database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-05 15:55:57 +03:00
Code Activity

Preliminary changes for a new implementation of RETURNING that captures all

Browse Source 
results in a buffer and plays them all back after the DML statement
completes.  This avoids problems with interleaved DML statements.
This particular check-in is a non-functional work in progress.

FossilOrigin-Name: 04b77d63216ce11b4e797946953bcde504fc005807c7a5ac757fbf47d78698dc
This commit is contained in:
drh
2021-02-04 17:29:04 +00:00
parent 8ab79d6135
commit 381bdacc8f
5 changed files with 117 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

100
src/trigger.c
View File

@@ -70,6 +70,8 @@ Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
pTrig->pNext = pList;
pList = pTrig;
}else if( pTrig->op==TK_RETURNING ){
assert( pParse->bReturning );
assert( &(pParse->u1.pReturning->retTrig) == pTrig );
pTrig->table = pTab->zName;
pTrig->pTabSchema = pTab->pSchema;
pTrig->pNext = pList;
@@ -857,6 +859,55 @@ static ExprList *sqlite3ExpandReturning(
return pNew;
}
/*
** Generate code for the RETURNING trigger. Unlike other triggers
** that invoke a subprogram in the bytecode, the code for RETURNING
** is generated in-line.
*/
static void codeReturningTrigger(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* The trigger step that defines the RETURNING */
Table *pTab, /* The table to code triggers from */
int reg /* The first in an array of registers */
){
Vdbe *v = pParse->pVdbe;
ExprList *pNew;
Returning *pReturning;
assert( v!=0 );
assert( pParse->bReturning );
pReturning = pParse->u1.pReturning;
assert( pTrigger == &(pReturning->retTrig) );
sqlite3VdbeAddOp0(v, OP_Noop);
VdbeComment((v, "RETURNING trigger goes here"));
pNew = sqlite3ExpandReturning(pParse, pReturning->pReturnEL, pTab);
if( pNew ){
pReturning->nRetCol = pNew->nExpr;
pReturning->iRetCur = pParse->nTab++;
sqlite3ExprListDelete(pParse->db, pNew);
}
#if 0
pSelect->pEList =
sqlite3ExpandReturning(pParse, pList, pParse->pTriggerTab);
sqlite3SelectDestInit(&sDest, SRT_Output, 0);
pNew = sqlite3SelectDup(db, pSelect, 0);
if( pNew ){
sqlite3Select(pParse, pNew, &sDest);
if( pNew->selFlags & (SF_Aggregate|SF_HasAgg|SF_WinRewrite) ){
sqlite3ErrorMsg(pParse, "aggregates not allowed in RETURNING");
}
sqlite3SelectDelete(db, pNew);
}
sqlite3ExprListDelete(db, pSelect->pEList);
pStep->pSelect->pEList = pList;
break;
}
#endif
}
/*
** Generate VDBE code for the statements inside the body of a single
** trigger.
@@ -928,7 +979,7 @@ static int codeTriggerProgram(
sqlite3VdbeAddOp0(v, OP_ResetCount);
break;
}
case TK_SELECT: {
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
@@ -936,26 +987,6 @@ static int codeTriggerProgram(
sqlite3SelectDelete(db, pSelect);
break;
}
default: assert( pStep->op==TK_RETURNING ); {
Select *pSelect = pStep->pSelect;
ExprList *pList = pSelect->pEList;
SelectDest sDest;
Select *pNew;
pSelect->pEList =
sqlite3ExpandReturning(pParse, pList, pParse->pTriggerTab);
sqlite3SelectDestInit(&sDest, SRT_Output, 0);
pNew = sqlite3SelectDup(db, pSelect, 0);
if( pNew ){
sqlite3Select(pParse, pNew, &sDest);
if( pNew->selFlags & (SF_Aggregate|SF_HasAgg|SF_WinRewrite) ){
sqlite3ErrorMsg(pParse, "aggregates not allowed in RETURNING");
}
sqlite3SelectDelete(db, pNew);
}
sqlite3ExprListDelete(db, pSelect->pEList);
pStep->pSelect->pEList = pList;
break;
}
}
}
@@ -1208,7 +1239,7 @@ void sqlite3CodeRowTriggerDirect(
** ... ...
** reg+N OLD.* value of right-most column of pTab
** reg+N+1 NEW.rowid
** reg+N+2 OLD.* value of left-most column of pTab
** reg+N+2 NEW.* value of left-most column of pTab
** ... ...
** reg+N+N+1 NEW.* value of right-most column of pTab
**
@@ -1261,12 +1292,12 @@ void sqlite3CodeRowTrigger(
if( (p->op==op || (p->bReturning && p->op==TK_INSERT && op==TK_UPDATE))
&& p->tr_tm==tr_tm
&& checkColumnOverlap(p->pColumns, pChanges)
&& (sqlite3IsToplevel(pParse) || !p->bReturning)
){
u8 origOp = p->op;
p->op = op;
sqlite3CodeRowTriggerDirect(pParse, p, pTab, reg, orconf, ignoreJump);
p->op = origOp;
if( !p->bReturning ){
sqlite3CodeRowTriggerDirect(pParse, p, pTab, reg, orconf, ignoreJump);
}else if( sqlite3IsToplevel(pParse) ){
codeReturningTrigger(pParse, p, pTab, reg);
}
}
}
}
@@ -1311,13 +1342,18 @@ u32 sqlite3TriggerColmask(
assert( isNew==1 || isNew==0 );
for(p=pTrigger; p; p=p->pNext){
if( p->op==op && (tr_tm&p->tr_tm)
if( p->op==op
&& (tr_tm&p->tr_tm)
&& checkColumnOverlap(p->pColumns,pChanges)
){
TriggerPrg *pPrg;
pPrg = getRowTrigger(pParse, p, pTab, orconf);
if( pPrg ){
mask |= pPrg->aColmask[isNew];
if( p->bReturning ){
mask = 0xffffffff;
}else{
TriggerPrg *pPrg;
pPrg = getRowTrigger(pParse, p, pTab, orconf);
if( pPrg ){
mask |= pPrg->aColmask[isNew];
}
}
}
}