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| 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 ** The actual function that does the work of creating a new module. | |
| 33 ** This function implements the sqlite3_create_module() and | |
| 34 ** sqlite3_create_module_v2() interfaces. | |
| 35 */ | |
| 36 static int createModule( | |
| 37 sqlite3 *db, /* Database in which module is registered */ | |
| 38 const char *zName, /* Name assigned to this module */ | |
| 39 const sqlite3_module *pModule, /* The definition of the module */ | |
| 40 void *pAux, /* Context pointer for xCreate/xConnect */ | |
| 41 void (*xDestroy)(void *) /* Module destructor function */ | |
| 42 ){ | |
| 43 int rc = SQLITE_OK; | |
| 44 int nName; | |
| 45 | |
| 46 sqlite3_mutex_enter(db->mutex); | |
| 47 nName = sqlite3Strlen30(zName); | |
| 48 if( sqlite3HashFind(&db->aModule, zName) ){ | |
| 49 rc = SQLITE_MISUSE_BKPT; | |
| 50 }else{ | |
| 51 Module *pMod; | |
| 52 pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1); | |
| 53 if( pMod ){ | |
| 54 Module *pDel; | |
| 55 char *zCopy = (char *)(&pMod[1]); | |
| 56 memcpy(zCopy, zName, nName+1); | |
| 57 pMod->zName = zCopy; | |
| 58 pMod->pModule = pModule; | |
| 59 pMod->pAux = pAux; | |
| 60 pMod->xDestroy = xDestroy; | |
| 61 pMod->pEpoTab = 0; | |
| 62 pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod); | |
| 63 assert( pDel==0 || pDel==pMod ); | |
| 64 if( pDel ){ | |
| 65 db->mallocFailed = 1; | |
| 66 sqlite3DbFree(db, pDel); | |
| 67 } | |
| 68 } | |
| 69 } | |
| 70 rc = sqlite3ApiExit(db, rc); | |
| 71 if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux); | |
| 72 | |
| 73 sqlite3_mutex_leave(db->mutex); | |
| 74 return rc; | |
| 75 } | |
| 76 | |
| 77 | |
| 78 /* | |
| 79 ** External API function used to create a new virtual-table module. | |
| 80 */ | |
| 81 int sqlite3_create_module( | |
| 82 sqlite3 *db, /* Database in which module is registered */ | |
| 83 const char *zName, /* Name assigned to this module */ | |
| 84 const sqlite3_module *pModule, /* The definition of the module */ | |
| 85 void *pAux /* Context pointer for xCreate/xConnect */ | |
| 86 ){ | |
| 87 #ifdef SQLITE_ENABLE_API_ARMOR | |
| 88 if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT; | |
| 89 #endif | |
| 90 return createModule(db, zName, pModule, pAux, 0); | |
| 91 } | |
| 92 | |
| 93 /* | |
| 94 ** External API function used to create a new virtual-table module. | |
| 95 */ | |
| 96 int sqlite3_create_module_v2( | |
| 97 sqlite3 *db, /* Database in which module is registered */ | |
| 98 const char *zName, /* Name assigned to this module */ | |
| 99 const sqlite3_module *pModule, /* The definition of the module */ | |
| 100 void *pAux, /* Context pointer for xCreate/xConnect */ | |
| 101 void (*xDestroy)(void *) /* Module destructor function */ | |
| 102 ){ | |
| 103 #ifdef SQLITE_ENABLE_API_ARMOR | |
| 104 if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT; | |
| 105 #endif | |
| 106 return createModule(db, zName, pModule, pAux, xDestroy); | |
| 107 } | |
| 108 | |
| 109 /* | |
| 110 ** Lock the virtual table so that it cannot be disconnected. | |
| 111 ** Locks nest. Every lock should have a corresponding unlock. | |
| 112 ** If an unlock is omitted, resources leaks will occur. | |
| 113 ** | |
| 114 ** If a disconnect is attempted while a virtual table is locked, | |
| 115 ** the disconnect is deferred until all locks have been removed. | |
| 116 */ | |
| 117 void sqlite3VtabLock(VTable *pVTab){ | |
| 118 pVTab->nRef++; | |
| 119 } | |
| 120 | |
| 121 | |
| 122 /* | |
| 123 ** pTab is a pointer to a Table structure representing a virtual-table. | |
| 124 ** Return a pointer to the VTable object used by connection db to access | |
| 125 ** this virtual-table, if one has been created, or NULL otherwise. | |
| 126 */ | |
| 127 VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){ | |
| 128 VTable *pVtab; | |
| 129 assert( IsVirtual(pTab) ); | |
| 130 for(pVtab=pTab->pVTable; pVtab && pVtab->db!=db; pVtab=pVtab->pNext); | |
| 131 return pVtab; | |
| 132 } | |
| 133 | |
| 134 /* | |
| 135 ** Decrement the ref-count on a virtual table object. When the ref-count | |
| 136 ** reaches zero, call the xDisconnect() method to delete the object. | |
| 137 */ | |
| 138 void sqlite3VtabUnlock(VTable *pVTab){ | |
| 139 sqlite3 *db = pVTab->db; | |
| 140 | |
| 141 assert( db ); | |
| 142 assert( pVTab->nRef>0 ); | |
| 143 assert( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ZOMBIE ); | |
| 144 | |
| 145 pVTab->nRef--; | |
| 146 if( pVTab->nRef==0 ){ | |
| 147 sqlite3_vtab *p = pVTab->pVtab; | |
| 148 if( p ){ | |
| 149 p->pModule->xDisconnect(p); | |
| 150 } | |
| 151 sqlite3DbFree(db, pVTab); | |
| 152 } | |
| 153 } | |
| 154 | |
| 155 /* | |
| 156 ** Table p is a virtual table. This function moves all elements in the | |
| 157 ** p->pVTable list to the sqlite3.pDisconnect lists of their associated | |
| 158 ** database connections to be disconnected at the next opportunity. | |
| 159 ** Except, if argument db is not NULL, then the entry associated with | |
| 160 ** connection db is left in the p->pVTable list. | |
| 161 */ | |
| 162 static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){ | |
| 163 VTable *pRet = 0; | |
| 164 VTable *pVTable = p->pVTable; | |
| 165 p->pVTable = 0; | |
| 166 | |
| 167 /* Assert that the mutex (if any) associated with the BtShared database | |
| 168 ** that contains table p is held by the caller. See header comments | |
| 169 ** above function sqlite3VtabUnlockList() for an explanation of why | |
| 170 ** this makes it safe to access the sqlite3.pDisconnect list of any | |
| 171 ** database connection that may have an entry in the p->pVTable list. | |
| 172 */ | |
| 173 assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) ); | |
| 174 | |
| 175 while( pVTable ){ | |
| 176 sqlite3 *db2 = pVTable->db; | |
| 177 VTable *pNext = pVTable->pNext; | |
| 178 assert( db2 ); | |
| 179 if( db2==db ){ | |
| 180 pRet = pVTable; | |
| 181 p->pVTable = pRet; | |
| 182 pRet->pNext = 0; | |
| 183 }else{ | |
| 184 pVTable->pNext = db2->pDisconnect; | |
| 185 db2->pDisconnect = pVTable; | |
| 186 } | |
| 187 pVTable = pNext; | |
| 188 } | |
| 189 | |
| 190 assert( !db || pRet ); | |
| 191 return pRet; | |
| 192 } | |
| 193 | |
| 194 /* | |
| 195 ** Table *p is a virtual table. This function removes the VTable object | |
| 196 ** for table *p associated with database connection db from the linked | |
| 197 ** list in p->pVTab. It also decrements the VTable ref count. This is | |
| 198 ** used when closing database connection db to free all of its VTable | |
| 199 ** objects without disturbing the rest of the Schema object (which may | |
| 200 ** be being used by other shared-cache connections). | |
| 201 */ | |
| 202 void sqlite3VtabDisconnect(sqlite3 *db, Table *p){ | |
| 203 VTable **ppVTab; | |
| 204 | |
| 205 assert( IsVirtual(p) ); | |
| 206 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
| 207 assert( sqlite3_mutex_held(db->mutex) ); | |
| 208 | |
| 209 for(ppVTab=&p->pVTable; *ppVTab; ppVTab=&(*ppVTab)->pNext){ | |
| 210 if( (*ppVTab)->db==db ){ | |
| 211 VTable *pVTab = *ppVTab; | |
| 212 *ppVTab = pVTab->pNext; | |
| 213 sqlite3VtabUnlock(pVTab); | |
| 214 break; | |
| 215 } | |
| 216 } | |
| 217 } | |
| 218 | |
| 219 | |
| 220 /* | |
| 221 ** Disconnect all the virtual table objects in the sqlite3.pDisconnect list. | |
| 222 ** | |
| 223 ** This function may only be called when the mutexes associated with all | |
| 224 ** shared b-tree databases opened using connection db are held by the | |
| 225 ** caller. This is done to protect the sqlite3.pDisconnect list. The | |
| 226 ** sqlite3.pDisconnect list is accessed only as follows: | |
| 227 ** | |
| 228 ** 1) By this function. In this case, all BtShared mutexes and the mutex | |
| 229 ** associated with the database handle itself must be held. | |
| 230 ** | |
| 231 ** 2) By function vtabDisconnectAll(), when it adds a VTable entry to | |
| 232 ** the sqlite3.pDisconnect list. In this case either the BtShared mutex | |
| 233 ** associated with the database the virtual table is stored in is held | |
| 234 ** or, if the virtual table is stored in a non-sharable database, then | |
| 235 ** the database handle mutex is held. | |
| 236 ** | |
| 237 ** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously | |
| 238 ** by multiple threads. It is thread-safe. | |
| 239 */ | |
| 240 void sqlite3VtabUnlockList(sqlite3 *db){ | |
| 241 VTable *p = db->pDisconnect; | |
| 242 db->pDisconnect = 0; | |
| 243 | |
| 244 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
| 245 assert( sqlite3_mutex_held(db->mutex) ); | |
| 246 | |
| 247 if( p ){ | |
| 248 sqlite3ExpirePreparedStatements(db); | |
| 249 do { | |
| 250 VTable *pNext = p->pNext; | |
| 251 sqlite3VtabUnlock(p); | |
| 252 p = pNext; | |
| 253 }while( p ); | |
| 254 } | |
| 255 } | |
| 256 | |
| 257 /* | |
| 258 ** Clear any and all virtual-table information from the Table record. | |
| 259 ** This routine is called, for example, just before deleting the Table | |
| 260 ** record. | |
| 261 ** | |
| 262 ** Since it is a virtual-table, the Table structure contains a pointer | |
| 263 ** to the head of a linked list of VTable structures. Each VTable | |
| 264 ** structure is associated with a single sqlite3* user of the schema. | |
| 265 ** The reference count of the VTable structure associated with database | |
| 266 ** connection db is decremented immediately (which may lead to the | |
| 267 ** structure being xDisconnected and free). Any other VTable structures | |
| 268 ** in the list are moved to the sqlite3.pDisconnect list of the associated | |
| 269 ** database connection. | |
| 270 */ | |
| 271 void sqlite3VtabClear(sqlite3 *db, Table *p){ | |
| 272 if( !db || db->pnBytesFreed==0 ) vtabDisconnectAll(0, p); | |
| 273 if( p->azModuleArg ){ | |
| 274 int i; | |
| 275 for(i=0; i<p->nModuleArg; i++){ | |
| 276 if( i!=1 ) sqlite3DbFree(db, p->azModuleArg[i]); | |
| 277 } | |
| 278 sqlite3DbFree(db, p->azModuleArg); | |
| 279 } | |
| 280 } | |
| 281 | |
| 282 /* | |
| 283 ** Add a new module argument to pTable->azModuleArg[]. | |
| 284 ** The string is not copied - the pointer is stored. The | |
| 285 ** string will be freed automatically when the table is | |
| 286 ** deleted. | |
| 287 */ | |
| 288 static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){ | |
| 289 int nBytes = sizeof(char *)*(2+pTable->nModuleArg); | |
| 290 char **azModuleArg; | |
| 291 azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes); | |
| 292 if( azModuleArg==0 ){ | |
| 293 sqlite3DbFree(db, zArg); | |
| 294 }else{ | |
| 295 int i = pTable->nModuleArg++; | |
| 296 azModuleArg[i] = zArg; | |
| 297 azModuleArg[i+1] = 0; | |
| 298 pTable->azModuleArg = azModuleArg; | |
| 299 } | |
| 300 } | |
| 301 | |
| 302 /* | |
| 303 ** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE | |
| 304 ** statement. The module name has been parsed, but the optional list | |
| 305 ** of parameters that follow the module name are still pending. | |
| 306 */ | |
| 307 void sqlite3VtabBeginParse( | |
| 308 Parse *pParse, /* Parsing context */ | |
| 309 Token *pName1, /* Name of new table, or database name */ | |
| 310 Token *pName2, /* Name of new table or NULL */ | |
| 311 Token *pModuleName, /* Name of the module for the virtual table */ | |
| 312 int ifNotExists /* No error if the table already exists */ | |
| 313 ){ | |
| 314 int iDb; /* The database the table is being created in */ | |
| 315 Table *pTable; /* The new virtual table */ | |
| 316 sqlite3 *db; /* Database connection */ | |
| 317 | |
| 318 sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists); | |
| 319 pTable = pParse->pNewTable; | |
| 320 if( pTable==0 ) return; | |
| 321 assert( 0==pTable->pIndex ); | |
| 322 | |
| 323 db = pParse->db; | |
| 324 iDb = sqlite3SchemaToIndex(db, pTable->pSchema); | |
| 325 assert( iDb>=0 ); | |
| 326 | |
| 327 pTable->tabFlags |= TF_Virtual; | |
| 328 pTable->nModuleArg = 0; | |
| 329 addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName)); | |
| 330 addModuleArgument(db, pTable, 0); | |
| 331 addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName)); | |
| 332 assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0) | |
| 333 || (pParse->sNameToken.z==pName1->z && pName2->z==0) | |
| 334 ); | |
| 335 pParse->sNameToken.n = (int)( | |
| 336 &pModuleName->z[pModuleName->n] - pParse->sNameToken.z | |
| 337 ); | |
| 338 | |
| 339 #ifndef SQLITE_OMIT_AUTHORIZATION | |
| 340 /* Creating a virtual table invokes the authorization callback twice. | |
| 341 ** The first invocation, to obtain permission to INSERT a row into the | |
| 342 ** sqlite_master table, has already been made by sqlite3StartTable(). | |
| 343 ** The second call, to obtain permission to create the table, is made now. | |
| 344 */ | |
| 345 if( pTable->azModuleArg ){ | |
| 346 sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, | |
| 347 pTable->azModuleArg[0], pParse->db->aDb[iDb].zName); | |
| 348 } | |
| 349 #endif | |
| 350 } | |
| 351 | |
| 352 /* | |
| 353 ** This routine takes the module argument that has been accumulating | |
| 354 ** in pParse->zArg[] and appends it to the list of arguments on the | |
| 355 ** virtual table currently under construction in pParse->pTable. | |
| 356 */ | |
| 357 static void addArgumentToVtab(Parse *pParse){ | |
| 358 if( pParse->sArg.z && pParse->pNewTable ){ | |
| 359 const char *z = (const char*)pParse->sArg.z; | |
| 360 int n = pParse->sArg.n; | |
| 361 sqlite3 *db = pParse->db; | |
| 362 addModuleArgument(db, pParse->pNewTable, sqlite3DbStrNDup(db, z, n)); | |
| 363 } | |
| 364 } | |
| 365 | |
| 366 /* | |
| 367 ** The parser calls this routine after the CREATE VIRTUAL TABLE statement | |
| 368 ** has been completely parsed. | |
| 369 */ | |
| 370 void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){ | |
| 371 Table *pTab = pParse->pNewTable; /* The table being constructed */ | |
| 372 sqlite3 *db = pParse->db; /* The database connection */ | |
| 373 | |
| 374 if( pTab==0 ) return; | |
| 375 addArgumentToVtab(pParse); | |
| 376 pParse->sArg.z = 0; | |
| 377 if( pTab->nModuleArg<1 ) return; | |
| 378 | |
| 379 /* If the CREATE VIRTUAL TABLE statement is being entered for the | |
| 380 ** first time (in other words if the virtual table is actually being | |
| 381 ** created now instead of just being read out of sqlite_master) then | |
| 382 ** do additional initialization work and store the statement text | |
| 383 ** in the sqlite_master table. | |
| 384 */ | |
| 385 if( !db->init.busy ){ | |
| 386 char *zStmt; | |
| 387 char *zWhere; | |
| 388 int iDb; | |
| 389 int iReg; | |
| 390 Vdbe *v; | |
| 391 | |
| 392 /* Compute the complete text of the CREATE VIRTUAL TABLE statement */ | |
| 393 if( pEnd ){ | |
| 394 pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n; | |
| 395 } | |
| 396 zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken); | |
| 397 | |
| 398 /* A slot for the record has already been allocated in the | |
| 399 ** SQLITE_MASTER table. We just need to update that slot with all | |
| 400 ** the information we've collected. | |
| 401 ** | |
| 402 ** The VM register number pParse->regRowid holds the rowid of an | |
| 403 ** entry in the sqlite_master table tht was created for this vtab | |
| 404 ** by sqlite3StartTable(). | |
| 405 */ | |
| 406 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); | |
| 407 sqlite3NestedParse(pParse, | |
| 408 "UPDATE %Q.%s " | |
| 409 "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q " | |
| 410 "WHERE rowid=#%d", | |
| 411 db->aDb[iDb].zName, SCHEMA_TABLE(iDb), | |
| 412 pTab->zName, | |
| 413 pTab->zName, | |
| 414 zStmt, | |
| 415 pParse->regRowid | |
| 416 ); | |
| 417 sqlite3DbFree(db, zStmt); | |
| 418 v = sqlite3GetVdbe(pParse); | |
| 419 sqlite3ChangeCookie(pParse, iDb); | |
| 420 | |
| 421 sqlite3VdbeAddOp2(v, OP_Expire, 0, 0); | |
| 422 zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName); | |
| 423 sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere); | |
| 424 | |
| 425 iReg = ++pParse->nMem; | |
| 426 sqlite3VdbeLoadString(v, iReg, pTab->zName); | |
| 427 sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg); | |
| 428 } | |
| 429 | |
| 430 /* If we are rereading the sqlite_master table create the in-memory | |
| 431 ** record of the table. The xConnect() method is not called until | |
| 432 ** the first time the virtual table is used in an SQL statement. This | |
| 433 ** allows a schema that contains virtual tables to be loaded before | |
| 434 ** the required virtual table implementations are registered. */ | |
| 435 else { | |
| 436 Table *pOld; | |
| 437 Schema *pSchema = pTab->pSchema; | |
| 438 const char *zName = pTab->zName; | |
| 439 assert( sqlite3SchemaMutexHeld(db, 0, pSchema) ); | |
| 440 pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab); | |
| 441 if( pOld ){ | |
| 442 db->mallocFailed = 1; | |
| 443 assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */ | |
| 444 return; | |
| 445 } | |
| 446 pParse->pNewTable = 0; | |
| 447 } | |
| 448 } | |
| 449 | |
| 450 /* | |
| 451 ** The parser calls this routine when it sees the first token | |
| 452 ** of an argument to the module name in a CREATE VIRTUAL TABLE statement. | |
| 453 */ | |
| 454 void sqlite3VtabArgInit(Parse *pParse){ | |
| 455 addArgumentToVtab(pParse); | |
| 456 pParse->sArg.z = 0; | |
| 457 pParse->sArg.n = 0; | |
| 458 } | |
| 459 | |
| 460 /* | |
| 461 ** The parser calls this routine for each token after the first token | |
| 462 ** in an argument to the module name in a CREATE VIRTUAL TABLE statement. | |
| 463 */ | |
| 464 void sqlite3VtabArgExtend(Parse *pParse, Token *p){ | |
| 465 Token *pArg = &pParse->sArg; | |
| 466 if( pArg->z==0 ){ | |
| 467 pArg->z = p->z; | |
| 468 pArg->n = p->n; | |
| 469 }else{ | |
| 470 assert(pArg->z <= p->z); | |
| 471 pArg->n = (int)(&p->z[p->n] - pArg->z); | |
| 472 } | |
| 473 } | |
| 474 | |
| 475 /* | |
| 476 ** Invoke a virtual table constructor (either xCreate or xConnect). The | |
| 477 ** pointer to the function to invoke is passed as the fourth parameter | |
| 478 ** to this procedure. | |
| 479 */ | |
| 480 static int vtabCallConstructor( | |
| 481 sqlite3 *db, | |
| 482 Table *pTab, | |
| 483 Module *pMod, | |
| 484 int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**), | |
| 485 char **pzErr | |
| 486 ){ | |
| 487 VtabCtx sCtx; | |
| 488 VTable *pVTable; | |
| 489 int rc; | |
| 490 const char *const*azArg = (const char *const*)pTab->azModuleArg; | |
| 491 int nArg = pTab->nModuleArg; | |
| 492 char *zErr = 0; | |
| 493 char *zModuleName; | |
| 494 int iDb; | |
| 495 VtabCtx *pCtx; | |
| 496 | |
| 497 /* Check that the virtual-table is not already being initialized */ | |
| 498 for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){ | |
| 499 if( pCtx->pTab==pTab ){ | |
| 500 *pzErr = sqlite3MPrintf(db, | |
| 501 "vtable constructor called recursively: %s", pTab->zName | |
| 502 ); | |
| 503 return SQLITE_LOCKED; | |
| 504 } | |
| 505 } | |
| 506 | |
| 507 zModuleName = sqlite3MPrintf(db, "%s", pTab->zName); | |
| 508 if( !zModuleName ){ | |
| 509 return SQLITE_NOMEM; | |
| 510 } | |
| 511 | |
| 512 pVTable = sqlite3DbMallocZero(db, sizeof(VTable)); | |
| 513 if( !pVTable ){ | |
| 514 sqlite3DbFree(db, zModuleName); | |
| 515 return SQLITE_NOMEM; | |
| 516 } | |
| 517 pVTable->db = db; | |
| 518 pVTable->pMod = pMod; | |
| 519 | |
| 520 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); | |
| 521 pTab->azModuleArg[1] = db->aDb[iDb].zName; | |
| 522 | |
| 523 /* Invoke the virtual table constructor */ | |
| 524 assert( &db->pVtabCtx ); | |
| 525 assert( xConstruct ); | |
| 526 sCtx.pTab = pTab; | |
| 527 sCtx.pVTable = pVTable; | |
| 528 sCtx.pPrior = db->pVtabCtx; | |
| 529 sCtx.bDeclared = 0; | |
| 530 db->pVtabCtx = &sCtx; | |
| 531 rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr); | |
| 532 db->pVtabCtx = sCtx.pPrior; | |
| 533 if( rc==SQLITE_NOMEM ) db->mallocFailed = 1; | |
| 534 assert( sCtx.pTab==pTab ); | |
| 535 | |
| 536 if( SQLITE_OK!=rc ){ | |
| 537 if( zErr==0 ){ | |
| 538 *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName); | |
| 539 }else { | |
| 540 *pzErr = sqlite3MPrintf(db, "%s", zErr); | |
| 541 sqlite3_free(zErr); | |
| 542 } | |
| 543 sqlite3DbFree(db, pVTable); | |
| 544 }else if( ALWAYS(pVTable->pVtab) ){ | |
| 545 /* Justification of ALWAYS(): A correct vtab constructor must allocate | |
| 546 ** the sqlite3_vtab object if successful. */ | |
| 547 memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0])); | |
| 548 pVTable->pVtab->pModule = pMod->pModule; | |
| 549 pVTable->nRef = 1; | |
| 550 if( sCtx.bDeclared==0 ){ | |
| 551 const char *zFormat = "vtable constructor did not declare schema: %s"; | |
| 552 *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName); | |
| 553 sqlite3VtabUnlock(pVTable); | |
| 554 rc = SQLITE_ERROR; | |
| 555 }else{ | |
| 556 int iCol; | |
| 557 u8 oooHidden = 0; | |
| 558 /* If everything went according to plan, link the new VTable structure | |
| 559 ** into the linked list headed by pTab->pVTable. Then loop through the | |
| 560 ** columns of the table to see if any of them contain the token "hidden". | |
| 561 ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from | |
| 562 ** the type string. */ | |
| 563 pVTable->pNext = pTab->pVTable; | |
| 564 pTab->pVTable = pVTable; | |
| 565 | |
| 566 for(iCol=0; iCol<pTab->nCol; iCol++){ | |
| 567 char *zType = pTab->aCol[iCol].zType; | |
| 568 int nType; | |
| 569 int i = 0; | |
| 570 if( !zType ){ | |
| 571 pTab->tabFlags |= oooHidden; | |
| 572 continue; | |
| 573 } | |
| 574 nType = sqlite3Strlen30(zType); | |
| 575 if( sqlite3StrNICmp("hidden", zType, 6)||(zType[6] && zType[6]!=' ') ){ | |
| 576 for(i=0; i<nType; i++){ | |
| 577 if( (0==sqlite3StrNICmp(" hidden", &zType[i], 7)) | |
| 578 && (zType[i+7]=='\0' || zType[i+7]==' ') | |
| 579 ){ | |
| 580 i++; | |
| 581 break; | |
| 582 } | |
| 583 } | |
| 584 } | |
| 585 if( i<nType ){ | |
| 586 int j; | |
| 587 int nDel = 6 + (zType[i+6] ? 1 : 0); | |
| 588 for(j=i; (j+nDel)<=nType; j++){ | |
| 589 zType[j] = zType[j+nDel]; | |
| 590 } | |
| 591 if( zType[i]=='\0' && i>0 ){ | |
| 592 assert(zType[i-1]==' '); | |
| 593 zType[i-1] = '\0'; | |
| 594 } | |
| 595 pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN; | |
| 596 oooHidden = TF_OOOHidden; | |
| 597 }else{ | |
| 598 pTab->tabFlags |= oooHidden; | |
| 599 } | |
| 600 } | |
| 601 } | |
| 602 } | |
| 603 | |
| 604 sqlite3DbFree(db, zModuleName); | |
| 605 return rc; | |
| 606 } | |
| 607 | |
| 608 /* | |
| 609 ** This function is invoked by the parser to call the xConnect() method | |
| 610 ** of the virtual table pTab. If an error occurs, an error code is returned | |
| 611 ** and an error left in pParse. | |
| 612 ** | |
| 613 ** This call is a no-op if table pTab is not a virtual table. | |
| 614 */ | |
| 615 int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){ | |
| 616 sqlite3 *db = pParse->db; | |
| 617 const char *zMod; | |
| 618 Module *pMod; | |
| 619 int rc; | |
| 620 | |
| 621 assert( pTab ); | |
| 622 if( (pTab->tabFlags & TF_Virtual)==0 || sqlite3GetVTable(db, pTab) ){ | |
| 623 return SQLITE_OK; | |
| 624 } | |
| 625 | |
| 626 /* Locate the required virtual table module */ | |
| 627 zMod = pTab->azModuleArg[0]; | |
| 628 pMod = (Module*)sqlite3HashFind(&db->aModule, zMod); | |
| 629 | |
| 630 if( !pMod ){ | |
| 631 const char *zModule = pTab->azModuleArg[0]; | |
| 632 sqlite3ErrorMsg(pParse, "no such module: %s", zModule); | |
| 633 rc = SQLITE_ERROR; | |
| 634 }else{ | |
| 635 char *zErr = 0; | |
| 636 rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr); | |
| 637 if( rc!=SQLITE_OK ){ | |
| 638 sqlite3ErrorMsg(pParse, "%s", zErr); | |
| 639 } | |
| 640 sqlite3DbFree(db, zErr); | |
| 641 } | |
| 642 | |
| 643 return rc; | |
| 644 } | |
| 645 /* | |
| 646 ** Grow the db->aVTrans[] array so that there is room for at least one | |
| 647 ** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise. | |
| 648 */ | |
| 649 static int growVTrans(sqlite3 *db){ | |
| 650 const int ARRAY_INCR = 5; | |
| 651 | |
| 652 /* Grow the sqlite3.aVTrans array if required */ | |
| 653 if( (db->nVTrans%ARRAY_INCR)==0 ){ | |
| 654 VTable **aVTrans; | |
| 655 int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR); | |
| 656 aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes); | |
| 657 if( !aVTrans ){ | |
| 658 return SQLITE_NOMEM; | |
| 659 } | |
| 660 memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR); | |
| 661 db->aVTrans = aVTrans; | |
| 662 } | |
| 663 | |
| 664 return SQLITE_OK; | |
| 665 } | |
| 666 | |
| 667 /* | |
| 668 ** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should | |
| 669 ** have already been reserved using growVTrans(). | |
| 670 */ | |
| 671 static void addToVTrans(sqlite3 *db, VTable *pVTab){ | |
| 672 /* Add pVtab to the end of sqlite3.aVTrans */ | |
| 673 db->aVTrans[db->nVTrans++] = pVTab; | |
| 674 sqlite3VtabLock(pVTab); | |
| 675 } | |
| 676 | |
| 677 /* | |
| 678 ** This function is invoked by the vdbe to call the xCreate method | |
| 679 ** of the virtual table named zTab in database iDb. | |
| 680 ** | |
| 681 ** If an error occurs, *pzErr is set to point an an English language | |
| 682 ** description of the error and an SQLITE_XXX error code is returned. | |
| 683 ** In this case the caller must call sqlite3DbFree(db, ) on *pzErr. | |
| 684 */ | |
| 685 int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){ | |
| 686 int rc = SQLITE_OK; | |
| 687 Table *pTab; | |
| 688 Module *pMod; | |
| 689 const char *zMod; | |
| 690 | |
| 691 pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName); | |
| 692 assert( pTab && (pTab->tabFlags & TF_Virtual)!=0 && !pTab->pVTable ); | |
| 693 | |
| 694 /* Locate the required virtual table module */ | |
| 695 zMod = pTab->azModuleArg[0]; | |
| 696 pMod = (Module*)sqlite3HashFind(&db->aModule, zMod); | |
| 697 | |
| 698 /* If the module has been registered and includes a Create method, | |
| 699 ** invoke it now. If the module has not been registered, return an | |
| 700 ** error. Otherwise, do nothing. | |
| 701 */ | |
| 702 if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){ | |
| 703 *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod); | |
| 704 rc = SQLITE_ERROR; | |
| 705 }else{ | |
| 706 rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr); | |
| 707 } | |
| 708 | |
| 709 /* Justification of ALWAYS(): The xConstructor method is required to | |
| 710 ** create a valid sqlite3_vtab if it returns SQLITE_OK. */ | |
| 711 if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){ | |
| 712 rc = growVTrans(db); | |
| 713 if( rc==SQLITE_OK ){ | |
| 714 addToVTrans(db, sqlite3GetVTable(db, pTab)); | |
| 715 } | |
| 716 } | |
| 717 | |
| 718 return rc; | |
| 719 } | |
| 720 | |
| 721 /* | |
| 722 ** This function is used to set the schema of a virtual table. It is only | |
| 723 ** valid to call this function from within the xCreate() or xConnect() of a | |
| 724 ** virtual table module. | |
| 725 */ | |
| 726 int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){ | |
| 727 VtabCtx *pCtx; | |
| 728 Parse *pParse; | |
| 729 int rc = SQLITE_OK; | |
| 730 Table *pTab; | |
| 731 char *zErr = 0; | |
| 732 | |
| 733 #ifdef SQLITE_ENABLE_API_ARMOR | |
| 734 if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){ | |
| 735 return SQLITE_MISUSE_BKPT; | |
| 736 } | |
| 737 #endif | |
| 738 sqlite3_mutex_enter(db->mutex); | |
| 739 pCtx = db->pVtabCtx; | |
| 740 if( !pCtx || pCtx->bDeclared ){ | |
| 741 sqlite3Error(db, SQLITE_MISUSE); | |
| 742 sqlite3_mutex_leave(db->mutex); | |
| 743 return SQLITE_MISUSE_BKPT; | |
| 744 } | |
| 745 pTab = pCtx->pTab; | |
| 746 assert( (pTab->tabFlags & TF_Virtual)!=0 ); | |
| 747 | |
| 748 pParse = sqlite3StackAllocZero(db, sizeof(*pParse)); | |
| 749 if( pParse==0 ){ | |
| 750 rc = SQLITE_NOMEM; | |
| 751 }else{ | |
| 752 pParse->declareVtab = 1; | |
| 753 pParse->db = db; | |
| 754 pParse->nQueryLoop = 1; | |
| 755 | |
| 756 if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) | |
| 757 && pParse->pNewTable | |
| 758 && !db->mallocFailed | |
| 759 && !pParse->pNewTable->pSelect | |
| 760 && (pParse->pNewTable->tabFlags & TF_Virtual)==0 | |
| 761 ){ | |
| 762 if( !pTab->aCol ){ | |
| 763 pTab->aCol = pParse->pNewTable->aCol; | |
| 764 pTab->nCol = pParse->pNewTable->nCol; | |
| 765 pParse->pNewTable->nCol = 0; | |
| 766 pParse->pNewTable->aCol = 0; | |
| 767 } | |
| 768 pCtx->bDeclared = 1; | |
| 769 }else{ | |
| 770 sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr); | |
| 771 sqlite3DbFree(db, zErr); | |
| 772 rc = SQLITE_ERROR; | |
| 773 } | |
| 774 pParse->declareVtab = 0; | |
| 775 | |
| 776 if( pParse->pVdbe ){ | |
| 777 sqlite3VdbeFinalize(pParse->pVdbe); | |
| 778 } | |
| 779 sqlite3DeleteTable(db, pParse->pNewTable); | |
| 780 sqlite3ParserReset(pParse); | |
| 781 sqlite3StackFree(db, pParse); | |
| 782 } | |
| 783 | |
| 784 assert( (rc&0xff)==rc ); | |
| 785 rc = sqlite3ApiExit(db, rc); | |
| 786 sqlite3_mutex_leave(db->mutex); | |
| 787 return rc; | |
| 788 } | |
| 789 | |
| 790 /* | |
| 791 ** This function is invoked by the vdbe to call the xDestroy method | |
| 792 ** of the virtual table named zTab in database iDb. This occurs | |
| 793 ** when a DROP TABLE is mentioned. | |
| 794 ** | |
| 795 ** This call is a no-op if zTab is not a virtual table. | |
| 796 */ | |
| 797 int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){ | |
| 798 int rc = SQLITE_OK; | |
| 799 Table *pTab; | |
| 800 | |
| 801 pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName); | |
| 802 if( ALWAYS(pTab!=0 && pTab->pVTable!=0) ){ | |
| 803 VTable *p; | |
| 804 int (*xDestroy)(sqlite3_vtab *); | |
| 805 for(p=pTab->pVTable; p; p=p->pNext){ | |
| 806 assert( p->pVtab ); | |
| 807 if( p->pVtab->nRef>0 ){ | |
| 808 return SQLITE_LOCKED; | |
| 809 } | |
| 810 } | |
| 811 p = vtabDisconnectAll(db, pTab); | |
| 812 xDestroy = p->pMod->pModule->xDestroy; | |
| 813 assert( xDestroy!=0 ); /* Checked before the virtual table is created */ | |
| 814 rc = xDestroy(p->pVtab); | |
| 815 /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */ | |
| 816 if( rc==SQLITE_OK ){ | |
| 817 assert( pTab->pVTable==p && p->pNext==0 ); | |
| 818 p->pVtab = 0; | |
| 819 pTab->pVTable = 0; | |
| 820 sqlite3VtabUnlock(p); | |
| 821 } | |
| 822 } | |
| 823 | |
| 824 return rc; | |
| 825 } | |
| 826 | |
| 827 /* | |
| 828 ** This function invokes either the xRollback or xCommit method | |
| 829 ** of each of the virtual tables in the sqlite3.aVTrans array. The method | |
| 830 ** called is identified by the second argument, "offset", which is | |
| 831 ** the offset of the method to call in the sqlite3_module structure. | |
| 832 ** | |
| 833 ** The array is cleared after invoking the callbacks. | |
| 834 */ | |
| 835 static void callFinaliser(sqlite3 *db, int offset){ | |
| 836 int i; | |
| 837 if( db->aVTrans ){ | |
| 838 VTable **aVTrans = db->aVTrans; | |
| 839 db->aVTrans = 0; | |
| 840 for(i=0; i<db->nVTrans; i++){ | |
| 841 VTable *pVTab = aVTrans[i]; | |
| 842 sqlite3_vtab *p = pVTab->pVtab; | |
| 843 if( p ){ | |
| 844 int (*x)(sqlite3_vtab *); | |
| 845 x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset); | |
| 846 if( x ) x(p); | |
| 847 } | |
| 848 pVTab->iSavepoint = 0; | |
| 849 sqlite3VtabUnlock(pVTab); | |
| 850 } | |
| 851 sqlite3DbFree(db, aVTrans); | |
| 852 db->nVTrans = 0; | |
| 853 } | |
| 854 } | |
| 855 | |
| 856 /* | |
| 857 ** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans | |
| 858 ** array. Return the error code for the first error that occurs, or | |
| 859 ** SQLITE_OK if all xSync operations are successful. | |
| 860 ** | |
| 861 ** If an error message is available, leave it in p->zErrMsg. | |
| 862 */ | |
| 863 int sqlite3VtabSync(sqlite3 *db, Vdbe *p){ | |
| 864 int i; | |
| 865 int rc = SQLITE_OK; | |
| 866 VTable **aVTrans = db->aVTrans; | |
| 867 | |
| 868 db->aVTrans = 0; | |
| 869 for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){ | |
| 870 int (*x)(sqlite3_vtab *); | |
| 871 sqlite3_vtab *pVtab = aVTrans[i]->pVtab; | |
| 872 if( pVtab && (x = pVtab->pModule->xSync)!=0 ){ | |
| 873 rc = x(pVtab); | |
| 874 sqlite3VtabImportErrmsg(p, pVtab); | |
| 875 } | |
| 876 } | |
| 877 db->aVTrans = aVTrans; | |
| 878 return rc; | |
| 879 } | |
| 880 | |
| 881 /* | |
| 882 ** Invoke the xRollback method of all virtual tables in the | |
| 883 ** sqlite3.aVTrans array. Then clear the array itself. | |
| 884 */ | |
| 885 int sqlite3VtabRollback(sqlite3 *db){ | |
| 886 callFinaliser(db, offsetof(sqlite3_module,xRollback)); | |
| 887 return SQLITE_OK; | |
| 888 } | |
| 889 | |
| 890 /* | |
| 891 ** Invoke the xCommit method of all virtual tables in the | |
| 892 ** sqlite3.aVTrans array. Then clear the array itself. | |
| 893 */ | |
| 894 int sqlite3VtabCommit(sqlite3 *db){ | |
| 895 callFinaliser(db, offsetof(sqlite3_module,xCommit)); | |
| 896 return SQLITE_OK; | |
| 897 } | |
| 898 | |
| 899 /* | |
| 900 ** If the virtual table pVtab supports the transaction interface | |
| 901 ** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is | |
| 902 ** not currently open, invoke the xBegin method now. | |
| 903 ** | |
| 904 ** If the xBegin call is successful, place the sqlite3_vtab pointer | |
| 905 ** in the sqlite3.aVTrans array. | |
| 906 */ | |
| 907 int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){ | |
| 908 int rc = SQLITE_OK; | |
| 909 const sqlite3_module *pModule; | |
| 910 | |
| 911 /* Special case: If db->aVTrans is NULL and db->nVTrans is greater | |
| 912 ** than zero, then this function is being called from within a | |
| 913 ** virtual module xSync() callback. It is illegal to write to | |
| 914 ** virtual module tables in this case, so return SQLITE_LOCKED. | |
| 915 */ | |
| 916 if( sqlite3VtabInSync(db) ){ | |
| 917 return SQLITE_LOCKED; | |
| 918 } | |
| 919 if( !pVTab ){ | |
| 920 return SQLITE_OK; | |
| 921 } | |
| 922 pModule = pVTab->pVtab->pModule; | |
| 923 | |
| 924 if( pModule->xBegin ){ | |
| 925 int i; | |
| 926 | |
| 927 /* If pVtab is already in the aVTrans array, return early */ | |
| 928 for(i=0; i<db->nVTrans; i++){ | |
| 929 if( db->aVTrans[i]==pVTab ){ | |
| 930 return SQLITE_OK; | |
| 931 } | |
| 932 } | |
| 933 | |
| 934 /* Invoke the xBegin method. If successful, add the vtab to the | |
| 935 ** sqlite3.aVTrans[] array. */ | |
| 936 rc = growVTrans(db); | |
| 937 if( rc==SQLITE_OK ){ | |
| 938 rc = pModule->xBegin(pVTab->pVtab); | |
| 939 if( rc==SQLITE_OK ){ | |
| 940 int iSvpt = db->nStatement + db->nSavepoint; | |
| 941 addToVTrans(db, pVTab); | |
| 942 if( iSvpt ) rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN, iSvpt-1); | |
| 943 } | |
| 944 } | |
| 945 } | |
| 946 return rc; | |
| 947 } | |
| 948 | |
| 949 /* | |
| 950 ** Invoke either the xSavepoint, xRollbackTo or xRelease method of all | |
| 951 ** virtual tables that currently have an open transaction. Pass iSavepoint | |
| 952 ** as the second argument to the virtual table method invoked. | |
| 953 ** | |
| 954 ** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is | |
| 955 ** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is | |
| 956 ** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with | |
| 957 ** an open transaction is invoked. | |
| 958 ** | |
| 959 ** If any virtual table method returns an error code other than SQLITE_OK, | |
| 960 ** processing is abandoned and the error returned to the caller of this | |
| 961 ** function immediately. If all calls to virtual table methods are successful, | |
| 962 ** SQLITE_OK is returned. | |
| 963 */ | |
| 964 int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){ | |
| 965 int rc = SQLITE_OK; | |
| 966 | |
| 967 assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN ); | |
| 968 assert( iSavepoint>=-1 ); | |
| 969 if( db->aVTrans ){ | |
| 970 int i; | |
| 971 for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){ | |
| 972 VTable *pVTab = db->aVTrans[i]; | |
| 973 const sqlite3_module *pMod = pVTab->pMod->pModule; | |
| 974 if( pVTab->pVtab && pMod->iVersion>=2 ){ | |
| 975 int (*xMethod)(sqlite3_vtab *, int); | |
| 976 switch( op ){ | |
| 977 case SAVEPOINT_BEGIN: | |
| 978 xMethod = pMod->xSavepoint; | |
| 979 pVTab->iSavepoint = iSavepoint+1; | |
| 980 break; | |
| 981 case SAVEPOINT_ROLLBACK: | |
| 982 xMethod = pMod->xRollbackTo; | |
| 983 break; | |
| 984 default: | |
| 985 xMethod = pMod->xRelease; | |
| 986 break; | |
| 987 } | |
| 988 if( xMethod && pVTab->iSavepoint>iSavepoint ){ | |
| 989 rc = xMethod(pVTab->pVtab, iSavepoint); | |
| 990 } | |
| 991 } | |
| 992 } | |
| 993 } | |
| 994 return rc; | |
| 995 } | |
| 996 | |
| 997 /* | |
| 998 ** The first parameter (pDef) is a function implementation. The | |
| 999 ** second parameter (pExpr) is the first argument to this function. | |
| 1000 ** If pExpr is a column in a virtual table, then let the virtual | |
| 1001 ** table implementation have an opportunity to overload the function. | |
| 1002 ** | |
| 1003 ** This routine is used to allow virtual table implementations to | |
| 1004 ** overload MATCH, LIKE, GLOB, and REGEXP operators. | |
| 1005 ** | |
| 1006 ** Return either the pDef argument (indicating no change) or a | |
| 1007 ** new FuncDef structure that is marked as ephemeral using the | |
| 1008 ** SQLITE_FUNC_EPHEM flag. | |
| 1009 */ | |
| 1010 FuncDef *sqlite3VtabOverloadFunction( | |
| 1011 sqlite3 *db, /* Database connection for reporting malloc problems */ | |
| 1012 FuncDef *pDef, /* Function to possibly overload */ | |
| 1013 int nArg, /* Number of arguments to the function */ | |
| 1014 Expr *pExpr /* First argument to the function */ | |
| 1015 ){ | |
| 1016 Table *pTab; | |
| 1017 sqlite3_vtab *pVtab; | |
| 1018 sqlite3_module *pMod; | |
| 1019 void (*xFunc)(sqlite3_context*,int,sqlite3_value**) = 0; | |
| 1020 void *pArg = 0; | |
| 1021 FuncDef *pNew; | |
| 1022 int rc = 0; | |
| 1023 char *zLowerName; | |
| 1024 unsigned char *z; | |
| 1025 | |
| 1026 | |
| 1027 /* Check to see the left operand is a column in a virtual table */ | |
| 1028 if( NEVER(pExpr==0) ) return pDef; | |
| 1029 if( pExpr->op!=TK_COLUMN ) return pDef; | |
| 1030 pTab = pExpr->pTab; | |
| 1031 if( NEVER(pTab==0) ) return pDef; | |
| 1032 if( (pTab->tabFlags & TF_Virtual)==0 ) return pDef; | |
| 1033 pVtab = sqlite3GetVTable(db, pTab)->pVtab; | |
| 1034 assert( pVtab!=0 ); | |
| 1035 assert( pVtab->pModule!=0 ); | |
| 1036 pMod = (sqlite3_module *)pVtab->pModule; | |
| 1037 if( pMod->xFindFunction==0 ) return pDef; | |
| 1038 | |
| 1039 /* Call the xFindFunction method on the virtual table implementation | |
| 1040 ** to see if the implementation wants to overload this function | |
| 1041 */ | |
| 1042 zLowerName = sqlite3DbStrDup(db, pDef->zName); | |
| 1043 if( zLowerName ){ | |
| 1044 for(z=(unsigned char*)zLowerName; *z; z++){ | |
| 1045 *z = sqlite3UpperToLower[*z]; | |
| 1046 } | |
| 1047 rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg); | |
| 1048 sqlite3DbFree(db, zLowerName); | |
| 1049 } | |
| 1050 if( rc==0 ){ | |
| 1051 return pDef; | |
| 1052 } | |
| 1053 | |
| 1054 /* Create a new ephemeral function definition for the overloaded | |
| 1055 ** function */ | |
| 1056 pNew = sqlite3DbMallocZero(db, sizeof(*pNew) | |
| 1057 + sqlite3Strlen30(pDef->zName) + 1); | |
| 1058 if( pNew==0 ){ | |
| 1059 return pDef; | |
| 1060 } | |
| 1061 *pNew = *pDef; | |
| 1062 pNew->zName = (char *)&pNew[1]; | |
| 1063 memcpy(pNew->zName, pDef->zName, sqlite3Strlen30(pDef->zName)+1); | |
| 1064 pNew->xFunc = xFunc; | |
| 1065 pNew->pUserData = pArg; | |
| 1066 pNew->funcFlags |= SQLITE_FUNC_EPHEM; | |
| 1067 return pNew; | |
| 1068 } | |
| 1069 | |
| 1070 /* | |
| 1071 ** Make sure virtual table pTab is contained in the pParse->apVirtualLock[] | |
| 1072 ** array so that an OP_VBegin will get generated for it. Add pTab to the | |
| 1073 ** array if it is missing. If pTab is already in the array, this routine | |
| 1074 ** is a no-op. | |
| 1075 */ | |
| 1076 void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){ | |
| 1077 Parse *pToplevel = sqlite3ParseToplevel(pParse); | |
| 1078 int i, n; | |
| 1079 Table **apVtabLock; | |
| 1080 | |
| 1081 assert( IsVirtual(pTab) ); | |
| 1082 for(i=0; i<pToplevel->nVtabLock; i++){ | |
| 1083 if( pTab==pToplevel->apVtabLock[i] ) return; | |
| 1084 } | |
| 1085 n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]); | |
| 1086 apVtabLock = sqlite3_realloc64(pToplevel->apVtabLock, n); | |
| 1087 if( apVtabLock ){ | |
| 1088 pToplevel->apVtabLock = apVtabLock; | |
| 1089 pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab; | |
| 1090 }else{ | |
| 1091 pToplevel->db->mallocFailed = 1; | |
| 1092 } | |
| 1093 } | |
| 1094 | |
| 1095 /* | |
| 1096 ** Check to see if virtual tale module pMod can be have an eponymous | |
| 1097 ** virtual table instance. If it can, create one if one does not already | |
| 1098 ** exist. Return non-zero if the eponymous virtual table instance exists | |
| 1099 ** when this routine returns, and return zero if it does not exist. | |
| 1100 ** | |
| 1101 ** An eponymous virtual table instance is one that is named after its | |
| 1102 ** module, and more importantly, does not require a CREATE VIRTUAL TABLE | |
| 1103 ** statement in order to come into existance. Eponymous virtual table | |
| 1104 ** instances always exist. They cannot be DROP-ed. | |
| 1105 ** | |
| 1106 ** Any virtual table module for which xConnect and xCreate are the same | |
| 1107 ** method can have an eponymous virtual table instance. | |
| 1108 */ | |
| 1109 int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){ | |
| 1110 const sqlite3_module *pModule = pMod->pModule; | |
| 1111 Table *pTab; | |
| 1112 char *zErr = 0; | |
| 1113 int nName; | |
| 1114 int rc; | |
| 1115 sqlite3 *db = pParse->db; | |
| 1116 if( pMod->pEpoTab ) return 1; | |
| 1117 if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0; | |
| 1118 nName = sqlite3Strlen30(pMod->zName) + 1; | |
| 1119 pTab = sqlite3DbMallocZero(db, sizeof(Table) + nName); | |
| 1120 if( pTab==0 ) return 0; | |
| 1121 pMod->pEpoTab = pTab; | |
| 1122 pTab->zName = (char*)&pTab[1]; | |
| 1123 memcpy(pTab->zName, pMod->zName, nName); | |
| 1124 pTab->nRef = 1; | |
| 1125 pTab->pSchema = db->aDb[0].pSchema; | |
| 1126 pTab->tabFlags |= TF_Virtual; | |
| 1127 pTab->nModuleArg = 0; | |
| 1128 pTab->iPKey = -1; | |
| 1129 addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName)); | |
| 1130 addModuleArgument(db, pTab, 0); | |
| 1131 addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName)); | |
| 1132 rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr); | |
| 1133 if( rc ){ | |
| 1134 sqlite3ErrorMsg(pParse, "%s", zErr); | |
| 1135 sqlite3DbFree(db, zErr); | |
| 1136 sqlite3VtabEponymousTableClear(db, pMod); | |
| 1137 return 0; | |
| 1138 } | |
| 1139 return 1; | |
| 1140 } | |
| 1141 | |
| 1142 /* | |
| 1143 ** Erase the eponymous virtual table instance associated with | |
| 1144 ** virtual table module pMod, if it exists. | |
| 1145 */ | |
| 1146 void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){ | |
| 1147 Table *pTab = pMod->pEpoTab; | |
| 1148 if( pTab!=0 ){ | |
| 1149 sqlite3DeleteColumnNames(db, pTab); | |
| 1150 sqlite3VtabClear(db, pTab); | |
| 1151 sqlite3DbFree(db, pTab); | |
| 1152 pMod->pEpoTab = 0; | |
| 1153 } | |
| 1154 } | |
| 1155 | |
| 1156 /* | |
| 1157 ** Return the ON CONFLICT resolution mode in effect for the virtual | |
| 1158 ** table update operation currently in progress. | |
| 1159 ** | |
| 1160 ** The results of this routine are undefined unless it is called from | |
| 1161 ** within an xUpdate method. | |
| 1162 */ | |
| 1163 int sqlite3_vtab_on_conflict(sqlite3 *db){ | |
| 1164 static const unsigned char aMap[] = { | |
| 1165 SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE | |
| 1166 }; | |
| 1167 #ifdef SQLITE_ENABLE_API_ARMOR | |
| 1168 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; | |
| 1169 #endif | |
| 1170 assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 ); | |
| 1171 assert( OE_Ignore==4 && OE_Replace==5 ); | |
| 1172 assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 ); | |
| 1173 return (int)aMap[db->vtabOnConflict-1]; | |
| 1174 } | |
| 1175 | |
| 1176 /* | |
| 1177 ** Call from within the xCreate() or xConnect() methods to provide | |
| 1178 ** the SQLite core with additional information about the behavior | |
| 1179 ** of the virtual table being implemented. | |
| 1180 */ | |
| 1181 int sqlite3_vtab_config(sqlite3 *db, int op, ...){ | |
| 1182 va_list ap; | |
| 1183 int rc = SQLITE_OK; | |
| 1184 | |
| 1185 #ifdef SQLITE_ENABLE_API_ARMOR | |
| 1186 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; | |
| 1187 #endif | |
| 1188 sqlite3_mutex_enter(db->mutex); | |
| 1189 va_start(ap, op); | |
| 1190 switch( op ){ | |
| 1191 case SQLITE_VTAB_CONSTRAINT_SUPPORT: { | |
| 1192 VtabCtx *p = db->pVtabCtx; | |
| 1193 if( !p ){ | |
| 1194 rc = SQLITE_MISUSE_BKPT; | |
| 1195 }else{ | |
| 1196 assert( p->pTab==0 || (p->pTab->tabFlags & TF_Virtual)!=0 ); | |
| 1197 p->pVTable->bConstraint = (u8)va_arg(ap, int); | |
| 1198 } | |
| 1199 break; | |
| 1200 } | |
| 1201 default: | |
| 1202 rc = SQLITE_MISUSE_BKPT; | |
| 1203 break; | |
| 1204 } | |
| 1205 va_end(ap); | |
| 1206 | |
| 1207 if( rc!=SQLITE_OK ) sqlite3Error(db, rc); | |
| 1208 sqlite3_mutex_leave(db->mutex); | |
| 1209 return rc; | |
| 1210 } | |
| 1211 | |
| 1212 #endif /* SQLITE_OMIT_VIRTUALTABLE */ | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2846743003:
[sql] Remove SQLite 3.10.2 reference directory. (Closed)
