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apache / hawq / c4da083e0d1c3a4630531307db264d24994d3d65 / . / src / backend / commands / trigger.c
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/*-------------------------------------------------------------------------
*
* trigger.c
* PostgreSQL TRIGGERs support code.
*
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.210.2.4 2007/08/15 19:15:55 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/catquery.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/instrument.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/memutils.h"
#include "utils/syscache.h"
#include "cdb/cdbvars.h"
#include "cdb/cdbdisp.h"
#include "cdb/dispatcher.h"
static void InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx);
static HeapTuple GetTupleForTrigger(EState *estate,
ResultRelInfo *relinfo,
ItemPointer tid,
CommandId cid,
TupleTableSlot **newSlot);
static void AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event,
bool row_trigger, HeapTuple oldtup, HeapTuple newtup);
/*
* Create a trigger. Returns the OID of the created trigger.
*
* relOid, if nonzero, is the relation on which the trigger should be
* created. If zero, the name provided in the statement will be looked up.
*
* refRelOid, if nonzero, is the relation to which the constraint trigger
* refers. If zero, the constraint relation name provided in the statement
* will be looked up as needed.
*
* 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, Oid relOid, Oid refRelOid,
bool forConstraint)
{
int16 tgtype;
int2vector *tgattr;
Datum values[Natts_pg_trigger];
bool nulls[Natts_pg_trigger];
Relation rel;
AclResult aclresult;
Relation tgrel;
cqContext *pcqCtx;
cqContext cqc;
cqContext *pcqCtx2;
cqContext cqc2;
Relation pgrel;
HeapTuple tuple;
Oid fargtypes[1]; /* dummy */
Oid funcoid;
Oid funcrettype;
Oid trigoid;
int found = 0;
int i;
char constrtrigname[NAMEDATALEN];
char *trigname;
char *constrname;
Oid constrrelid = InvalidOid;
ObjectAddress myself,
referenced;
if (OidIsValid(relOid))
{
rel = heap_open(relOid, AccessExclusiveLock);
}
else
{
rel = heap_openrv(stmt->relation, AccessExclusiveLock);
}
if (OidIsValid(refRelOid))
{
constrrelid = refRelOid;
}
else if (stmt->constrrel != NULL)
{
constrrelid = RangeVarGetRelid(stmt->constrrel, false, false /*allowHcatalog*/);
}
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(lfirst(list_tail((stmt->funcname)))), "RI_FKey_check_", 14) == 0)
{
/* A trigger on FK table. */
needconstrrelid = true;
if (list_length(stmt->args) > RI_PK_RELNAME_ARGNO)
elem = list_nth(stmt->args, RI_PK_RELNAME_ARGNO);
}
else if (strncmp(strVal(lfirst(list_tail((stmt->funcname)))), "RI_FKey_", 8) == 0)
{
/* A trigger on PK table. */
needconstrrelid = true;
if (list_length(stmt->args) > RI_FK_RELNAME_ARGNO)
elem = list_nth(stmt->args, RI_FK_RELNAME_ARGNO);
}
if (elem != NULL)
{
RangeVar *rel = makeRangeVar(NULL /*catalogname*/, NULL, strVal(elem), -1);
constrrelid = RangeVarGetRelid(rel, true, false /*allowHcatalog*/);
}
if (needconstrrelid && constrrelid == InvalidOid)
if (Gp_role != GP_ROLE_EXECUTE)
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 (!allowSystemTableModsDDL && 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.
*/
tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), tgrel),
cql("INSERT INTO pg_trigger ",
NULL));
if (OidIsValid(stmt->trigOid))
trigoid = stmt->trigOid;
else
trigoid = GetNewOid(tgrel);
/*
* 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.
*/
pcqCtx2 = caql_beginscan(
caql_addrel(cqclr(&cqc2), tgrel),
cql("SELECT * FROM pg_trigger "
" WHERE tgrelid = :1 ",
ObjectIdGetDatum(RelationGetRelid(rel))));
while (HeapTupleIsValid(tuple = caql_getnext(pcqCtx2)))
{
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, RelationGetRelationName(rel))));
found++;
}
caql_endscan(pcqCtx2);
/*
* Find and validate the trigger function.
*/
funcoid = LookupFuncName(stmt->funcname, 0, fargtypes, false);
aclresult = pg_proc_aclcheck(funcoid, GetUserId(), ACL_EXECUTE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_PROC,
NameListToString(stmt->funcname));
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)
{
if (Gp_role != GP_ROLE_EXECUTE)
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, false, Natts_pg_trigger * sizeof(bool));
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);
/*
* Special for Greenplum Database: Ignore foreign keys for now
*/
if ((stmt->isconstraint) && (Gp_role == GP_ROLE_DISPATCH || Gp_role == GP_ROLE_EXECUTE))
{
/*
* Create the tigger as disabled
*/
values[Anum_pg_trigger_tgenabled - 1] = BoolGetDatum(false);
}
else
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)
{
ListCell *le;
char *args;
int16 nargs = list_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(""));
}
/* tgattr is currently always a zero-length array */
tgattr = buildint2vector(NULL, 0);
values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr);
tuple = caql_form_tuple(pcqCtx, values, nulls);
/* force tuple to have the desired OID */
HeapTupleSetOid(tuple, trigoid);
/*
* Insert tuple into pg_trigger.
*/
caql_insert(pcqCtx, tuple); /* implicit update of index as well */
myself.classId = TriggerRelationId;
myself.objectId = trigoid;
myself.objectSubId = 0;
heap_freetuple(tuple);
caql_endscan(pcqCtx);
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_open(RelationRelationId, RowExclusiveLock);
pcqCtx = caql_addrel(cqclr(&cqc), pgrel);
tuple = caql_getfirst(
pcqCtx,
cql("SELECT * FROM pg_class "
" WHERE oid = :1 "
" FOR UPDATE ",
ObjectIdGetDatum(RelationGetRelid(rel))));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u",
RelationGetRelid(rel));
((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found + 1;
caql_update_current(pcqCtx, tuple);
/* and Update indexes (implicit) */
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 = ProcedureRelationId;
referenced.objectId = funcoid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
if (!forConstraint)
{
referenced.classId = RelationRelationId;
referenced.objectId = RelationGetRelid(rel);
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
if (constrrelid != InvalidOid)
{
referenced.classId = RelationRelationId;
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,
bool missing_ok)
{
int fetchCount;
ObjectAddress object;
/*
* Find the trigger, verify permissions, set up object address
*/
object.classId = TriggerRelationId;
object.objectSubId = 0;
object.objectId = caql_getoid_plus(
NULL,
&fetchCount,
NULL,
cql("SELECT oid FROM pg_trigger "
" WHERE tgrelid = :1 "
" AND tgname = :2 ",
ObjectIdGetDatum(relid),
CStringGetDatum((char *) trigname)));
if (0 == fetchCount)
{
if (!missing_ok)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("trigger \"%s\" for table \"%s\" does not exist",
trigname, get_rel_name(relid))));
else
ereport(NOTICE,
(errmsg("trigger \"%s\" for table \"%s\" does not exist, skipping",
trigname, get_rel_name(relid))));
/* cleanup */
return;
}
if (!pg_class_ownercheck(relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
get_rel_name(relid));
/*
* Do the deletion
*/
performDeletion(&object, behavior);
}
/*
* Guts of trigger deletion.
*/
void
RemoveTriggerById(Oid trigOid)
{
Relation tgrel;
cqContext cqc;
cqContext *pcqCtx;
HeapTuple tup;
Oid relid;
Relation rel;
Relation pgrel;
HeapTuple tuple;
Form_pg_class classForm;
tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
pcqCtx = caql_addrel(cqclr(&cqc), tgrel);
/*
* Find the trigger to delete.
*/
tup = caql_getfirst(
pcqCtx,
cql("SELECT * FROM pg_trigger "
" WHERE oid = :1 "
" FOR UPDATE ",
ObjectIdGetDatum(trigOid)));
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 (!allowSystemTableModsDDL && IsSystemRelation(rel))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(rel))));
/*
* Delete the pg_trigger tuple.
*/
caql_delete_current(pcqCtx);
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_open(RelationRelationId, RowExclusiveLock);
pcqCtx = caql_addrel(cqclr(&cqc), pgrel);
tuple = caql_getfirst(
pcqCtx,
cql("SELECT * FROM pg_class "
" WHERE oid = :1 "
" FOR UPDATE ",
ObjectIdGetDatum(relid)));
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--;
caql_update_current(pcqCtx, tuple);
/* and Update indexes (implicit) */
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;
cqContext cqc;
cqContext *pcqCtx;
/*
* 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_open(TriggerRelationId, RowExclusiveLock);
/*
* First pass -- look for name conflict
*/
if (caql_getcount(
caql_addrel(cqclr(&cqc), tgrel),
cql("SELECT count(*) FROM pg_trigger "
" WHERE tgrelid = :1 "
" AND tgname = :2 ",
ObjectIdGetDatum(relid),
PointerGetDatum((char *) newname))))
{
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("trigger \"%s\" for relation \"%s\" already exists",
newname, RelationGetRelationName(targetrel))));
}
/*
* Second pass -- look for trigger existing with oldname and update
*/
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), tgrel),
cql("SELECT * FROM pg_trigger "
" WHERE tgrelid = :1 "
" AND tgname = :2 "
" FOR UPDATE ",
ObjectIdGetDatum(relid),
PointerGetDatum((char *) oldname)));
if (HeapTupleIsValid(tuple = caql_getnext(pcqCtx)))
{
/*
* Update pg_trigger tuple with new tgname.
*/
tuple = heap_copytuple(tuple); /* need a modifiable copy */
namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname, newname);
caql_update_current(pcqCtx, 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))));
}
caql_endscan(pcqCtx);
heap_close(tgrel, RowExclusiveLock);
/*
* Close rel, but keep exclusive lock!
*/
heap_close(targetrel, NoLock);
}
/*
* EnableDisableTrigger()
*
* Called by ALTER TABLE ENABLE/DISABLE TRIGGER
* to change 'tgenabled' flag for the specified trigger(s)
*
* rel: relation to process (caller must hold suitable lock on it)
* tgname: trigger to process, or NULL to scan all triggers
* enable: new value for tgenabled flag
* skip_system: if true, skip "system" triggers (constraint triggers)
*
* Caller should have checked permissions for the table; here we also
* enforce that superuser privilege is required to alter the state of
* system triggers
*/
void
EnableDisableTrigger(Relation rel, const char *tgname,
bool enable, bool skip_system)
{
Relation tgrel;
cqContext cqc;
cqContext *pcqCtx;
HeapTuple tuple;
bool found;
bool changed;
/* Scan the relevant entries in pg_triggers */
tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
if (tgname)
{
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), tgrel),
cql("SELECT * FROM pg_trigger "
" WHERE tgrelid = :1 "
" AND tgname = :2 "
" FOR UPDATE ",
ObjectIdGetDatum(RelationGetRelid(rel)),
CStringGetDatum((char *) tgname)));
}
else
{
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), tgrel),
cql("SELECT * FROM pg_trigger "
" WHERE tgrelid = :1 "
" FOR UPDATE ",
ObjectIdGetDatum(RelationGetRelid(rel))));
}
found = changed = false;
while (HeapTupleIsValid(tuple = caql_getnext(pcqCtx)))
{
Form_pg_trigger oldtrig = (Form_pg_trigger) GETSTRUCT(tuple);
if (oldtrig->tgisconstraint)
{
/* system trigger ... ok to process? */
if (skip_system)
continue;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system trigger",
NameStr(oldtrig->tgname))));
}
found = true;
if (oldtrig->tgenabled != enable)
{
/* need to change this one ... make a copy to scribble on */
HeapTuple newtup = heap_copytuple(tuple);
Form_pg_trigger newtrig = (Form_pg_trigger) GETSTRUCT(newtup);
newtrig->tgenabled = enable;
caql_update_current(pcqCtx, newtup);
/* and Update indexes (implicit) */
heap_freetuple(newtup);
changed = true;
}
}
caql_endscan(pcqCtx);
heap_close(tgrel, RowExclusiveLock);
if (tgname && !found)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("trigger \"%s\" for table \"%s\" does not exist",
tgname, RelationGetRelationName(rel))));
/*
* If we changed anything, broadcast a SI inval message to force each
* backend (including our own!) to rebuild relation's relcache entry.
* Otherwise they will fail to apply the change promptly.
*/
if (changed)
CacheInvalidateRelcache(rel);
}
/*
* 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;
cqContext cqc;
cqContext *pcqCtx;
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 TriggerRelidNameIndexId, we will
* be reading the triggers in name order, except possibly during
* emergency-recovery operations (ie, IgnoreSystemIndexes). This in turn
* ensures that triggers will be fired in name order.
*/
/* XXX XXX: ORDER BY */
tgrel = heap_open(TriggerRelationId, AccessShareLock);
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), tgrel),
cql("SELECT * FROM pg_trigger "
" WHERE tgrelid = :1 "
" ORDER BY tgrelid, tgname",
ObjectIdGetDatum(RelationGetRelid(relation))));
while (HeapTupleIsValid(htup = caql_getnext(pcqCtx)))
{
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;
/* tgattr is first var-width field, so OK to access directly */
build->tgnattr = pg_trigger->tgattr.dim1;
if (build->tgnattr > 0)
{
build->tgattr = (int2 *) palloc(build->tgnattr * sizeof(int2));
memcpy(build->tgattr, &(pg_trigger->tgattr.values),
build->tgnattr * sizeof(int2));
}
else
build->tgattr = NULL;
if (build->tgnargs > 0)
{
bytea *val;
bool isnull;
char *p;
int i;
val = DatumGetByteaP(fastgetattr(htup,
Anum_pg_trigger_tgargs,
RelationGetDescr(tgrel), &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++;
}
caql_endscan(pcqCtx);
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->tgnattr > 0)
{
int2 *newattr;
newattr = (int2 *) palloc(trigger->tgnattr * sizeof(int2));
memcpy(newattr, trigger->tgattr,
trigger->tgnattr * sizeof(int2));
trigger->tgattr = newattr;
}
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->tgnattr > 0)
pfree(trigger->tgattr);
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 (trig1->tgnattr != trig2->tgnattr)
return false;
if (trig1->tgnattr > 0 &&
memcmp(trig1->tgattr, trig2->tgattr,
trig1->tgnattr * sizeof(int2)) != 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.
* tgindx: trigger's index in finfo and instr arrays.
* finfo: array of cached trigger function call information.
* instr: optional array of EXPLAIN ANALYZE instrumentation state.
* per_tuple_context: memory context to execute the function in.
*
* Returns the tuple (or NULL) as returned by the function.
*/
HeapTuple
ExecCallTriggerFunc(TriggerData *trigdata,
int tgindx,
FmgrInfo *finfo,
Instrumentation *instr,
MemoryContext per_tuple_context)
{
FunctionCallInfoData fcinfo;
Datum result;
MemoryContext oldContext;
finfo += tgindx;
/*
* 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);
/*
* If doing EXPLAIN ANALYZE, start charging time to this trigger.
*/
if (instr)
InstrStartNode(instr + tgindx);
/*
* 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.
*/
InitFunctionCallInfoData(fcinfo, finfo, 0, (Node *) trigdata, NULL);
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)));
/*
* If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count
* one "tuple returned" (really the number of firings).
*/
if (instr)
InstrStopNode(instr + tgindx, 1);
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;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
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,
tgindx[i],
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
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)
AfterTriggerSaveEvent(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;
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;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = oldtuple = newtuple;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
tgindx[i],
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
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)
{
if(RelationIsParquet(relinfo->ri_RelationDesc))
elog(ERROR, "Trigger is not supported on Parquet yet");
AfterTriggerSaveEvent(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;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
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,
tgindx[i],
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
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)
AfterTriggerSaveEvent(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];
bool result = true;
TriggerData LocTriggerData;
HeapTuple trigtuple;
HeapTuple newtuple;
TupleTableSlot *newSlot;
int i;
trigtuple = GetTupleForTrigger(estate, relinfo, tupleid, cid, &newSlot);
if (trigtuple == NULL)
return false;
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;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = trigtuple;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
tgindx[i],
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (newtuple == NULL)
{
result = false; /* tell caller to suppress delete */
break;
}
if (newtuple != trigtuple)
heap_freetuple(newtuple);
}
heap_freetuple(trigtuple);
return result;
}
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);
AfterTriggerSaveEvent(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;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
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,
tgindx[i],
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
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)
AfterTriggerSaveEvent(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);
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_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
tgindx[i],
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
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);
AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE,
true, trigtuple, newtuple);
heap_freetuple(trigtuple);
}
}
static HeapTuple
GetTupleForTrigger(EState *estate, ResultRelInfo *relinfo,
ItemPointer tid, CommandId cid,
TupleTableSlot **newSlot)
{
MIRROREDLOCK_BUFMGR_DECLARE;
Relation relation = relinfo->ri_RelationDesc;
HeapTupleData tuple;
HeapTuple result;
Buffer buffer;
if (newSlot != NULL)
{
HTSU_Result test;
ItemPointerData update_ctid;
TransactionId update_xmax;
*newSlot = NULL;
/*
* lock tuple for update
*/
ltrmark:;
tuple.t_self = *tid;
test = heap_lock_tuple(relation, &tuple, &buffer,
&update_ctid, &update_xmax, cid,
LockTupleExclusive, LockTupleWait);
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(&update_ctid, &tuple.t_self))
{
/* it was updated, so look at the updated version */
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
relinfo->ri_RangeTableIndex,
&update_ctid,
update_xmax,
cid);
if (!TupIsNull(epqslot))
{
*tid = update_ctid;
*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_lock_tuple status: %u", test);
return NULL; /* keep compiler quiet */
}
}
else
{
PageHeader dp;
ItemId lp;
// -------- MirroredLock ----------
MIRROREDLOCK_BUFMGR_LOCK;
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
MIRROREDLOCK_BUFMGR_UNLOCK;
// -------- MirroredLock ----------
dp = (PageHeader) BufferGetPage(buffer);
lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
Assert(ItemIdIsUsed(lp));
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;
}
/* ----------
* After-trigger stuff
*
* The AfterTriggersData struct holds data about pending AFTER trigger events
* during the current transaction tree. (BEFORE triggers are fired
* immediately so we don't need any persistent state about them.) The struct
* and most of its subsidiary data are kept in TopTransactionContext; however
* the individual event records are kept in separate contexts, to make them
* easy to delete during subtransaction abort.
*
* Because the list of pending events can grow large, we go to some effort
* to minimize memory consumption. We do not use the generic List mechanism
* but thread the events manually.
*
* XXX We need to be able to save the per-event data in a file if it grows too
* large.
* ----------
*/
/* Per-trigger SET CONSTRAINT status */
typedef struct SetConstraintTriggerData
{
Oid sct_tgoid;
bool sct_tgisdeferred;
} SetConstraintTriggerData;
typedef struct SetConstraintTriggerData *SetConstraintTrigger;
/*
* SET CONSTRAINT intra-transaction status.
*
* We make this a single palloc'd object so it can be copied and freed easily.
*
* all_isset and all_isdeferred are used to keep track
* of SET CONSTRAINTS ALL {DEFERRED, IMMEDIATE}.
*
* trigstates[] stores per-trigger tgisdeferred settings.
*/
typedef struct SetConstraintStateData
{
bool all_isset;
bool all_isdeferred;
int numstates; /* number of trigstates[] entries in use */
int numalloc; /* allocated size of trigstates[] */
SetConstraintTriggerData trigstates[1]; /* VARIABLE LENGTH ARRAY */
} SetConstraintStateData;
typedef SetConstraintStateData *SetConstraintState;
/*
* Per-trigger-event data
*
* Note: ate_firing_id is meaningful when either AFTER_TRIGGER_DONE
* or AFTER_TRIGGER_IN_PROGRESS is set. It indicates which trigger firing
* cycle the trigger was or will be fired in.
*/
typedef struct AfterTriggerEventData *AfterTriggerEvent;
typedef struct AfterTriggerEventData
{
AfterTriggerEvent ate_next; /* list link */
TriggerEvent ate_event; /* event type and status bits */
CommandId ate_firing_id; /* ID for firing cycle */
Oid ate_tgoid; /* the trigger's ID */
Oid ate_relid; /* the relation it's on */
ItemPointerData ate_oldctid; /* specific tuple(s) involved */
ItemPointerData ate_newctid;
} AfterTriggerEventData;
/* A list of events */
typedef struct AfterTriggerEventList
{
AfterTriggerEvent head;
AfterTriggerEvent tail;
} AfterTriggerEventList;
/*
* All per-transaction data for the AFTER TRIGGERS module.
*
* AfterTriggersData has the following fields:
*
* firing_counter is incremented for each call of afterTriggerInvokeEvents.
* We mark firable events with the current firing cycle's ID so that we can
* tell which ones to work on. This ensures sane behavior if a trigger
* function chooses to do SET CONSTRAINTS: the inner SET CONSTRAINTS will
* only fire those events that weren't already scheduled for firing.
*
* state keeps track of the transaction-local effects of SET CONSTRAINTS.
* This is saved and restored across failed subtransactions.
*
* events is the current list of deferred events. This is global across
* all subtransactions of the current transaction. In a subtransaction
* abort, we know that the events added by the subtransaction are at the
* end of the list, so it is relatively easy to discard them. The event
* structs themselves are stored in event_cxt if generated by the top-level
* transaction, else in per-subtransaction contexts identified by the
* entries in cxt_stack.
*
* query_depth is the current depth of nested AfterTriggerBeginQuery calls
* (-1 when the stack is empty).
*
* query_stack[query_depth] is a list of AFTER trigger events queued by the
* current query (and the query_stack entries below it are lists of trigger
* events queued by calling queries). None of these are valid until the
* matching AfterTriggerEndQuery call occurs. At that point we fire
* immediate-mode triggers, and append any deferred events to the main events
* list.
*
* maxquerydepth is just the allocated length of query_stack.
*
* state_stack is a stack of pointers to saved copies of the SET CONSTRAINTS
* state data; each subtransaction level that modifies that state first
* saves a copy, which we use to restore the state if we abort.
*
* events_stack is a stack of copies of the events head/tail pointers,
* which we use to restore those values during subtransaction abort.
*
* depth_stack is a stack of copies of subtransaction-start-time query_depth,
* which we similarly use to clean up at subtransaction abort.
*
* firing_stack is a stack of copies of subtransaction-start-time
* firing_counter. We use this to recognize which deferred triggers were
* fired (or marked for firing) within an aborted subtransaction.
*
* We use GetCurrentTransactionNestLevel() to determine the correct array
* index in these stacks. maxtransdepth is the number of allocated entries in
* each stack. (By not keeping our own stack pointer, we can avoid trouble
* in cases where errors during subxact abort cause multiple invocations
* of AfterTriggerEndSubXact() at the same nesting depth.)
*/
typedef struct AfterTriggersData
{
CommandId firing_counter; /* next firing ID to assign */
SetConstraintState state; /* the active S C state */
AfterTriggerEventList events; /* deferred-event list */
int query_depth; /* current query list index */
AfterTriggerEventList *query_stack; /* events pending from each query */
int maxquerydepth; /* allocated len of above array */
MemoryContext event_cxt; /* top transaction's event context, if any */
MemoryContext *cxt_stack; /* per-subtransaction event contexts */
/* these fields are just for resetting at subtrans abort: */
SetConstraintState *state_stack; /* stacked S C states */
AfterTriggerEventList *events_stack; /* stacked list pointers */
int *depth_stack; /* stacked query_depths */
CommandId *firing_stack; /* stacked firing_counters */
int maxtransdepth; /* allocated len of above arrays */
} AfterTriggersData;
typedef AfterTriggersData *AfterTriggers;
static AfterTriggers afterTriggers;
static void AfterTriggerExecute(AfterTriggerEvent event,
Relation rel, TriggerDesc *trigdesc,
FmgrInfo *finfo,
Instrumentation *instr,
MemoryContext per_tuple_context);
static SetConstraintState SetConstraintStateCreate(int numalloc);
static SetConstraintState SetConstraintStateCopy(SetConstraintState state);
static SetConstraintState SetConstraintStateAddItem(SetConstraintState state,
Oid tgoid, bool tgisdeferred);
/* ----------
* afterTriggerCheckState()
*
* Returns true if the trigger identified by tgoid is actually
* in state DEFERRED.
* ----------
*/
static bool
afterTriggerCheckState(Oid tgoid, TriggerEvent eventstate)
{
SetConstraintState state = afterTriggers->state;
int i;
/*
* For not-deferrable triggers (i.e. normal AFTER ROW triggers and
* constraints declared NOT DEFERRABLE), the state is always false.
*/
if ((eventstate & AFTER_TRIGGER_DEFERRABLE) == 0)
return false;
/*
* Check if SET CONSTRAINTS has been executed for this specific trigger.
*/
for (i = 0; i < state->numstates; i++)
{
if (state->trigstates[i].sct_tgoid == tgoid)
return state->trigstates[i].sct_tgisdeferred;
}
/*
* Check if SET CONSTRAINTS ALL has been executed; if so use that.
*/
if (state->all_isset)
return state->all_isdeferred;
/*
* Otherwise return the default state for the trigger.
*/
return ((eventstate & AFTER_TRIGGER_INITDEFERRED) != 0);
}
/* ----------
* afterTriggerAddEvent()
*
* Add a new trigger event to the current query's queue.
* ----------
*/
static void
afterTriggerAddEvent(AfterTriggerEvent event)
{
AfterTriggerEventList *events;
Assert(event->ate_next == NULL);
/* Must be inside a query */
Assert(afterTriggers->query_depth >= 0);
events = &afterTriggers->query_stack[afterTriggers->query_depth];
if (events->tail == NULL)
{
/* first list entry */
events->head = event;
events->tail = event;
}
else
{
events->tail->ate_next = event;
events->tail = event;
}
}
/* ----------
* AfterTriggerExecute()
*
* 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. (For triggers fired at
* the end of a query, we can even piggyback on the executor's state.)
*
* event: 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).
* instr: array of EXPLAIN ANALYZE instrumentation nodes (one per trigger),
* or NULL if no instrumentation is wanted.
* per_tuple_context: memory context to call trigger function in.
* ----------
*/
static void
AfterTriggerExecute(AfterTriggerEvent event,
Relation rel, TriggerDesc *trigdesc,
FmgrInfo *finfo, Instrumentation *instr,
MemoryContext per_tuple_context)
{
Oid tgoid = event->ate_tgoid;
TriggerData LocTriggerData;
HeapTupleData oldtuple;
HeapTupleData newtuple;
HeapTuple rettuple;
Buffer oldbuffer = InvalidBuffer;
Buffer newbuffer = InvalidBuffer;
int tgindx;
/*
* Locate trigger in trigdesc.
*/
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);
/*
* If doing EXPLAIN ANALYZE, start charging time to this trigger. We want
* to include time spent re-fetching tuples in the trigger cost.
*/
if (instr)
InstrStartNode(instr + tgindx);
/*
* Fetch the required OLD and NEW tuples.
*/
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
if (ItemPointerIsValid(&(event->ate_oldctid)))
{
ItemPointerCopy(&(event->ate_oldctid), &(oldtuple.t_self));
if (!heap_fetch(rel, SnapshotAny, &oldtuple, &oldbuffer, false, NULL))
elog(ERROR, "failed to fetch old tuple for AFTER trigger");
LocTriggerData.tg_trigtuple = &oldtuple;
LocTriggerData.tg_trigtuplebuf = oldbuffer;
}
if (ItemPointerIsValid(&(event->ate_newctid)))
{
ItemPointerCopy(&(event->ate_newctid), &(newtuple.t_self));
if (!heap_fetch(rel, SnapshotAny, &newtuple, &newbuffer, false, NULL))
elog(ERROR, "failed to fetch new tuple for AFTER trigger");
if (LocTriggerData.tg_trigtuple != NULL)
{
LocTriggerData.tg_newtuple = &newtuple;
LocTriggerData.tg_newtuplebuf = newbuffer;
}
else
{
LocTriggerData.tg_trigtuple = &newtuple;
LocTriggerData.tg_trigtuplebuf = newbuffer;
}
}
/*
* Setup the remaining trigger information
*/
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event =
event->ate_event & (TRIGGER_EVENT_OPMASK | TRIGGER_EVENT_ROW);
LocTriggerData.tg_relation = rel;
MemoryContextReset(per_tuple_context);
/*
* Call the trigger and throw away any possibly returned updated tuple.
* (Don't let ExecCallTriggerFunc measure EXPLAIN time.)
*/
rettuple = ExecCallTriggerFunc(&LocTriggerData,
tgindx,
finfo,
NULL,
per_tuple_context);
if (rettuple != NULL && rettuple != &oldtuple && rettuple != &newtuple)
heap_freetuple(rettuple);
/*
* Release buffers
*/
if (oldbuffer != InvalidBuffer)
ReleaseBuffer(oldbuffer);
if (newbuffer != InvalidBuffer)
ReleaseBuffer(newbuffer);
/*
* If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count
* one "tuple returned" (really the number of firings).
*/
if (instr)
InstrStopNode(instr + tgindx, 1);
}
/*
* afterTriggerMarkEvents()
*
* Scan the given event list for not yet invoked events. Mark the ones
* that can be invoked now with the current firing ID.
*
* If move_list isn't NULL, events that are not to be invoked now are
* removed from the given list and appended to move_list.
*
* When immediate_only is TRUE, do not invoke currently-deferred triggers.
* (This will be FALSE only at main transaction exit.)
*
* Returns TRUE if any invokable events were found.
*/
static bool
afterTriggerMarkEvents(AfterTriggerEventList *events,
AfterTriggerEventList *move_list,
bool immediate_only)
{
bool found = false;
AfterTriggerEvent event,
prev_event;
prev_event = NULL;
event = events->head;
while (event != NULL)
{
bool defer_it = false;
AfterTriggerEvent next_event;
if (!(event->ate_event &
(AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS)))
{
/*
* This trigger hasn't been called or scheduled yet. Check if we
* should call it now.
*/
if (immediate_only &&
afterTriggerCheckState(event->ate_tgoid, event->ate_event))
{
defer_it = true;
}
else
{
/*
* Mark it as to be fired in this firing cycle.
*/
event->ate_firing_id = afterTriggers->firing_counter;
event->ate_event |= AFTER_TRIGGER_IN_PROGRESS;
found = true;
}
}
/*
* If it's deferred, move it to move_list, if requested.
*/
next_event = event->ate_next;
if (defer_it && move_list != NULL)
{
/* Delink it from input list */
if (prev_event)
prev_event->ate_next = next_event;
else
events->head = next_event;
/* and add it to move_list */
event->ate_next = NULL;
if (move_list->tail == NULL)
{
/* first list entry */
move_list->head = event;
move_list->tail = event;
}
else
{
move_list->tail->ate_next = event;
move_list->tail = event;
}
}
else
{
/* Keep it in input list */
prev_event = event;
}
event = next_event;
}
/* Update list tail pointer in case we moved tail event */
events->tail = prev_event;
return found;
}
/* ----------
* afterTriggerInvokeEvents()
*
* Scan the given event list for events that are marked as to be fired
* in the current firing cycle, and fire them.
*
* If estate isn't NULL, then we expect that all the firable events are
* for triggers of the relations included in the estate's result relation
* array. This allows us to re-use the estate's open relations and
* trigger cache info. When estate is NULL, we have to find the relations
* the hard way.
*
* When delete_ok is TRUE, it's okay to delete fully-processed events.
* The events list pointers are updated.
* ----------
*/
static void
afterTriggerInvokeEvents(AfterTriggerEventList *events,
CommandId firing_id,
EState *estate,
bool delete_ok)
{
AfterTriggerEvent event,
prev_event;
MemoryContext per_tuple_context;
bool locally_opened = false;
Relation rel = NULL;
TriggerDesc *trigdesc = NULL;
FmgrInfo *finfo = NULL;
Instrumentation *instr = NULL;
/* Make a per-tuple memory context for trigger function calls */
per_tuple_context =
AllocSetContextCreate(CurrentMemoryContext,
"AfterTriggerTupleContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
prev_event = NULL;
event = events->head;
while (event != NULL)
{
AfterTriggerEvent next_event;
/*
* Is it one for me to fire?
*/
if ((event->ate_event & AFTER_TRIGGER_IN_PROGRESS) &&
event->ate_firing_id == firing_id)
{
/*
* 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->ate_relid)
{
if (locally_opened)
{
/* close prior rel if any */
if (rel)
heap_close(rel, NoLock);
if (trigdesc)
FreeTriggerDesc(trigdesc);
if (finfo)
pfree(finfo);
Assert(instr == NULL); /* never used in this case */
}
locally_opened = true;
if (estate)
{
/* Find target relation among estate's result rels */
ResultRelInfo *rInfo;
int nr;
rInfo = estate->es_result_relations;
nr = estate->es_num_result_relations;
while (nr > 0)
{
if (rInfo->ri_RelationDesc->rd_id == event->ate_relid)
{
rel = rInfo->ri_RelationDesc;
trigdesc = rInfo->ri_TrigDesc;
finfo = rInfo->ri_TrigFunctions;
instr = rInfo->ri_TrigInstrument;
locally_opened = false;
break;
}
rInfo++;
nr--;
}
}
if (locally_opened)
{
/* Hard way: open target relation for ourselves */
/*
* We assume that an appropriate lock is still held by the
* executor, so grab no new lock here.
*/
rel = heap_open(event->ate_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->ate_relid);
/*
* Allocate space to cache fmgr lookup info for triggers.
*/
finfo = (FmgrInfo *)
palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
/* Never any EXPLAIN info in this case */
instr = NULL;
}
}
/*
* Fire it. Note that the AFTER_TRIGGER_IN_PROGRESS flag is still
* set, so recursive examinations of the event list won't try to
* re-fire it.
*/
AfterTriggerExecute(event, rel, trigdesc, finfo, instr,
per_tuple_context);
/*
* Mark the event as done.
*/
event->ate_event &= ~AFTER_TRIGGER_IN_PROGRESS;
event->ate_event |= AFTER_TRIGGER_DONE;
}
/*
* If it's now done, throw it away, if allowed.
*
* NB: it's possible the trigger call 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 at all points
* here.
*/
next_event = event->ate_next;
if ((event->ate_event & AFTER_TRIGGER_DONE) && delete_ok)
{
/* Delink it from list and free it */
if (prev_event)
prev_event->ate_next = next_event;
else
events->head = next_event;
pfree(event);
}
else
{
/* Keep it in list */
prev_event = event;
}
event = next_event;
}
/* Update list tail pointer in case we just deleted tail event */
events->tail = prev_event;
/* Release working resources */
if (locally_opened)
{
if (rel)
heap_close(rel, NoLock);
if (trigdesc)
FreeTriggerDesc(trigdesc);
if (finfo)
pfree(finfo);
Assert(instr == NULL); /* never used in this case */
}
MemoryContextDelete(per_tuple_context);
}
/* ----------
* AfterTriggerBeginXact()
*
* Called at transaction start (either BEGIN or implicit for single
* statement outside of transaction block).
* ----------
*/
void
AfterTriggerBeginXact(void)
{
Assert(afterTriggers == NULL);
/*
* Build empty after-trigger state structure
*/
afterTriggers = (AfterTriggers)
MemoryContextAlloc(TopTransactionContext,
sizeof(AfterTriggersData));
afterTriggers->firing_counter = FirstCommandId;
afterTriggers->state = SetConstraintStateCreate(8);
afterTriggers->events.head = NULL;
afterTriggers->events.tail = NULL;
afterTriggers->query_depth = -1;
/* We initialize the query stack to a reasonable size */
afterTriggers->query_stack = (AfterTriggerEventList *)
MemoryContextAlloc(TopTransactionContext,
8 * sizeof(AfterTriggerEventList));
afterTriggers->maxquerydepth = 8;
/* Context for events is created only when needed */
afterTriggers->event_cxt = NULL;
/* Subtransaction stack is empty until/unless needed */
afterTriggers->cxt_stack = NULL;
afterTriggers->state_stack = NULL;
afterTriggers->events_stack = NULL;
afterTriggers->depth_stack = NULL;
afterTriggers->firing_stack = NULL;
afterTriggers->maxtransdepth = 0;
}
/* ----------
* AfterTriggerBeginQuery()
*
* Called just before we start processing a single query within a
* transaction (or subtransaction). Set up to record AFTER trigger
* events queued by the query. Note that it is allowed to have
* nested queries within a (sub)transaction.
* ----------
*/
void
AfterTriggerBeginQuery(void)
{
/* Must be inside a transaction */
Assert(afterTriggers != NULL);
/* Increase the query stack depth */
afterTriggers->query_depth++;
/*
* Allocate more space in the query stack if needed.
*/
if (afterTriggers->query_depth >= afterTriggers->maxquerydepth)
{
/* repalloc will keep the stack in the same context */
int new_alloc = afterTriggers->maxquerydepth * 2;
afterTriggers->query_stack = (AfterTriggerEventList *)
repalloc(afterTriggers->query_stack,
new_alloc * sizeof(AfterTriggerEventList));
afterTriggers->maxquerydepth = new_alloc;
}
/* Initialize this query's list to empty */
afterTriggers->query_stack[afterTriggers->query_depth].head = NULL;
afterTriggers->query_stack[afterTriggers->query_depth].tail = NULL;
}
/* ----------
* AfterTriggerEndQuery()
*
* Called after one query has been completely processed. At this time
* we invoke all AFTER IMMEDIATE trigger events queued by the query, and
* transfer deferred trigger events to the global deferred-trigger list.
*
* Note that this should be called just BEFORE closing down the executor
* with ExecutorEnd, because we make use of the EState's info about
* target relations.
* ----------
*/
void
AfterTriggerEndQuery(EState *estate)
{
AfterTriggerEventList *events;
/* Must be inside a transaction */
Assert(afterTriggers != NULL);
/* Must be inside a query, too */
Assert(afterTriggers->query_depth >= 0);
/*
* Process all immediate-mode triggers queued by the query, and move the
* deferred ones to the main list of deferred events.
*
* Notice that we decide which ones will be fired, and put the deferred
* ones on the main list, before anything is actually fired. This ensures
* reasonably sane behavior if a trigger function does SET CONSTRAINTS ...
* IMMEDIATE: all events we have decided to defer will be available for it
* to fire.
*
* We loop in case a trigger queues more events.
*
* If we find no firable events, we don't have to increment
* firing_counter.
*/
events = &afterTriggers->query_stack[afterTriggers->query_depth];
while (afterTriggerMarkEvents(events, &afterTriggers->events, true))
{
CommandId firing_id = afterTriggers->firing_counter++;
/* OK to delete the immediate events after processing them */
afterTriggerInvokeEvents(events, firing_id, estate, true);
}
afterTriggers->query_depth--;
}
/* ----------
* AfterTriggerFireDeferred()
*
* Called just before the current transaction is committed. At this
* time we invoke all pending DEFERRED triggers.
*
* It is possible for other modules to queue additional deferred triggers
* during pre-commit processing; therefore xact.c may have to call this
* multiple times.
* ----------
*/
void
AfterTriggerFireDeferred(void)
{
AfterTriggerEventList *events;
/* Must be inside a transaction */
Assert(afterTriggers != NULL);
/* ... but not inside a query */
Assert(afterTriggers->query_depth == -1);
/*
* If there are any triggers to fire, make sure we have set a snapshot for
* them to use. (Since PortalRunUtility doesn't set a snap for COMMIT, we
* can't assume ActiveSnapshot is valid on entry.)
*/
events = &afterTriggers->events;
if (events->head != NULL)
ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
/*
* Run all the remaining triggers. Loop until they are all gone, in
* case some trigger queues more for us to do.
*/
while (afterTriggerMarkEvents(events, NULL, false))
{
CommandId firing_id = afterTriggers->firing_counter++;
afterTriggerInvokeEvents(events, firing_id, NULL, true);
}
Assert(events->head == NULL);
}
/* ----------
* AfterTriggerEndXact()
*
* The current transaction is finishing.
*
* Any unfired triggers are canceled so we simply throw
* away anything we know.
*
* Note: it is possible for this to be called repeatedly in case of
* error during transaction abort; therefore, do not complain if
* already closed down.
* ----------
*/
void
AfterTriggerEndXact(bool isCommit)
{
/*
* Forget everything we know about AFTER triggers.
*
* Since all the info is in TopTransactionContext or children thereof, we
* don't really need to do anything to reclaim memory. However, the
* pending-events list could be large, and so it's useful to discard
* it as soon as possible --- especially if we are aborting because we
* ran out of memory for the list!
*
* (Note: any event_cxts of child subtransactions could also be
* deleted here, but we have no convenient way to find them, so we
* leave it to TopTransactionContext reset to clean them up.)
*/
if (afterTriggers && afterTriggers->event_cxt)
MemoryContextDelete(afterTriggers->event_cxt);
afterTriggers = NULL;
}
/*
* AfterTriggerBeginSubXact()
*
* Start a subtransaction.
*/
void
AfterTriggerBeginSubXact(void)
{
int my_level = GetCurrentTransactionNestLevel();
/*
* Ignore call if the transaction is in aborted state. (Probably
* shouldn't happen?)
*/
if (afterTriggers == NULL)
return;
/*
* Allocate more space in the stacks if needed. (Note: because the
* minimum nest level of a subtransaction is 2, we waste the first
* couple entries of each array; not worth the notational effort to
* avoid it.)
*/
while (my_level >= afterTriggers->maxtransdepth)
{
if (afterTriggers->maxtransdepth == 0)
{
MemoryContext old_cxt;
old_cxt = MemoryContextSwitchTo(TopTransactionContext);
#define DEFTRIG_INITALLOC 8
afterTriggers->cxt_stack = (MemoryContext *)
palloc(DEFTRIG_INITALLOC * sizeof(MemoryContext));
afterTriggers->state_stack = (SetConstraintState *)
palloc(DEFTRIG_INITALLOC * sizeof(SetConstraintState));
afterTriggers->events_stack = (AfterTriggerEventList *)
palloc(DEFTRIG_INITALLOC * sizeof(AfterTriggerEventList));
afterTriggers->depth_stack = (int *)
palloc(DEFTRIG_INITALLOC * sizeof(int));
afterTriggers->firing_stack = (CommandId *)
palloc(DEFTRIG_INITALLOC * sizeof(CommandId));
afterTriggers->maxtransdepth = DEFTRIG_INITALLOC;
MemoryContextSwitchTo(old_cxt);
}
else
{
/* repalloc will keep the stacks in the same context */
int new_alloc = afterTriggers->maxtransdepth * 2;
afterTriggers->cxt_stack = (MemoryContext *)
repalloc(afterTriggers->cxt_stack,
new_alloc * sizeof(MemoryContext));
afterTriggers->state_stack = (SetConstraintState *)
repalloc(afterTriggers->state_stack,
new_alloc * sizeof(SetConstraintState));
afterTriggers->events_stack = (AfterTriggerEventList *)
repalloc(afterTriggers->events_stack,
new_alloc * sizeof(AfterTriggerEventList));
afterTriggers->depth_stack = (int *)
repalloc(afterTriggers->depth_stack,
new_alloc * sizeof(int));
afterTriggers->firing_stack = (CommandId *)
repalloc(afterTriggers->firing_stack,
new_alloc * sizeof(CommandId));
afterTriggers->maxtransdepth = new_alloc;
}
}
/*
* Push the current information into the stack. The SET CONSTRAINTS state
* is not saved until/unless changed. Likewise, we don't make a
* per-subtransaction event context until needed.
*/
afterTriggers->cxt_stack[my_level] = NULL;
afterTriggers->state_stack[my_level] = NULL;
afterTriggers->events_stack[my_level] = afterTriggers->events;
afterTriggers->depth_stack[my_level] = afterTriggers->query_depth;
afterTriggers->firing_stack[my_level] = afterTriggers->firing_counter;
}
/*
* AfterTriggerEndSubXact()
*
* The current subtransaction is ending.
*/
void
AfterTriggerEndSubXact(bool isCommit)
{
int my_level = GetCurrentTransactionNestLevel();
SetConstraintState state;
AfterTriggerEvent event;
CommandId subxact_firing_id;
/*
* Ignore call if the transaction is in aborted state. (Probably
* unneeded)
*/
if (afterTriggers == NULL)
return;
/*
* Pop the prior state if needed.
*/
Assert(my_level < afterTriggers->maxtransdepth);
if (isCommit)
{
/* If we saved a prior state, we don't need it anymore */
state = afterTriggers->state_stack[my_level];
if (state != NULL)
pfree(state);
/* this avoids double pfree if error later: */
afterTriggers->state_stack[my_level] = NULL;
Assert(afterTriggers->query_depth ==
afterTriggers->depth_stack[my_level]);
/*
* It's entirely possible that the subxact created an event_cxt but
* there is not anything left in it (because all the triggers were
* fired at end-of-statement). If so, we should release the context
* to prevent memory leakage in a long sequence of subtransactions.
* We can detect whether there's anything of use in the context by
* seeing if anything was added to the global events list since
* subxact start. (This test doesn't catch every case where the
* context is deletable; for instance maybe the only additions were
* from a sub-sub-xact. But it handles the common case.)
*/
if (afterTriggers->cxt_stack[my_level] &&
afterTriggers->events.tail == afterTriggers->events_stack[my_level].tail)
{
MemoryContextDelete(afterTriggers->cxt_stack[my_level]);
/* avoid double delete if abort later */
afterTriggers->cxt_stack[my_level] = NULL;
}
}
else
{
/*
* Aborting. We don't really need to release the subxact's event_cxt,
* since it will go away anyway when CurTransactionContext gets reset,
* but doing so early in subxact abort helps free space we might need.
*
* (Note: any event_cxts of child subtransactions could also be
* deleted here, but we have no convenient way to find them, so we
* leave it to CurTransactionContext reset to clean them up.)
*/
if (afterTriggers->cxt_stack[my_level])
{
MemoryContextDelete(afterTriggers->cxt_stack[my_level]);
/* avoid double delete if repeated aborts */
afterTriggers->cxt_stack[my_level] = NULL;
}
/*
* Restore the pointers from the stacks.
*/
afterTriggers->events = afterTriggers->events_stack[my_level];
afterTriggers->query_depth = afterTriggers->depth_stack[my_level];
/*
* Cleanup the tail of the list.
*/
if (afterTriggers->events.tail != NULL)
afterTriggers->events.tail->ate_next = NULL;
/*
* Restore the trigger state. If the saved state is NULL, then this
* subxact didn't save it, so it doesn't need restoring.
*/
state = afterTriggers->state_stack[my_level];
if (state != NULL)
{
pfree(afterTriggers->state);
afterTriggers->state = state;
}
/* this avoids double pfree if error later: */
afterTriggers->state_stack[my_level] = NULL;
/*
* Scan for any remaining deferred events that were marked DONE or IN
* PROGRESS by this subxact or a child, and un-mark them. We can
* recognize such events because they have a firing ID greater than or
* equal to the firing_counter value we saved at subtransaction start.
* (This essentially assumes that the current subxact includes all
* subxacts started after it.)
*/
subxact_firing_id = afterTriggers->firing_stack[my_level];
for (event = afterTriggers->events.head;
event != NULL;
event = event->ate_next)
{
if (event->ate_event &
(AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS))
{
if (event->ate_firing_id >= subxact_firing_id)
event->ate_event &=
~(AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS);
}
}
}
}
/*
* Create an empty SetConstraintState with room for numalloc trigstates
*/
static SetConstraintState
SetConstraintStateCreate(int numalloc)
{
SetConstraintState state;
/* Behave sanely with numalloc == 0 */
if (numalloc <= 0)
numalloc = 1;
/*
* We assume that zeroing will correctly initialize the state values.
*/
state = (SetConstraintState)
MemoryContextAllocZero(TopTransactionContext,
sizeof(SetConstraintStateData) +
(numalloc - 1) *sizeof(SetConstraintTriggerData));
state->numalloc = numalloc;
return state;
}
/*
* Copy a SetConstraintState
*/
static SetConstraintState
SetConstraintStateCopy(SetConstraintState origstate)
{
SetConstraintState state;
state = SetConstraintStateCreate(origstate->numstates);
state->all_isset = origstate->all_isset;
state->all_isdeferred = origstate->all_isdeferred;
state->numstates = origstate->numstates;
memcpy(state->trigstates, origstate->trigstates,
origstate->numstates * sizeof(SetConstraintTriggerData));
return state;
}
/*
* Add a per-trigger item to a SetConstraintState. Returns possibly-changed
* pointer to the state object (it will change if we have to repalloc).
*/
static SetConstraintState
SetConstraintStateAddItem(SetConstraintState state,
Oid tgoid, bool tgisdeferred)
{
if (state->numstates >= state->numalloc)
{
int newalloc = state->numalloc * 2;
newalloc = Max(newalloc, 8); /* in case original has size 0 */
state = (SetConstraintState)
repalloc(state,
sizeof(SetConstraintStateData) +
(newalloc - 1) *sizeof(SetConstraintTriggerData));
state->numalloc = newalloc;
Assert(state->numstates < state->numalloc);
}
state->trigstates[state->numstates].sct_tgoid = tgoid;
state->trigstates[state->numstates].sct_tgisdeferred = tgisdeferred;
state->numstates++;
return state;
}
/* ----------
* AfterTriggerSetState()
*
* Execute the SET CONSTRAINTS ... utility command.
* ----------
*/
void
AfterTriggerSetState(ConstraintsSetStmt *stmt)
{
int my_level = GetCurrentTransactionNestLevel();
/*
* Ignore call if we aren't in a transaction. (Shouldn't happen?)
*/
if (afterTriggers == NULL)
return;
/*
* If in a subtransaction, and we didn't save the current state already,
* save it so it can be restored if the subtransaction aborts.
*/
if (my_level > 1 &&
afterTriggers->state_stack[my_level] == NULL)
{
afterTriggers->state_stack[my_level] =
SetConstraintStateCopy(afterTriggers->state);
}
/*
* Handle SET CONSTRAINTS ALL ...
*/
if (stmt->constraints == NIL)
{
/*
* Forget any previous SET CONSTRAINTS commands in this transaction.
*/
afterTriggers->state->numstates = 0;
/*
* Set the per-transaction ALL state to known.
*/
afterTriggers->state->all_isset = true;
afterTriggers->state->all_isdeferred = stmt->deferred;
}
else
{
Relation tgrel;
ListCell *l;
List *oidlist = NIL;
/* ----------
* Handle SET CONSTRAINTS constraint-name [, ...]
* First lookup all trigger Oid's for the constraint names.
* ----------
*/
tgrel = heap_open(TriggerRelationId, AccessShareLock);
foreach(l, stmt->constraints)
{
RangeVar *constraint = lfirst(l);
cqContext cqc;
cqContext *pcqCtx;
HeapTuple htup;
bool found;
List *namespaceSearchList;
ListCell *namespaceSearchCell;
if (constraint->catalogname)
{
if (strcmp(constraint->catalogname, get_database_name(MyDatabaseId)) != 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cross-database references are not implemented: \"%s.%s.%s\"",
constraint->catalogname, constraint->schemaname,
constraint->relname)));
}
/*
* If we're given the schema name with the constraint, look only
* in that schema. If given a bare constraint name, use the
* search path to find the first matching constraint.
*/
if (constraint->schemaname)
{
Oid namespaceId = LookupExplicitNamespace(constraint->schemaname, NSPDBOID_CURRENT);
namespaceSearchList = list_make1_oid(namespaceId);
}
else
{
namespaceSearchList = fetch_search_path(true);
}
found = false;
foreach(namespaceSearchCell, namespaceSearchList)
{
Oid searchNamespaceId = lfirst_oid(namespaceSearchCell);
/*
* Setup to scan pg_trigger by tgconstrname ...
*/
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), tgrel),
cql("SELECT * FROM pg_trigger "
" WHERE tgconstrname = :1 ",
PointerGetDatum(constraint->relname)));
/*
* ... and search for the constraint trigger row
*/
while (HeapTupleIsValid(htup = caql_getnext(pcqCtx)))
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
Oid constraintNamespaceId;
/*
* Foreign key constraints have triggers on both the
* parent and child tables. Since these tables may be in
* different schemas we must pick the child table because
* that table "owns" the constraint.
*
* Referential triggers on the parent table other than
* NOACTION_DEL and NOACTION_UPD are ignored below, so it
* is possible to not check them here, but it seems safer
* to always check.
*/
if (pg_trigger->tgfoid == F_RI_FKEY_NOACTION_DEL ||
pg_trigger->tgfoid == F_RI_FKEY_NOACTION_UPD ||
pg_trigger->tgfoid == F_RI_FKEY_RESTRICT_UPD ||
pg_trigger->tgfoid == F_RI_FKEY_RESTRICT_DEL ||
pg_trigger->tgfoid == F_RI_FKEY_CASCADE_UPD ||
pg_trigger->tgfoid == F_RI_FKEY_CASCADE_DEL ||
pg_trigger->tgfoid == F_RI_FKEY_SETNULL_UPD ||
pg_trigger->tgfoid == F_RI_FKEY_SETNULL_DEL ||
pg_trigger->tgfoid == F_RI_FKEY_SETDEFAULT_UPD ||
pg_trigger->tgfoid == F_RI_FKEY_SETDEFAULT_DEL)
constraintNamespaceId = get_rel_namespace(pg_trigger->tgconstrrelid);
else
constraintNamespaceId = get_rel_namespace(pg_trigger->tgrelid);
/*
* If this constraint is not in the schema we're currently
* searching for, keep looking.
*/
if (constraintNamespaceId != searchNamespaceId)
continue;
/*
* If we found some, check that they fit the deferrability
* but skip referential action ones, since they are
* silently never deferrable.
*/
if (pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_UPD &&
pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_DEL &&
pg_trigger->tgfoid != F_RI_FKEY_CASCADE_UPD &&
pg_trigger->tgfoid != F_RI_FKEY_CASCADE_DEL &&
pg_trigger->tgfoid != F_RI_FKEY_SETNULL_UPD &&
pg_trigger->tgfoid != F_RI_FKEY_SETNULL_DEL &&
pg_trigger->tgfoid != F_RI_FKEY_SETDEFAULT_UPD &&
pg_trigger->tgfoid != F_RI_FKEY_SETDEFAULT_DEL)
{
if (stmt->deferred && !pg_trigger->tgdeferrable)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" is not deferrable",
constraint->relname)));
oidlist = lappend_oid(oidlist, HeapTupleGetOid(htup));
}
found = true;
}
caql_endscan(pcqCtx);
/*
* Once we've found a matching constraint we do not search
* later parts of the search path.
*/
if (found)
break;
}
list_free(namespaceSearchList);
/*
* Not found ?
*/
if (!found)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" does not exist",
constraint->relname)));
}
heap_close(tgrel, AccessShareLock);
/*
* Set the trigger states of individual triggers for this xact.
*/
foreach(l, oidlist)
{
Oid tgoid = lfirst_oid(l);
SetConstraintState state = afterTriggers->state;
bool found = false;
int i;
for (i = 0; i < state->numstates; i++)
{
if (state->trigstates[i].sct_tgoid == tgoid)
{
state->trigstates[i].sct_tgisdeferred = stmt->deferred;
found = true;
break;
}
}
if (!found)
{
afterTriggers->state =
SetConstraintStateAddItem(state, tgoid, stmt->deferred);
}
}
}
/*
* 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
* apply retroactively. We've updated the constraints state, so scan the
* list of previously deferred events to fire any that have now become
* immediate.
*
* Obviously, if this was SET ... DEFERRED then it can't have converted
* any unfired events to immediate, so we need do nothing in that case.
*/
if (!stmt->deferred)
{
AfterTriggerEventList *events = &afterTriggers->events;
while (afterTriggerMarkEvents(events, NULL, true))
{
CommandId firing_id = afterTriggers->firing_counter++;
/*
* We can delete fired events if we are at top transaction level,
* but we'd better not if inside a subtransaction, since the
* subtransaction could later get rolled back.
*/
afterTriggerInvokeEvents(events, firing_id, NULL,
!IsSubTransaction());
}
}
if (Gp_role == GP_ROLE_DISPATCH)
{
dispatch_statement_node((Node *) stmt, NULL, NULL, NULL);
}
}
/* ----------
* AfterTriggerPendingOnRel()
* Test to see if there are any pending after-trigger events for rel.
*
* This is used by TRUNCATE, CLUSTER, ALTER TABLE, etc to detect whether
* it is unsafe to perform major surgery on a relation. Note that only
* local pending events are examined. We assume that having exclusive lock
* on a rel guarantees there are no unserviced events in other backends ---
* but having a lock does not prevent there being such events in our own.
*
* In some scenarios it'd be reasonable to remove pending events (more
* specifically, mark them DONE by the current subxact) but without a lot
* of knowledge of the trigger semantics we can't do this in general.
* ----------
*/
bool
AfterTriggerPendingOnRel(Oid relid)
{
AfterTriggerEvent event;
int depth;
/* No-op if we aren't in a transaction. (Shouldn't happen?) */
if (afterTriggers == NULL)
return false;
/* Scan queued events */
for (event = afterTriggers->events.head;
event != NULL;
event = event->ate_next)
{
/*
* We can ignore completed events. (Even if a DONE flag is rolled
* back by subxact abort, it's OK because the effects of the TRUNCATE
* or whatever must get rolled back too.)
*/
if (event->ate_event & AFTER_TRIGGER_DONE)
continue;
if (event->ate_relid == relid)
return true;
}
/*
* Also scan events queued by incomplete queries. This could only matter
* if TRUNCATE/etc is executed by a function or trigger within an updating
* query on the same relation, which is pretty perverse, but let's check.
*/
for (depth = 0; depth <= afterTriggers->query_depth; depth++)
{
for (event = afterTriggers->query_stack[depth].head;
event != NULL;
event = event->ate_next)
{
if (event->ate_event & AFTER_TRIGGER_DONE)
continue;
if (event->ate_relid == relid)
return true;
}
}
return false;
}
/* ----------
* AfterTriggerSaveEvent()
*
* Called by ExecA[RS]...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
AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger,
HeapTuple oldtup, HeapTuple newtup)
{
Relation rel = relinfo->ri_RelationDesc;
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
int my_level = GetCurrentTransactionNestLevel();
MemoryContext *cxtptr;
AfterTriggerEvent new_event;
int i;
int ntriggers;
int *tgindx;
ItemPointerData oldctid;
ItemPointerData newctid;
if (afterTriggers == NULL)
elog(ERROR, "AfterTriggerSaveEvent() 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));
/*
* Scan the appropriate set of triggers
*/
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];
}
for (i = 0; i < ntriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
/* Ignore disabled triggers */
if (!trigger->tgenabled)
continue;
/*
* If this is an UPDATE of a PK table or FK table that does not change
* the PK or FK respectively, we can skip queuing the event: there is
* no need to fire the trigger.
*/
if ((event & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_UPDATE)
{
switch (RI_FKey_trigger_type(trigger->tgfoid))
{
case RI_TRIGGER_PK:
/* Update on PK table */
if (RI_FKey_keyequal_upd_pk(trigger, rel, oldtup, newtup))
{
/* key unchanged, so skip queuing this event */
continue;
}
break;
case RI_TRIGGER_FK:
/*
* Update on FK table
*
* There is one exception when updating FK tables: if the
* updated row was inserted by our own transaction and the
* FK is deferred, we still need to fire the trigger. This
* is because our UPDATE will invalidate the INSERT so the
* end-of-transaction INSERT RI trigger will not do
* anything, so we have to do the check for the UPDATE
* anyway.
*/
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(oldtup->t_data)) &&
RI_FKey_keyequal_upd_fk(trigger, rel, oldtup, newtup))
{
continue;
}
break;
case RI_TRIGGER_NONE:
/* Not an FK trigger */
break;
}
}
/*
* If we don't yet have an event context for the current (sub)xact,
* create one. Make it a child of CurTransactionContext to ensure it
* will go away if the subtransaction aborts.
*/
if (my_level > 1) /* subtransaction? */
{
Assert(my_level < afterTriggers->maxtransdepth);
cxtptr = &afterTriggers->cxt_stack[my_level];
}
else
cxtptr = &afterTriggers->event_cxt;
if (*cxtptr == NULL)
*cxtptr = AllocSetContextCreate(CurTransactionContext,
"AfterTriggerEvents",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* Create a new event.
*/
new_event = (AfterTriggerEvent)
MemoryContextAlloc(*cxtptr, sizeof(AfterTriggerEventData));
new_event->ate_next = NULL;
new_event->ate_event =
(event & TRIGGER_EVENT_OPMASK) |
(row_trigger ? TRIGGER_EVENT_ROW : 0) |
(trigger->tgdeferrable ? AFTER_TRIGGER_DEFERRABLE : 0) |
(trigger->tginitdeferred ? AFTER_TRIGGER_INITDEFERRED : 0);
new_event->ate_firing_id = 0;
new_event->ate_tgoid = trigger->tgoid;
new_event->ate_relid = rel->rd_id;
ItemPointerCopy(&oldctid, &(new_event->ate_oldctid));
ItemPointerCopy(&newctid, &(new_event->ate_newctid));
/*
* Add the new event to the queue.
*/
afterTriggerAddEvent(new_event);
}
}