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87bd956385
postgresql/src/backend/commands/trigger.c
Tom Lane 87bd956385 Restructure smgr API as per recent proposal. smgr no longer depends on 
the relcache, and so the notion of 'blind write' is gone.  This should
improve efficiency in bgwriter and background checkpoint processes.
Internal restructuring in md.c to remove the not-very-useful array of
MdfdVec objects --- might as well just use pointers.
Also remove the long-dead 'persistent main memory' storage manager (mm.c),
since it seems quite unlikely to ever get resurrected.
2004-02-10 01:55:27 +00:00

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/*-------------------------------------------------------------------------
*
* trigger.c
* PostgreSQL TRIGGERs support code.
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.164 2004/02/10 01:55:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/catname.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "parser/parse_func.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
static void InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx);
static HeapTuple GetTupleForTrigger(EState *estate,
ResultRelInfo *relinfo,
ItemPointer tid,
CommandId cid,
TupleTableSlot **newSlot);
static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata,
FmgrInfo *finfo,
MemoryContext per_tuple_context);
static void DeferredTriggerSaveEvent(ResultRelInfo *relinfo, int event,
bool row_trigger, HeapTuple oldtup, HeapTuple newtup);
static void DeferredTriggerExecute(DeferredTriggerEvent event, int itemno,
Relation rel, TriggerDesc *trigdesc, FmgrInfo *finfo,
MemoryContext per_tuple_context);
/*
* Create a trigger. Returns the OID of the created trigger.
*
* forConstraint, if true, says that this trigger is being created to
* implement a constraint. The caller will then be expected to make
* a pg_depend entry linking the trigger to that constraint (and thereby
* to the owning relation(s)).
*/
Oid
CreateTrigger(CreateTrigStmt *stmt, bool forConstraint)
{
int16 tgtype;
int16 tgattr[FUNC_MAX_ARGS];
Datum values[Natts_pg_trigger];
char nulls[Natts_pg_trigger];
Relation rel;
AclResult aclresult;
Relation tgrel;
SysScanDesc tgscan;
ScanKeyData key;
Relation pgrel;
HeapTuple tuple;
Oid fargtypes[FUNC_MAX_ARGS];
Oid funcoid;
Oid funcrettype;
Oid trigoid;
int found = 0;
int i;
char constrtrigname[NAMEDATALEN];
char *trigname;
char *constrname;
Oid constrrelid = InvalidOid;
ObjectAddress myself,
referenced;
rel = heap_openrv(stmt->relation, AccessExclusiveLock);
if (stmt->constrrel != NULL)
constrrelid = RangeVarGetRelid(stmt->constrrel, false);
else if (stmt->isconstraint)
{
/*
* If this trigger is a constraint (and a foreign key one) then we
* really need a constrrelid. Since we don't have one, we'll try
* to generate one from the argument information.
*
* This is really just a workaround for a long-ago pg_dump bug that
* omitted the FROM clause in dumped CREATE CONSTRAINT TRIGGER
* commands. We don't want to bomb out completely here if we
* can't determine the correct relation, because that would
* prevent loading the dump file. Instead, NOTICE here and ERROR
* in the trigger.
*/
bool needconstrrelid = false;
void *elem = NULL;
if (strncmp(strVal(llast(stmt->funcname)), "RI_FKey_check_", 14) == 0)
{
/* A trigger on FK table. */
needconstrrelid = true;
if (length(stmt->args) > RI_PK_RELNAME_ARGNO)
elem = nth(RI_PK_RELNAME_ARGNO, stmt->args);
}
else if (strncmp(strVal(llast(stmt->funcname)), "RI_FKey_", 8) == 0)
{
/* A trigger on PK table. */
needconstrrelid = true;
if (length(stmt->args) > RI_FK_RELNAME_ARGNO)
elem = nth(RI_FK_RELNAME_ARGNO, stmt->args);
}
if (elem != NULL)
{
RangeVar *rel = makeRangeVar(NULL, strVal(elem));
constrrelid = RangeVarGetRelid(rel, true);
}
if (needconstrrelid && constrrelid == InvalidOid)
ereport(NOTICE,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("could not determine referenced table for constraint \"%s\"",
stmt->trigname)));
}
if (rel->rd_rel->relkind != RELKIND_RELATION)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table",
RelationGetRelationName(rel))));
if (!allowSystemTableMods && IsSystemRelation(rel))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(rel))));
/* permission checks */
if (stmt->isconstraint)
{
/* foreign key constraint trigger */
aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
ACL_REFERENCES);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS,
RelationGetRelationName(rel));
if (constrrelid != InvalidOid)
{
aclresult = pg_class_aclcheck(constrrelid, GetUserId(),
ACL_REFERENCES);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS,
get_rel_name(constrrelid));
}
}
else
{
/* real trigger */
aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
ACL_TRIGGER);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS,
RelationGetRelationName(rel));
}
/*
* Generate the trigger's OID now, so that we can use it in the name
* if needed.
*/
trigoid = newoid();
/*
* If trigger is an RI constraint, use specified trigger name as
* constraint name and build a unique trigger name instead. This is
* mainly for backwards compatibility with CREATE CONSTRAINT TRIGGER
* commands.
*/
if (stmt->isconstraint)
{
snprintf(constrtrigname, sizeof(constrtrigname),
"RI_ConstraintTrigger_%u", trigoid);
trigname = constrtrigname;
constrname = stmt->trigname;
}
else
{
trigname = stmt->trigname;
constrname = "";
}
TRIGGER_CLEAR_TYPE(tgtype);
if (stmt->before)
TRIGGER_SETT_BEFORE(tgtype);
if (stmt->row)
TRIGGER_SETT_ROW(tgtype);
for (i = 0; stmt->actions[i]; i++)
{
switch (stmt->actions[i])
{
case 'i':
if (TRIGGER_FOR_INSERT(tgtype))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("multiple INSERT events specified")));
TRIGGER_SETT_INSERT(tgtype);
break;
case 'd':
if (TRIGGER_FOR_DELETE(tgtype))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("multiple DELETE events specified")));
TRIGGER_SETT_DELETE(tgtype);
break;
case 'u':
if (TRIGGER_FOR_UPDATE(tgtype))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("multiple UPDATE events specified")));
TRIGGER_SETT_UPDATE(tgtype);
break;
default:
elog(ERROR, "unrecognized trigger event: %d",
(int) stmt->actions[i]);
break;
}
}
/*
* Scan pg_trigger for existing triggers on relation. We do this
* mainly because we must count them; a secondary benefit is to give a
* nice error message if there's already a trigger of the same name.
* (The unique index on tgrelid/tgname would complain anyway.)
*
* NOTE that this is cool only because we have AccessExclusiveLock on the
* relation, so the trigger set won't be changing underneath us.
*/
tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
ScanKeyInit(&key,
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
SnapshotNow, 1, &key);
while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
if (namestrcmp(&(pg_trigger->tgname), trigname) == 0)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("trigger \"%s\" for relation \"%s\" already exists",
trigname, stmt->relation->relname)));
found++;
}
systable_endscan(tgscan);
/*
* Find and validate the trigger function.
*/
MemSet(fargtypes, 0, FUNC_MAX_ARGS * sizeof(Oid));
funcoid = LookupFuncName(stmt->funcname, 0, fargtypes, false);
funcrettype = get_func_rettype(funcoid);
if (funcrettype != TRIGGEROID)
{
/*
* We allow OPAQUE just so we can load old dump files. When we
* see a trigger function declared OPAQUE, change it to TRIGGER.
*/
if (funcrettype == OPAQUEOID)
{
ereport(WARNING,
(errmsg("changing return type of function %s from \"opaque\" to \"trigger\"",
NameListToString(stmt->funcname))));
SetFunctionReturnType(funcoid, TRIGGEROID);
}
else
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("function %s must return type \"trigger\"",
NameListToString(stmt->funcname))));
}
/*
* Build the new pg_trigger tuple.
*/
MemSet(nulls, ' ', Natts_pg_trigger * sizeof(char));
values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel));
values[Anum_pg_trigger_tgname - 1] = DirectFunctionCall1(namein,
CStringGetDatum(trigname));
values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid);
values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype);
values[Anum_pg_trigger_tgenabled - 1] = BoolGetDatum(true);
values[Anum_pg_trigger_tgisconstraint - 1] = BoolGetDatum(stmt->isconstraint);
values[Anum_pg_trigger_tgconstrname - 1] = DirectFunctionCall1(namein,
CStringGetDatum(constrname));
values[Anum_pg_trigger_tgconstrrelid - 1] = ObjectIdGetDatum(constrrelid);
values[Anum_pg_trigger_tgdeferrable - 1] = BoolGetDatum(stmt->deferrable);
values[Anum_pg_trigger_tginitdeferred - 1] = BoolGetDatum(stmt->initdeferred);
if (stmt->args)
{
List *le;
char *args;
int16 nargs = length(stmt->args);
int len = 0;
foreach(le, stmt->args)
{
char *ar = strVal(lfirst(le));
len += strlen(ar) + 4;
for (; *ar; ar++)
{
if (*ar == '\\')
len++;
}
}
args = (char *) palloc(len + 1);
args[0] = '\0';
foreach(le, stmt->args)
{
char *s = strVal(lfirst(le));
char *d = args + strlen(args);
while (*s)
{
if (*s == '\\')
*d++ = '\\';
*d++ = *s++;
}
strcpy(d, "\\000");
}
values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs);
values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
CStringGetDatum(args));
}
else
{
values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0);
values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
CStringGetDatum(""));
}
MemSet(tgattr, 0, FUNC_MAX_ARGS * sizeof(int16));
values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr);
tuple = heap_formtuple(tgrel->rd_att, values, nulls);
/* force tuple to have the desired OID */
HeapTupleSetOid(tuple, trigoid);
/*
* Insert tuple into pg_trigger.
*/
simple_heap_insert(tgrel, tuple);
CatalogUpdateIndexes(tgrel, tuple);
myself.classId = RelationGetRelid(tgrel);
myself.objectId = trigoid;
myself.objectSubId = 0;
heap_freetuple(tuple);
heap_close(tgrel, RowExclusiveLock);
pfree(DatumGetPointer(values[Anum_pg_trigger_tgname - 1]));
pfree(DatumGetPointer(values[Anum_pg_trigger_tgargs - 1]));
/*
* Update relation's pg_class entry. Crucial side-effect: other
* backends (and this one too!) are sent SI message to make them
* rebuild relcache entries.
*/
pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
tuple = SearchSysCacheCopy(RELOID,
ObjectIdGetDatum(RelationGetRelid(rel)),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u",
RelationGetRelid(rel));
((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found + 1;
simple_heap_update(pgrel, &tuple->t_self, tuple);
CatalogUpdateIndexes(pgrel, tuple);
heap_freetuple(tuple);
heap_close(pgrel, RowExclusiveLock);
/*
* We used to try to update the rel's relcache entry here, but that's
* fairly pointless since it will happen as a byproduct of the
* upcoming CommandCounterIncrement...
*/
/*
* Record dependencies for trigger. Always place a normal dependency
* on the function. If we are doing this in response to an explicit
* CREATE TRIGGER command, also make trigger be auto-dropped if its
* relation is dropped or if the FK relation is dropped. (Auto drop
* is compatible with our pre-7.3 behavior.) If the trigger is being
* made for a constraint, we can skip the relation links; the
* dependency on the constraint will indirectly depend on the
* relations.
*/
referenced.classId = RelOid_pg_proc;
referenced.objectId = funcoid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
if (!forConstraint)
{
referenced.classId = RelOid_pg_class;
referenced.objectId = RelationGetRelid(rel);
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
if (constrrelid != InvalidOid)
{
referenced.classId = RelOid_pg_class;
referenced.objectId = constrrelid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
}
}
/* Keep lock on target rel until end of xact */
heap_close(rel, NoLock);
return trigoid;
}
/*
* DropTrigger - drop an individual trigger by name
*/
void
DropTrigger(Oid relid, const char *trigname, DropBehavior behavior)
{
Relation tgrel;
ScanKeyData skey[2];
SysScanDesc tgscan;
HeapTuple tup;
ObjectAddress object;
/*
* Find the trigger, verify permissions, set up object address
*/
tgrel = heap_openr(TriggerRelationName, AccessShareLock);
ScanKeyInit(&skey[0],
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
ScanKeyInit(&skey[1],
Anum_pg_trigger_tgname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(trigname));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
SnapshotNow, 2, skey);
tup = systable_getnext(tgscan);
if (!HeapTupleIsValid(tup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("trigger \"%s\" for table \"%s\" does not exist",
trigname, get_rel_name(relid))));
if (!pg_class_ownercheck(relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
get_rel_name(relid));
object.classId = RelationGetRelid(tgrel);
object.objectId = HeapTupleGetOid(tup);
object.objectSubId = 0;
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
/*
* Do the deletion
*/
performDeletion(&object, behavior);
}
/*
* Guts of trigger deletion.
*/
void
RemoveTriggerById(Oid trigOid)
{
Relation tgrel;
SysScanDesc tgscan;
ScanKeyData skey[1];
HeapTuple tup;
Oid relid;
Relation rel;
Relation pgrel;
HeapTuple tuple;
Form_pg_class classForm;
tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
/*
* Find the trigger to delete.
*/
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(trigOid));
tgscan = systable_beginscan(tgrel, TriggerOidIndex, true,
SnapshotNow, 1, skey);
tup = systable_getnext(tgscan);
if (!HeapTupleIsValid(tup))
elog(ERROR, "could not find tuple for trigger %u", trigOid);
/*
* Open and exclusive-lock the relation the trigger belongs to.
*/
relid = ((Form_pg_trigger) GETSTRUCT(tup))->tgrelid;
rel = heap_open(relid, AccessExclusiveLock);
if (rel->rd_rel->relkind != RELKIND_RELATION)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table",
RelationGetRelationName(rel))));
if (!allowSystemTableMods && IsSystemRelation(rel))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(rel))));
/*
* Delete the pg_trigger tuple.
*/
simple_heap_delete(tgrel, &tup->t_self);
systable_endscan(tgscan);
heap_close(tgrel, RowExclusiveLock);
/*
* Update relation's pg_class entry. Crucial side-effect: other
* backends (and this one too!) are sent SI message to make them
* rebuild relcache entries.
*
* Note this is OK only because we have AccessExclusiveLock on the rel,
* so no one else is creating/deleting triggers on this rel at the
* same time.
*/
pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
tuple = SearchSysCacheCopy(RELOID,
ObjectIdGetDatum(relid),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
classForm = (Form_pg_class) GETSTRUCT(tuple);
if (classForm->reltriggers == 0) /* should not happen */
elog(ERROR, "relation \"%s\" has reltriggers = 0",
RelationGetRelationName(rel));
classForm->reltriggers--;
simple_heap_update(pgrel, &tuple->t_self, tuple);
CatalogUpdateIndexes(pgrel, tuple);
heap_freetuple(tuple);
heap_close(pgrel, RowExclusiveLock);
/* Keep lock on trigger's rel until end of xact */
heap_close(rel, NoLock);
}
/*
* renametrig - changes the name of a trigger on a relation
*
* trigger name is changed in trigger catalog.
* No record of the previous name is kept.
*
* get proper relrelation from relation catalog (if not arg)
* scan trigger catalog
* for name conflict (within rel)
* for original trigger (if not arg)
* modify tgname in trigger tuple
* update row in catalog
*/
void
renametrig(Oid relid,
const char *oldname,
const char *newname)
{
Relation targetrel;
Relation tgrel;
HeapTuple tuple;
SysScanDesc tgscan;
ScanKeyData key[2];
/*
* Grab an exclusive lock on the target table, which we will NOT
* release until end of transaction.
*/
targetrel = heap_open(relid, AccessExclusiveLock);
/*
* Scan pg_trigger twice for existing triggers on relation. We do
* this in order to ensure a trigger does not exist with newname (The
* unique index on tgrelid/tgname would complain anyway) and to ensure
* a trigger does exist with oldname.
*
* NOTE that this is cool only because we have AccessExclusiveLock on the
* relation, so the trigger set won't be changing underneath us.
*/
tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
/*
* First pass -- look for name conflict
*/
ScanKeyInit(&key[0],
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
ScanKeyInit(&key[1],
Anum_pg_trigger_tgname,
BTEqualStrategyNumber, F_NAMEEQ,
PointerGetDatum(newname));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
SnapshotNow, 2, key);
if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("trigger \"%s\" for relation \"%s\" already exists",
newname, RelationGetRelationName(targetrel))));
systable_endscan(tgscan);
/*
* Second pass -- look for trigger existing with oldname and update
*/
ScanKeyInit(&key[0],
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
ScanKeyInit(&key[1],
Anum_pg_trigger_tgname,
BTEqualStrategyNumber, F_NAMEEQ,
PointerGetDatum(oldname));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
SnapshotNow, 2, key);
if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
{
/*
* Update pg_trigger tuple with new tgname.
*/
tuple = heap_copytuple(tuple); /* need a modifiable copy */
namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname, newname);
simple_heap_update(tgrel, &tuple->t_self, tuple);
/* keep system catalog indexes current */
CatalogUpdateIndexes(tgrel, tuple);
/*
* Invalidate relation's relcache entry so that other backends
* (and this one too!) are sent SI message to make them rebuild
* relcache entries. (Ideally this should happen
* automatically...)
*/
CacheInvalidateRelcache(targetrel);
}
else
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("trigger \"%s\" for table \"%s\" does not exist",
oldname, RelationGetRelationName(targetrel))));
}
systable_endscan(tgscan);
heap_close(tgrel, RowExclusiveLock);
/*
* Close rel, but keep exclusive lock!
*/
heap_close(targetrel, NoLock);
}
/*
* Build trigger data to attach to the given relcache entry.
*
* Note that trigger data attached to a relcache entry must be stored in
* CacheMemoryContext to ensure it survives as long as the relcache entry.
* But we should be running in a less long-lived working context. To avoid
* leaking cache memory if this routine fails partway through, we build a
* temporary TriggerDesc in working memory and then copy the completed
* structure into cache memory.
*/
void
RelationBuildTriggers(Relation relation)
{
TriggerDesc *trigdesc;
int ntrigs = relation->rd_rel->reltriggers;
Trigger *triggers;
int found = 0;
Relation tgrel;
ScanKeyData skey;
SysScanDesc tgscan;
HeapTuple htup;
MemoryContext oldContext;
Assert(ntrigs > 0); /* else I should not have been called */
triggers = (Trigger *) palloc(ntrigs * sizeof(Trigger));
/*
* Note: since we scan the triggers using TriggerRelidNameIndex, we
* will be reading the triggers in name order, except possibly during
* emergency-recovery operations (ie, IsIgnoringSystemIndexes). This
* in turn ensures that triggers will be fired in name order.
*/
ScanKeyInit(&skey,
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(relation)));
tgrel = heap_openr(TriggerRelationName, AccessShareLock);
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
SnapshotNow, 1, &skey);
while (HeapTupleIsValid(htup = systable_getnext(tgscan)))
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
Trigger *build;
if (found >= ntrigs)
elog(ERROR, "too many trigger records found for relation \"%s\"",
RelationGetRelationName(relation));
build = &(triggers[found]);
build->tgoid = HeapTupleGetOid(htup);
build->tgname = DatumGetCString(DirectFunctionCall1(nameout,
NameGetDatum(&pg_trigger->tgname)));
build->tgfoid = pg_trigger->tgfoid;
build->tgtype = pg_trigger->tgtype;
build->tgenabled = pg_trigger->tgenabled;
build->tgisconstraint = pg_trigger->tgisconstraint;
build->tgconstrrelid = pg_trigger->tgconstrrelid;
build->tgdeferrable = pg_trigger->tgdeferrable;
build->tginitdeferred = pg_trigger->tginitdeferred;
build->tgnargs = pg_trigger->tgnargs;
memcpy(build->tgattr, &(pg_trigger->tgattr),
FUNC_MAX_ARGS * sizeof(int16));
if (build->tgnargs > 0)
{
bytea *val;
bool isnull;
char *p;
int i;
val = (bytea *) fastgetattr(htup,
Anum_pg_trigger_tgargs,
tgrel->rd_att, &isnull);
if (isnull)
elog(ERROR, "tgargs is null in trigger for relation \"%s\"",
RelationGetRelationName(relation));
p = (char *) VARDATA(val);
build->tgargs = (char **) palloc(build->tgnargs * sizeof(char *));
for (i = 0; i < build->tgnargs; i++)
{
build->tgargs[i] = pstrdup(p);
p += strlen(p) + 1;
}
}
else
build->tgargs = NULL;
found++;
}
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
if (found != ntrigs)
elog(ERROR, "%d trigger record(s) not found for relation \"%s\"",
ntrigs - found,
RelationGetRelationName(relation));
/* Build trigdesc */
trigdesc = (TriggerDesc *) palloc0(sizeof(TriggerDesc));
trigdesc->triggers = triggers;
trigdesc->numtriggers = ntrigs;
for (found = 0; found < ntrigs; found++)
InsertTrigger(trigdesc, &(triggers[found]), found);
/* Copy completed trigdesc into cache storage */
oldContext = MemoryContextSwitchTo(CacheMemoryContext);
relation->trigdesc = CopyTriggerDesc(trigdesc);
MemoryContextSwitchTo(oldContext);
/* Release working memory */
FreeTriggerDesc(trigdesc);
}
/*
* Insert the given trigger into the appropriate index list(s) for it
*
* To simplify storage management, we allocate each index list at the max
* possible size (trigdesc->numtriggers) if it's used at all. This does
* not waste space permanently since we're only building a temporary
* trigdesc at this point.
*/
static void
InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx)
{
uint16 *n;
int **t,
**tp;
if (TRIGGER_FOR_ROW(trigger->tgtype))
{
/* ROW trigger */
if (TRIGGER_FOR_BEFORE(trigger->tgtype))
{
n = trigdesc->n_before_row;
t = trigdesc->tg_before_row;
}
else
{
n = trigdesc->n_after_row;
t = trigdesc->tg_after_row;
}
}
else
{
/* STATEMENT trigger */
if (TRIGGER_FOR_BEFORE(trigger->tgtype))
{
n = trigdesc->n_before_statement;
t = trigdesc->tg_before_statement;
}
else
{
n = trigdesc->n_after_statement;
t = trigdesc->tg_after_statement;
}
}
if (TRIGGER_FOR_INSERT(trigger->tgtype))
{
tp = &(t[TRIGGER_EVENT_INSERT]);
if (*tp == NULL)
*tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
(*tp)[n[TRIGGER_EVENT_INSERT]] = indx;
(n[TRIGGER_EVENT_INSERT])++;
}
if (TRIGGER_FOR_DELETE(trigger->tgtype))
{
tp = &(t[TRIGGER_EVENT_DELETE]);
if (*tp == NULL)
*tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
(*tp)[n[TRIGGER_EVENT_DELETE]] = indx;
(n[TRIGGER_EVENT_DELETE])++;
}
if (TRIGGER_FOR_UPDATE(trigger->tgtype))
{
tp = &(t[TRIGGER_EVENT_UPDATE]);
if (*tp == NULL)
*tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
(*tp)[n[TRIGGER_EVENT_UPDATE]] = indx;
(n[TRIGGER_EVENT_UPDATE])++;
}
}
/*
* Copy a TriggerDesc data structure.
*
* The copy is allocated in the current memory context.
*/
TriggerDesc *
CopyTriggerDesc(TriggerDesc *trigdesc)
{
TriggerDesc *newdesc;
uint16 *n;
int **t,
*tnew;
Trigger *trigger;
int i;
if (trigdesc == NULL || trigdesc->numtriggers <= 0)
return NULL;
newdesc = (TriggerDesc *) palloc(sizeof(TriggerDesc));
memcpy(newdesc, trigdesc, sizeof(TriggerDesc));
trigger = (Trigger *) palloc(trigdesc->numtriggers * sizeof(Trigger));
memcpy(trigger, trigdesc->triggers,
trigdesc->numtriggers * sizeof(Trigger));
newdesc->triggers = trigger;
for (i = 0; i < trigdesc->numtriggers; i++)
{
trigger->tgname = pstrdup(trigger->tgname);
if (trigger->tgnargs > 0)
{
char **newargs;
int16 j;
newargs = (char **) palloc(trigger->tgnargs * sizeof(char *));
for (j = 0; j < trigger->tgnargs; j++)
newargs[j] = pstrdup(trigger->tgargs[j]);
trigger->tgargs = newargs;
}
trigger++;
}
n = newdesc->n_before_statement;
t = newdesc->tg_before_statement;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
{
if (n[i] > 0)
{
tnew = (int *) palloc(n[i] * sizeof(int));
memcpy(tnew, t[i], n[i] * sizeof(int));
t[i] = tnew;
}
else
t[i] = NULL;
}
n = newdesc->n_before_row;
t = newdesc->tg_before_row;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
{
if (n[i] > 0)
{
tnew = (int *) palloc(n[i] * sizeof(int));
memcpy(tnew, t[i], n[i] * sizeof(int));
t[i] = tnew;
}
else
t[i] = NULL;
}
n = newdesc->n_after_row;
t = newdesc->tg_after_row;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
{
if (n[i] > 0)
{
tnew = (int *) palloc(n[i] * sizeof(int));
memcpy(tnew, t[i], n[i] * sizeof(int));
t[i] = tnew;
}
else
t[i] = NULL;
}
n = newdesc->n_after_statement;
t = newdesc->tg_after_statement;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
{
if (n[i] > 0)
{
tnew = (int *) palloc(n[i] * sizeof(int));
memcpy(tnew, t[i], n[i] * sizeof(int));
t[i] = tnew;
}
else
t[i] = NULL;
}
return newdesc;
}
/*
* Free a TriggerDesc data structure.
*/
void
FreeTriggerDesc(TriggerDesc *trigdesc)
{
int **t;
Trigger *trigger;
int i;
if (trigdesc == NULL)
return;
t = trigdesc->tg_before_statement;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
if (t[i] != NULL)
pfree(t[i]);
t = trigdesc->tg_before_row;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
if (t[i] != NULL)
pfree(t[i]);
t = trigdesc->tg_after_row;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
if (t[i] != NULL)
pfree(t[i]);
t = trigdesc->tg_after_statement;
for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
if (t[i] != NULL)
pfree(t[i]);
trigger = trigdesc->triggers;
for (i = 0; i < trigdesc->numtriggers; i++)
{
pfree(trigger->tgname);
if (trigger->tgnargs > 0)
{
while (--(trigger->tgnargs) >= 0)
pfree(trigger->tgargs[trigger->tgnargs]);
pfree(trigger->tgargs);
}
trigger++;
}
pfree(trigdesc->triggers);
pfree(trigdesc);
}
/*
* Compare two TriggerDesc structures for logical equality.
*/
#ifdef NOT_USED
bool
equalTriggerDescs(TriggerDesc *trigdesc1, TriggerDesc *trigdesc2)
{
int i,
j;
/*
* We need not examine the "index" data, just the trigger array
* itself; if we have the same triggers with the same types, the
* derived index data should match.
*
* As of 7.3 we assume trigger set ordering is significant in the
* comparison; so we just compare corresponding slots of the two sets.
*/
if (trigdesc1 != NULL)
{
if (trigdesc2 == NULL)
return false;
if (trigdesc1->numtriggers != trigdesc2->numtriggers)
return false;
for (i = 0; i < trigdesc1->numtriggers; i++)
{
Trigger *trig1 = trigdesc1->triggers + i;
Trigger *trig2 = trigdesc2->triggers + i;
if (trig1->tgoid != trig2->tgoid)
return false;
if (strcmp(trig1->tgname, trig2->tgname) != 0)
return false;
if (trig1->tgfoid != trig2->tgfoid)
return false;
if (trig1->tgtype != trig2->tgtype)
return false;
if (trig1->tgenabled != trig2->tgenabled)
return false;
if (trig1->tgisconstraint != trig2->tgisconstraint)
return false;
if (trig1->tgconstrrelid != trig2->tgconstrrelid)
return false;
if (trig1->tgdeferrable != trig2->tgdeferrable)
return false;
if (trig1->tginitdeferred != trig2->tginitdeferred)
return false;
if (trig1->tgnargs != trig2->tgnargs)
return false;
if (memcmp(trig1->tgattr, trig2->tgattr,
sizeof(trig1->tgattr)) != 0)
return false;
for (j = 0; j < trig1->tgnargs; j++)
if (strcmp(trig1->tgargs[j], trig2->tgargs[j]) != 0)
return false;
}
}
else if (trigdesc2 != NULL)
return false;
return true;
}
#endif /* NOT_USED */
/*
* Call a trigger function.
*
* trigdata: trigger descriptor.
* finfo: possibly-cached call info for the function.
* per_tuple_context: memory context to execute the function in.
*
* Returns the tuple (or NULL) as returned by the function.
*/
static HeapTuple
ExecCallTriggerFunc(TriggerData *trigdata,
FmgrInfo *finfo,
MemoryContext per_tuple_context)
{
FunctionCallInfoData fcinfo;
Datum result;
MemoryContext oldContext;
/*
* We cache fmgr lookup info, to avoid making the lookup again on each
* call.
*/
if (finfo->fn_oid == InvalidOid)
fmgr_info(trigdata->tg_trigger->tgfoid, finfo);
Assert(finfo->fn_oid == trigdata->tg_trigger->tgfoid);
/*
* Do the function evaluation in the per-tuple memory context, so that
* leaked memory will be reclaimed once per tuple. Note in particular
* that any new tuple created by the trigger function will live till
* the end of the tuple cycle.
*/
oldContext = MemoryContextSwitchTo(per_tuple_context);
/*
* Call the function, passing no arguments but setting a context.
*/
MemSet(&fcinfo, 0, sizeof(fcinfo));
fcinfo.flinfo = finfo;
fcinfo.context = (Node *) trigdata;
result = FunctionCallInvoke(&fcinfo);
MemoryContextSwitchTo(oldContext);
/*
* Trigger protocol allows function to return a null pointer, but NOT
* to set the isnull result flag.
*/
if (fcinfo.isnull)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("trigger function %u returned null value",
fcinfo.flinfo->fn_oid)));
return (HeapTuple) DatumGetPointer(result);
}
void
ExecBSInsertTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int ntrigs;
int *tgindx;
int i;
TriggerData LocTriggerData;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
ntrigs = trigdesc->n_before_statement[TRIGGER_EVENT_INSERT];
tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_INSERT];
if (ntrigs == 0)
return;
/* Allocate cache space for fmgr lookup info, if not done yet */
if (relinfo->ri_TrigFunctions == NULL)
relinfo->ri_TrigFunctions = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuple = NULL;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
HeapTuple newtuple;
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
GetPerTupleMemoryContext(estate));
if (newtuple)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("BEFORE STATEMENT trigger cannot return a value")));
}
}
void
ExecASInsertTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_INSERT] > 0)
DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT,
false, NULL, NULL);
}
HeapTuple
ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
HeapTuple trigtuple)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
int ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_INSERT];
int *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_INSERT];
HeapTuple newtuple = trigtuple;
HeapTuple oldtuple;
TriggerData LocTriggerData;
int i;
/* Allocate cache space for fmgr lookup info, if not done yet */
if (relinfo->ri_TrigFunctions == NULL)
relinfo->ri_TrigFunctions = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = oldtuple = newtuple;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
GetPerTupleMemoryContext(estate));
if (oldtuple != newtuple && oldtuple != trigtuple)
heap_freetuple(oldtuple);
if (newtuple == NULL)
break;
}
return newtuple;
}
void
ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo,
HeapTuple trigtuple)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0)
DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT,
true, NULL, trigtuple);
}
void
ExecBSDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int ntrigs;
int *tgindx;
int i;
TriggerData LocTriggerData;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
ntrigs = trigdesc->n_before_statement[TRIGGER_EVENT_DELETE];
tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_DELETE];
if (ntrigs == 0)
return;
/* Allocate cache space for fmgr lookup info, if not done yet */
if (relinfo->ri_TrigFunctions == NULL)
relinfo->ri_TrigFunctions = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuple = NULL;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
HeapTuple newtuple;
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
GetPerTupleMemoryContext(estate));
if (newtuple)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("BEFORE STATEMENT trigger cannot return a value")));
}
}
void
ExecASDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_DELETE] > 0)
DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE,
false, NULL, NULL);
}
bool
ExecBRDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid,
CommandId cid)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
int ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_DELETE];
int *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_DELETE];
TriggerData LocTriggerData;
HeapTuple trigtuple;
HeapTuple newtuple = NULL;
TupleTableSlot *newSlot;
int i;
trigtuple = GetTupleForTrigger(estate, relinfo, tupleid, cid, &newSlot);
if (trigtuple == NULL)
return false;
/* Allocate cache space for fmgr lookup info, if not done yet */
if (relinfo->ri_TrigFunctions == NULL)
relinfo->ri_TrigFunctions = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = trigtuple;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
GetPerTupleMemoryContext(estate));
if (newtuple == NULL)
break;
if (newtuple != trigtuple)
heap_freetuple(newtuple);
}
heap_freetuple(trigtuple);
return (newtuple == NULL) ? false : true;
}
void
ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0)
{
HeapTuple trigtuple = GetTupleForTrigger(estate, relinfo,
tupleid,
(CommandId) 0,
NULL);
DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE,
true, trigtuple, NULL);
heap_freetuple(trigtuple);
}
}
void
ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int ntrigs;
int *tgindx;
int i;
TriggerData LocTriggerData;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
ntrigs = trigdesc->n_before_statement[TRIGGER_EVENT_UPDATE];
tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_UPDATE];
if (ntrigs == 0)
return;
/* Allocate cache space for fmgr lookup info, if not done yet */
if (relinfo->ri_TrigFunctions == NULL)
relinfo->ri_TrigFunctions = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuple = NULL;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
HeapTuple newtuple;
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
GetPerTupleMemoryContext(estate));
if (newtuple)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("BEFORE STATEMENT trigger cannot return a value")));
}
}
void
ExecASUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_UPDATE] > 0)
DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE,
false, NULL, NULL);
}
HeapTuple
ExecBRUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid, HeapTuple newtuple,
CommandId cid)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
int ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_UPDATE];
int *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_UPDATE];
TriggerData LocTriggerData;
HeapTuple trigtuple;
HeapTuple oldtuple;
HeapTuple intuple = newtuple;
TupleTableSlot *newSlot;
int i;
trigtuple = GetTupleForTrigger(estate, relinfo, tupleid, cid, &newSlot);
if (trigtuple == NULL)
return NULL;
/*
* In READ COMMITTED isolation level it's possible that newtuple was
* changed due to concurrent update.
*/
if (newSlot != NULL)
intuple = newtuple = ExecRemoveJunk(estate->es_junkFilter, newSlot);
/* Allocate cache space for fmgr lookup info, if not done yet */
if (relinfo->ri_TrigFunctions == NULL)
relinfo->ri_TrigFunctions = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = trigtuple;
LocTriggerData.tg_newtuple = oldtuple = newtuple;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
GetPerTupleMemoryContext(estate));
if (oldtuple != newtuple && oldtuple != intuple)
heap_freetuple(oldtuple);
if (newtuple == NULL)
break;
}
heap_freetuple(trigtuple);
return newtuple;
}
void
ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid, HeapTuple newtuple)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0)
{
HeapTuple trigtuple = GetTupleForTrigger(estate, relinfo,
tupleid,
(CommandId) 0,
NULL);
DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE,
true, trigtuple, newtuple);
heap_freetuple(trigtuple);
}
}
static HeapTuple
GetTupleForTrigger(EState *estate, ResultRelInfo *relinfo,
ItemPointer tid, CommandId cid,
TupleTableSlot **newSlot)
{
Relation relation = relinfo->ri_RelationDesc;
HeapTupleData tuple;
HeapTuple result;
Buffer buffer;
if (newSlot != NULL)
{
int test;
/*
* mark tuple for update
*/
*newSlot = NULL;
tuple.t_self = *tid;
ltrmark:;
test = heap_mark4update(relation, &tuple, &buffer, cid);
switch (test)
{
case HeapTupleSelfUpdated:
/* treat it as deleted; do not process */
ReleaseBuffer(buffer);
return NULL;
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
ReleaseBuffer(buffer);
if (IsXactIsoLevelSerializable)
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
else if (!(ItemPointerEquals(&(tuple.t_self), tid)))
{
TupleTableSlot *epqslot = EvalPlanQual(estate,
relinfo->ri_RangeTableIndex,
&(tuple.t_self));
if (!(TupIsNull(epqslot)))
{
*tid = tuple.t_self;
*newSlot = epqslot;
goto ltrmark;
}
}
/*
* if tuple was deleted or PlanQual failed for updated
* tuple - we have not process this tuple!
*/
return NULL;
default:
ReleaseBuffer(buffer);
elog(ERROR, "unrecognized heap_mark4update status: %u",
test);
return NULL; /* keep compiler quiet */
}
}
else
{
PageHeader dp;
ItemId lp;
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
if (!BufferIsValid(buffer))
elog(ERROR, "ReadBuffer failed");
dp = (PageHeader) BufferGetPage(buffer);
lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
Assert(ItemIdIsUsed(lp));
tuple.t_datamcxt = NULL;
tuple.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp);
tuple.t_len = ItemIdGetLength(lp);
tuple.t_self = *tid;
}
result = heap_copytuple(&tuple);
ReleaseBuffer(buffer);
return result;
}
/* ----------
* Deferred trigger stuff
* ----------
*/
typedef struct DeferredTriggersData
{
/* Internal data is held in a per-transaction memory context */
MemoryContext deftrig_cxt;
/* ALL DEFERRED or ALL IMMEDIATE */
bool deftrig_all_isset;
bool deftrig_all_isdeferred;
/* Per trigger state */
List *deftrig_trigstates;
/* List of pending deferred triggers. Previous comment below */
DeferredTriggerEvent deftrig_events;
DeferredTriggerEvent deftrig_events_imm;
DeferredTriggerEvent deftrig_event_tail;
} DeferredTriggersData;
/* ----------
* deftrig_events, deftrig_event_tail:
* The list of pending deferred trigger events during the current transaction.
*
* deftrig_events is the head, deftrig_event_tail is the last entry.
* Because this can grow pretty large, we don't use separate List nodes,
* but instead thread the list through the dte_next fields of the member
* nodes. Saves just a few bytes per entry, but that adds up.
*
* deftrig_events_imm holds the tail pointer as of the last
* deferredTriggerInvokeEvents call; we can use this to avoid rescanning
* entries unnecessarily. It is NULL if deferredTriggerInvokeEvents
* hasn't run since the last state change.
*
* XXX Need to be able to shove this data out to a file if it grows too
* large...
* ----------
*/
typedef DeferredTriggersData *DeferredTriggers;
static DeferredTriggers deferredTriggers;
/* ----------
* deferredTriggerCheckState()
*
* Returns true if the trigger identified by tgoid is actually
* in state DEFERRED.
* ----------
*/
static bool
deferredTriggerCheckState(Oid tgoid, int32 itemstate)
{
MemoryContext oldcxt;
List *sl;
DeferredTriggerStatus trigstate;
/*
* Not deferrable triggers (i.e. normal AFTER ROW triggers and
* constraints declared NOT DEFERRABLE, the state is always false.
*/
if ((itemstate & TRIGGER_DEFERRED_DEFERRABLE) == 0)
return false;
/*
* Lookup if we know an individual state for this trigger
*/
foreach(sl, deferredTriggers->deftrig_trigstates)
{
trigstate = (DeferredTriggerStatus) lfirst(sl);
if (trigstate->dts_tgoid == tgoid)
return trigstate->dts_tgisdeferred;
}
/*
* No individual state known - so if the user issued a SET CONSTRAINT
* ALL ..., we return that instead of the triggers default state.
*/
if (deferredTriggers->deftrig_all_isset)
return deferredTriggers->deftrig_all_isdeferred;
/*
* No ALL state known either, remember the default state as the
* current and return that.
*/
oldcxt = MemoryContextSwitchTo(deferredTriggers->deftrig_cxt);
trigstate = (DeferredTriggerStatus)
palloc(sizeof(DeferredTriggerStatusData));
trigstate->dts_tgoid = tgoid;
trigstate->dts_tgisdeferred =
((itemstate & TRIGGER_DEFERRED_INITDEFERRED) != 0);
deferredTriggers->deftrig_trigstates =
lappend(deferredTriggers->deftrig_trigstates, trigstate);
MemoryContextSwitchTo(oldcxt);
return trigstate->dts_tgisdeferred;
}
/* ----------
* deferredTriggerAddEvent()
*
* Add a new trigger event to the queue.
* ----------
*/
static void
deferredTriggerAddEvent(DeferredTriggerEvent event)
{
/*
* Since the event list could grow quite long, we keep track of the
* list tail and append there, rather than just doing a stupid
* "lappend". This avoids O(N^2) behavior for large numbers of events.
*/
event->dte_next = NULL;
if (deferredTriggers->deftrig_event_tail == NULL)
{
/* first list entry */
deferredTriggers->deftrig_events = event;
deferredTriggers->deftrig_event_tail = event;
}
else
{
deferredTriggers->deftrig_event_tail->dte_next = event;
deferredTriggers->deftrig_event_tail = event;
}
}
/* ----------
* DeferredTriggerExecute()
*
* Fetch the required tuples back from the heap and fire one
* single trigger function.
*
* Frequently, this will be fired many times in a row for triggers of
* a single relation. Therefore, we cache the open relation and provide
* fmgr lookup cache space at the caller level.
*
* event: event currently being fired.
* itemno: item within event currently being fired.
* rel: open relation for event.
* trigdesc: working copy of rel's trigger info.
* finfo: array of fmgr lookup cache entries (one per trigger in trigdesc).
* per_tuple_context: memory context to call trigger function in.
* ----------
*/
static void
DeferredTriggerExecute(DeferredTriggerEvent event, int itemno,
Relation rel, TriggerDesc *trigdesc, FmgrInfo *finfo,
MemoryContext per_tuple_context)
{
Oid tgoid = event->dte_item[itemno].dti_tgoid;
TriggerData LocTriggerData;
HeapTupleData oldtuple;
HeapTupleData newtuple;
HeapTuple rettuple;
Buffer oldbuffer;
Buffer newbuffer;
int tgindx;
/*
* Fetch the required OLD and NEW tuples.
*/
if (ItemPointerIsValid(&(event->dte_oldctid)))
{
ItemPointerCopy(&(event->dte_oldctid), &(oldtuple.t_self));
if (!heap_fetch(rel, SnapshotAny, &oldtuple, &oldbuffer, false, NULL))
elog(ERROR, "failed to fetch old tuple for deferred trigger");
}
if (ItemPointerIsValid(&(event->dte_newctid)))
{
ItemPointerCopy(&(event->dte_newctid), &(newtuple.t_self));
if (!heap_fetch(rel, SnapshotAny, &newtuple, &newbuffer, false, NULL))
elog(ERROR, "failed to fetch new tuple for deferred trigger");
}
/*
* Setup the trigger information
*/
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = (event->dte_event & TRIGGER_EVENT_OPMASK) |
(event->dte_event & TRIGGER_EVENT_ROW);
LocTriggerData.tg_relation = rel;
LocTriggerData.tg_trigger = NULL;
for (tgindx = 0; tgindx < trigdesc->numtriggers; tgindx++)
{
if (trigdesc->triggers[tgindx].tgoid == tgoid)
{
LocTriggerData.tg_trigger = &(trigdesc->triggers[tgindx]);
break;
}
}
if (LocTriggerData.tg_trigger == NULL)
elog(ERROR, "could not find trigger %u", tgoid);
switch (event->dte_event & TRIGGER_EVENT_OPMASK)
{
case TRIGGER_EVENT_INSERT:
LocTriggerData.tg_trigtuple = &newtuple;
LocTriggerData.tg_newtuple = NULL;
break;
case TRIGGER_EVENT_UPDATE:
LocTriggerData.tg_trigtuple = &oldtuple;
LocTriggerData.tg_newtuple = &newtuple;
break;
case TRIGGER_EVENT_DELETE:
LocTriggerData.tg_trigtuple = &oldtuple;
LocTriggerData.tg_newtuple = NULL;
break;
}
/*
* Call the trigger and throw away any eventually returned updated
* tuple.
*/
rettuple = ExecCallTriggerFunc(&LocTriggerData,
finfo + tgindx,
per_tuple_context);
if (rettuple != NULL && rettuple != &oldtuple && rettuple != &newtuple)
heap_freetuple(rettuple);
/*
* Release buffers
*/
if (ItemPointerIsValid(&(event->dte_oldctid)))
ReleaseBuffer(oldbuffer);
if (ItemPointerIsValid(&(event->dte_newctid)))
ReleaseBuffer(newbuffer);
}
/* ----------
* deferredTriggerInvokeEvents()
*
* Scan the event queue for not yet invoked triggers. Check if they
* should be invoked now and do so.
* ----------
*/
static void
deferredTriggerInvokeEvents(bool immediate_only)
{
DeferredTriggerEvent event,
prev_event;
MemoryContext per_tuple_context;
Relation rel = NULL;
TriggerDesc *trigdesc = NULL;
FmgrInfo *finfo = NULL;
/*
* If immediate_only is true, we remove fully-processed events from
* the event queue to recycle space. If immediate_only is false, we
* are going to discard the whole event queue on return anyway, so no
* need to bother with "retail" pfree's.
*
* If immediate_only is true, we need only scan from where the end of the
* queue was at the previous deferredTriggerInvokeEvents call; any
* non-deferred events before that point are already fired. (But if
* the deferral state changes, we must reset the saved position to the
* beginning of the queue, so as to process all events once with the
* new states. See DeferredTriggerSetState.)
*/
/* Make a per-tuple memory context for trigger function calls */
per_tuple_context =
AllocSetContextCreate(CurrentMemoryContext,
"DeferredTriggerTupleContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* If immediate_only is true, then the only events that could need
* firing are those since deftrig_events_imm. (But if
* deftrig_events_imm is NULL, we must scan the entire list.)
*/
if (immediate_only && deferredTriggers->deftrig_events_imm != NULL)
{
prev_event = deferredTriggers->deftrig_events_imm;
event = prev_event->dte_next;
}
else
{
prev_event = NULL;
event = deferredTriggers->deftrig_events;
}
while (event != NULL)
{
bool still_deferred_ones = false;
DeferredTriggerEvent next_event;
int i;
/*
* Check if event is already completely done.
*/
if (!(event->dte_event & (TRIGGER_DEFERRED_DONE |
TRIGGER_DEFERRED_CANCELED)))
{
MemoryContextReset(per_tuple_context);
/*
* Check each trigger item in the event.
*/
for (i = 0; i < event->dte_n_items; i++)
{
if (event->dte_item[i].dti_state & TRIGGER_DEFERRED_DONE)
continue;
/*
* This trigger item hasn't been called yet. Check if we
* should call it now.
*/
if (immediate_only &&
deferredTriggerCheckState(event->dte_item[i].dti_tgoid,
event->dte_item[i].dti_state))
{
still_deferred_ones = true;
continue;
}
/*
* So let's fire it... but first, open the correct
* relation if this is not the same relation as before.
*/
if (rel == NULL || rel->rd_id != event->dte_relid)
{
if (rel)
heap_close(rel, NoLock);
FreeTriggerDesc(trigdesc);
if (finfo)
pfree(finfo);
/*
* We assume that an appropriate lock is still held by
* the executor, so grab no new lock here.
*/
rel = heap_open(event->dte_relid, NoLock);
/*
* Copy relation's trigger info so that we have a
* stable copy no matter what the called triggers do.
*/
trigdesc = CopyTriggerDesc(rel->trigdesc);
if (trigdesc == NULL) /* should not happen */
elog(ERROR, "relation %u has no triggers",
event->dte_relid);
/*
* Allocate space to cache fmgr lookup info for
* triggers.
*/
finfo = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
}
DeferredTriggerExecute(event, i, rel, trigdesc, finfo,
per_tuple_context);
event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE;
} /* end loop over items within event */
}
/*
* If it's now completely done, throw it away.
*
* NB: it's possible the trigger calls above added more events to the
* queue, or that calls we will do later will want to add more, so
* we have to be careful about maintaining list validity here.
*/
next_event = event->dte_next;
if (still_deferred_ones)
{
/* Not done, keep in list */
prev_event = event;
}
else
{
/* Done */
if (immediate_only)
{
/* delink it from list and free it */
if (prev_event)
prev_event->dte_next = next_event;
else
deferredTriggers->deftrig_events = next_event;
pfree(event);
}
else
{
/*
* We will clean up later, but just for paranoia's sake,
* mark the event done.
*/
event->dte_event |= TRIGGER_DEFERRED_DONE;
}
}
event = next_event;
}
/* Update list tail pointer in case we just deleted tail event */
deferredTriggers->deftrig_event_tail = prev_event;
/* Set the immediate event pointer for next time */
deferredTriggers->deftrig_events_imm = prev_event;
/* Release working resources */
if (rel)
heap_close(rel, NoLock);
FreeTriggerDesc(trigdesc);
if (finfo)
pfree(finfo);
MemoryContextDelete(per_tuple_context);
}
/* ----------
* DeferredTriggerInit()
*
* Initialize the deferred trigger mechanism. This is called during
* backend startup and is guaranteed to be before the first of all
* transactions.
* ----------
*/
void
DeferredTriggerInit(void)
{
/* Nothing to do */
;
}
/* ----------
* DeferredTriggerBeginXact()
*
* Called at transaction start (either BEGIN or implicit for single
* statement outside of transaction block).
* ----------
*/
void
DeferredTriggerBeginXact(void)
{
/*
* This will be changed to a special context when the nested
* transactions project moves forward.
*/
MemoryContext cxt = TopTransactionContext;
deferredTriggers = (DeferredTriggers) MemoryContextAlloc(TopTransactionContext,
sizeof(DeferredTriggersData));
/*
* Create the per transaction memory context
*/
deferredTriggers->deftrig_cxt = AllocSetContextCreate(cxt,
"DeferredTriggerXact",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* If unspecified, constraints default to IMMEDIATE, per SQL
*/
deferredTriggers->deftrig_all_isdeferred = false;
deferredTriggers->deftrig_all_isset = false;
deferredTriggers->deftrig_trigstates = NIL;
deferredTriggers->deftrig_events = NULL;
deferredTriggers->deftrig_events_imm = NULL;
deferredTriggers->deftrig_event_tail = NULL;
}
/* ----------
* DeferredTriggerEndQuery()
*
* Called after one query sent down by the user has completely been
* processed. At this time we invoke all outstanding IMMEDIATE triggers.
* ----------
*/
void
DeferredTriggerEndQuery(void)
{
/*
* Ignore call if we aren't in a transaction.
*/
if (deferredTriggers == NULL)
return;
deferredTriggerInvokeEvents(true);
}
/* ----------
* DeferredTriggerEndXact()
*
* Called just before the current transaction is committed. At this
* time we invoke all DEFERRED triggers and tidy up.
* ----------
*/
void
DeferredTriggerEndXact(void)
{
/*
* Ignore call if we aren't in a transaction.
*/
if (deferredTriggers == NULL)
return;
deferredTriggerInvokeEvents(false);
deferredTriggers = NULL;
}
/* ----------
* DeferredTriggerAbortXact()
*
* The current transaction has entered the abort state.
* All outstanding triggers are canceled so we simply throw
* away anything we know.
* ----------
*/
void
DeferredTriggerAbortXact(void)
{
/*
* Ignore call if we aren't in a transaction.
*/
if (deferredTriggers == NULL)
return;
/*
* Forget everything we know about deferred triggers.
*/
deferredTriggers = NULL;
}
/* ----------
* DeferredTriggerSetState()
*
* Called for the SET CONSTRAINTS ... utility command.
* ----------
*/
void
DeferredTriggerSetState(ConstraintsSetStmt *stmt)
{
List *l;
/*
* Ignore call if we aren't in a transaction.
*/
if (deferredTriggers == NULL)
return;
/*
* Handle SET CONSTRAINTS ALL ...
*/
if (stmt->constraints == NIL)
{
/*
* Drop all per-transaction information about individual trigger
* states.
*/
l = deferredTriggers->deftrig_trigstates;
while (l != NIL)
{
List *next = lnext(l);
pfree(lfirst(l));
pfree(l);
l = next;
}
deferredTriggers->deftrig_trigstates = NIL;
/*
* Set the per-transaction ALL state to known.
*/
deferredTriggers->deftrig_all_isset = true;
deferredTriggers->deftrig_all_isdeferred = stmt->deferred;
}
else
{
Relation tgrel;
MemoryContext oldcxt;
bool found;
DeferredTriggerStatus state;
List *ls;
List *loid = NIL;
/* ----------
* Handle SET CONSTRAINTS constraint-name [, ...]
* First lookup all trigger Oid's for the constraint names.
* ----------
*/
tgrel = heap_openr(TriggerRelationName, AccessShareLock);
foreach(l, stmt->constraints)
{
char *cname = strVal(lfirst(l));
ScanKeyData skey;
SysScanDesc tgscan;
HeapTuple htup;
/*
* Check that only named constraints are set explicitly
*/
if (strlen(cname) == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("unnamed constraints cannot be set explicitly")));
/*
* Setup to scan pg_trigger by tgconstrname ...
*/
ScanKeyInit(&skey,
Anum_pg_trigger_tgconstrname,
BTEqualStrategyNumber, F_NAMEEQ,
PointerGetDatum(cname));
tgscan = systable_beginscan(tgrel, TriggerConstrNameIndex, true,
SnapshotNow, 1, &skey);
/*
* ... and search for the constraint trigger row
*/
found = false;
while (HeapTupleIsValid(htup = systable_getnext(tgscan)))
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
Oid constr_oid;
/*
* If we found some, check that they fit the deferrability
* but skip ON <event> RESTRICT ones, since they are
* silently never deferrable.
*/
if (stmt->deferred && !pg_trigger->tgdeferrable &&
pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_UPD &&
pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_DEL)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" is not deferrable",
cname)));
constr_oid = HeapTupleGetOid(htup);
loid = lappendo(loid, constr_oid);
found = true;
}
systable_endscan(tgscan);
/*
* Not found ?
*/
if (!found)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" does not exist", cname)));
}
heap_close(tgrel, AccessShareLock);
/*
* Inside of a transaction block set the trigger states of
* individual triggers on transaction level.
*/
oldcxt = MemoryContextSwitchTo(deferredTriggers->deftrig_cxt);
foreach(l, loid)
{
found = false;
foreach(ls, deferredTriggers->deftrig_trigstates)
{
state = (DeferredTriggerStatus) lfirst(ls);
if (state->dts_tgoid == lfirsto(l))
{
state->dts_tgisdeferred = stmt->deferred;
found = true;
break;
}
}
if (!found)
{
state = (DeferredTriggerStatus)
palloc(sizeof(DeferredTriggerStatusData));
state->dts_tgoid = lfirsto(l);
state->dts_tgisdeferred = stmt->deferred;
deferredTriggers->deftrig_trigstates =
lappend(deferredTriggers->deftrig_trigstates, state);
}
}
MemoryContextSwitchTo(oldcxt);
}
/*
* SQL99 requires that when a constraint is set to IMMEDIATE, any
* deferred checks against that constraint must be made when the SET
* CONSTRAINTS command is executed -- i.e. the effects of the SET
* CONSTRAINTS command applies retroactively. This happens "for free"
* since we have already made the necessary modifications to the
* constraints, and deferredTriggerEndQuery() is called by
* finish_xact_command(). But we must reset
* deferredTriggerInvokeEvents' tail pointer to make it rescan the
* entire list, in case some deferred events are now immediately
* invokable.
*/
deferredTriggers->deftrig_events_imm = NULL;
}
/* ----------
* DeferredTriggerSaveEvent()
*
* Called by ExecAR...Triggers() to add the event to the queue.
*
* NOTE: should be called only if we've determined that an event must
* be added to the queue.
* ----------
*/
static void
DeferredTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger,
HeapTuple oldtup, HeapTuple newtup)
{
Relation rel = relinfo->ri_RelationDesc;
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
MemoryContext oldcxt;
DeferredTriggerEvent new_event;
int new_size;
int i;
int ntriggers;
int n_enabled_triggers = 0;
int *tgindx;
ItemPointerData oldctid;
ItemPointerData newctid;
if (deferredTriggers == NULL)
elog(ERROR, "DeferredTriggerSaveEvent() called outside of transaction");
/*
* Get the CTID's of OLD and NEW
*/
if (oldtup != NULL)
ItemPointerCopy(&(oldtup->t_self), &(oldctid));
else
ItemPointerSetInvalid(&(oldctid));
if (newtup != NULL)
ItemPointerCopy(&(newtup->t_self), &(newctid));
else
ItemPointerSetInvalid(&(newctid));
if (row_trigger)
{
ntriggers = trigdesc->n_after_row[event];
tgindx = trigdesc->tg_after_row[event];
}
else
{
ntriggers = trigdesc->n_after_statement[event];
tgindx = trigdesc->tg_after_statement[event];
}
/*
* Count the number of triggers that are actually enabled. Since we
* only add enabled triggers to the queue, we only need allocate
* enough space to hold them (and not any disabled triggers that may
* be associated with the relation).
*/
for (i = 0; i < ntriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (trigger->tgenabled)
n_enabled_triggers++;
}
/*
* If all the triggers on this relation are disabled, we're done.
*/
if (n_enabled_triggers == 0)
return;
/*
* Create a new event
*/
oldcxt = MemoryContextSwitchTo(deferredTriggers->deftrig_cxt);
new_size = offsetof(DeferredTriggerEventData, dte_item[0]) +
n_enabled_triggers * sizeof(DeferredTriggerEventItem);
new_event = (DeferredTriggerEvent) palloc(new_size);
new_event->dte_next = NULL;
new_event->dte_event = event & TRIGGER_EVENT_OPMASK;
if (row_trigger)
new_event->dte_event |= TRIGGER_EVENT_ROW;
new_event->dte_relid = rel->rd_id;
ItemPointerCopy(&oldctid, &(new_event->dte_oldctid));
ItemPointerCopy(&newctid, &(new_event->dte_newctid));
new_event->dte_n_items = ntriggers;
for (i = 0; i < ntriggers; i++)
{
DeferredTriggerEventItem *ev_item;
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!trigger->tgenabled)
continue;
ev_item = &(new_event->dte_item[i]);
ev_item->dti_tgoid = trigger->tgoid;
ev_item->dti_state =
((trigger->tgdeferrable) ?
TRIGGER_DEFERRED_DEFERRABLE : 0) |
((trigger->tginitdeferred) ?
TRIGGER_DEFERRED_INITDEFERRED : 0);
if (row_trigger && (trigdesc->n_before_row[event] > 0))
ev_item->dti_state |= TRIGGER_DEFERRED_HAS_BEFORE;
else if (!row_trigger && (trigdesc->n_before_statement[event] > 0))
ev_item->dti_state |= TRIGGER_DEFERRED_HAS_BEFORE;
}
MemoryContextSwitchTo(oldcxt);
switch (event & TRIGGER_EVENT_OPMASK)
{
case TRIGGER_EVENT_INSERT:
/* nothing to do */
break;
case TRIGGER_EVENT_UPDATE:
/*
* Check if one of the referenced keys is changed.
*/
for (i = 0; i < ntriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
bool is_ri_trigger;
bool key_unchanged;
TriggerData LocTriggerData;
/*
* We are interested in RI_FKEY triggers only.
*/
switch (trigger->tgfoid)
{
case F_RI_FKEY_NOACTION_UPD:
case F_RI_FKEY_CASCADE_UPD:
case F_RI_FKEY_RESTRICT_UPD:
case F_RI_FKEY_SETNULL_UPD:
case F_RI_FKEY_SETDEFAULT_UPD:
is_ri_trigger = true;
break;
default:
is_ri_trigger = false;
break;
}
if (!is_ri_trigger)
continue;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE;
LocTriggerData.tg_relation = rel;
LocTriggerData.tg_trigtuple = oldtup;
LocTriggerData.tg_newtuple = newtup;
LocTriggerData.tg_trigger = trigger;
key_unchanged = RI_FKey_keyequal_upd(&LocTriggerData);
if (key_unchanged)
{
/*
* The key hasn't changed, so no need later to invoke
* the trigger at all.
*/
new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE;
}
}
break;
case TRIGGER_EVENT_DELETE:
/* nothing to do */
break;
}
/*
* Add the new event to the queue.
*/
deferredTriggerAddEvent(new_event);
}
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