diff options
Diffstat (limited to 'kopete/plugins/statistics/sqlite/trigger.c')
| -rw-r--r-- | kopete/plugins/statistics/sqlite/trigger.c | 804 |
1 files changed, 804 insertions, 0 deletions
diff --git a/kopete/plugins/statistics/sqlite/trigger.c b/kopete/plugins/statistics/sqlite/trigger.c new file mode 100644 index 00000000..bbb526f8 --- /dev/null +++ b/kopete/plugins/statistics/sqlite/trigger.c @@ -0,0 +1,804 @@ +/* +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +* +*/ +#include "sqliteInt.h" + +/* +** Delete a linked list of TriggerStep structures. +*/ +void sqlite3DeleteTriggerStep(TriggerStep *pTriggerStep){ + while( pTriggerStep ){ + TriggerStep * pTmp = pTriggerStep; + pTriggerStep = pTriggerStep->pNext; + + if( pTmp->target.dyn ) sqliteFree((char*)pTmp->target.z); + sqlite3ExprDelete(pTmp->pWhere); + sqlite3ExprListDelete(pTmp->pExprList); + sqlite3SelectDelete(pTmp->pSelect); + sqlite3IdListDelete(pTmp->pIdList); + + sqliteFree(pTmp); + } +} + +/* +** This is called by the parser when it sees a CREATE TRIGGER statement +** up to the point of the BEGIN before the trigger actions. A Trigger +** structure is generated based on the information available and stored +** in pParse->pNewTrigger. After the trigger actions have been parsed, the +** sqlite3FinishTrigger() function is called to complete the trigger +** construction process. +*/ +void sqlite3BeginTrigger( + Parse *pParse, /* The parse context of the CREATE TRIGGER statement */ + Token *pName1, /* The name of the trigger */ + Token *pName2, /* The name of the trigger */ + int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */ + int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */ + IdList *pColumns, /* column list if this is an UPDATE OF trigger */ + SrcList *pTableName,/* The name of the table/view the trigger applies to */ + int foreach, /* One of TK_ROW or TK_STATEMENT */ + Expr *pWhen, /* WHEN clause */ + int isTemp /* True if the TEMPORARY keyword is present */ +){ + Trigger *pTrigger; + Table *pTab; + char *zName = 0; /* Name of the trigger */ + sqlite3 *db = pParse->db; + int iDb; /* The database to store the trigger in */ + Token *pName; /* The unqualified db name */ + DbFixer sFix; + + if( isTemp ){ + /* If TEMP was specified, then the trigger name may not be qualified. */ + if( pName2 && pName2->n>0 ){ + sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name"); + goto trigger_cleanup; + } + iDb = 1; + pName = pName1; + }else{ + /* Figure out the db that the the trigger will be created in */ + iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName); + if( iDb<0 ){ + goto trigger_cleanup; + } + } + + /* If the trigger name was unqualified, and the table is a temp table, + ** then set iDb to 1 to create the trigger in the temporary database. + ** If sqlite3SrcListLookup() returns 0, indicating the table does not + ** exist, the error is caught by the block below. + */ + if( !pTableName || sqlite3_malloc_failed ) goto trigger_cleanup; + pTab = sqlite3SrcListLookup(pParse, pTableName); + if( pName2->n==0 && pTab && pTab->iDb==1 ){ + iDb = 1; + } + + /* Ensure the table name matches database name and that the table exists */ + if( sqlite3_malloc_failed ) goto trigger_cleanup; + assert( pTableName->nSrc==1 ); + if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) && + sqlite3FixSrcList(&sFix, pTableName) ){ + goto trigger_cleanup; + } + pTab = sqlite3SrcListLookup(pParse, pTableName); + if( !pTab ){ + /* The table does not exist. */ + goto trigger_cleanup; + } + + /* Check that the trigger name is not reserved and that no trigger of the + ** specified name exists */ + zName = sqlite3NameFromToken(pName); + if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ + goto trigger_cleanup; + } + if( sqlite3HashFind(&(db->aDb[iDb].trigHash), zName,pName->n+1) ){ + sqlite3ErrorMsg(pParse, "trigger %T already exists", pName); + goto trigger_cleanup; + } + + /* Do not create a trigger on a system table */ + if( (iDb!=1 && sqlite3StrICmp(pTab->zName, MASTER_NAME)==0) || + (iDb==1 && sqlite3StrICmp(pTab->zName, TEMP_MASTER_NAME)==0) + ){ + sqlite3ErrorMsg(pParse, "cannot create trigger on system table"); + pParse->nErr++; + goto trigger_cleanup; + } + + /* INSTEAD of triggers are only for views and views only support INSTEAD + ** of triggers. + */ + if( pTab->pSelect && tr_tm!=TK_INSTEAD ){ + sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S", + (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0); + goto trigger_cleanup; + } + if( !pTab->pSelect && tr_tm==TK_INSTEAD ){ + sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF" + " trigger on table: %S", pTableName, 0); + goto trigger_cleanup; + } + +#ifndef SQLITE_OMIT_AUTHORIZATION + { + int code = SQLITE_CREATE_TRIGGER; + const char *zDb = db->aDb[pTab->iDb].zName; + const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb; + if( pTab->iDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER; + if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){ + goto trigger_cleanup; + } + if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(pTab->iDb),0,zDb)){ + goto trigger_cleanup; + } + } +#endif + + /* INSTEAD OF triggers can only appear on views and BEFORE triggers + ** cannot appear on views. So we might as well translate every + ** INSTEAD OF trigger into a BEFORE trigger. It simplifies code + ** elsewhere. + */ + if (tr_tm == TK_INSTEAD){ + tr_tm = TK_BEFORE; + } + + /* Build the Trigger object */ + pTrigger = (Trigger*)sqliteMalloc(sizeof(Trigger)); + if( pTrigger==0 ) goto trigger_cleanup; + pTrigger->name = zName; + zName = 0; + pTrigger->table = sqliteStrDup(pTableName->a[0].zName); + if( sqlite3_malloc_failed ) goto trigger_cleanup; + pTrigger->iDb = iDb; + pTrigger->iTabDb = pTab->iDb; + pTrigger->op = op; + pTrigger->tr_tm = tr_tm; + pTrigger->pWhen = sqlite3ExprDup(pWhen); + pTrigger->pColumns = sqlite3IdListDup(pColumns); + pTrigger->foreach = foreach; + sqlite3TokenCopy(&pTrigger->nameToken,pName); + assert( pParse->pNewTrigger==0 ); + pParse->pNewTrigger = pTrigger; + +trigger_cleanup: + sqliteFree(zName); + sqlite3SrcListDelete(pTableName); + sqlite3IdListDelete(pColumns); + sqlite3ExprDelete(pWhen); +} + +/* +** This routine is called after all of the trigger actions have been parsed +** in order to complete the process of building the trigger. +*/ +void sqlite3FinishTrigger( + Parse *pParse, /* Parser context */ + TriggerStep *pStepList, /* The triggered program */ + Token *pAll /* Token that describes the complete CREATE TRIGGER */ +){ + Trigger *nt = 0; /* The trigger whose construction is finishing up */ + sqlite3 *db = pParse->db; /* The database */ + DbFixer sFix; + + if( pParse->nErr || pParse->pNewTrigger==0 ) goto triggerfinish_cleanup; + nt = pParse->pNewTrigger; + pParse->pNewTrigger = 0; + nt->step_list = pStepList; + while( pStepList ){ + pStepList->pTrig = nt; + pStepList = pStepList->pNext; + } + if( sqlite3FixInit(&sFix, pParse, nt->iDb, "trigger", &nt->nameToken) + && sqlite3FixTriggerStep(&sFix, nt->step_list) ){ + goto triggerfinish_cleanup; + } + + /* if we are not initializing, and this trigger is not on a TEMP table, + ** build the sqlite_master entry + */ + if( !db->init.busy ){ + static const VdbeOpList insertTrig[] = { + { OP_NewRecno, 0, 0, 0 }, + { OP_String8, 0, 0, "trigger" }, + { OP_String8, 0, 0, 0 }, /* 2: trigger name */ + { OP_String8, 0, 0, 0 }, /* 3: table name */ + { OP_Integer, 0, 0, 0 }, + { OP_String8, 0, 0, "CREATE TRIGGER "}, + { OP_String8, 0, 0, 0 }, /* 6: SQL */ + { OP_Concat, 0, 0, 0 }, + { OP_MakeRecord, 5, 0, "tttit" }, + { OP_PutIntKey, 0, 0, 0 }, + }; + int addr; + Vdbe *v; + + /* Make an entry in the sqlite_master table */ + v = sqlite3GetVdbe(pParse); + if( v==0 ) goto triggerfinish_cleanup; + sqlite3BeginWriteOperation(pParse, 0, nt->iDb); + sqlite3OpenMasterTable(v, nt->iDb); + addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig); + sqlite3VdbeChangeP3(v, addr+2, nt->name, 0); + sqlite3VdbeChangeP3(v, addr+3, nt->table, 0); + sqlite3VdbeChangeP3(v, addr+6, pAll->z, pAll->n); + if( nt->iDb!=0 ){ + sqlite3ChangeCookie(db, v, nt->iDb); + } + sqlite3VdbeAddOp(v, OP_Close, 0, 0); + sqlite3VdbeOp3(v, OP_ParseSchema, nt->iDb, 0, + sqlite3MPrintf("type='trigger' AND name='%q'", nt->name), P3_DYNAMIC); + } + + if( db->init.busy ){ + Table *pTab; + sqlite3HashInsert(&db->aDb[nt->iDb].trigHash, + nt->name, strlen(nt->name)+1, nt); + pTab = sqlite3LocateTable(pParse, nt->table, db->aDb[nt->iTabDb].zName); + assert( pTab!=0 ); + nt->pNext = pTab->pTrigger; + pTab->pTrigger = nt; + nt = 0; + } + +triggerfinish_cleanup: + sqlite3DeleteTrigger(nt); + sqlite3DeleteTrigger(pParse->pNewTrigger); + pParse->pNewTrigger = 0; + sqlite3DeleteTriggerStep(pStepList); +} + +/* +** Make a copy of all components of the given trigger step. This has +** the effect of copying all Expr.token.z values into memory obtained +** from sqliteMalloc(). As initially created, the Expr.token.z values +** all point to the input string that was fed to the parser. But that +** string is ephemeral - it will go away as soon as the sqlite3_exec() +** call that started the parser exits. This routine makes a persistent +** copy of all the Expr.token.z strings so that the TriggerStep structure +** will be valid even after the sqlite3_exec() call returns. +*/ +static void sqlitePersistTriggerStep(TriggerStep *p){ + if( p->target.z ){ + p->target.z = sqliteStrNDup(p->target.z, p->target.n); + p->target.dyn = 1; + } + if( p->pSelect ){ + Select *pNew = sqlite3SelectDup(p->pSelect); + sqlite3SelectDelete(p->pSelect); + p->pSelect = pNew; + } + if( p->pWhere ){ + Expr *pNew = sqlite3ExprDup(p->pWhere); + sqlite3ExprDelete(p->pWhere); + p->pWhere = pNew; + } + if( p->pExprList ){ + ExprList *pNew = sqlite3ExprListDup(p->pExprList); + sqlite3ExprListDelete(p->pExprList); + p->pExprList = pNew; + } + if( p->pIdList ){ + IdList *pNew = sqlite3IdListDup(p->pIdList); + sqlite3IdListDelete(p->pIdList); + p->pIdList = pNew; + } +} + +/* +** Turn a SELECT statement (that the pSelect parameter points to) into +** a trigger step. Return a pointer to a TriggerStep structure. +** +** The parser calls this routine when it finds a SELECT statement in +** body of a TRIGGER. +*/ +TriggerStep *sqlite3TriggerSelectStep(Select *pSelect){ + TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep)); + if( pTriggerStep==0 ) return 0; + + pTriggerStep->op = TK_SELECT; + pTriggerStep->pSelect = pSelect; + pTriggerStep->orconf = OE_Default; + sqlitePersistTriggerStep(pTriggerStep); + + return pTriggerStep; +} + +/* +** Build a trigger step out of an INSERT statement. Return a pointer +** to the new trigger step. +** +** The parser calls this routine when it sees an INSERT inside the +** body of a trigger. +*/ +TriggerStep *sqlite3TriggerInsertStep( + Token *pTableName, /* Name of the table into which we insert */ + IdList *pColumn, /* List of columns in pTableName to insert into */ + ExprList *pEList, /* The VALUE clause: a list of values to be inserted */ + Select *pSelect, /* A SELECT statement that supplies values */ + int orconf /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */ +){ + TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep)); + if( pTriggerStep==0 ) return 0; + + assert(pEList == 0 || pSelect == 0); + assert(pEList != 0 || pSelect != 0); + + pTriggerStep->op = TK_INSERT; + pTriggerStep->pSelect = pSelect; + pTriggerStep->target = *pTableName; + pTriggerStep->pIdList = pColumn; + pTriggerStep->pExprList = pEList; + pTriggerStep->orconf = orconf; + sqlitePersistTriggerStep(pTriggerStep); + + return pTriggerStep; +} + +/* +** Construct a trigger step that implements an UPDATE statement and return +** a pointer to that trigger step. The parser calls this routine when it +** sees an UPDATE statement inside the body of a CREATE TRIGGER. +*/ +TriggerStep *sqlite3TriggerUpdateStep( + Token *pTableName, /* Name of the table to be updated */ + ExprList *pEList, /* The SET clause: list of column and new values */ + Expr *pWhere, /* The WHERE clause */ + int orconf /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */ +){ + TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep)); + if( pTriggerStep==0 ) return 0; + + pTriggerStep->op = TK_UPDATE; + pTriggerStep->target = *pTableName; + pTriggerStep->pExprList = pEList; + pTriggerStep->pWhere = pWhere; + pTriggerStep->orconf = orconf; + sqlitePersistTriggerStep(pTriggerStep); + + return pTriggerStep; +} + +/* +** Construct a trigger step that implements a DELETE statement and return +** a pointer to that trigger step. The parser calls this routine when it +** sees a DELETE statement inside the body of a CREATE TRIGGER. +*/ +TriggerStep *sqlite3TriggerDeleteStep(Token *pTableName, Expr *pWhere){ + TriggerStep *pTriggerStep = sqliteMalloc(sizeof(TriggerStep)); + if( pTriggerStep==0 ) return 0; + + pTriggerStep->op = TK_DELETE; + pTriggerStep->target = *pTableName; + pTriggerStep->pWhere = pWhere; + pTriggerStep->orconf = OE_Default; + sqlitePersistTriggerStep(pTriggerStep); + + return pTriggerStep; +} + +/* +** Recursively delete a Trigger structure +*/ +void sqlite3DeleteTrigger(Trigger *pTrigger){ + if( pTrigger==0 ) return; + sqlite3DeleteTriggerStep(pTrigger->step_list); + sqliteFree(pTrigger->name); + sqliteFree(pTrigger->table); + sqlite3ExprDelete(pTrigger->pWhen); + sqlite3IdListDelete(pTrigger->pColumns); + if( pTrigger->nameToken.dyn ) sqliteFree((char*)pTrigger->nameToken.z); + sqliteFree(pTrigger); +} + +/* +** This function is called to drop a trigger from the database schema. +** +** This may be called directly from the parser and therefore identifies +** the trigger by name. The sqlite3DropTriggerPtr() routine does the +** same job as this routine except it takes a pointer to the trigger +** instead of the trigger name. +**/ +void sqlite3DropTrigger(Parse *pParse, SrcList *pName){ + Trigger *pTrigger = 0; + int i; + const char *zDb; + const char *zName; + int nName; + sqlite3 *db = pParse->db; + + if( sqlite3_malloc_failed ) goto drop_trigger_cleanup; + if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){ + goto drop_trigger_cleanup; + } + + assert( pName->nSrc==1 ); + zDb = pName->a[0].zDatabase; + zName = pName->a[0].zName; + nName = strlen(zName); + for(i=0; i<db->nDb; i++){ + int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */ + if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue; + pTrigger = sqlite3HashFind(&(db->aDb[j].trigHash), zName, nName+1); + if( pTrigger ) break; + } + if( !pTrigger ){ + sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0); + goto drop_trigger_cleanup; + } + sqlite3DropTriggerPtr(pParse, pTrigger, 0); + +drop_trigger_cleanup: + sqlite3SrcListDelete(pName); +} + +/* +** Return a pointer to the Table structure for the table that a trigger +** is set on. +*/ +static Table *tableOfTrigger(sqlite3 *db, Trigger *pTrigger){ + return sqlite3FindTable(db,pTrigger->table,db->aDb[pTrigger->iTabDb].zName); +} + + +/* +** Drop a trigger given a pointer to that trigger. If nested is false, +** then also generate code to remove the trigger from the SQLITE_MASTER +** table. +*/ +void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger, int nested){ + Table *pTable; + Vdbe *v; + sqlite3 *db = pParse->db; + int iDb; + + iDb = pTrigger->iDb; + assert( iDb>=0 && iDb<db->nDb ); + pTable = tableOfTrigger(db, pTrigger); + assert(pTable); + assert( pTable->iDb==iDb || iDb==1 ); +#ifndef SQLITE_OMIT_AUTHORIZATION + { + int code = SQLITE_DROP_TRIGGER; + const char *zDb = db->aDb[iDb].zName; + const char *zTab = SCHEMA_TABLE(iDb); + if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER; + if( sqlite3AuthCheck(pParse, code, pTrigger->name, pTable->zName, zDb) || + sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){ + return; + } + } +#endif + + /* Generate code to destroy the database record of the trigger. + */ + if( pTable!=0 && (v = sqlite3GetVdbe(pParse))!=0 ){ + int base; + static const VdbeOpList dropTrigger[] = { + { OP_Rewind, 0, ADDR(9), 0}, + { OP_String8, 0, 0, 0}, /* 1 */ + { OP_Column, 0, 1, 0}, + { OP_Ne, 0, ADDR(8), 0}, + { OP_String8, 0, 0, "trigger"}, + { OP_Column, 0, 0, 0}, + { OP_Ne, 0, ADDR(8), 0}, + { OP_Delete, 0, 0, 0}, + { OP_Next, 0, ADDR(1), 0}, /* 8 */ + }; + + sqlite3BeginWriteOperation(pParse, 0, iDb); + sqlite3OpenMasterTable(v, iDb); + base = sqlite3VdbeAddOpList(v, ArraySize(dropTrigger), dropTrigger); + sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0); + sqlite3ChangeCookie(db, v, iDb); + sqlite3VdbeAddOp(v, OP_Close, 0, 0); + sqlite3VdbeOp3(v, OP_DropTrigger, iDb, 0, pTrigger->name, 0); + } +} + +/* +** Remove a trigger from the hash tables of the sqlite* pointer. +*/ +void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){ + Trigger *pTrigger; + int nName = strlen(zName); + pTrigger = sqlite3HashInsert(&(db->aDb[iDb].trigHash), zName, nName+1, 0); + if( pTrigger ){ + Table *pTable = tableOfTrigger(db, pTrigger); + assert( pTable!=0 ); + if( pTable->pTrigger == pTrigger ){ + pTable->pTrigger = pTrigger->pNext; + }else{ + Trigger *cc = pTable->pTrigger; + while( cc ){ + if( cc->pNext == pTrigger ){ + cc->pNext = cc->pNext->pNext; + break; + } + cc = cc->pNext; + } + assert(cc); + } + sqlite3DeleteTrigger(pTrigger); + db->flags |= SQLITE_InternChanges; + } +} + +/* +** pEList is the SET clause of an UPDATE statement. Each entry +** in pEList is of the format <id>=<expr>. If any of the entries +** in pEList have an <id> which matches an identifier in pIdList, +** then return TRUE. If pIdList==NULL, then it is considered a +** wildcard that matches anything. Likewise if pEList==NULL then +** it matches anything so always return true. Return false only +** if there is no match. +*/ +static int checkColumnOverLap(IdList *pIdList, ExprList *pEList){ + int e; + if( !pIdList || !pEList ) return 1; + for(e=0; e<pEList->nExpr; e++){ + if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1; + } + return 0; +} + +/* A global variable that is TRUE if we should always set up temp tables for + * for triggers, even if there are no triggers to code. This is used to test + * how much overhead the triggers algorithm is causing. + * + * This flag can be set or cleared using the "trigger_overhead_test" pragma. + * The pragma is not documented since it is not really part of the interface + * to SQLite, just the test procedure. +*/ +int sqlite3_always_code_trigger_setup = 0; + +/* + * Returns true if a trigger matching op, tr_tm and foreach that is NOT already + * on the Parse objects trigger-stack (to prevent recursive trigger firing) is + * found in the list specified as pTrigger. + */ +int sqlite3TriggersExist( + Parse *pParse, /* Used to check for recursive triggers */ + Trigger *pTrigger, /* A list of triggers associated with a table */ + int op, /* one of TK_DELETE, TK_INSERT, TK_UPDATE */ + int tr_tm, /* one of TK_BEFORE, TK_AFTER */ + int foreach, /* one of TK_ROW or TK_STATEMENT */ + ExprList *pChanges /* Columns that change in an UPDATE statement */ +){ + Trigger * pTriggerCursor; + + if( sqlite3_always_code_trigger_setup ){ + return 1; + } + + pTriggerCursor = pTrigger; + while( pTriggerCursor ){ + if( pTriggerCursor->op == op && + pTriggerCursor->tr_tm == tr_tm && + pTriggerCursor->foreach == foreach && + checkColumnOverLap(pTriggerCursor->pColumns, pChanges) ){ + TriggerStack * ss; + ss = pParse->trigStack; + while( ss && ss->pTrigger != pTrigger ){ + ss = ss->pNext; + } + if( !ss )return 1; + } + pTriggerCursor = pTriggerCursor->pNext; + } + + return 0; +} + +/* +** Convert the pStep->target token into a SrcList and return a pointer +** to that SrcList. +** +** This routine adds a specific database name, if needed, to the target when +** forming the SrcList. This prevents a trigger in one database from +** referring to a target in another database. An exception is when the +** trigger is in TEMP in which case it can refer to any other database it +** wants. +*/ +static SrcList *targetSrcList( + Parse *pParse, /* The parsing context */ + TriggerStep *pStep /* The trigger containing the target token */ +){ + Token sDb; /* Dummy database name token */ + int iDb; /* Index of the database to use */ + SrcList *pSrc; /* SrcList to be returned */ + + iDb = pStep->pTrig->iDb; + if( iDb==0 || iDb>=2 ){ + assert( iDb<pParse->db->nDb ); + sDb.z = pParse->db->aDb[iDb].zName; + sDb.n = strlen(sDb.z); + pSrc = sqlite3SrcListAppend(0, &sDb, &pStep->target); + } else { + pSrc = sqlite3SrcListAppend(0, &pStep->target, 0); + } + return pSrc; +} + +/* +** Generate VDBE code for zero or more statements inside the body of a +** trigger. +*/ +static int codeTriggerProgram( + Parse *pParse, /* The parser context */ + TriggerStep *pStepList, /* List of statements inside the trigger body */ + int orconfin /* Conflict algorithm. (OE_Abort, etc) */ +){ + TriggerStep * pTriggerStep = pStepList; + int orconf; + Vdbe *v = pParse->pVdbe; + + assert( pTriggerStep!=0 ); + assert( v!=0 ); + sqlite3VdbeAddOp(v, OP_ContextPush, 0, 0); + VdbeComment((v, "# begin trigger %s", pStepList->pTrig->name)); + while( pTriggerStep ){ + orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin; + pParse->trigStack->orconf = orconf; + switch( pTriggerStep->op ){ + case TK_SELECT: { + Select * ss = sqlite3SelectDup(pTriggerStep->pSelect); + assert(ss); + assert(ss->pSrc); + sqlite3Select(pParse, ss, SRT_Discard, 0, 0, 0, 0, 0); + sqlite3SelectDelete(ss); + break; + } + case TK_UPDATE: { + SrcList *pSrc; + pSrc = targetSrcList(pParse, pTriggerStep); + sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0); + sqlite3Update(pParse, pSrc, + sqlite3ExprListDup(pTriggerStep->pExprList), + sqlite3ExprDup(pTriggerStep->pWhere), orconf); + sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0); + break; + } + case TK_INSERT: { + SrcList *pSrc; + pSrc = targetSrcList(pParse, pTriggerStep); + sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0); + sqlite3Insert(pParse, pSrc, + sqlite3ExprListDup(pTriggerStep->pExprList), + sqlite3SelectDup(pTriggerStep->pSelect), + sqlite3IdListDup(pTriggerStep->pIdList), orconf); + sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0); + break; + } + case TK_DELETE: { + SrcList *pSrc; + sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0); + pSrc = targetSrcList(pParse, pTriggerStep); + sqlite3DeleteFrom(pParse, pSrc, sqlite3ExprDup(pTriggerStep->pWhere)); + sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0); + break; + } + default: + assert(0); + } + pTriggerStep = pTriggerStep->pNext; + } + sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0); + VdbeComment((v, "# end trigger %s", pStepList->pTrig->name)); + + return 0; +} + +/* +** This is called to code FOR EACH ROW triggers. +** +** When the code that this function generates is executed, the following +** must be true: +** +** 1. No cursors may be open in the main database. (But newIdx and oldIdx +** can be indices of cursors in temporary tables. See below.) +** +** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then +** a temporary vdbe cursor (index newIdx) must be open and pointing at +** a row containing values to be substituted for new.* expressions in the +** trigger program(s). +** +** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then +** a temporary vdbe cursor (index oldIdx) must be open and pointing at +** a row containing values to be substituted for old.* expressions in the +** trigger program(s). +** +*/ +int sqlite3CodeRowTrigger( + Parse *pParse, /* Parse context */ + int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */ + ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ + int tr_tm, /* One of TK_BEFORE, TK_AFTER */ + Table *pTab, /* The table to code triggers from */ + int newIdx, /* The indice of the "new" row to access */ + int oldIdx, /* The indice of the "old" row to access */ + int orconf, /* ON CONFLICT policy */ + int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ +){ + Trigger *pTrigger; + TriggerStack *pStack; + TriggerStack trigStackEntry; + + assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); + assert(tr_tm == TK_BEFORE || tr_tm == TK_AFTER ); + + assert(newIdx != -1 || oldIdx != -1); + + pTrigger = pTab->pTrigger; + while( pTrigger ){ + int fire_this = 0; + + /* determine whether we should code this trigger */ + if( pTrigger->op == op && pTrigger->tr_tm == tr_tm && + pTrigger->foreach == TK_ROW ){ + fire_this = 1; + for(pStack=pParse->trigStack; pStack; pStack=pStack->pNext){ + if( pStack->pTrigger==pTrigger ){ + fire_this = 0; + } + } + if( op == TK_UPDATE && pTrigger->pColumns && + !checkColumnOverLap(pTrigger->pColumns, pChanges) ){ + fire_this = 0; + } + } + + if( fire_this ){ + int endTrigger; + SrcList dummyTablist; + Expr * whenExpr; + AuthContext sContext; + + dummyTablist.nSrc = 0; + + /* Push an entry on to the trigger stack */ + trigStackEntry.pTrigger = pTrigger; + trigStackEntry.newIdx = newIdx; + trigStackEntry.oldIdx = oldIdx; + trigStackEntry.pTab = pTab; + trigStackEntry.pNext = pParse->trigStack; + trigStackEntry.ignoreJump = ignoreJump; + pParse->trigStack = &trigStackEntry; + sqlite3AuthContextPush(pParse, &sContext, pTrigger->name); + + /* code the WHEN clause */ + endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe); + whenExpr = sqlite3ExprDup(pTrigger->pWhen); + if( sqlite3ExprResolveIds(pParse, &dummyTablist, 0, whenExpr) ){ + pParse->trigStack = trigStackEntry.pNext; + sqlite3ExprDelete(whenExpr); + return 1; + } + sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1); + sqlite3ExprDelete(whenExpr); + + codeTriggerProgram(pParse, pTrigger->step_list, orconf); + + /* Pop the entry off the trigger stack */ + pParse->trigStack = trigStackEntry.pNext; + sqlite3AuthContextPop(&sContext); + + sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger); + } + pTrigger = pTrigger->pNext; + } + return 0; +} |