1 /* 2 ** 2006 June 10 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 code used to help implement virtual tables. 13 */ 14 #ifndef SQLITE_OMIT_VIRTUALTABLE 15 #include "sqliteInt.h" 16 17 /* 18 ** Before a virtual table xCreate() or xConnect() method is invoked, the 19 ** sqlite3.pVtabCtx member variable is set to point to an instance of 20 ** this struct allocated on the stack. It is used by the implementation of 21 ** the sqlite3_declare_vtab() and sqlite3_vtab_config() APIs, both of which 22 ** are invoked only from within xCreate and xConnect methods. 23 */ 24 struct VtabCtx { 25 VTable *pVTable; /* The virtual table being constructed */ 26 Table *pTab; /* The Table object to which the virtual table belongs */ 27 VtabCtx *pPrior; /* Parent context (if any) */ 28 int bDeclared; /* True after sqlite3_declare_vtab() is called */ 29 }; 30 31 /* 32 ** Construct and install a Module object for a virtual table. When this 33 ** routine is called, it is guaranteed that all appropriate locks are held 34 ** and the module is not already part of the connection. 35 ** 36 ** If there already exists a module with zName, replace it with the new one. 37 ** If pModule==0, then delete the module zName if it exists. 38 */ 39 Module *sqlite3VtabCreateModule( 40 sqlite3 *db, /* Database in which module is registered */ 41 const char *zName, /* Name assigned to this module */ 42 const sqlite3_module *pModule, /* The definition of the module */ 43 void *pAux, /* Context pointer for xCreate/xConnect */ 44 void (*xDestroy)(void *) /* Module destructor function */ 45 ){ 46 Module *pMod; 47 Module *pDel; 48 char *zCopy; 49 if( pModule==0 ){ 50 zCopy = (char*)zName; 51 pMod = 0; 52 }else{ 53 int nName = sqlite3Strlen30(zName); 54 pMod = (Module *)sqlite3Malloc(sizeof(Module) + nName + 1); 55 if( pMod==0 ){ 56 sqlite3OomFault(db); 57 return 0; 58 } 59 zCopy = (char *)(&pMod[1]); 60 memcpy(zCopy, zName, nName+1); 61 pMod->zName = zCopy; 62 pMod->pModule = pModule; 63 pMod->pAux = pAux; 64 pMod->xDestroy = xDestroy; 65 pMod->pEpoTab = 0; 66 pMod->nRefModule = 1; 67 } 68 pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod); 69 if( pDel ){ 70 if( pDel==pMod ){ 71 sqlite3OomFault(db); 72 sqlite3DbFree(db, pDel); 73 pMod = 0; 74 }else{ 75 sqlite3VtabEponymousTableClear(db, pDel); 76 sqlite3VtabModuleUnref(db, pDel); 77 } 78 } 79 return pMod; 80 } 81 82 /* 83 ** The actual function that does the work of creating a new module. 84 ** This function implements the sqlite3_create_module() and 85 ** sqlite3_create_module_v2() interfaces. 86 */ 87 static int createModule( 88 sqlite3 *db, /* Database in which module is registered */ 89 const char *zName, /* Name assigned to this module */ 90 const sqlite3_module *pModule, /* The definition of the module */ 91 void *pAux, /* Context pointer for xCreate/xConnect */ 92 void (*xDestroy)(void *) /* Module destructor function */ 93 ){ 94 int rc = SQLITE_OK; 95 96 sqlite3_mutex_enter(db->mutex); 97 (void)sqlite3VtabCreateModule(db, zName, pModule, pAux, xDestroy); 98 rc = sqlite3ApiExit(db, rc); 99 if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux); 100 sqlite3_mutex_leave(db->mutex); 101 return rc; 102 } 103 104 105 /* 106 ** External API function used to create a new virtual-table module. 107 */ 108 int sqlite3_create_module( 109 sqlite3 *db, /* Database in which module is registered */ 110 const char *zName, /* Name assigned to this module */ 111 const sqlite3_module *pModule, /* The definition of the module */ 112 void *pAux /* Context pointer for xCreate/xConnect */ 113 ){ 114 #ifdef SQLITE_ENABLE_API_ARMOR 115 if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT; 116 #endif 117 return createModule(db, zName, pModule, pAux, 0); 118 } 119 120 /* 121 ** External API function used to create a new virtual-table module. 122 */ 123 int sqlite3_create_module_v2( 124 sqlite3 *db, /* Database in which module is registered */ 125 const char *zName, /* Name assigned to this module */ 126 const sqlite3_module *pModule, /* The definition of the module */ 127 void *pAux, /* Context pointer for xCreate/xConnect */ 128 void (*xDestroy)(void *) /* Module destructor function */ 129 ){ 130 #ifdef SQLITE_ENABLE_API_ARMOR 131 if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT; 132 #endif 133 return createModule(db, zName, pModule, pAux, xDestroy); 134 } 135 136 /* 137 ** External API to drop all virtual-table modules, except those named 138 ** on the azNames list. 139 */ 140 int sqlite3_drop_modules(sqlite3 *db, const char** azNames){ 141 HashElem *pThis, *pNext; 142 #ifdef SQLITE_ENABLE_API_ARMOR 143 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; 144 #endif 145 for(pThis=sqliteHashFirst(&db->aModule); pThis; pThis=pNext){ 146 Module *pMod = (Module*)sqliteHashData(pThis); 147 pNext = sqliteHashNext(pThis); 148 if( azNames ){ 149 int ii; 150 for(ii=0; azNames[ii]!=0 && strcmp(azNames[ii],pMod->zName)!=0; ii++){} 151 if( azNames[ii]!=0 ) continue; 152 } 153 createModule(db, pMod->zName, 0, 0, 0); 154 } 155 return SQLITE_OK; 156 } 157 158 /* 159 ** Decrement the reference count on a Module object. Destroy the 160 ** module when the reference count reaches zero. 161 */ 162 void sqlite3VtabModuleUnref(sqlite3 *db, Module *pMod){ 163 assert( pMod->nRefModule>0 ); 164 pMod->nRefModule--; 165 if( pMod->nRefModule==0 ){ 166 if( pMod->xDestroy ){ 167 pMod->xDestroy(pMod->pAux); 168 } 169 assert( pMod->pEpoTab==0 ); 170 sqlite3DbFree(db, pMod); 171 } 172 } 173 174 /* 175 ** Lock the virtual table so that it cannot be disconnected. 176 ** Locks nest. Every lock should have a corresponding unlock. 177 ** If an unlock is omitted, resources leaks will occur. 178 ** 179 ** If a disconnect is attempted while a virtual table is locked, 180 ** the disconnect is deferred until all locks have been removed. 181 */ 182 void sqlite3VtabLock(VTable *pVTab){ 183 pVTab->nRef++; 184 } 185 186 187 /* 188 ** pTab is a pointer to a Table structure representing a virtual-table. 189 ** Return a pointer to the VTable object used by connection db to access 190 ** this virtual-table, if one has been created, or NULL otherwise. 191 */ 192 VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){ 193 VTable *pVtab; 194 assert( IsVirtual(pTab) ); 195 for(pVtab=pTab->u.vtab.p; pVtab && pVtab->db!=db; pVtab=pVtab->pNext); 196 return pVtab; 197 } 198 199 /* 200 ** Decrement the ref-count on a virtual table object. When the ref-count 201 ** reaches zero, call the xDisconnect() method to delete the object. 202 */ 203 void sqlite3VtabUnlock(VTable *pVTab){ 204 sqlite3 *db = pVTab->db; 205 206 assert( db ); 207 assert( pVTab->nRef>0 ); 208 assert( db->eOpenState==SQLITE_STATE_OPEN 209 || db->eOpenState==SQLITE_STATE_ZOMBIE ); 210 211 pVTab->nRef--; 212 if( pVTab->nRef==0 ){ 213 sqlite3_vtab *p = pVTab->pVtab; 214 sqlite3VtabModuleUnref(pVTab->db, pVTab->pMod); 215 if( p ){ 216 p->pModule->xDisconnect(p); 217 } 218 sqlite3DbFree(db, pVTab); 219 } 220 } 221 222 /* 223 ** Table p is a virtual table. This function moves all elements in the 224 ** p->u.vtab.p list to the sqlite3.pDisconnect lists of their associated 225 ** database connections to be disconnected at the next opportunity. 226 ** Except, if argument db is not NULL, then the entry associated with 227 ** connection db is left in the p->u.vtab.p list. 228 */ 229 static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){ 230 VTable *pRet = 0; 231 VTable *pVTable; 232 233 assert( IsVirtual(p) ); 234 pVTable = p->u.vtab.p; 235 p->u.vtab.p = 0; 236 237 /* Assert that the mutex (if any) associated with the BtShared database 238 ** that contains table p is held by the caller. See header comments 239 ** above function sqlite3VtabUnlockList() for an explanation of why 240 ** this makes it safe to access the sqlite3.pDisconnect list of any 241 ** database connection that may have an entry in the p->u.vtab.p list. 242 */ 243 assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) ); 244 245 while( pVTable ){ 246 sqlite3 *db2 = pVTable->db; 247 VTable *pNext = pVTable->pNext; 248 assert( db2 ); 249 if( db2==db ){ 250 pRet = pVTable; 251 p->u.vtab.p = pRet; 252 pRet->pNext = 0; 253 }else{ 254 pVTable->pNext = db2->pDisconnect; 255 db2->pDisconnect = pVTable; 256 } 257 pVTable = pNext; 258 } 259 260 assert( !db || pRet ); 261 return pRet; 262 } 263 264 /* 265 ** Table *p is a virtual table. This function removes the VTable object 266 ** for table *p associated with database connection db from the linked 267 ** list in p->pVTab. It also decrements the VTable ref count. This is 268 ** used when closing database connection db to free all of its VTable 269 ** objects without disturbing the rest of the Schema object (which may 270 ** be being used by other shared-cache connections). 271 */ 272 void sqlite3VtabDisconnect(sqlite3 *db, Table *p){ 273 VTable **ppVTab; 274 275 assert( IsVirtual(p) ); 276 assert( sqlite3BtreeHoldsAllMutexes(db) ); 277 assert( sqlite3_mutex_held(db->mutex) ); 278 279 for(ppVTab=&p->u.vtab.p; *ppVTab; ppVTab=&(*ppVTab)->pNext){ 280 if( (*ppVTab)->db==db ){ 281 VTable *pVTab = *ppVTab; 282 *ppVTab = pVTab->pNext; 283 sqlite3VtabUnlock(pVTab); 284 break; 285 } 286 } 287 } 288 289 290 /* 291 ** Disconnect all the virtual table objects in the sqlite3.pDisconnect list. 292 ** 293 ** This function may only be called when the mutexes associated with all 294 ** shared b-tree databases opened using connection db are held by the 295 ** caller. This is done to protect the sqlite3.pDisconnect list. The 296 ** sqlite3.pDisconnect list is accessed only as follows: 297 ** 298 ** 1) By this function. In this case, all BtShared mutexes and the mutex 299 ** associated with the database handle itself must be held. 300 ** 301 ** 2) By function vtabDisconnectAll(), when it adds a VTable entry to 302 ** the sqlite3.pDisconnect list. In this case either the BtShared mutex 303 ** associated with the database the virtual table is stored in is held 304 ** or, if the virtual table is stored in a non-sharable database, then 305 ** the database handle mutex is held. 306 ** 307 ** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously 308 ** by multiple threads. It is thread-safe. 309 */ 310 void sqlite3VtabUnlockList(sqlite3 *db){ 311 VTable *p = db->pDisconnect; 312 313 assert( sqlite3BtreeHoldsAllMutexes(db) ); 314 assert( sqlite3_mutex_held(db->mutex) ); 315 316 if( p ){ 317 db->pDisconnect = 0; 318 sqlite3ExpirePreparedStatements(db, 0); 319 do { 320 VTable *pNext = p->pNext; 321 sqlite3VtabUnlock(p); 322 p = pNext; 323 }while( p ); 324 } 325 } 326 327 /* 328 ** Clear any and all virtual-table information from the Table record. 329 ** This routine is called, for example, just before deleting the Table 330 ** record. 331 ** 332 ** Since it is a virtual-table, the Table structure contains a pointer 333 ** to the head of a linked list of VTable structures. Each VTable 334 ** structure is associated with a single sqlite3* user of the schema. 335 ** The reference count of the VTable structure associated with database 336 ** connection db is decremented immediately (which may lead to the 337 ** structure being xDisconnected and free). Any other VTable structures 338 ** in the list are moved to the sqlite3.pDisconnect list of the associated 339 ** database connection. 340 */ 341 void sqlite3VtabClear(sqlite3 *db, Table *p){ 342 assert( IsVirtual(p) ); 343 if( !db || db->pnBytesFreed==0 ) vtabDisconnectAll(0, p); 344 if( p->u.vtab.azArg ){ 345 int i; 346 for(i=0; i<p->u.vtab.nArg; i++){ 347 if( i!=1 ) sqlite3DbFree(db, p->u.vtab.azArg[i]); 348 } 349 sqlite3DbFree(db, p->u.vtab.azArg); 350 } 351 } 352 353 /* 354 ** Add a new module argument to pTable->u.vtab.azArg[]. 355 ** The string is not copied - the pointer is stored. The 356 ** string will be freed automatically when the table is 357 ** deleted. 358 */ 359 static void addModuleArgument(Parse *pParse, Table *pTable, char *zArg){ 360 sqlite3_int64 nBytes; 361 char **azModuleArg; 362 sqlite3 *db = pParse->db; 363 364 assert( IsVirtual(pTable) ); 365 nBytes = sizeof(char *)*(2+pTable->u.vtab.nArg); 366 if( pTable->u.vtab.nArg+3>=db->aLimit[SQLITE_LIMIT_COLUMN] ){ 367 sqlite3ErrorMsg(pParse, "too many columns on %s", pTable->zName); 368 } 369 azModuleArg = sqlite3DbRealloc(db, pTable->u.vtab.azArg, nBytes); 370 if( azModuleArg==0 ){ 371 sqlite3DbFree(db, zArg); 372 }else{ 373 int i = pTable->u.vtab.nArg++; 374 azModuleArg[i] = zArg; 375 azModuleArg[i+1] = 0; 376 pTable->u.vtab.azArg = azModuleArg; 377 } 378 } 379 380 /* 381 ** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE 382 ** statement. The module name has been parsed, but the optional list 383 ** of parameters that follow the module name are still pending. 384 */ 385 void sqlite3VtabBeginParse( 386 Parse *pParse, /* Parsing context */ 387 Token *pName1, /* Name of new table, or database name */ 388 Token *pName2, /* Name of new table or NULL */ 389 Token *pModuleName, /* Name of the module for the virtual table */ 390 int ifNotExists /* No error if the table already exists */ 391 ){ 392 Table *pTable; /* The new virtual table */ 393 sqlite3 *db; /* Database connection */ 394 395 sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists); 396 pTable = pParse->pNewTable; 397 if( pTable==0 ) return; 398 assert( 0==pTable->pIndex ); 399 pTable->eTabType = TABTYP_VTAB; 400 401 db = pParse->db; 402 403 assert( pTable->u.vtab.nArg==0 ); 404 addModuleArgument(pParse, pTable, sqlite3NameFromToken(db, pModuleName)); 405 addModuleArgument(pParse, pTable, 0); 406 addModuleArgument(pParse, pTable, sqlite3DbStrDup(db, pTable->zName)); 407 assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0) 408 || (pParse->sNameToken.z==pName1->z && pName2->z==0) 409 ); 410 pParse->sNameToken.n = (int)( 411 &pModuleName->z[pModuleName->n] - pParse->sNameToken.z 412 ); 413 414 #ifndef SQLITE_OMIT_AUTHORIZATION 415 /* Creating a virtual table invokes the authorization callback twice. 416 ** The first invocation, to obtain permission to INSERT a row into the 417 ** sqlite_schema table, has already been made by sqlite3StartTable(). 418 ** The second call, to obtain permission to create the table, is made now. 419 */ 420 if( pTable->u.vtab.azArg ){ 421 int iDb = sqlite3SchemaToIndex(db, pTable->pSchema); 422 assert( iDb>=0 ); /* The database the table is being created in */ 423 sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 424 pTable->u.vtab.azArg[0], pParse->db->aDb[iDb].zDbSName); 425 } 426 #endif 427 } 428 429 /* 430 ** This routine takes the module argument that has been accumulating 431 ** in pParse->zArg[] and appends it to the list of arguments on the 432 ** virtual table currently under construction in pParse->pTable. 433 */ 434 static void addArgumentToVtab(Parse *pParse){ 435 if( pParse->sArg.z && pParse->pNewTable ){ 436 const char *z = (const char*)pParse->sArg.z; 437 int n = pParse->sArg.n; 438 sqlite3 *db = pParse->db; 439 addModuleArgument(pParse, pParse->pNewTable, sqlite3DbStrNDup(db, z, n)); 440 } 441 } 442 443 /* 444 ** The parser calls this routine after the CREATE VIRTUAL TABLE statement 445 ** has been completely parsed. 446 */ 447 void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){ 448 Table *pTab = pParse->pNewTable; /* The table being constructed */ 449 sqlite3 *db = pParse->db; /* The database connection */ 450 451 if( pTab==0 ) return; 452 assert( IsVirtual(pTab) ); 453 addArgumentToVtab(pParse); 454 pParse->sArg.z = 0; 455 if( pTab->u.vtab.nArg<1 ) return; 456 457 /* If the CREATE VIRTUAL TABLE statement is being entered for the 458 ** first time (in other words if the virtual table is actually being 459 ** created now instead of just being read out of sqlite_schema) then 460 ** do additional initialization work and store the statement text 461 ** in the sqlite_schema table. 462 */ 463 if( !db->init.busy ){ 464 char *zStmt; 465 char *zWhere; 466 int iDb; 467 int iReg; 468 Vdbe *v; 469 470 sqlite3MayAbort(pParse); 471 472 /* Compute the complete text of the CREATE VIRTUAL TABLE statement */ 473 if( pEnd ){ 474 pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n; 475 } 476 zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken); 477 478 /* A slot for the record has already been allocated in the 479 ** schema table. We just need to update that slot with all 480 ** the information we've collected. 481 ** 482 ** The VM register number pParse->regRowid holds the rowid of an 483 ** entry in the sqlite_schema table tht was created for this vtab 484 ** by sqlite3StartTable(). 485 */ 486 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); 487 sqlite3NestedParse(pParse, 488 "UPDATE %Q." DFLT_SCHEMA_TABLE " " 489 "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q " 490 "WHERE rowid=#%d", 491 db->aDb[iDb].zDbSName, 492 pTab->zName, 493 pTab->zName, 494 zStmt, 495 pParse->regRowid 496 ); 497 v = sqlite3GetVdbe(pParse); 498 sqlite3ChangeCookie(pParse, iDb); 499 500 sqlite3VdbeAddOp0(v, OP_Expire); 501 zWhere = sqlite3MPrintf(db, "name=%Q AND sql=%Q", pTab->zName, zStmt); 502 sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere, 0); 503 sqlite3DbFree(db, zStmt); 504 505 iReg = ++pParse->nMem; 506 sqlite3VdbeLoadString(v, iReg, pTab->zName); 507 sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg); 508 }else{ 509 /* If we are rereading the sqlite_schema table create the in-memory 510 ** record of the table. */ 511 Table *pOld; 512 Schema *pSchema = pTab->pSchema; 513 const char *zName = pTab->zName; 514 assert( zName!=0 ); 515 sqlite3MarkAllShadowTablesOf(db, pTab); 516 pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab); 517 if( pOld ){ 518 sqlite3OomFault(db); 519 assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */ 520 return; 521 } 522 pParse->pNewTable = 0; 523 } 524 } 525 526 /* 527 ** The parser calls this routine when it sees the first token 528 ** of an argument to the module name in a CREATE VIRTUAL TABLE statement. 529 */ 530 void sqlite3VtabArgInit(Parse *pParse){ 531 addArgumentToVtab(pParse); 532 pParse->sArg.z = 0; 533 pParse->sArg.n = 0; 534 } 535 536 /* 537 ** The parser calls this routine for each token after the first token 538 ** in an argument to the module name in a CREATE VIRTUAL TABLE statement. 539 */ 540 void sqlite3VtabArgExtend(Parse *pParse, Token *p){ 541 Token *pArg = &pParse->sArg; 542 if( pArg->z==0 ){ 543 pArg->z = p->z; 544 pArg->n = p->n; 545 }else{ 546 assert(pArg->z <= p->z); 547 pArg->n = (int)(&p->z[p->n] - pArg->z); 548 } 549 } 550 551 /* 552 ** Invoke a virtual table constructor (either xCreate or xConnect). The 553 ** pointer to the function to invoke is passed as the fourth parameter 554 ** to this procedure. 555 */ 556 static int vtabCallConstructor( 557 sqlite3 *db, 558 Table *pTab, 559 Module *pMod, 560 int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**), 561 char **pzErr 562 ){ 563 VtabCtx sCtx; 564 VTable *pVTable; 565 int rc; 566 const char *const*azArg; 567 int nArg = pTab->u.vtab.nArg; 568 char *zErr = 0; 569 char *zModuleName; 570 int iDb; 571 VtabCtx *pCtx; 572 573 assert( IsVirtual(pTab) ); 574 azArg = (const char *const*)pTab->u.vtab.azArg; 575 576 /* Check that the virtual-table is not already being initialized */ 577 for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){ 578 if( pCtx->pTab==pTab ){ 579 *pzErr = sqlite3MPrintf(db, 580 "vtable constructor called recursively: %s", pTab->zName 581 ); 582 return SQLITE_LOCKED; 583 } 584 } 585 586 zModuleName = sqlite3DbStrDup(db, pTab->zName); 587 if( !zModuleName ){ 588 return SQLITE_NOMEM_BKPT; 589 } 590 591 pVTable = sqlite3MallocZero(sizeof(VTable)); 592 if( !pVTable ){ 593 sqlite3OomFault(db); 594 sqlite3DbFree(db, zModuleName); 595 return SQLITE_NOMEM_BKPT; 596 } 597 pVTable->db = db; 598 pVTable->pMod = pMod; 599 pVTable->eVtabRisk = SQLITE_VTABRISK_Normal; 600 601 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); 602 pTab->u.vtab.azArg[1] = db->aDb[iDb].zDbSName; 603 604 /* Invoke the virtual table constructor */ 605 assert( &db->pVtabCtx ); 606 assert( xConstruct ); 607 sCtx.pTab = pTab; 608 sCtx.pVTable = pVTable; 609 sCtx.pPrior = db->pVtabCtx; 610 sCtx.bDeclared = 0; 611 db->pVtabCtx = &sCtx; 612 rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr); 613 db->pVtabCtx = sCtx.pPrior; 614 if( rc==SQLITE_NOMEM ) sqlite3OomFault(db); 615 assert( sCtx.pTab==pTab ); 616 617 if( SQLITE_OK!=rc ){ 618 if( zErr==0 ){ 619 *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName); 620 }else { 621 *pzErr = sqlite3MPrintf(db, "%s", zErr); 622 sqlite3_free(zErr); 623 } 624 sqlite3DbFree(db, pVTable); 625 }else if( ALWAYS(pVTable->pVtab) ){ 626 /* Justification of ALWAYS(): A correct vtab constructor must allocate 627 ** the sqlite3_vtab object if successful. */ 628 memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0])); 629 pVTable->pVtab->pModule = pMod->pModule; 630 pMod->nRefModule++; 631 pVTable->nRef = 1; 632 if( sCtx.bDeclared==0 ){ 633 const char *zFormat = "vtable constructor did not declare schema: %s"; 634 *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName); 635 sqlite3VtabUnlock(pVTable); 636 rc = SQLITE_ERROR; 637 }else{ 638 int iCol; 639 u16 oooHidden = 0; 640 /* If everything went according to plan, link the new VTable structure 641 ** into the linked list headed by pTab->u.vtab.p. Then loop through the 642 ** columns of the table to see if any of them contain the token "hidden". 643 ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from 644 ** the type string. */ 645 pVTable->pNext = pTab->u.vtab.p; 646 pTab->u.vtab.p = pVTable; 647 648 for(iCol=0; iCol<pTab->nCol; iCol++){ 649 char *zType = sqlite3ColumnType(&pTab->aCol[iCol], ""); 650 int nType; 651 int i = 0; 652 nType = sqlite3Strlen30(zType); 653 for(i=0; i<nType; i++){ 654 if( 0==sqlite3StrNICmp("hidden", &zType[i], 6) 655 && (i==0 || zType[i-1]==' ') 656 && (zType[i+6]=='\0' || zType[i+6]==' ') 657 ){ 658 break; 659 } 660 } 661 if( i<nType ){ 662 int j; 663 int nDel = 6 + (zType[i+6] ? 1 : 0); 664 for(j=i; (j+nDel)<=nType; j++){ 665 zType[j] = zType[j+nDel]; 666 } 667 if( zType[i]=='\0' && i>0 ){ 668 assert(zType[i-1]==' '); 669 zType[i-1] = '\0'; 670 } 671 pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN; 672 pTab->tabFlags |= TF_HasHidden; 673 oooHidden = TF_OOOHidden; 674 }else{ 675 pTab->tabFlags |= oooHidden; 676 } 677 } 678 } 679 } 680 681 sqlite3DbFree(db, zModuleName); 682 return rc; 683 } 684 685 /* 686 ** This function is invoked by the parser to call the xConnect() method 687 ** of the virtual table pTab. If an error occurs, an error code is returned 688 ** and an error left in pParse. 689 ** 690 ** This call is a no-op if table pTab is not a virtual table. 691 */ 692 int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){ 693 sqlite3 *db = pParse->db; 694 const char *zMod; 695 Module *pMod; 696 int rc; 697 698 assert( pTab ); 699 if( !IsVirtual(pTab) || sqlite3GetVTable(db, pTab) ){ 700 return SQLITE_OK; 701 } 702 703 /* Locate the required virtual table module */ 704 zMod = pTab->u.vtab.azArg[0]; 705 pMod = (Module*)sqlite3HashFind(&db->aModule, zMod); 706 707 if( !pMod ){ 708 const char *zModule = pTab->u.vtab.azArg[0]; 709 sqlite3ErrorMsg(pParse, "no such module: %s", zModule); 710 rc = SQLITE_ERROR; 711 }else{ 712 char *zErr = 0; 713 rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr); 714 if( rc!=SQLITE_OK ){ 715 sqlite3ErrorMsg(pParse, "%s", zErr); 716 pParse->rc = rc; 717 } 718 sqlite3DbFree(db, zErr); 719 } 720 721 return rc; 722 } 723 /* 724 ** Grow the db->aVTrans[] array so that there is room for at least one 725 ** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise. 726 */ 727 static int growVTrans(sqlite3 *db){ 728 const int ARRAY_INCR = 5; 729 730 /* Grow the sqlite3.aVTrans array if required */ 731 if( (db->nVTrans%ARRAY_INCR)==0 ){ 732 VTable **aVTrans; 733 sqlite3_int64 nBytes = sizeof(sqlite3_vtab*)* 734 ((sqlite3_int64)db->nVTrans + ARRAY_INCR); 735 aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes); 736 if( !aVTrans ){ 737 return SQLITE_NOMEM_BKPT; 738 } 739 memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR); 740 db->aVTrans = aVTrans; 741 } 742 743 return SQLITE_OK; 744 } 745 746 /* 747 ** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should 748 ** have already been reserved using growVTrans(). 749 */ 750 static void addToVTrans(sqlite3 *db, VTable *pVTab){ 751 /* Add pVtab to the end of sqlite3.aVTrans */ 752 db->aVTrans[db->nVTrans++] = pVTab; 753 sqlite3VtabLock(pVTab); 754 } 755 756 /* 757 ** This function is invoked by the vdbe to call the xCreate method 758 ** of the virtual table named zTab in database iDb. 759 ** 760 ** If an error occurs, *pzErr is set to point to an English language 761 ** description of the error and an SQLITE_XXX error code is returned. 762 ** In this case the caller must call sqlite3DbFree(db, ) on *pzErr. 763 */ 764 int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){ 765 int rc = SQLITE_OK; 766 Table *pTab; 767 Module *pMod; 768 const char *zMod; 769 770 pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName); 771 assert( pTab && IsVirtual(pTab) && !pTab->u.vtab.p ); 772 773 /* Locate the required virtual table module */ 774 zMod = pTab->u.vtab.azArg[0]; 775 pMod = (Module*)sqlite3HashFind(&db->aModule, zMod); 776 777 /* If the module has been registered and includes a Create method, 778 ** invoke it now. If the module has not been registered, return an 779 ** error. Otherwise, do nothing. 780 */ 781 if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){ 782 *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod); 783 rc = SQLITE_ERROR; 784 }else{ 785 rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr); 786 } 787 788 /* Justification of ALWAYS(): The xConstructor method is required to 789 ** create a valid sqlite3_vtab if it returns SQLITE_OK. */ 790 if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){ 791 rc = growVTrans(db); 792 if( rc==SQLITE_OK ){ 793 addToVTrans(db, sqlite3GetVTable(db, pTab)); 794 } 795 } 796 797 return rc; 798 } 799 800 /* 801 ** This function is used to set the schema of a virtual table. It is only 802 ** valid to call this function from within the xCreate() or xConnect() of a 803 ** virtual table module. 804 */ 805 int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){ 806 VtabCtx *pCtx; 807 int rc = SQLITE_OK; 808 Table *pTab; 809 char *zErr = 0; 810 Parse sParse; 811 int initBusy; 812 813 #ifdef SQLITE_ENABLE_API_ARMOR 814 if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){ 815 return SQLITE_MISUSE_BKPT; 816 } 817 #endif 818 sqlite3_mutex_enter(db->mutex); 819 pCtx = db->pVtabCtx; 820 if( !pCtx || pCtx->bDeclared ){ 821 sqlite3Error(db, SQLITE_MISUSE); 822 sqlite3_mutex_leave(db->mutex); 823 return SQLITE_MISUSE_BKPT; 824 } 825 pTab = pCtx->pTab; 826 assert( IsVirtual(pTab) ); 827 828 memset(&sParse, 0, sizeof(sParse)); 829 sParse.eParseMode = PARSE_MODE_DECLARE_VTAB; 830 sParse.db = db; 831 /* We should never be able to reach this point while loading the 832 ** schema. Nevertheless, defend against that (turn off db->init.busy) 833 ** in case a bug arises. */ 834 assert( db->init.busy==0 ); 835 initBusy = db->init.busy; 836 db->init.busy = 0; 837 sParse.nQueryLoop = 1; 838 if( SQLITE_OK==sqlite3RunParser(&sParse, zCreateTable, &zErr) 839 && sParse.pNewTable 840 && !db->mallocFailed 841 && IsOrdinaryTable(sParse.pNewTable) 842 ){ 843 if( !pTab->aCol ){ 844 Table *pNew = sParse.pNewTable; 845 Index *pIdx; 846 pTab->aCol = pNew->aCol; 847 sqlite3ExprListDelete(db, pNew->u.tab.pDfltList); 848 pTab->nNVCol = pTab->nCol = pNew->nCol; 849 pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid); 850 pNew->nCol = 0; 851 pNew->aCol = 0; 852 assert( pTab->pIndex==0 ); 853 assert( HasRowid(pNew) || sqlite3PrimaryKeyIndex(pNew)!=0 ); 854 if( !HasRowid(pNew) 855 && pCtx->pVTable->pMod->pModule->xUpdate!=0 856 && sqlite3PrimaryKeyIndex(pNew)->nKeyCol!=1 857 ){ 858 /* WITHOUT ROWID virtual tables must either be read-only (xUpdate==0) 859 ** or else must have a single-column PRIMARY KEY */ 860 rc = SQLITE_ERROR; 861 } 862 pIdx = pNew->pIndex; 863 if( pIdx ){ 864 assert( pIdx->pNext==0 ); 865 pTab->pIndex = pIdx; 866 pNew->pIndex = 0; 867 pIdx->pTable = pTab; 868 } 869 } 870 pCtx->bDeclared = 1; 871 }else{ 872 sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr); 873 sqlite3DbFree(db, zErr); 874 rc = SQLITE_ERROR; 875 } 876 sParse.eParseMode = PARSE_MODE_NORMAL; 877 878 if( sParse.pVdbe ){ 879 sqlite3VdbeFinalize(sParse.pVdbe); 880 } 881 sqlite3DeleteTable(db, sParse.pNewTable); 882 sqlite3ParserReset(&sParse); 883 db->init.busy = initBusy; 884 885 assert( (rc&0xff)==rc ); 886 rc = sqlite3ApiExit(db, rc); 887 sqlite3_mutex_leave(db->mutex); 888 return rc; 889 } 890 891 /* 892 ** This function is invoked by the vdbe to call the xDestroy method 893 ** of the virtual table named zTab in database iDb. This occurs 894 ** when a DROP TABLE is mentioned. 895 ** 896 ** This call is a no-op if zTab is not a virtual table. 897 */ 898 int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){ 899 int rc = SQLITE_OK; 900 Table *pTab; 901 902 pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName); 903 if( pTab!=0 && ALWAYS(IsVirtual(pTab)) && ALWAYS(pTab->u.vtab.p!=0) ){ 904 VTable *p; 905 int (*xDestroy)(sqlite3_vtab *); 906 for(p=pTab->u.vtab.p; p; p=p->pNext){ 907 assert( p->pVtab ); 908 if( p->pVtab->nRef>0 ){ 909 return SQLITE_LOCKED; 910 } 911 } 912 p = vtabDisconnectAll(db, pTab); 913 xDestroy = p->pMod->pModule->xDestroy; 914 if( xDestroy==0 ) xDestroy = p->pMod->pModule->xDisconnect; 915 assert( xDestroy!=0 ); 916 pTab->nTabRef++; 917 rc = xDestroy(p->pVtab); 918 /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */ 919 if( rc==SQLITE_OK ){ 920 assert( pTab->u.vtab.p==p && p->pNext==0 ); 921 p->pVtab = 0; 922 pTab->u.vtab.p = 0; 923 sqlite3VtabUnlock(p); 924 } 925 sqlite3DeleteTable(db, pTab); 926 } 927 928 return rc; 929 } 930 931 /* 932 ** This function invokes either the xRollback or xCommit method 933 ** of each of the virtual tables in the sqlite3.aVTrans array. The method 934 ** called is identified by the second argument, "offset", which is 935 ** the offset of the method to call in the sqlite3_module structure. 936 ** 937 ** The array is cleared after invoking the callbacks. 938 */ 939 static void callFinaliser(sqlite3 *db, int offset){ 940 int i; 941 if( db->aVTrans ){ 942 VTable **aVTrans = db->aVTrans; 943 db->aVTrans = 0; 944 for(i=0; i<db->nVTrans; i++){ 945 VTable *pVTab = aVTrans[i]; 946 sqlite3_vtab *p = pVTab->pVtab; 947 if( p ){ 948 int (*x)(sqlite3_vtab *); 949 x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset); 950 if( x ) x(p); 951 } 952 pVTab->iSavepoint = 0; 953 sqlite3VtabUnlock(pVTab); 954 } 955 sqlite3DbFree(db, aVTrans); 956 db->nVTrans = 0; 957 } 958 } 959 960 /* 961 ** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans 962 ** array. Return the error code for the first error that occurs, or 963 ** SQLITE_OK if all xSync operations are successful. 964 ** 965 ** If an error message is available, leave it in p->zErrMsg. 966 */ 967 int sqlite3VtabSync(sqlite3 *db, Vdbe *p){ 968 int i; 969 int rc = SQLITE_OK; 970 VTable **aVTrans = db->aVTrans; 971 972 db->aVTrans = 0; 973 for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){ 974 int (*x)(sqlite3_vtab *); 975 sqlite3_vtab *pVtab = aVTrans[i]->pVtab; 976 if( pVtab && (x = pVtab->pModule->xSync)!=0 ){ 977 rc = x(pVtab); 978 sqlite3VtabImportErrmsg(p, pVtab); 979 } 980 } 981 db->aVTrans = aVTrans; 982 return rc; 983 } 984 985 /* 986 ** Invoke the xRollback method of all virtual tables in the 987 ** sqlite3.aVTrans array. Then clear the array itself. 988 */ 989 int sqlite3VtabRollback(sqlite3 *db){ 990 callFinaliser(db, offsetof(sqlite3_module,xRollback)); 991 return SQLITE_OK; 992 } 993 994 /* 995 ** Invoke the xCommit method of all virtual tables in the 996 ** sqlite3.aVTrans array. Then clear the array itself. 997 */ 998 int sqlite3VtabCommit(sqlite3 *db){ 999 callFinaliser(db, offsetof(sqlite3_module,xCommit)); 1000 return SQLITE_OK; 1001 } 1002 1003 /* 1004 ** If the virtual table pVtab supports the transaction interface 1005 ** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is 1006 ** not currently open, invoke the xBegin method now. 1007 ** 1008 ** If the xBegin call is successful, place the sqlite3_vtab pointer 1009 ** in the sqlite3.aVTrans array. 1010 */ 1011 int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){ 1012 int rc = SQLITE_OK; 1013 const sqlite3_module *pModule; 1014 1015 /* Special case: If db->aVTrans is NULL and db->nVTrans is greater 1016 ** than zero, then this function is being called from within a 1017 ** virtual module xSync() callback. It is illegal to write to 1018 ** virtual module tables in this case, so return SQLITE_LOCKED. 1019 */ 1020 if( sqlite3VtabInSync(db) ){ 1021 return SQLITE_LOCKED; 1022 } 1023 if( !pVTab ){ 1024 return SQLITE_OK; 1025 } 1026 pModule = pVTab->pVtab->pModule; 1027 1028 if( pModule->xBegin ){ 1029 int i; 1030 1031 /* If pVtab is already in the aVTrans array, return early */ 1032 for(i=0; i<db->nVTrans; i++){ 1033 if( db->aVTrans[i]==pVTab ){ 1034 return SQLITE_OK; 1035 } 1036 } 1037 1038 /* Invoke the xBegin method. If successful, add the vtab to the 1039 ** sqlite3.aVTrans[] array. */ 1040 rc = growVTrans(db); 1041 if( rc==SQLITE_OK ){ 1042 rc = pModule->xBegin(pVTab->pVtab); 1043 if( rc==SQLITE_OK ){ 1044 int iSvpt = db->nStatement + db->nSavepoint; 1045 addToVTrans(db, pVTab); 1046 if( iSvpt && pModule->xSavepoint ){ 1047 pVTab->iSavepoint = iSvpt; 1048 rc = pModule->xSavepoint(pVTab->pVtab, iSvpt-1); 1049 } 1050 } 1051 } 1052 } 1053 return rc; 1054 } 1055 1056 /* 1057 ** Invoke either the xSavepoint, xRollbackTo or xRelease method of all 1058 ** virtual tables that currently have an open transaction. Pass iSavepoint 1059 ** as the second argument to the virtual table method invoked. 1060 ** 1061 ** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is 1062 ** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is 1063 ** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with 1064 ** an open transaction is invoked. 1065 ** 1066 ** If any virtual table method returns an error code other than SQLITE_OK, 1067 ** processing is abandoned and the error returned to the caller of this 1068 ** function immediately. If all calls to virtual table methods are successful, 1069 ** SQLITE_OK is returned. 1070 */ 1071 int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){ 1072 int rc = SQLITE_OK; 1073 1074 assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN ); 1075 assert( iSavepoint>=-1 ); 1076 if( db->aVTrans ){ 1077 int i; 1078 for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){ 1079 VTable *pVTab = db->aVTrans[i]; 1080 const sqlite3_module *pMod = pVTab->pMod->pModule; 1081 if( pVTab->pVtab && pMod->iVersion>=2 ){ 1082 int (*xMethod)(sqlite3_vtab *, int); 1083 sqlite3VtabLock(pVTab); 1084 switch( op ){ 1085 case SAVEPOINT_BEGIN: 1086 xMethod = pMod->xSavepoint; 1087 pVTab->iSavepoint = iSavepoint+1; 1088 break; 1089 case SAVEPOINT_ROLLBACK: 1090 xMethod = pMod->xRollbackTo; 1091 break; 1092 default: 1093 xMethod = pMod->xRelease; 1094 break; 1095 } 1096 if( xMethod && pVTab->iSavepoint>iSavepoint ){ 1097 rc = xMethod(pVTab->pVtab, iSavepoint); 1098 } 1099 sqlite3VtabUnlock(pVTab); 1100 } 1101 } 1102 } 1103 return rc; 1104 } 1105 1106 /* 1107 ** The first parameter (pDef) is a function implementation. The 1108 ** second parameter (pExpr) is the first argument to this function. 1109 ** If pExpr is a column in a virtual table, then let the virtual 1110 ** table implementation have an opportunity to overload the function. 1111 ** 1112 ** This routine is used to allow virtual table implementations to 1113 ** overload MATCH, LIKE, GLOB, and REGEXP operators. 1114 ** 1115 ** Return either the pDef argument (indicating no change) or a 1116 ** new FuncDef structure that is marked as ephemeral using the 1117 ** SQLITE_FUNC_EPHEM flag. 1118 */ 1119 FuncDef *sqlite3VtabOverloadFunction( 1120 sqlite3 *db, /* Database connection for reporting malloc problems */ 1121 FuncDef *pDef, /* Function to possibly overload */ 1122 int nArg, /* Number of arguments to the function */ 1123 Expr *pExpr /* First argument to the function */ 1124 ){ 1125 Table *pTab; 1126 sqlite3_vtab *pVtab; 1127 sqlite3_module *pMod; 1128 void (*xSFunc)(sqlite3_context*,int,sqlite3_value**) = 0; 1129 void *pArg = 0; 1130 FuncDef *pNew; 1131 int rc = 0; 1132 1133 /* Check to see the left operand is a column in a virtual table */ 1134 if( NEVER(pExpr==0) ) return pDef; 1135 if( pExpr->op!=TK_COLUMN ) return pDef; 1136 assert( ExprUseYTab(pExpr) ); 1137 pTab = pExpr->y.pTab; 1138 if( pTab==0 ) return pDef; 1139 if( !IsVirtual(pTab) ) return pDef; 1140 pVtab = sqlite3GetVTable(db, pTab)->pVtab; 1141 assert( pVtab!=0 ); 1142 assert( pVtab->pModule!=0 ); 1143 pMod = (sqlite3_module *)pVtab->pModule; 1144 if( pMod->xFindFunction==0 ) return pDef; 1145 1146 /* Call the xFindFunction method on the virtual table implementation 1147 ** to see if the implementation wants to overload this function. 1148 ** 1149 ** Though undocumented, we have historically always invoked xFindFunction 1150 ** with an all lower-case function name. Continue in this tradition to 1151 ** avoid any chance of an incompatibility. 1152 */ 1153 #ifdef SQLITE_DEBUG 1154 { 1155 int i; 1156 for(i=0; pDef->zName[i]; i++){ 1157 unsigned char x = (unsigned char)pDef->zName[i]; 1158 assert( x==sqlite3UpperToLower[x] ); 1159 } 1160 } 1161 #endif 1162 rc = pMod->xFindFunction(pVtab, nArg, pDef->zName, &xSFunc, &pArg); 1163 if( rc==0 ){ 1164 return pDef; 1165 } 1166 1167 /* Create a new ephemeral function definition for the overloaded 1168 ** function */ 1169 pNew = sqlite3DbMallocZero(db, sizeof(*pNew) 1170 + sqlite3Strlen30(pDef->zName) + 1); 1171 if( pNew==0 ){ 1172 return pDef; 1173 } 1174 *pNew = *pDef; 1175 pNew->zName = (const char*)&pNew[1]; 1176 memcpy((char*)&pNew[1], pDef->zName, sqlite3Strlen30(pDef->zName)+1); 1177 pNew->xSFunc = xSFunc; 1178 pNew->pUserData = pArg; 1179 pNew->funcFlags |= SQLITE_FUNC_EPHEM; 1180 return pNew; 1181 } 1182 1183 /* 1184 ** Make sure virtual table pTab is contained in the pParse->apVirtualLock[] 1185 ** array so that an OP_VBegin will get generated for it. Add pTab to the 1186 ** array if it is missing. If pTab is already in the array, this routine 1187 ** is a no-op. 1188 */ 1189 void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){ 1190 Parse *pToplevel = sqlite3ParseToplevel(pParse); 1191 int i, n; 1192 Table **apVtabLock; 1193 1194 assert( IsVirtual(pTab) ); 1195 for(i=0; i<pToplevel->nVtabLock; i++){ 1196 if( pTab==pToplevel->apVtabLock[i] ) return; 1197 } 1198 n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]); 1199 apVtabLock = sqlite3Realloc(pToplevel->apVtabLock, n); 1200 if( apVtabLock ){ 1201 pToplevel->apVtabLock = apVtabLock; 1202 pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab; 1203 }else{ 1204 sqlite3OomFault(pToplevel->db); 1205 } 1206 } 1207 1208 /* 1209 ** Check to see if virtual table module pMod can be have an eponymous 1210 ** virtual table instance. If it can, create one if one does not already 1211 ** exist. Return non-zero if either the eponymous virtual table instance 1212 ** exists when this routine returns or if an attempt to create it failed 1213 ** and an error message was left in pParse. 1214 ** 1215 ** An eponymous virtual table instance is one that is named after its 1216 ** module, and more importantly, does not require a CREATE VIRTUAL TABLE 1217 ** statement in order to come into existance. Eponymous virtual table 1218 ** instances always exist. They cannot be DROP-ed. 1219 ** 1220 ** Any virtual table module for which xConnect and xCreate are the same 1221 ** method can have an eponymous virtual table instance. 1222 */ 1223 int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){ 1224 const sqlite3_module *pModule = pMod->pModule; 1225 Table *pTab; 1226 char *zErr = 0; 1227 int rc; 1228 sqlite3 *db = pParse->db; 1229 if( pMod->pEpoTab ) return 1; 1230 if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0; 1231 pTab = sqlite3DbMallocZero(db, sizeof(Table)); 1232 if( pTab==0 ) return 0; 1233 pTab->zName = sqlite3DbStrDup(db, pMod->zName); 1234 if( pTab->zName==0 ){ 1235 sqlite3DbFree(db, pTab); 1236 return 0; 1237 } 1238 pMod->pEpoTab = pTab; 1239 pTab->nTabRef = 1; 1240 pTab->eTabType = TABTYP_VTAB; 1241 pTab->pSchema = db->aDb[0].pSchema; 1242 assert( pTab->u.vtab.nArg==0 ); 1243 pTab->iPKey = -1; 1244 pTab->tabFlags |= TF_Eponymous; 1245 addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName)); 1246 addModuleArgument(pParse, pTab, 0); 1247 addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName)); 1248 rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr); 1249 if( rc ){ 1250 sqlite3ErrorMsg(pParse, "%s", zErr); 1251 sqlite3DbFree(db, zErr); 1252 sqlite3VtabEponymousTableClear(db, pMod); 1253 } 1254 return 1; 1255 } 1256 1257 /* 1258 ** Erase the eponymous virtual table instance associated with 1259 ** virtual table module pMod, if it exists. 1260 */ 1261 void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){ 1262 Table *pTab = pMod->pEpoTab; 1263 if( pTab!=0 ){ 1264 /* Mark the table as Ephemeral prior to deleting it, so that the 1265 ** sqlite3DeleteTable() routine will know that it is not stored in 1266 ** the schema. */ 1267 pTab->tabFlags |= TF_Ephemeral; 1268 sqlite3DeleteTable(db, pTab); 1269 pMod->pEpoTab = 0; 1270 } 1271 } 1272 1273 /* 1274 ** Return the ON CONFLICT resolution mode in effect for the virtual 1275 ** table update operation currently in progress. 1276 ** 1277 ** The results of this routine are undefined unless it is called from 1278 ** within an xUpdate method. 1279 */ 1280 int sqlite3_vtab_on_conflict(sqlite3 *db){ 1281 static const unsigned char aMap[] = { 1282 SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE 1283 }; 1284 #ifdef SQLITE_ENABLE_API_ARMOR 1285 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; 1286 #endif 1287 assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 ); 1288 assert( OE_Ignore==4 && OE_Replace==5 ); 1289 assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 ); 1290 return (int)aMap[db->vtabOnConflict-1]; 1291 } 1292 1293 /* 1294 ** Call from within the xCreate() or xConnect() methods to provide 1295 ** the SQLite core with additional information about the behavior 1296 ** of the virtual table being implemented. 1297 */ 1298 int sqlite3_vtab_config(sqlite3 *db, int op, ...){ 1299 va_list ap; 1300 int rc = SQLITE_OK; 1301 VtabCtx *p; 1302 1303 #ifdef SQLITE_ENABLE_API_ARMOR 1304 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; 1305 #endif 1306 sqlite3_mutex_enter(db->mutex); 1307 p = db->pVtabCtx; 1308 if( !p ){ 1309 rc = SQLITE_MISUSE_BKPT; 1310 }else{ 1311 assert( p->pTab==0 || IsVirtual(p->pTab) ); 1312 va_start(ap, op); 1313 switch( op ){ 1314 case SQLITE_VTAB_CONSTRAINT_SUPPORT: { 1315 p->pVTable->bConstraint = (u8)va_arg(ap, int); 1316 break; 1317 } 1318 case SQLITE_VTAB_INNOCUOUS: { 1319 p->pVTable->eVtabRisk = SQLITE_VTABRISK_Low; 1320 break; 1321 } 1322 case SQLITE_VTAB_DIRECTONLY: { 1323 p->pVTable->eVtabRisk = SQLITE_VTABRISK_High; 1324 break; 1325 } 1326 default: { 1327 rc = SQLITE_MISUSE_BKPT; 1328 break; 1329 } 1330 } 1331 va_end(ap); 1332 } 1333 1334 if( rc!=SQLITE_OK ) sqlite3Error(db, rc); 1335 sqlite3_mutex_leave(db->mutex); 1336 return rc; 1337 } 1338 1339 #endif /* SQLITE_OMIT_VIRTUALTABLE */ 1340