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authordan <dan@noemail.net>2009-11-27 12:12:34 +0000
committerdan <dan@noemail.net>2009-11-27 12:12:34 +0000
commitbb5f168f2e76930161bd7e77a771de736b227c97 (patch)
treed96f1c5de45d10d87f62b767c385e9ed1b034d20 /src/trigger.c
parent5f18a221a186919e804c8416c314903e413d2cfe (diff)
downloadsqlite-bb5f168f2e76930161bd7e77a771de736b227c97.tar.gz
sqlite-bb5f168f2e76930161bd7e77a771de736b227c97.zip
Move [7d30880114] to the trunk. Add optimizations to reduce the number of opcodes used for BEFORE UPDATE triggers.
FossilOrigin-Name: 1b7c5250ccb63182324bfc3f1ea28f17b6db357a
Diffstat (limited to 'src/trigger.c')
-rw-r--r--src/trigger.c43
1 files changed, 28 insertions, 15 deletions
diff --git a/src/trigger.c b/src/trigger.c
index b1256190c..51969ce23 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -811,7 +811,8 @@ static TriggerPrg *codeRowTrigger(
pProgram->nRef = 1;
pPrg->pTrigger = pTrigger;
pPrg->orconf = orconf;
- pPrg->oldmask = 0xffffffff;
+ pPrg->aColmask[0] = 0xffffffff;
+ pPrg->aColmask[1] = 0xffffffff;
/* Allocate and populate a new Parse context to use for coding the
** trigger sub-program. */
@@ -872,7 +873,8 @@ static TriggerPrg *codeRowTrigger(
pProgram->nMem = pSubParse->nMem;
pProgram->nCsr = pSubParse->nTab;
pProgram->token = (void *)pTrigger;
- pPrg->oldmask = pSubParse->oldmask;
+ pPrg->aColmask[0] = pSubParse->oldmask;
+ pPrg->aColmask[1] = pSubParse->newmask;
sqlite3VdbeDelete(v);
}
@@ -1032,28 +1034,36 @@ void sqlite3CodeRowTrigger(
}
/*
-** Triggers fired by UPDATE or DELETE statements may access values stored
-** in the old.* pseudo-table. This function returns a 32-bit bitmask
-** indicating which columns of the old.* table actually are used by
-** triggers. This information may be used by the caller to avoid having
-** to load the entire old.* record into memory when executing an UPDATE
-** or DELETE command.
+** Triggers may access values stored in the old.* or new.* pseudo-table.
+** This function returns a 32-bit bitmask indicating which columns of the
+** old.* or new.* tables actually are used by triggers. This information
+** may be used by the caller, for example, to avoid having to load the entire
+** old.* record into memory when executing an UPDATE or DELETE command.
**
** Bit 0 of the returned mask is set if the left-most column of the
-** table may be accessed using an old.<col> reference. Bit 1 is set if
+** table may be accessed using an [old|new].<col> reference. Bit 1 is set if
** the second leftmost column value is required, and so on. If there
** are more than 32 columns in the table, and at least one of the columns
** with an index greater than 32 may be accessed, 0xffffffff is returned.
**
-** It is not possible to determine if the old.rowid column is accessed
-** by triggers. The caller must always assume that it is.
+** It is not possible to determine if the old.rowid or new.rowid column is
+** accessed by triggers. The caller must always assume that it is.
**
-** There is no equivalent function for new.* references.
+** Parameter isNew must be either 1 or 0. If it is 0, then the mask returned
+** applies to the old.* table. If 1, the new.* table.
+**
+** Parameter tr_tm must be a mask with one or both of the TRIGGER_BEFORE
+** and TRIGGER_AFTER bits set. Values accessed by BEFORE triggers are only
+** included in the returned mask if the TRIGGER_BEFORE bit is set in the
+** tr_tm parameter. Similarly, values accessed by AFTER triggers are only
+** included in the returned mask if the TRIGGER_AFTER bit is set in tr_tm.
*/
-u32 sqlite3TriggerOldmask(
+u32 sqlite3TriggerColmask(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* List of triggers on table pTab */
ExprList *pChanges, /* Changes list for any UPDATE OF triggers */
+ int isNew, /* 1 for new.* ref mask, 0 for old.* ref mask */
+ int tr_tm, /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
Table *pTab, /* The table to code triggers from */
int orconf /* Default ON CONFLICT policy for trigger steps */
){
@@ -1061,12 +1071,15 @@ u32 sqlite3TriggerOldmask(
u32 mask = 0;
Trigger *p;
+ assert( isNew==1 || isNew==0 );
for(p=pTrigger; p; p=p->pNext){
- if( p->op==op && checkColumnOverlap(p->pColumns,pChanges) ){
+ 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->oldmask;
+ mask |= pPrg->aColmask[isNew];
}
}
}