* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/utils/adt/trigfuncs.c,v 1.1 2008/11/03 20:17:20 adunstan Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/trigfuncs.c,v 1.2 2008/11/04 00:29:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
-
-
-
#include "postgres.h"
-#include "commands/trigger.h"
+
#include "access/htup.h"
+#include "commands/trigger.h"
+#include "utils/builtins.h"
+
/*
* suppress_redundant_updates_trigger
*
* This trigger function will inhibit an update from being done
* if the OLD and NEW records are identical.
- *
*/
-
Datum
suppress_redundant_updates_trigger(PG_FUNCTION_ARGS)
{
/* make sure it's called as a trigger */
if (!CALLED_AS_TRIGGER(fcinfo))
- elog(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
- errmsg("suppress_redundant_updates_trigger: must be called as trigger")));
+ ereport(ERROR,
+ (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+ errmsg("suppress_redundant_updates_trigger: must be called as trigger")));
/* and that it's called on update */
if (! TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
- ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
- errmsg( "suppress_redundant_updates_trigger: may only be called on update")));
+ ereport(ERROR,
+ (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+ errmsg("suppress_redundant_updates_trigger: must be called on update")));
/* and that it's called before update */
if (! TRIGGER_FIRED_BEFORE(trigdata->tg_event))
- ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
- errmsg( "suppress_redundant_updates_trigger: may only be called before update")));
+ ereport(ERROR,
+ (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+ errmsg("suppress_redundant_updates_trigger: must be called before update")));
/* and that it's called for each row */
if (! TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
- ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
- errmsg( "suppress_redundant_updates_trigger: may only be called for each row")));
+ ereport(ERROR,
+ (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+ errmsg("suppress_redundant_updates_trigger: must be called for each row")));
- /* get tuple data, set default return */
+ /* get tuple data, set default result */
rettuple = newtuple = trigdata->tg_newtuple;
oldtuple = trigdata->tg_trigtuple;
newheader = newtuple->t_data;
oldheader = oldtuple->t_data;
+ /* if the tuple payload is the same ... */
if (newtuple->t_len == oldtuple->t_len &&
newheader->t_hoff == oldheader->t_hoff &&
(HeapTupleHeaderGetNatts(newheader) ==
- HeapTupleHeaderGetNatts(oldheader) ) &&
+ HeapTupleHeaderGetNatts(oldheader)) &&
((newheader->t_infomask & ~HEAP_XACT_MASK) ==
- (oldheader->t_infomask & ~HEAP_XACT_MASK) )&&
+ (oldheader->t_infomask & ~HEAP_XACT_MASK)) &&
memcmp(((char *)newheader) + offsetof(HeapTupleHeaderData, t_bits),
((char *)oldheader) + offsetof(HeapTupleHeaderData, t_bits),
newtuple->t_len - offsetof(HeapTupleHeaderData, t_bits)) == 0)
{
+ /* ... then suppress the update */
rettuple = NULL;
}