); sqlite3TransferBindings(pNew, (sqlite3_stmt*)p); sqlite3VdbeResetStepResult((Vdbe*)pNew); sqlite3VdbeFinalize((Vdbe*)pNew); return SQLITE_OK; } /* ** Two versions of the official API. Legacy and new use. In the legacy ** version, the original SQL text is not saved in the prepared statement ** and so if a schema change occurs, SQLITE_SCHEMA is returned by ** sqlite3_step(). In the new version, the original SQL text is retained ** and the statement is automatically recompiled if an schema change ** occurs. */ int sqlite3_prepare( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ int rc; rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,0,ppStmt,pzTail); assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ return rc; } int sqlite3_prepare_v2( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ int rc; /* EVIDENCE-OF: R-37923-12173 The sqlite3_prepare_v2() interface works ** exactly the same as sqlite3_prepare_v3() with a zero prepFlags ** parameter. ** ** Proof in that the 5th parameter to sqlite3LockAndPrepare is 0 */ rc = sqlite3LockAndPrepare(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,0, ppStmt,pzTail); assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); return rc; } int sqlite3_prepare_v3( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_* flags */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char **pzTail /* OUT: End of parsed string */ ){ int rc; /* EVIDENCE-OF: R-56861-42673 sqlite3_prepare_v3() differs from ** sqlite3_prepare_v2() only in having the extra prepFlags parameter, ** which is a bit array consisting of zero or more of the ** SQLITE_PREPARE_* flags. ** ** Proof by comparison to the implementation of sqlite3_prepare_v2() ** directly above. */ rc = sqlite3LockAndPrepare(db,zSql,nBytes, SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK), 0,ppStmt,pzTail); assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); return rc; } #ifndef SQLITE_OMIT_UTF16 /* ** Compile the UTF-16 encoded SQL statement zSql into a statement handle. */ static int sqlite3Prepare16( sqlite3 *db, /* Database handle. */ const void *zSql, /* UTF-16 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const void **pzTail /* OUT: End of parsed string */ ){ /* This function currently works by first transforming the UTF-16 ** encoded string to UTF-8, then invoking sqlite3_prepare(). The ** tricky bit is figuring out the pointer to return in *pzTail. */ char *zSql8; const char *zTail8 = 0; int rc = SQLITE_OK; #ifdef SQLITE_ENABLE_API_ARMOR if( ppStmt==0 ) return SQLITE_MISUSE_BKPT; #endif *ppStmt = 0; if( !sqlite3SafetyCheckOk(db)||zSql==0 ){ return SQLITE_MISUSE_BKPT; } if( nBytes>=0 ){ int sz; const char *z = (const char*)zSql; for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){} nBytes = sz; } sqlite3_mutex_enter(db->mutex); zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE); if( zSql8 ){ rc = sqlite3LockAndPrepare(db, zSql8, -1, prepFlags, 0, ppStmt, &zTail8); } if( zTail8 && pzTail ){ /* If sqlite3_prepare returns a tail pointer, we calculate the ** equivalent pointer into the UTF-16 string by counting the unicode ** characters between zSql8 and zTail8, and then returning a pointer ** the same number of characters into the UTF-16 string. */ int chars_parsed = sqlite3Utf8CharLen(zSql8, (int)(zTail8-zSql8)); *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed); } sqlite3DbFree(db, zSql8); rc = sqlite3ApiExit(db, rc); sqlite3_mutex_leave(db->mutex); return rc; } /* ** Two versions of the official API. Legacy and new use. In the legacy ** version, the original SQL text is not saved in the prepared statement ** and so if a schema change occurs, SQLITE_SCHEMA is returned by ** sqlite3_step(). In the new version, the original SQL text is retained ** and the statement is automatically recompiled if an schema change ** occurs. */ int sqlite3_prepare16( sqlite3 *db, /* Database handle. */ const void *zSql, /* UTF-16 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const void **pzTail /* OUT: End of parsed string */ ){ int rc; rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail); assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ return rc; } int sqlite3_prepare16_v2( sqlite3 *db, /* Database handle. */ const void *zSql, /* UTF-16 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const void **pzTail /* OUT: End of parsed string */ ){ int rc; rc = sqlite3Prepare16(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,ppStmt,pzTail); assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ return rc; } int sqlite3_prepare16_v3( sqlite3 *db, /* Database handle. */ const void *zSql, /* UTF-16 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_* flags */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const void **pzTail /* OUT: End of parsed string */ ){ int rc; rc = sqlite3Prepare16(db,zSql,nBytes, SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK), ppStmt,pzTail); assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */ return rc; } #endif /* SQLITE_OMIT_UTF16 */ |
| You are visitor 01402520 — GeezerVison does not store the pages you look up. Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required. |