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author | dan <dan@noemail.net> | 2009-11-27 12:12:34 +0000 |
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committer | dan <dan@noemail.net> | 2009-11-27 12:12:34 +0000 |
commit | bb5f168f2e76930161bd7e77a771de736b227c97 (patch) | |
tree | d96f1c5de45d10d87f62b767c385e9ed1b034d20 /src/trigger.c | |
parent | 5f18a221a186919e804c8416c314903e413d2cfe (diff) | |
download | sqlite-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.c | 43 |
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]; } } } |