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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 }; | |
| 28 | |
| 29 /* | |
| 30 ** The actual function that does the work of creating a new module. | |
| 31 ** This function implements the sqlite3_create_module() and | |
| 32 ** sqlite3_create_module_v2() interfaces. | |
| 33 */ | |
| 34 static int createModule( | |
| 35 sqlite3 *db, /* Database in which module is registered */ | |
| 36 const char *zName, /* Name assigned to this module */ | |
| 37 const sqlite3_module *pModule, /* The definition of the module */ | |
| 38 void *pAux, /* Context pointer for xCreate/xConnect */ | |
| 39 void (*xDestroy)(void *) /* Module destructor function */ | |
| 40 ){ | |
| 41 int rc = SQLITE_OK; | |
| 42 int nName; | |
| 43 | |
| 44 sqlite3_mutex_enter(db->mutex); | |
| 45 nName = sqlite3Strlen30(zName); | |
| 46 if( sqlite3HashFind(&db->aModule, zName) ){ | |
| 47 rc = SQLITE_MISUSE_BKPT; | |
| 48 }else{ | |
| 49 Module *pMod; | |
| 50 pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1); | |
| 51 if( pMod ){ | |
| 52 Module *pDel; | |
| 53 char *zCopy = (char *)(&pMod[1]); | |
| 54 memcpy(zCopy, zName, nName+1); | |
| 55 pMod->zName = zCopy; | |
| 56 pMod->pModule = pModule; | |
| 57 pMod->pAux = pAux; | |
| 58 pMod->xDestroy = xDestroy; | |
| 59 pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod); | |
| 60 assert( pDel==0 || pDel==pMod ); | |
| 61 if( pDel ){ | |
| 62 db->mallocFailed = 1; | |
| 63 sqlite3DbFree(db, pDel); | |
| 64 } | |
| 65 } | |
| 66 } | |
| 67 rc = sqlite3ApiExit(db, rc); | |
| 68 if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux); | |
| 69 | |
| 70 sqlite3_mutex_leave(db->mutex); | |
| 71 return rc; | |
| 72 } | |
| 73 | |
| 74 | |
| 75 /* | |
| 76 ** External API function used to create a new virtual-table module. | |
| 77 */ | |
| 78 int sqlite3_create_module( | |
| 79 sqlite3 *db, /* Database in which module is registered */ | |
| 80 const char *zName, /* Name assigned to this module */ | |
| 81 const sqlite3_module *pModule, /* The definition of the module */ | |
| 82 void *pAux /* Context pointer for xCreate/xConnect */ | |
| 83 ){ | |
| 84 return createModule(db, zName, pModule, pAux, 0); | |
| 85 } | |
| 86 | |
| 87 /* | |
| 88 ** External API function used to create a new virtual-table module. | |
| 89 */ | |
| 90 int sqlite3_create_module_v2( | |
| 91 sqlite3 *db, /* Database in which module is registered */ | |
| 92 const char *zName, /* Name assigned to this module */ | |
| 93 const sqlite3_module *pModule, /* The definition of the module */ | |
| 94 void *pAux, /* Context pointer for xCreate/xConnect */ | |
| 95 void (*xDestroy)(void *) /* Module destructor function */ | |
| 96 ){ | |
| 97 return createModule(db, zName, pModule, pAux, xDestroy); | |
| 98 } | |
| 99 | |
| 100 /* | |
| 101 ** Lock the virtual table so that it cannot be disconnected. | |
| 102 ** Locks nest. Every lock should have a corresponding unlock. | |
| 103 ** If an unlock is omitted, resources leaks will occur. | |
| 104 ** | |
| 105 ** If a disconnect is attempted while a virtual table is locked, | |
| 106 ** the disconnect is deferred until all locks have been removed. | |
| 107 */ | |
| 108 void sqlite3VtabLock(VTable *pVTab){ | |
| 109 pVTab->nRef++; | |
| 110 } | |
| 111 | |
| 112 | |
| 113 /* | |
| 114 ** pTab is a pointer to a Table structure representing a virtual-table. | |
| 115 ** Return a pointer to the VTable object used by connection db to access | |
| 116 ** this virtual-table, if one has been created, or NULL otherwise. | |
| 117 */ | |
| 118 VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){ | |
| 119 VTable *pVtab; | |
| 120 assert( IsVirtual(pTab) ); | |
| 121 for(pVtab=pTab->pVTable; pVtab && pVtab->db!=db; pVtab=pVtab->pNext); | |
| 122 return pVtab; | |
| 123 } | |
| 124 | |
| 125 /* | |
| 126 ** Decrement the ref-count on a virtual table object. When the ref-count | |
| 127 ** reaches zero, call the xDisconnect() method to delete the object. | |
| 128 */ | |
| 129 void sqlite3VtabUnlock(VTable *pVTab){ | |
| 130 sqlite3 *db = pVTab->db; | |
| 131 | |
| 132 assert( db ); | |
| 133 assert( pVTab->nRef>0 ); | |
| 134 assert( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ZOMBIE ); | |
| 135 | |
| 136 pVTab->nRef--; | |
| 137 if( pVTab->nRef==0 ){ | |
| 138 sqlite3_vtab *p = pVTab->pVtab; | |
| 139 if( p ){ | |
| 140 p->pModule->xDisconnect(p); | |
| 141 } | |
| 142 sqlite3DbFree(db, pVTab); | |
| 143 } | |
| 144 } | |
| 145 | |
| 146 /* | |
| 147 ** Table p is a virtual table. This function moves all elements in the | |
| 148 ** p->pVTable list to the sqlite3.pDisconnect lists of their associated | |
| 149 ** database connections to be disconnected at the next opportunity. | |
| 150 ** Except, if argument db is not NULL, then the entry associated with | |
| 151 ** connection db is left in the p->pVTable list. | |
| 152 */ | |
| 153 static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){ | |
| 154 VTable *pRet = 0; | |
| 155 VTable *pVTable = p->pVTable; | |
| 156 p->pVTable = 0; | |
| 157 | |
| 158 /* Assert that the mutex (if any) associated with the BtShared database | |
| 159 ** that contains table p is held by the caller. See header comments | |
| 160 ** above function sqlite3VtabUnlockList() for an explanation of why | |
| 161 ** this makes it safe to access the sqlite3.pDisconnect list of any | |
| 162 ** database connection that may have an entry in the p->pVTable list. | |
| 163 */ | |
| 164 assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) ); | |
| 165 | |
| 166 while( pVTable ){ | |
| 167 sqlite3 *db2 = pVTable->db; | |
| 168 VTable *pNext = pVTable->pNext; | |
| 169 assert( db2 ); | |
| 170 if( db2==db ){ | |
| 171 pRet = pVTable; | |
| 172 p->pVTable = pRet; | |
| 173 pRet->pNext = 0; | |
| 174 }else{ | |
| 175 pVTable->pNext = db2->pDisconnect; | |
| 176 db2->pDisconnect = pVTable; | |
| 177 } | |
| 178 pVTable = pNext; | |
| 179 } | |
| 180 | |
| 181 assert( !db || pRet ); | |
| 182 return pRet; | |
| 183 } | |
| 184 | |
| 185 /* | |
| 186 ** Table *p is a virtual table. This function removes the VTable object | |
| 187 ** for table *p associated with database connection db from the linked | |
| 188 ** list in p->pVTab. It also decrements the VTable ref count. This is | |
| 189 ** used when closing database connection db to free all of its VTable | |
| 190 ** objects without disturbing the rest of the Schema object (which may | |
| 191 ** be being used by other shared-cache connections). | |
| 192 */ | |
| 193 void sqlite3VtabDisconnect(sqlite3 *db, Table *p){ | |
| 194 VTable **ppVTab; | |
| 195 | |
| 196 assert( IsVirtual(p) ); | |
| 197 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
| 198 assert( sqlite3_mutex_held(db->mutex) ); | |
| 199 | |
| 200 for(ppVTab=&p->pVTable; *ppVTab; ppVTab=&(*ppVTab)->pNext){ | |
| 201 if( (*ppVTab)->db==db ){ | |
| 202 VTable *pVTab = *ppVTab; | |
| 203 *ppVTab = pVTab->pNext; | |
| 204 sqlite3VtabUnlock(pVTab); | |
| 205 break; | |
| 206 } | |
| 207 } | |
| 208 } | |
| 209 | |
| 210 | |
| 211 /* | |
| 212 ** Disconnect all the virtual table objects in the sqlite3.pDisconnect list. | |
| 213 ** | |
| 214 ** This function may only be called when the mutexes associated with all | |
| 215 ** shared b-tree databases opened using connection db are held by the | |
| 216 ** caller. This is done to protect the sqlite3.pDisconnect list. The | |
| 217 ** sqlite3.pDisconnect list is accessed only as follows: | |
| 218 ** | |
| 219 ** 1) By this function. In this case, all BtShared mutexes and the mutex | |
| 220 ** associated with the database handle itself must be held. | |
| 221 ** | |
| 222 ** 2) By function vtabDisconnectAll(), when it adds a VTable entry to | |
| 223 ** the sqlite3.pDisconnect list. In this case either the BtShared mutex | |
| 224 ** associated with the database the virtual table is stored in is held | |
| 225 ** or, if the virtual table is stored in a non-sharable database, then | |
| 226 ** the database handle mutex is held. | |
| 227 ** | |
| 228 ** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously | |
| 229 ** by multiple threads. It is thread-safe. | |
| 230 */ | |
| 231 void sqlite3VtabUnlockList(sqlite3 *db){ | |
| 232 VTable *p = db->pDisconnect; | |
| 233 db->pDisconnect = 0; | |
| 234 | |
| 235 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
| 236 assert( sqlite3_mutex_held(db->mutex) ); | |
| 237 | |
| 238 if( p ){ | |
| 239 sqlite3ExpirePreparedStatements(db); | |
| 240 do { | |
| 241 VTable *pNext = p->pNext; | |
| 242 sqlite3VtabUnlock(p); | |
| 243 p = pNext; | |
| 244 }while( p ); | |
| 245 } | |
| 246 } | |
| 247 | |
| 248 /* | |
| 249 ** Clear any and all virtual-table information from the Table record. | |
| 250 ** This routine is called, for example, just before deleting the Table | |
| 251 ** record. | |
| 252 ** | |
| 253 ** Since it is a virtual-table, the Table structure contains a pointer | |
| 254 ** to the head of a linked list of VTable structures. Each VTable | |
| 255 ** structure is associated with a single sqlite3* user of the schema. | |
| 256 ** The reference count of the VTable structure associated with database | |
| 257 ** connection db is decremented immediately (which may lead to the | |
| 258 ** structure being xDisconnected and free). Any other VTable structures | |
| 259 ** in the list are moved to the sqlite3.pDisconnect list of the associated | |
| 260 ** database connection. | |
| 261 */ | |
| 262 void sqlite3VtabClear(sqlite3 *db, Table *p){ | |
| 263 if( !db || db->pnBytesFreed==0 ) vtabDisconnectAll(0, p); | |
| 264 if( p->azModuleArg ){ | |
| 265 int i; | |
| 266 for(i=0; i<p->nModuleArg; i++){ | |
| 267 if( i!=1 ) sqlite3DbFree(db, p->azModuleArg[i]); | |
| 268 } | |
| 269 sqlite3DbFree(db, p->azModuleArg); | |
| 270 } | |
| 271 } | |
| 272 | |
| 273 /* | |
| 274 ** Add a new module argument to pTable->azModuleArg[]. | |
| 275 ** The string is not copied - the pointer is stored. The | |
| 276 ** string will be freed automatically when the table is | |
| 277 ** deleted. | |
| 278 */ | |
| 279 static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){ | |
| 280 int i = pTable->nModuleArg++; | |
| 281 int nBytes = sizeof(char *)*(1+pTable->nModuleArg); | |
| 282 char **azModuleArg; | |
| 283 azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes); | |
| 284 if( azModuleArg==0 ){ | |
| 285 int j; | |
| 286 for(j=0; j<i; j++){ | |
| 287 sqlite3DbFree(db, pTable->azModuleArg[j]); | |
| 288 } | |
| 289 sqlite3DbFree(db, zArg); | |
| 290 sqlite3DbFree(db, pTable->azModuleArg); | |
| 291 pTable->nModuleArg = 0; | |
| 292 }else{ | |
| 293 azModuleArg[i] = zArg; | |
| 294 azModuleArg[i+1] = 0; | |
| 295 } | |
| 296 pTable->azModuleArg = azModuleArg; | |
| 297 } | |
| 298 | |
| 299 /* | |
| 300 ** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE | |
| 301 ** statement. The module name has been parsed, but the optional list | |
| 302 ** of parameters that follow the module name are still pending. | |
| 303 */ | |
| 304 void sqlite3VtabBeginParse( | |
| 305 Parse *pParse, /* Parsing context */ | |
| 306 Token *pName1, /* Name of new table, or database name */ | |
| 307 Token *pName2, /* Name of new table or NULL */ | |
| 308 Token *pModuleName, /* Name of the module for the virtual table */ | |
| 309 int ifNotExists /* No error if the table already exists */ | |
| 310 ){ | |
| 311 int iDb; /* The database the table is being created in */ | |
| 312 Table *pTable; /* The new virtual table */ | |
| 313 sqlite3 *db; /* Database connection */ | |
| 314 | |
| 315 sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists); | |
| 316 pTable = pParse->pNewTable; | |
| 317 if( pTable==0 ) return; | |
| 318 assert( 0==pTable->pIndex ); | |
| 319 | |
| 320 db = pParse->db; | |
| 321 iDb = sqlite3SchemaToIndex(db, pTable->pSchema); | |
| 322 assert( iDb>=0 ); | |
| 323 | |
| 324 pTable->tabFlags |= TF_Virtual; | |
| 325 pTable->nModuleArg = 0; | |
| 326 addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName)); | |
| 327 addModuleArgument(db, pTable, 0); | |
| 328 addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName)); | |
| 329 pParse->sNameToken.n = (int)(&pModuleName->z[pModuleName->n] - pName1->z); | |
| 330 | |
| 331 #ifndef SQLITE_OMIT_AUTHORIZATION | |
| 332 /* Creating a virtual table invokes the authorization callback twice. | |
| 333 ** The first invocation, to obtain permission to INSERT a row into the | |
| 334 ** sqlite_master table, has already been made by sqlite3StartTable(). | |
| 335 ** The second call, to obtain permission to create the table, is made now. | |
| 336 */ | |
| 337 if( pTable->azModuleArg ){ | |
| 338 sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, | |
| 339 pTable->azModuleArg[0], pParse->db->aDb[iDb].zName); | |
| 340 } | |
| 341 #endif | |
| 342 } | |
| 343 | |
| 344 /* | |
| 345 ** This routine takes the module argument that has been accumulating | |
| 346 ** in pParse->zArg[] and appends it to the list of arguments on the | |
| 347 ** virtual table currently under construction in pParse->pTable. | |
| 348 */ | |
| 349 static void addArgumentToVtab(Parse *pParse){ | |
| 350 if( pParse->sArg.z && pParse->pNewTable ){ | |
| 351 const char *z = (const char*)pParse->sArg.z; | |
| 352 int n = pParse->sArg.n; | |
| 353 sqlite3 *db = pParse->db; | |
| 354 addModuleArgument(db, pParse->pNewTable, sqlite3DbStrNDup(db, z, n)); | |
| 355 } | |
| 356 } | |
| 357 | |
| 358 /* | |
| 359 ** The parser calls this routine after the CREATE VIRTUAL TABLE statement | |
| 360 ** has been completely parsed. | |
| 361 */ | |
| 362 void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){ | |
| 363 Table *pTab = pParse->pNewTable; /* The table being constructed */ | |
| 364 sqlite3 *db = pParse->db; /* The database connection */ | |
| 365 | |
| 366 if( pTab==0 ) return; | |
| 367 addArgumentToVtab(pParse); | |
| 368 pParse->sArg.z = 0; | |
| 369 if( pTab->nModuleArg<1 ) return; | |
| 370 | |
| 371 /* If the CREATE VIRTUAL TABLE statement is being entered for the | |
| 372 ** first time (in other words if the virtual table is actually being | |
| 373 ** created now instead of just being read out of sqlite_master) then | |
| 374 ** do additional initialization work and store the statement text | |
| 375 ** in the sqlite_master table. | |
| 376 */ | |
| 377 if( !db->init.busy ){ | |
| 378 char *zStmt; | |
| 379 char *zWhere; | |
| 380 int iDb; | |
| 381 Vdbe *v; | |
| 382 | |
| 383 /* Compute the complete text of the CREATE VIRTUAL TABLE statement */ | |
| 384 if( pEnd ){ | |
| 385 pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n; | |
| 386 } | |
| 387 zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken); | |
| 388 | |
| 389 /* A slot for the record has already been allocated in the | |
| 390 ** SQLITE_MASTER table. We just need to update that slot with all | |
| 391 ** the information we've collected. | |
| 392 ** | |
| 393 ** The VM register number pParse->regRowid holds the rowid of an | |
| 394 ** entry in the sqlite_master table tht was created for this vtab | |
| 395 ** by sqlite3StartTable(). | |
| 396 */ | |
| 397 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); | |
| 398 sqlite3NestedParse(pParse, | |
| 399 "UPDATE %Q.%s " | |
| 400 "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q " | |
| 401 "WHERE rowid=#%d", | |
| 402 db->aDb[iDb].zName, SCHEMA_TABLE(iDb), | |
| 403 pTab->zName, | |
| 404 pTab->zName, | |
| 405 zStmt, | |
| 406 pParse->regRowid | |
| 407 ); | |
| 408 sqlite3DbFree(db, zStmt); | |
| 409 v = sqlite3GetVdbe(pParse); | |
| 410 sqlite3ChangeCookie(pParse, iDb); | |
| 411 | |
| 412 sqlite3VdbeAddOp2(v, OP_Expire, 0, 0); | |
| 413 zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName); | |
| 414 sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere); | |
| 415 sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0, | |
| 416 pTab->zName, sqlite3Strlen30(pTab->zName) + 1); | |
| 417 } | |
| 418 | |
| 419 /* If we are rereading the sqlite_master table create the in-memory | |
| 420 ** record of the table. The xConnect() method is not called until | |
| 421 ** the first time the virtual table is used in an SQL statement. This | |
| 422 ** allows a schema that contains virtual tables to be loaded before | |
| 423 ** the required virtual table implementations are registered. */ | |
| 424 else { | |
| 425 Table *pOld; | |
| 426 Schema *pSchema = pTab->pSchema; | |
| 427 const char *zName = pTab->zName; | |
| 428 assert( sqlite3SchemaMutexHeld(db, 0, pSchema) ); | |
| 429 pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab); | |
| 430 if( pOld ){ | |
| 431 db->mallocFailed = 1; | |
| 432 assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */ | |
| 433 return; | |
| 434 } | |
| 435 pParse->pNewTable = 0; | |
| 436 } | |
| 437 } | |
| 438 | |
| 439 /* | |
| 440 ** The parser calls this routine when it sees the first token | |
| 441 ** of an argument to the module name in a CREATE VIRTUAL TABLE statement. | |
| 442 */ | |
| 443 void sqlite3VtabArgInit(Parse *pParse){ | |
| 444 addArgumentToVtab(pParse); | |
| 445 pParse->sArg.z = 0; | |
| 446 pParse->sArg.n = 0; | |
| 447 } | |
| 448 | |
| 449 /* | |
| 450 ** The parser calls this routine for each token after the first token | |
| 451 ** in an argument to the module name in a CREATE VIRTUAL TABLE statement. | |
| 452 */ | |
| 453 void sqlite3VtabArgExtend(Parse *pParse, Token *p){ | |
| 454 Token *pArg = &pParse->sArg; | |
| 455 if( pArg->z==0 ){ | |
| 456 pArg->z = p->z; | |
| 457 pArg->n = p->n; | |
| 458 }else{ | |
| 459 assert(pArg->z < p->z); | |
| 460 pArg->n = (int)(&p->z[p->n] - pArg->z); | |
| 461 } | |
| 462 } | |
| 463 | |
| 464 /* | |
| 465 ** Invoke a virtual table constructor (either xCreate or xConnect). The | |
| 466 ** pointer to the function to invoke is passed as the fourth parameter | |
| 467 ** to this procedure. | |
| 468 */ | |
| 469 static int vtabCallConstructor( | |
| 470 sqlite3 *db, | |
| 471 Table *pTab, | |
| 472 Module *pMod, | |
| 473 int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**), | |
| 474 char **pzErr | |
| 475 ){ | |
| 476 VtabCtx sCtx, *pPriorCtx; | |
| 477 VTable *pVTable; | |
| 478 int rc; | |
| 479 const char *const*azArg = (const char *const*)pTab->azModuleArg; | |
| 480 int nArg = pTab->nModuleArg; | |
| 481 char *zErr = 0; | |
| 482 char *zModuleName = sqlite3MPrintf(db, "%s", pTab->zName); | |
| 483 int iDb; | |
| 484 | |
| 485 if( !zModuleName ){ | |
| 486 return SQLITE_NOMEM; | |
| 487 } | |
| 488 | |
| 489 pVTable = sqlite3DbMallocZero(db, sizeof(VTable)); | |
| 490 if( !pVTable ){ | |
| 491 sqlite3DbFree(db, zModuleName); | |
| 492 return SQLITE_NOMEM; | |
| 493 } | |
| 494 pVTable->db = db; | |
| 495 pVTable->pMod = pMod; | |
| 496 | |
| 497 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); | |
| 498 pTab->azModuleArg[1] = db->aDb[iDb].zName; | |
| 499 | |
| 500 /* Invoke the virtual table constructor */ | |
| 501 assert( &db->pVtabCtx ); | |
| 502 assert( xConstruct ); | |
| 503 sCtx.pTab = pTab; | |
| 504 sCtx.pVTable = pVTable; | |
| 505 pPriorCtx = db->pVtabCtx; | |
| 506 db->pVtabCtx = &sCtx; | |
| 507 rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr); | |
| 508 db->pVtabCtx = pPriorCtx; | |
| 509 if( rc==SQLITE_NOMEM ) db->mallocFailed = 1; | |
| 510 | |
| 511 if( SQLITE_OK!=rc ){ | |
| 512 if( zErr==0 ){ | |
| 513 *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName); | |
| 514 }else { | |
| 515 *pzErr = sqlite3MPrintf(db, "%s", zErr); | |
| 516 sqlite3_free(zErr); | |
| 517 } | |
| 518 sqlite3DbFree(db, pVTable); | |
| 519 }else if( ALWAYS(pVTable->pVtab) ){ | |
| 520 /* Justification of ALWAYS(): A correct vtab constructor must allocate | |
| 521 ** the sqlite3_vtab object if successful. */ | |
| 522 memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0])); | |
| 523 pVTable->pVtab->pModule = pMod->pModule; | |
| 524 pVTable->nRef = 1; | |
| 525 if( sCtx.pTab ){ | |
| 526 const char *zFormat = "vtable constructor did not declare schema: %s"; | |
| 527 *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName); | |
| 528 sqlite3VtabUnlock(pVTable); | |
| 529 rc = SQLITE_ERROR; | |
| 530 }else{ | |
| 531 int iCol; | |
| 532 /* If everything went according to plan, link the new VTable structure | |
| 533 ** into the linked list headed by pTab->pVTable. Then loop through the | |
| 534 ** columns of the table to see if any of them contain the token "hidden". | |
| 535 ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from | |
| 536 ** the type string. */ | |
| 537 pVTable->pNext = pTab->pVTable; | |
| 538 pTab->pVTable = pVTable; | |
| 539 | |
| 540 for(iCol=0; iCol<pTab->nCol; iCol++){ | |
| 541 char *zType = pTab->aCol[iCol].zType; | |
| 542 int nType; | |
| 543 int i = 0; | |
| 544 if( !zType ) continue; | |
| 545 nType = sqlite3Strlen30(zType); | |
| 546 if( sqlite3StrNICmp("hidden", zType, 6)||(zType[6] && zType[6]!=' ') ){ | |
| 547 for(i=0; i<nType; i++){ | |
| 548 if( (0==sqlite3StrNICmp(" hidden", &zType[i], 7)) | |
| 549 && (zType[i+7]=='\0' || zType[i+7]==' ') | |
| 550 ){ | |
| 551 i++; | |
| 552 break; | |
| 553 } | |
| 554 } | |
| 555 } | |
| 556 if( i<nType ){ | |
| 557 int j; | |
| 558 int nDel = 6 + (zType[i+6] ? 1 : 0); | |
| 559 for(j=i; (j+nDel)<=nType; j++){ | |
| 560 zType[j] = zType[j+nDel]; | |
| 561 } | |
| 562 if( zType[i]=='\0' && i>0 ){ | |
| 563 assert(zType[i-1]==' '); | |
| 564 zType[i-1] = '\0'; | |
| 565 } | |
| 566 pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN; | |
| 567 } | |
| 568 } | |
| 569 } | |
| 570 } | |
| 571 | |
| 572 sqlite3DbFree(db, zModuleName); | |
| 573 return rc; | |
| 574 } | |
| 575 | |
| 576 /* | |
| 577 ** This function is invoked by the parser to call the xConnect() method | |
| 578 ** of the virtual table pTab. If an error occurs, an error code is returned | |
| 579 ** and an error left in pParse. | |
| 580 ** | |
| 581 ** This call is a no-op if table pTab is not a virtual table. | |
| 582 */ | |
| 583 int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){ | |
| 584 sqlite3 *db = pParse->db; | |
| 585 const char *zMod; | |
| 586 Module *pMod; | |
| 587 int rc; | |
| 588 | |
| 589 assert( pTab ); | |
| 590 if( (pTab->tabFlags & TF_Virtual)==0 || sqlite3GetVTable(db, pTab) ){ | |
| 591 return SQLITE_OK; | |
| 592 } | |
| 593 | |
| 594 /* Locate the required virtual table module */ | |
| 595 zMod = pTab->azModuleArg[0]; | |
| 596 pMod = (Module*)sqlite3HashFind(&db->aModule, zMod); | |
| 597 | |
| 598 if( !pMod ){ | |
| 599 const char *zModule = pTab->azModuleArg[0]; | |
| 600 sqlite3ErrorMsg(pParse, "no such module: %s", zModule); | |
| 601 rc = SQLITE_ERROR; | |
| 602 }else{ | |
| 603 char *zErr = 0; | |
| 604 rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr); | |
| 605 if( rc!=SQLITE_OK ){ | |
| 606 sqlite3ErrorMsg(pParse, "%s", zErr); | |
| 607 } | |
| 608 sqlite3DbFree(db, zErr); | |
| 609 } | |
| 610 | |
| 611 return rc; | |
| 612 } | |
| 613 /* | |
| 614 ** Grow the db->aVTrans[] array so that there is room for at least one | |
| 615 ** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise. | |
| 616 */ | |
| 617 static int growVTrans(sqlite3 *db){ | |
| 618 const int ARRAY_INCR = 5; | |
| 619 | |
| 620 /* Grow the sqlite3.aVTrans array if required */ | |
| 621 if( (db->nVTrans%ARRAY_INCR)==0 ){ | |
| 622 VTable **aVTrans; | |
| 623 int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR); | |
| 624 aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes); | |
| 625 if( !aVTrans ){ | |
| 626 return SQLITE_NOMEM; | |
| 627 } | |
| 628 memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR); | |
| 629 db->aVTrans = aVTrans; | |
| 630 } | |
| 631 | |
| 632 return SQLITE_OK; | |
| 633 } | |
| 634 | |
| 635 /* | |
| 636 ** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should | |
| 637 ** have already been reserved using growVTrans(). | |
| 638 */ | |
| 639 static void addToVTrans(sqlite3 *db, VTable *pVTab){ | |
| 640 /* Add pVtab to the end of sqlite3.aVTrans */ | |
| 641 db->aVTrans[db->nVTrans++] = pVTab; | |
| 642 sqlite3VtabLock(pVTab); | |
| 643 } | |
| 644 | |
| 645 /* | |
| 646 ** This function is invoked by the vdbe to call the xCreate method | |
| 647 ** of the virtual table named zTab in database iDb. | |
| 648 ** | |
| 649 ** If an error occurs, *pzErr is set to point an an English language | |
| 650 ** description of the error and an SQLITE_XXX error code is returned. | |
| 651 ** In this case the caller must call sqlite3DbFree(db, ) on *pzErr. | |
| 652 */ | |
| 653 int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){ | |
| 654 int rc = SQLITE_OK; | |
| 655 Table *pTab; | |
| 656 Module *pMod; | |
| 657 const char *zMod; | |
| 658 | |
| 659 pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName); | |
| 660 assert( pTab && (pTab->tabFlags & TF_Virtual)!=0 && !pTab->pVTable ); | |
| 661 | |
| 662 /* Locate the required virtual table module */ | |
| 663 zMod = pTab->azModuleArg[0]; | |
| 664 pMod = (Module*)sqlite3HashFind(&db->aModule, zMod); | |
| 665 | |
| 666 /* If the module has been registered and includes a Create method, | |
| 667 ** invoke it now. If the module has not been registered, return an | |
| 668 ** error. Otherwise, do nothing. | |
| 669 */ | |
| 670 if( !pMod ){ | |
| 671 *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod); | |
| 672 rc = SQLITE_ERROR; | |
| 673 }else{ | |
| 674 rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr); | |
| 675 } | |
| 676 | |
| 677 /* Justification of ALWAYS(): The xConstructor method is required to | |
| 678 ** create a valid sqlite3_vtab if it returns SQLITE_OK. */ | |
| 679 if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){ | |
| 680 rc = growVTrans(db); | |
| 681 if( rc==SQLITE_OK ){ | |
| 682 addToVTrans(db, sqlite3GetVTable(db, pTab)); | |
| 683 } | |
| 684 } | |
| 685 | |
| 686 return rc; | |
| 687 } | |
| 688 | |
| 689 /* | |
| 690 ** This function is used to set the schema of a virtual table. It is only | |
| 691 ** valid to call this function from within the xCreate() or xConnect() of a | |
| 692 ** virtual table module. | |
| 693 */ | |
| 694 int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){ | |
| 695 Parse *pParse; | |
| 696 | |
| 697 int rc = SQLITE_OK; | |
| 698 Table *pTab; | |
| 699 char *zErr = 0; | |
| 700 | |
| 701 sqlite3_mutex_enter(db->mutex); | |
| 702 if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){ | |
| 703 sqlite3Error(db, SQLITE_MISUSE); | |
| 704 sqlite3_mutex_leave(db->mutex); | |
| 705 return SQLITE_MISUSE_BKPT; | |
| 706 } | |
| 707 assert( (pTab->tabFlags & TF_Virtual)!=0 ); | |
| 708 | |
| 709 pParse = sqlite3StackAllocZero(db, sizeof(*pParse)); | |
| 710 if( pParse==0 ){ | |
| 711 rc = SQLITE_NOMEM; | |
| 712 }else{ | |
| 713 pParse->declareVtab = 1; | |
| 714 pParse->db = db; | |
| 715 pParse->nQueryLoop = 1; | |
| 716 | |
| 717 if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) | |
| 718 && pParse->pNewTable | |
| 719 && !db->mallocFailed | |
| 720 && !pParse->pNewTable->pSelect | |
| 721 && (pParse->pNewTable->tabFlags & TF_Virtual)==0 | |
| 722 ){ | |
| 723 if( !pTab->aCol ){ | |
| 724 pTab->aCol = pParse->pNewTable->aCol; | |
| 725 pTab->nCol = pParse->pNewTable->nCol; | |
| 726 pParse->pNewTable->nCol = 0; | |
| 727 pParse->pNewTable->aCol = 0; | |
| 728 } | |
| 729 db->pVtabCtx->pTab = 0; | |
| 730 }else{ | |
| 731 sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr); | |
| 732 sqlite3DbFree(db, zErr); | |
| 733 rc = SQLITE_ERROR; | |
| 734 } | |
| 735 pParse->declareVtab = 0; | |
| 736 | |
| 737 if( pParse->pVdbe ){ | |
| 738 sqlite3VdbeFinalize(pParse->pVdbe); | |
| 739 } | |
| 740 sqlite3DeleteTable(db, pParse->pNewTable); | |
| 741 sqlite3ParserReset(pParse); | |
| 742 sqlite3StackFree(db, pParse); | |
| 743 } | |
| 744 | |
| 745 assert( (rc&0xff)==rc ); | |
| 746 rc = sqlite3ApiExit(db, rc); | |
| 747 sqlite3_mutex_leave(db->mutex); | |
| 748 return rc; | |
| 749 } | |
| 750 | |
| 751 /* | |
| 752 ** This function is invoked by the vdbe to call the xDestroy method | |
| 753 ** of the virtual table named zTab in database iDb. This occurs | |
| 754 ** when a DROP TABLE is mentioned. | |
| 755 ** | |
| 756 ** This call is a no-op if zTab is not a virtual table. | |
| 757 */ | |
| 758 int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){ | |
| 759 int rc = SQLITE_OK; | |
| 760 Table *pTab; | |
| 761 | |
| 762 pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName); | |
| 763 if( ALWAYS(pTab!=0 && pTab->pVTable!=0) ){ | |
| 764 VTable *p = vtabDisconnectAll(db, pTab); | |
| 765 | |
| 766 assert( rc==SQLITE_OK ); | |
| 767 rc = p->pMod->pModule->xDestroy(p->pVtab); | |
| 768 | |
| 769 /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */ | |
| 770 if( rc==SQLITE_OK ){ | |
| 771 assert( pTab->pVTable==p && p->pNext==0 ); | |
| 772 p->pVtab = 0; | |
| 773 pTab->pVTable = 0; | |
| 774 sqlite3VtabUnlock(p); | |
| 775 } | |
| 776 } | |
| 777 | |
| 778 return rc; | |
| 779 } | |
| 780 | |
| 781 /* | |
| 782 ** This function invokes either the xRollback or xCommit method | |
| 783 ** of each of the virtual tables in the sqlite3.aVTrans array. The method | |
| 784 ** called is identified by the second argument, "offset", which is | |
| 785 ** the offset of the method to call in the sqlite3_module structure. | |
| 786 ** | |
| 787 ** The array is cleared after invoking the callbacks. | |
| 788 */ | |
| 789 static void callFinaliser(sqlite3 *db, int offset){ | |
| 790 int i; | |
| 791 if( db->aVTrans ){ | |
| 792 for(i=0; i<db->nVTrans; i++){ | |
| 793 VTable *pVTab = db->aVTrans[i]; | |
| 794 sqlite3_vtab *p = pVTab->pVtab; | |
| 795 if( p ){ | |
| 796 int (*x)(sqlite3_vtab *); | |
| 797 x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset); | |
| 798 if( x ) x(p); | |
| 799 } | |
| 800 pVTab->iSavepoint = 0; | |
| 801 sqlite3VtabUnlock(pVTab); | |
| 802 } | |
| 803 sqlite3DbFree(db, db->aVTrans); | |
| 804 db->nVTrans = 0; | |
| 805 db->aVTrans = 0; | |
| 806 } | |
| 807 } | |
| 808 | |
| 809 /* | |
| 810 ** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans | |
| 811 ** array. Return the error code for the first error that occurs, or | |
| 812 ** SQLITE_OK if all xSync operations are successful. | |
| 813 ** | |
| 814 ** If an error message is available, leave it in p->zErrMsg. | |
| 815 */ | |
| 816 int sqlite3VtabSync(sqlite3 *db, Vdbe *p){ | |
| 817 int i; | |
| 818 int rc = SQLITE_OK; | |
| 819 VTable **aVTrans = db->aVTrans; | |
| 820 | |
| 821 db->aVTrans = 0; | |
| 822 for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){ | |
| 823 int (*x)(sqlite3_vtab *); | |
| 824 sqlite3_vtab *pVtab = aVTrans[i]->pVtab; | |
| 825 if( pVtab && (x = pVtab->pModule->xSync)!=0 ){ | |
| 826 rc = x(pVtab); | |
| 827 sqlite3VtabImportErrmsg(p, pVtab); | |
| 828 } | |
| 829 } | |
| 830 db->aVTrans = aVTrans; | |
| 831 return rc; | |
| 832 } | |
| 833 | |
| 834 /* | |
| 835 ** Invoke the xRollback method of all virtual tables in the | |
| 836 ** sqlite3.aVTrans array. Then clear the array itself. | |
| 837 */ | |
| 838 int sqlite3VtabRollback(sqlite3 *db){ | |
| 839 callFinaliser(db, offsetof(sqlite3_module,xRollback)); | |
| 840 return SQLITE_OK; | |
| 841 } | |
| 842 | |
| 843 /* | |
| 844 ** Invoke the xCommit method of all virtual tables in the | |
| 845 ** sqlite3.aVTrans array. Then clear the array itself. | |
| 846 */ | |
| 847 int sqlite3VtabCommit(sqlite3 *db){ | |
| 848 callFinaliser(db, offsetof(sqlite3_module,xCommit)); | |
| 849 return SQLITE_OK; | |
| 850 } | |
| 851 | |
| 852 /* | |
| 853 ** If the virtual table pVtab supports the transaction interface | |
| 854 ** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is | |
| 855 ** not currently open, invoke the xBegin method now. | |
| 856 ** | |
| 857 ** If the xBegin call is successful, place the sqlite3_vtab pointer | |
| 858 ** in the sqlite3.aVTrans array. | |
| 859 */ | |
| 860 int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){ | |
| 861 int rc = SQLITE_OK; | |
| 862 const sqlite3_module *pModule; | |
| 863 | |
| 864 /* Special case: If db->aVTrans is NULL and db->nVTrans is greater | |
| 865 ** than zero, then this function is being called from within a | |
| 866 ** virtual module xSync() callback. It is illegal to write to | |
| 867 ** virtual module tables in this case, so return SQLITE_LOCKED. | |
| 868 */ | |
| 869 if( sqlite3VtabInSync(db) ){ | |
| 870 return SQLITE_LOCKED; | |
| 871 } | |
| 872 if( !pVTab ){ | |
| 873 return SQLITE_OK; | |
| 874 } | |
| 875 pModule = pVTab->pVtab->pModule; | |
| 876 | |
| 877 if( pModule->xBegin ){ | |
| 878 int i; | |
| 879 | |
| 880 /* If pVtab is already in the aVTrans array, return early */ | |
| 881 for(i=0; i<db->nVTrans; i++){ | |
| 882 if( db->aVTrans[i]==pVTab ){ | |
| 883 return SQLITE_OK; | |
| 884 } | |
| 885 } | |
| 886 | |
| 887 /* Invoke the xBegin method. If successful, add the vtab to the | |
| 888 ** sqlite3.aVTrans[] array. */ | |
| 889 rc = growVTrans(db); | |
| 890 if( rc==SQLITE_OK ){ | |
| 891 rc = pModule->xBegin(pVTab->pVtab); | |
| 892 if( rc==SQLITE_OK ){ | |
| 893 addToVTrans(db, pVTab); | |
| 894 } | |
| 895 } | |
| 896 } | |
| 897 return rc; | |
| 898 } | |
| 899 | |
| 900 /* | |
| 901 ** Invoke either the xSavepoint, xRollbackTo or xRelease method of all | |
| 902 ** virtual tables that currently have an open transaction. Pass iSavepoint | |
| 903 ** as the second argument to the virtual table method invoked. | |
| 904 ** | |
| 905 ** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is | |
| 906 ** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is | |
| 907 ** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with | |
| 908 ** an open transaction is invoked. | |
| 909 ** | |
| 910 ** If any virtual table method returns an error code other than SQLITE_OK, | |
| 911 ** processing is abandoned and the error returned to the caller of this | |
| 912 ** function immediately. If all calls to virtual table methods are successful, | |
| 913 ** SQLITE_OK is returned. | |
| 914 */ | |
| 915 int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){ | |
| 916 int rc = SQLITE_OK; | |
| 917 | |
| 918 assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN ); | |
| 919 assert( iSavepoint>=0 ); | |
| 920 if( db->aVTrans ){ | |
| 921 int i; | |
| 922 for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){ | |
| 923 VTable *pVTab = db->aVTrans[i]; | |
| 924 const sqlite3_module *pMod = pVTab->pMod->pModule; | |
| 925 if( pVTab->pVtab && pMod->iVersion>=2 ){ | |
| 926 int (*xMethod)(sqlite3_vtab *, int); | |
| 927 switch( op ){ | |
| 928 case SAVEPOINT_BEGIN: | |
| 929 xMethod = pMod->xSavepoint; | |
| 930 pVTab->iSavepoint = iSavepoint+1; | |
| 931 break; | |
| 932 case SAVEPOINT_ROLLBACK: | |
| 933 xMethod = pMod->xRollbackTo; | |
| 934 break; | |
| 935 default: | |
| 936 xMethod = pMod->xRelease; | |
| 937 break; | |
| 938 } | |
| 939 if( xMethod && pVTab->iSavepoint>iSavepoint ){ | |
| 940 rc = xMethod(pVTab->pVtab, iSavepoint); | |
| 941 } | |
| 942 } | |
| 943 } | |
| 944 } | |
| 945 return rc; | |
| 946 } | |
| 947 | |
| 948 /* | |
| 949 ** The first parameter (pDef) is a function implementation. The | |
| 950 ** second parameter (pExpr) is the first argument to this function. | |
| 951 ** If pExpr is a column in a virtual table, then let the virtual | |
| 952 ** table implementation have an opportunity to overload the function. | |
| 953 ** | |
| 954 ** This routine is used to allow virtual table implementations to | |
| 955 ** overload MATCH, LIKE, GLOB, and REGEXP operators. | |
| 956 ** | |
| 957 ** Return either the pDef argument (indicating no change) or a | |
| 958 ** new FuncDef structure that is marked as ephemeral using the | |
| 959 ** SQLITE_FUNC_EPHEM flag. | |
| 960 */ | |
| 961 FuncDef *sqlite3VtabOverloadFunction( | |
| 962 sqlite3 *db, /* Database connection for reporting malloc problems */ | |
| 963 FuncDef *pDef, /* Function to possibly overload */ | |
| 964 int nArg, /* Number of arguments to the function */ | |
| 965 Expr *pExpr /* First argument to the function */ | |
| 966 ){ | |
| 967 Table *pTab; | |
| 968 sqlite3_vtab *pVtab; | |
| 969 sqlite3_module *pMod; | |
| 970 void (*xFunc)(sqlite3_context*,int,sqlite3_value**) = 0; | |
| 971 void *pArg = 0; | |
| 972 FuncDef *pNew; | |
| 973 int rc = 0; | |
| 974 char *zLowerName; | |
| 975 unsigned char *z; | |
| 976 | |
| 977 | |
| 978 /* Check to see the left operand is a column in a virtual table */ | |
| 979 if( NEVER(pExpr==0) ) return pDef; | |
| 980 if( pExpr->op!=TK_COLUMN ) return pDef; | |
| 981 pTab = pExpr->pTab; | |
| 982 if( NEVER(pTab==0) ) return pDef; | |
| 983 if( (pTab->tabFlags & TF_Virtual)==0 ) return pDef; | |
| 984 pVtab = sqlite3GetVTable(db, pTab)->pVtab; | |
| 985 assert( pVtab!=0 ); | |
| 986 assert( pVtab->pModule!=0 ); | |
| 987 pMod = (sqlite3_module *)pVtab->pModule; | |
| 988 if( pMod->xFindFunction==0 ) return pDef; | |
| 989 | |
| 990 /* Call the xFindFunction method on the virtual table implementation | |
| 991 ** to see if the implementation wants to overload this function | |
| 992 */ | |
| 993 zLowerName = sqlite3DbStrDup(db, pDef->zName); | |
| 994 if( zLowerName ){ | |
| 995 for(z=(unsigned char*)zLowerName; *z; z++){ | |
| 996 *z = sqlite3UpperToLower[*z]; | |
| 997 } | |
| 998 rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg); | |
| 999 sqlite3DbFree(db, zLowerName); | |
| 1000 } | |
| 1001 if( rc==0 ){ | |
| 1002 return pDef; | |
| 1003 } | |
| 1004 | |
| 1005 /* Create a new ephemeral function definition for the overloaded | |
| 1006 ** function */ | |
| 1007 pNew = sqlite3DbMallocZero(db, sizeof(*pNew) | |
| 1008 + sqlite3Strlen30(pDef->zName) + 1); | |
| 1009 if( pNew==0 ){ | |
| 1010 return pDef; | |
| 1011 } | |
| 1012 *pNew = *pDef; | |
| 1013 pNew->zName = (char *)&pNew[1]; | |
| 1014 memcpy(pNew->zName, pDef->zName, sqlite3Strlen30(pDef->zName)+1); | |
| 1015 pNew->xFunc = xFunc; | |
| 1016 pNew->pUserData = pArg; | |
| 1017 pNew->funcFlags |= SQLITE_FUNC_EPHEM; | |
| 1018 return pNew; | |
| 1019 } | |
| 1020 | |
| 1021 /* | |
| 1022 ** Make sure virtual table pTab is contained in the pParse->apVirtualLock[] | |
| 1023 ** array so that an OP_VBegin will get generated for it. Add pTab to the | |
| 1024 ** array if it is missing. If pTab is already in the array, this routine | |
| 1025 ** is a no-op. | |
| 1026 */ | |
| 1027 void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){ | |
| 1028 Parse *pToplevel = sqlite3ParseToplevel(pParse); | |
| 1029 int i, n; | |
| 1030 Table **apVtabLock; | |
| 1031 | |
| 1032 assert( IsVirtual(pTab) ); | |
| 1033 for(i=0; i<pToplevel->nVtabLock; i++){ | |
| 1034 if( pTab==pToplevel->apVtabLock[i] ) return; | |
| 1035 } | |
| 1036 n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]); | |
| 1037 apVtabLock = sqlite3_realloc(pToplevel->apVtabLock, n); | |
| 1038 if( apVtabLock ){ | |
| 1039 pToplevel->apVtabLock = apVtabLock; | |
| 1040 pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab; | |
| 1041 }else{ | |
| 1042 pToplevel->db->mallocFailed = 1; | |
| 1043 } | |
| 1044 } | |
| 1045 | |
| 1046 /* | |
| 1047 ** Return the ON CONFLICT resolution mode in effect for the virtual | |
| 1048 ** table update operation currently in progress. | |
| 1049 ** | |
| 1050 ** The results of this routine are undefined unless it is called from | |
| 1051 ** within an xUpdate method. | |
| 1052 */ | |
| 1053 int sqlite3_vtab_on_conflict(sqlite3 *db){ | |
| 1054 static const unsigned char aMap[] = { | |
| 1055 SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE | |
| 1056 }; | |
| 1057 assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 ); | |
| 1058 assert( OE_Ignore==4 && OE_Replace==5 ); | |
| 1059 assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 ); | |
| 1060 return (int)aMap[db->vtabOnConflict-1]; | |
| 1061 } | |
| 1062 | |
| 1063 /* | |
| 1064 ** Call from within the xCreate() or xConnect() methods to provide | |
| 1065 ** the SQLite core with additional information about the behavior | |
| 1066 ** of the virtual table being implemented. | |
| 1067 */ | |
| 1068 int sqlite3_vtab_config(sqlite3 *db, int op, ...){ | |
| 1069 va_list ap; | |
| 1070 int rc = SQLITE_OK; | |
| 1071 | |
| 1072 sqlite3_mutex_enter(db->mutex); | |
| 1073 | |
| 1074 va_start(ap, op); | |
| 1075 switch( op ){ | |
| 1076 case SQLITE_VTAB_CONSTRAINT_SUPPORT: { | |
| 1077 VtabCtx *p = db->pVtabCtx; | |
| 1078 if( !p ){ | |
| 1079 rc = SQLITE_MISUSE_BKPT; | |
| 1080 }else{ | |
| 1081 assert( p->pTab==0 || (p->pTab->tabFlags & TF_Virtual)!=0 ); | |
| 1082 p->pVTable->bConstraint = (u8)va_arg(ap, int); | |
| 1083 } | |
| 1084 break; | |
| 1085 } | |
| 1086 default: | |
| 1087 rc = SQLITE_MISUSE_BKPT; | |
| 1088 break; | |
| 1089 } | |
| 1090 va_end(ap); | |
| 1091 | |
| 1092 if( rc!=SQLITE_OK ) sqlite3Error(db, rc); | |
| 1093 sqlite3_mutex_leave(db->mutex); | |
| 1094 return rc; | |
| 1095 } | |
| 1096 | |
| 1097 #endif /* SQLITE_OMIT_VIRTUALTABLE */ | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2363173002:
[sqlite] Remove obsolete reference version 3.8.7.4. (Closed)
