/*
** This function is invoked by the vdbe to call the xCreate method
** of the virtual table named zTab in database iDb.
**
** If an error occurs, *pzErr is set to point to an English language
** description of the error and an SQLITE_XXX error code is returned.
** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
*/
int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
int rc = SQLITE_OK;
Table *pTab;
Module *pMod;
const char *zMod;
pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
assert( pTab && (pTab->tabFlags & TF_Virtual)!=0 && !pTab->pVTable );
/* Locate the required virtual table module */
zMod = pTab->azModuleArg[0];
pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
/* If the module has been registered and includes a Create method,
** invoke it now. If the module has not been registered, return an
** error. Otherwise, do nothing.
*/
if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){
*pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);
rc = SQLITE_ERROR;
}else{
rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
}
/* Justification of ALWAYS(): The xConstructor method is required to
** create a valid sqlite3_vtab if it returns SQLITE_OK. */
if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){
rc = growVTrans(db);
if( rc==SQLITE_OK ){
addToVTrans(db, sqlite3GetVTable(db, pTab));
}
}
return rc;
}
/*
** This function is invoked by the parser to call the xConnect() method
** of the virtual table pTab. If an error occurs, an error code is returned
** and an error left in pParse.
**
** This call is a no-op if table pTab is not a virtual table.
*/
int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
sqlite3 *db = pParse->db;
const char *zMod;
Module *pMod;
int rc;
assert( pTab );
if( (pTab->tabFlags & TF_Virtual)==0 || sqlite3GetVTable(db, pTab) ){
return SQLITE_OK;
}
/* Locate the required virtual table module */
zMod = pTab->azModuleArg[0];
pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
if( !pMod ){
const char *zModule = pTab->azModuleArg[0];
sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
rc = SQLITE_ERROR;
}else{
char *zErr = 0;
rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
if( rc!=SQLITE_OK ){
sqlite3ErrorMsg(pParse, "%s", zErr);
}
sqlite3DbFree(db, zErr);
}
return rc;
}
/*
** This function is invoked by the vdbe to call the xCreate method
** of the virtual table named zTab in database iDb.
**
** If an error occurs, *pzErr is set to point an an English language
** description of the error and an SQLITE_XXX error code is returned.
** In this case the caller must call sqliteFree() on *pzErr.
*/
int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
int rc = SQLITE_OK;
Table *pTab;
Module *pMod;
const char *zModule;
pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
assert(pTab && pTab->isVirtual && !pTab->pVtab);
pMod = pTab->pMod;
zModule = pTab->azModuleArg[0];
/* If the module has been registered and includes a Create method,
** invoke it now. If the module has not been registered, return an
** error. Otherwise, do nothing.
*/
if( !pMod ){
*pzErr = sqlite3MPrintf("no such module: %s", zModule);
rc = SQLITE_ERROR;
}else{
rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
}
if( rc==SQLITE_OK && pTab->pVtab ){
rc = addToVTrans(db, pTab->pVtab);
}
return rc;
}
/*
** Check to see if virtual table module pMod can be have an eponymous
** virtual table instance. If it can, create one if one does not already
** exist. Return non-zero if the eponymous virtual table instance exists
** when this routine returns, and return zero if it does not exist.
**
** An eponymous virtual table instance is one that is named after its
** module, and more importantly, does not require a CREATE VIRTUAL TABLE
** statement in order to come into existance. Eponymous virtual table
** instances always exist. They cannot be DROP-ed.
**
** Any virtual table module for which xConnect and xCreate are the same
** method can have an eponymous virtual table instance.
*/
int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){
const sqlite3_module *pModule = pMod->pModule;
Table *pTab;
char *zErr = 0;
int rc;
sqlite3 *db = pParse->db;
if( pMod->pEpoTab ) return 1;
if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;
pTab = sqlite3DbMallocZero(db, sizeof(Table));
if( pTab==0 ) return 0;
pTab->zName = sqlite3DbStrDup(db, pMod->zName);
if( pTab->zName==0 ){
sqlite3DbFree(db, pTab);
return 0;
}
pMod->pEpoTab = pTab;
pTab->nTabRef = 1;
pTab->pSchema = db->aDb[0].pSchema;
pTab->tabFlags |= TF_Virtual;
pTab->nModuleArg = 0;
pTab->iPKey = -1;
addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
addModuleArgument(db, pTab, 0);
addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);
if( rc ){
sqlite3ErrorMsg(pParse, "%s", zErr);
sqlite3DbFree(db, zErr);
sqlite3VtabEponymousTableClear(db, pMod);
return 0;
}
return 1;
}
/*
** This function is invoked by the parser to call the xConnect() method
** of the virtual table pTab. If an error occurs, an error code is returned
** and an error left in pParse.
**
** This call is a no-op if table pTab is not a virtual table.
*/
int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
Module *pMod;
int rc = SQLITE_OK;
if( !pTab || !pTab->isVirtual || pTab->pVtab ){
return SQLITE_OK;
}
pMod = pTab->pMod;
if( !pMod ){
const char *zModule = pTab->azModuleArg[0];
sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
rc = SQLITE_ERROR;
} else {
char *zErr = 0;
sqlite3 *db = pParse->db;
rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
if( rc!=SQLITE_OK ){
sqlite3ErrorMsg(pParse, "%s", zErr);
}
sqliteFree(zErr);
}
return rc;
}
