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Changes to support recursive triggers.

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FossilOrigin-Name: 9b9c19211593d5ff7b39254a29c284560a8bcedb
This commit is contained in:
dan
2009-08-28 18:53:45 +00:00
parent e408edac16
commit 165921a742
25 changed files with 889 additions and 581 deletions
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376
src/trigger.c
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@@ -219,7 +219,7 @@ void sqlite3BeginTrigger(
/* Build the Trigger object */
pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->name = zName;
pTrigger->zName = zName;
zName = 0;
pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
pTrigger->pSchema = db->aDb[iDb].pSchema;
@@ -262,14 +262,14 @@ void sqlite3FinishTrigger(
pTrig = pParse->pNewTrigger;
pParse->pNewTrigger = 0;
if( NEVER(pParse->nErr) || !pTrig ) goto triggerfinish_cleanup;
zName = pTrig->name;
zName = pTrig->zName;
iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
pTrig->step_list = pStepList;
while( pStepList ){
pStepList->pTrig = pTrig;
pStepList = pStepList->pNext;
}
nameToken.z = pTrig->name;
nameToken.z = pTrig->zName;
nameToken.n = sqlite3Strlen30(nameToken.z);
if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken)
&& sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){
@@ -451,7 +451,7 @@ TriggerStep *sqlite3TriggerDeleteStep(
void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){
if( pTrigger==0 ) return;
sqlite3DeleteTriggerStep(db, pTrigger->step_list);
sqlite3DbFree(db, pTrigger->name);
sqlite3DbFree(db, pTrigger->zName);
sqlite3DbFree(db, pTrigger->table);
sqlite3ExprDelete(db, pTrigger->pWhen);
sqlite3IdListDelete(db, pTrigger->pColumns);
@@ -558,11 +558,11 @@ void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3OpenMasterTable(pParse, iDb);
base = sqlite3VdbeAddOpList(v, ArraySize(dropTrigger), dropTrigger);
sqlite3VdbeChangeP4(v, base+1, pTrigger->name, 0);
sqlite3VdbeChangeP4(v, base+1, pTrigger->zName, 0);
sqlite3VdbeChangeP4(v, base+4, "trigger", P4_STATIC);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->name, 0);
sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
if( pParse->nMem<3 ){
pParse->nMem = 3;
}
@@ -674,70 +674,226 @@ static int codeTriggerProgram(
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconfin /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep * pTriggerStep = pStepList;
int orconf;
TriggerStep * pStep = pStepList;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( pTriggerStep!=0 );
assert( pParse->pRoot );
assert( pStep!=0 );
assert( v!=0 );
sqlite3VdbeAddOp2(v, OP_ContextPush, 0, 0);
VdbeComment((v, "begin trigger %s", pStepList->pTrig->name));
while( pTriggerStep ){
sqlite3ExprCacheClear(pParse);
orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
pParse->trigStack->orconf = orconf;
switch( pTriggerStep->op ){
/* sqlite3VdbeAddOp2(v, OP_ContextPush, 0, 0); */
while( pStep ){
/* Figure out the ON CONFLICT policy that will be used for this step
** of the trigger program. If the statement that caused this trigger
** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
** the ON CONFLICT policy that was specified as part of the trigger
** step statement. Example:
**
** CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
** END;
**
** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy
** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy
*/
pParse->orconf = (orconfin==OE_Default)?pStep->orconf:orconfin;
switch( pStep->op ){
case TK_UPDATE: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
sqlite3Update(pParse, pSrc,
sqlite3ExprListDup(db, pTriggerStep->pExprList, 0),
sqlite3ExprDup(db, pTriggerStep->pWhere, 0), orconf);
sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
sqlite3Update(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3ExprDup(db, pStep->pWhere, 0),
pParse->orconf
);
break;
}
case TK_INSERT: {
SrcList *pSrc;
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
sqlite3Insert(pParse, pSrc,
sqlite3ExprListDup(db, pTriggerStep->pExprList, 0),
sqlite3SelectDup(db, pTriggerStep->pSelect, 0),
sqlite3IdListDup(db, pTriggerStep->pIdList), orconf);
sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
sqlite3Insert(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3SelectDup(db, pStep->pSelect, 0),
sqlite3IdListDup(db, pStep->pIdList),
pParse->orconf
);
break;
}
case TK_DELETE: {
SrcList *pSrc;
sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
pSrc = targetSrcList(pParse, pTriggerStep);
sqlite3DeleteFrom(pParse, pSrc,
sqlite3ExprDup(db, pTriggerStep->pWhere, 0));
sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
sqlite3DeleteFrom(pParse,
targetSrcList(pParse, pStep),
sqlite3ExprDup(db, pStep->pWhere, 0)
);
break;
}
default: assert( pTriggerStep->op==TK_SELECT ); {
Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect, 0);
if( ss ){
SelectDest dest;
sqlite3SelectDestInit(&dest, SRT_Discard, 0);
sqlite3Select(pParse, ss, &dest);
sqlite3SelectDelete(db, ss);
}
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
sqlite3Select(pParse, pSelect, &sDest);
sqlite3SelectDelete(db, pSelect);
break;
}
}
pTriggerStep = pTriggerStep->pNext;
pStep = pStep->pNext;
}
sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
VdbeComment((v, "end trigger %s", pStepList->pTrig->name));
/* sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0); */
return 0;
}
#ifdef SQLITE_DEBUG
/*
** This function is used to add VdbeComment() annotations to a VDBE
** program. It is not used in production code, only for debugging.
*/
static const char *onErrorText(int onError){
switch( onError ){
case OE_Abort: return "abort";
case OE_Rollback: return "rollback";
case OE_Fail: return "fail";
case OE_Replace: return "replace";
case OE_Ignore: return "ignore";
case OE_Default: return "default";
}
return "n/a";
}
#endif
/*
** Parse context structure pFrom has just been used to create a sub-vdbe
** (trigger program). If an error has occurred, transfer error information
** from pFrom to pTo.
*/
static void transferParseError(Parse *pTo, Parse *pFrom){
assert( pFrom->zErrMsg==0 || pFrom->nErr );
assert( pTo->zErrMsg==0 || pTo->nErr );
if( pTo->nErr==0 ){
pTo->zErrMsg = pFrom->zErrMsg;
pTo->nErr = pFrom->nErr;
}else{
sqlite3DbFree(pFrom->db, pFrom->zErrMsg);
}
}
static CodedTrigger *codeRowTrigger(
Parse *pRoot, /* Root parse context */
Parse *pParse, /* Current parse context */
Trigger *pTrigger, /* Trigger to code */
int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
Table *pTab, /* The table to code triggers from */
int orconf
){
sqlite3 *db = pParse->db;
CodedTrigger *pC;
Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */
Vdbe *v; /* Temporary VM */
AuthContext sContext; /* Auth context for sub-vdbe */
NameContext sNC; /* Name context for sub-vdbe */
SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */
Parse *pSubParse; /* Parse context for sub-vdbe */
int iEndTrigger = 0; /* Label to jump to if WHEN is false */
pC = sqlite3DbMallocZero(db, sizeof(CodedTrigger));
if( !pC ) return 0;
pC->pNext = pRoot->pCodedTrigger;
pRoot->pCodedTrigger = pC;
pC->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram));
if( !pProgram ) return 0;
pProgram->nRef = 1;
pSubParse = sqlite3StackAllocZero(db, sizeof(Parse));
if( !pSubParse ) return 0;
pC->pProgram = pProgram;
pC->pTrigger = pTrigger;
pC->orconf = orconf;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pSubParse;
pSubParse->db = db;
pSubParse->pTriggerTab = pTab;
pSubParse->pRoot = pRoot;
/* Push an entry on to the auth context stack */
sqlite3AuthContextPush(pParse, &sContext, pTrigger->name);
v = sqlite3GetVdbe(pSubParse);
if( v ){
VdbeComment((v, "Trigger: %s (%s %s%s%s ON %s) (%s)", pTrigger->zName,
(pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"),
(op==TK_UPDATE ? "UPDATE" : ""),
(op==TK_INSERT ? "INSERT" : ""),
(op==TK_DELETE ? "DELETE" : ""),
pTab->zName, onErrorText(orconf)
));
if( pTrigger->pWhen ){
/* Code the WHEN clause. If it evaluates to false (or NULL) the
** sub-vdbe is immediately halted. */
pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0);
if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) ){
iEndTrigger = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL);
}
sqlite3ExprDelete(db, pWhen);
}
/* Code the trigger program into the sub-vdbe. */
codeTriggerProgram(pSubParse, pTrigger->step_list, OE_Default);
if( iEndTrigger ){
sqlite3VdbeResolveLabel(v, iEndTrigger);
}
sqlite3VdbeAddOp0(v, OP_Halt);
transferParseError(pParse, pSubParse);
pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pParse->nArg);
pProgram->nMem = pSubParse->nMem;
pProgram->nCsr = pSubParse->nTab;
pProgram->token = (void *)pTrigger;
pC->oldmask = pSubParse->oldmask;
pC->newmask = pSubParse->newmask;
sqlite3VdbeDelete(v);
while( pSubParse->pAinc ){
AutoincInfo *p = pSubParse->pAinc;
pSubParse->pAinc = p->pNext;
sqlite3DbFree(db, p);
}
}
sqlite3StackFree(db, pSubParse);
/* Pop the entry off the authorization stack */
sqlite3AuthContextPop(&sContext);
return pC;
}
static CodedTrigger *getRowTrigger(
Parse *pParse,
Trigger *pTrigger, /* Trigger to code */
int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
Table *pTab, /* The table to code triggers from */
int orconf
){
CodedTrigger *pC;
Parse *pRoot = pParse;
/* It may be that this trigger has already been coded (or is in the
** process of being coded). If this is the case, then an entry with
** a matching CodedTrigger.pTrigger field will be present somewhere
** in the Parse.pCodedTrigger list. Search for such an entry. */
if( pParse->pRoot ){
pRoot = pParse->pRoot;
}
for(pC=pRoot->pCodedTrigger;
pC && (pC->pTrigger!=pTrigger || pC->orconf!=orconf);
pC=pC->pNext
);
if( !pC ){
pC = codeRowTrigger(pRoot, pParse, pTrigger, op, pTab, orconf);
}
return pC;
}
/*
** This is called to code FOR EACH ROW triggers.
**
@@ -765,7 +921,7 @@ static int codeTriggerProgram(
** output mask is set to the special value 0xffffffff.
**
*/
int sqlite3CodeRowTrigger(
void sqlite3CodeRowTrigger(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* List of triggers on table pTab */
int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
@@ -775,100 +931,68 @@ int sqlite3CodeRowTrigger(
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) */
u32 *piOldColMask, /* OUT: Mask of columns used from the OLD.* table */
u32 *piNewColMask /* OUT: Mask of columns used from the NEW.* table */
int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */
){
Trigger *p;
sqlite3 *db = pParse->db;
TriggerStack trigStackEntry;
trigStackEntry.oldColMask = 0;
trigStackEntry.newColMask = 0;
assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER );
assert(newIdx != -1 || oldIdx != -1);
for(p=pTrigger; p; p=p->pNext){
int fire_this = 0;
/* Sanity checking: The schema for the trigger and for the table are
** always defined. The trigger must be in the same schema as the table
** or else it must be a TEMP trigger. */
assert( p->pSchema!=0 );
assert( p->pTabSchema!=0 );
assert( p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema );
assert( p->pSchema==p->pTabSchema
|| p->pSchema==pParse->db->aDb[1].pSchema );
/* Determine whether we should code this trigger */
if(
p->op==op &&
p->tr_tm==tr_tm &&
checkColumnOverlap(p->pColumns,pChanges)
if( p->op==op
&& p->tr_tm==tr_tm
&& checkColumnOverlap(p->pColumns,pChanges)
){
TriggerStack *pS; /* Pointer to trigger-stack entry */
for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){}
if( !pS ){
fire_this = 1;
Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */
CodedTrigger *pC;
pC = getRowTrigger(pParse, p, op, pTab, orconf);
assert( pC || pParse->nErr || pParse->db->mallocFailed );
/* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program
** is a pointer to the sub-vdbe containing the trigger program. */
if( pC ){
sqlite3VdbeAddOp3(v, OP_Program, oldIdx, newIdx, ++pParse->nMem);
pC->pProgram->nRef++;
sqlite3VdbeChangeP4(v, -1, (const char *)pC->pProgram, P4_SUBPROGRAM);
VdbeComment((v, "Call trigger: %s (%s)", p->zName,onErrorText(orconf)));
}
#if 0 /* Give no warning for recursive triggers. Just do not do them */
else{
sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)",
p->name);
return SQLITE_ERROR;
}
#endif
}
if( fire_this ){
int endTrigger;
Expr * whenExpr;
AuthContext sContext;
NameContext sNC;
#ifndef SQLITE_OMIT_TRACE
sqlite3VdbeAddOp4(pParse->pVdbe, OP_Trace, 0, 0, 0,
sqlite3MPrintf(db, "-- TRIGGER %s", p->name),
P4_DYNAMIC);
#endif
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
/* Push an entry on to the trigger stack */
trigStackEntry.pTrigger = p;
trigStackEntry.newIdx = newIdx;
trigStackEntry.oldIdx = oldIdx;
trigStackEntry.pTab = pTab;
trigStackEntry.pNext = pParse->trigStack;
trigStackEntry.ignoreJump = ignoreJump;
pParse->trigStack = &trigStackEntry;
sqlite3AuthContextPush(pParse, &sContext, p->name);
/* code the WHEN clause */
endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe);
whenExpr = sqlite3ExprDup(db, p->pWhen, 0);
if( db->mallocFailed || sqlite3ResolveExprNames(&sNC, whenExpr) ){
pParse->trigStack = trigStackEntry.pNext;
sqlite3ExprDelete(db, whenExpr);
return 1;
}
sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, SQLITE_JUMPIFNULL);
sqlite3ExprDelete(db, whenExpr);
sqlite3ExprCachePush(pParse);
codeTriggerProgram(pParse, p->step_list, orconf);
sqlite3ExprCachePop(pParse, 1);
/* Pop the entry off the trigger stack */
pParse->trigStack = trigStackEntry.pNext;
sqlite3AuthContextPop(&sContext);
sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);
}
}
if( piOldColMask ) *piOldColMask |= trigStackEntry.oldColMask;
if( piNewColMask ) *piNewColMask |= trigStackEntry.newColMask;
return 0;
}
void sqlite3TriggerUses(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* List of triggers on table pTab */
int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
ExprList *pChanges, /* Changes list for any UPDATE OF triggers */
Table *pTab, /* The table to code triggers from */
int orconf, /* Default ON CONFLICT policy for trigger steps */
u32 *piOldColMask, /* OUT: Mask of columns used from the OLD.* table */
u32 *piNewColMask /* OUT: Mask of columns used from the NEW.* table */
){
Trigger *p;
assert(op==TK_UPDATE || op==TK_INSERT || op==TK_DELETE);
for(p=pTrigger; p; p=p->pNext){
if( p->op==op && checkColumnOverlap(p->pColumns,pChanges) ){
CodedTrigger *pC;
pC = getRowTrigger(pParse, p, op, pTab, orconf);
if( pC ){
*piOldColMask |= pC->oldmask;
*piNewColMask |= pC->newmask;
}
}
}
}
#endif /* !defined(SQLITE_OMIT_TRIGGER) */