postgresql/src/backend/commands/trigger.c

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/*-------------------------------------------------------------------------
*
* trigger.c
* PostgreSQL TRIGGERs support code.
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*
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* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.263 2010/07/28 05:22:24 sriggs Exp $
*
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*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/sysattr.h"
#include "access/xact.h"
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#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_proc.h"
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#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"
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#include "miscadmin.h"
#include "nodes/bitmapset.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/var.h"
#include "parser/parse_clause.h"
#include "parser/parse_func.h"
#include "parser/parse_relation.h"
#include "parser/parsetree.h"
#include "pgstat.h"
#include "rewrite/rewriteManip.h"
#include "storage/bufmgr.h"
#include "tcop/utility.h"
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#include "utils/acl.h"
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#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/fmgroids.h"
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#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/snapmgr.h"
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#include "utils/syscache.h"
#include "utils/tqual.h"
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/* GUC variables */
int SessionReplicationRole = SESSION_REPLICATION_ROLE_ORIGIN;
#define GetModifiedColumns(relinfo, estate) \
(rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->modifiedCols)
/* Local function prototypes */
static void ConvertTriggerToFK(CreateTrigStmt *stmt, Oid funcoid);
static void InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx);
static HeapTuple GetTupleForTrigger(EState *estate,
EPQState *epqstate,
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ResultRelInfo *relinfo,
ItemPointer tid,
TupleTableSlot **newSlot);
static bool TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
Trigger *trigger, TriggerEvent event,
Bitmapset *modifiedCols,
HeapTuple oldtup, HeapTuple newtup);
static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata,
int tgindx,
FmgrInfo *finfo,
Instrumentation *instr,
MemoryContext per_tuple_context);
static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo,
int event, bool row_trigger,
HeapTuple oldtup, HeapTuple newtup,
List *recheckIndexes, Bitmapset *modifiedCols);
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/*
* Create a trigger. Returns the OID of the created trigger.
*
* queryString is the source text of the CREATE TRIGGER command.
* This must be supplied if a whenClause is specified, else it can be NULL.
*
* constraintOid, if nonzero, says that this trigger is being created
* internally to implement that constraint. A suitable pg_depend entry will
* be made to link the trigger to that constraint. constraintOid is zero when
* executing a user-entered CREATE TRIGGER command. (For CREATE CONSTRAINT
* TRIGGER, we build a pg_constraint entry internally.)
*
* indexOid, if nonzero, is the OID of an index associated with the constraint.
* We do nothing with this except store it into pg_trigger.tgconstrindid.
*
* If isInternal is true then this is an internally-generated trigger.
* This argument sets the tgisinternal field of the pg_trigger entry, and
* if TRUE causes us to modify the given trigger name to ensure uniqueness.
*
* When isInternal is not true we require ACL_TRIGGER permissions on the
* relation. For internal triggers the caller must apply any required
* permission checks.
*
* Note: can return InvalidOid if we decided to not create a trigger at all,
* but a foreign-key constraint. This is a kluge for backwards compatibility.
*/
Oid
CreateTrigger(CreateTrigStmt *stmt, const char *queryString,
Oid constraintOid, Oid indexOid,
bool isInternal)
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{
int16 tgtype;
int ncolumns;
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int2 *columns;
int2vector *tgattr;
Node *whenClause;
List *whenRtable;
char *qual;
Datum values[Natts_pg_trigger];
bool nulls[Natts_pg_trigger];
Relation rel;
AclResult aclresult;
Relation tgrel;
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SysScanDesc tgscan;
ScanKeyData key;
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Relation pgrel;
HeapTuple tuple;
Oid fargtypes[1]; /* dummy */
Oid funcoid;
Oid funcrettype;
Oid trigoid;
char internaltrigname[NAMEDATALEN];
char *trigname;
Oid constrrelid = InvalidOid;
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ObjectAddress myself,
referenced;
/*
* ShareRowExclusiveLock is sufficient to prevent concurrent write activity
* to the relation, and thus to lock out any operations that might want to
* fire triggers on the relation. If we had ON SELECT triggers we would
* need to take an AccessExclusiveLock to add one of those, just as we do
* with ON SELECT rules.
*/
rel = heap_openrv(stmt->relation, ShareRowExclusiveLock);
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))));
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if (stmt->isconstraint && stmt->constrrel != NULL)
constrrelid = RangeVarGetRelid(stmt->constrrel, false);
/* permission checks */
if (!isInternal)
{
aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
ACL_TRIGGER);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS,
RelationGetRelationName(rel));
if (OidIsValid(constrrelid))
{
aclresult = pg_class_aclcheck(constrrelid, GetUserId(),
ACL_TRIGGER);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS,
get_rel_name(constrrelid));
}
}
/* Compute tgtype */
TRIGGER_CLEAR_TYPE(tgtype);
if (stmt->before)
TRIGGER_SETT_BEFORE(tgtype);
if (stmt->row)
TRIGGER_SETT_ROW(tgtype);
tgtype |= stmt->events;
/* Disallow ROW-level TRUNCATE triggers */
if (TRIGGER_FOR_ROW(tgtype) && TRIGGER_FOR_TRUNCATE(tgtype))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("TRUNCATE FOR EACH ROW triggers are not supported")));
/*
* Parse the WHEN clause, if any
*/
if (stmt->whenClause)
{
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ParseState *pstate;
RangeTblEntry *rte;
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List *varList;
ListCell *lc;
/* Set up a pstate to parse with */
pstate = make_parsestate(NULL);
pstate->p_sourcetext = queryString;
/*
* Set up RTEs for OLD and NEW references.
*
* 'OLD' must always have varno equal to 1 and 'NEW' equal to 2.
*/
rte = addRangeTableEntryForRelation(pstate, rel,
makeAlias("old", NIL),
false, false);
addRTEtoQuery(pstate, rte, false, true, true);
rte = addRangeTableEntryForRelation(pstate, rel,
makeAlias("new", NIL),
false, false);
addRTEtoQuery(pstate, rte, false, true, true);
/* Transform expression. Copy to be sure we don't modify original */
whenClause = transformWhereClause(pstate,
copyObject(stmt->whenClause),
"WHEN");
/*
* No subplans or aggregates, please
*/
if (pstate->p_hasSubLinks)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot use subquery in trigger WHEN condition")));
if (pstate->p_hasAggs)
ereport(ERROR,
(errcode(ERRCODE_GROUPING_ERROR),
errmsg("cannot use aggregate function in trigger WHEN condition")));
if (pstate->p_hasWindowFuncs)
ereport(ERROR,
(errcode(ERRCODE_WINDOWING_ERROR),
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errmsg("cannot use window function in trigger WHEN condition")));
/*
* Check for disallowed references to OLD/NEW.
*
* NB: pull_var_clause is okay here only because we don't allow
* subselects in WHEN clauses; it would fail to examine the contents
* of subselects.
*/
varList = pull_var_clause(whenClause, PVC_REJECT_PLACEHOLDERS);
foreach(lc, varList)
{
Var *var = (Var *) lfirst(lc);
switch (var->varno)
{
case PRS2_OLD_VARNO:
if (!TRIGGER_FOR_ROW(tgtype))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("statement trigger's WHEN condition cannot reference column values"),
parser_errposition(pstate, var->location)));
if (TRIGGER_FOR_INSERT(tgtype))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("INSERT trigger's WHEN condition cannot reference OLD values"),
parser_errposition(pstate, var->location)));
/* system columns are okay here */
break;
case PRS2_NEW_VARNO:
if (!TRIGGER_FOR_ROW(tgtype))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("statement trigger's WHEN condition cannot reference column values"),
parser_errposition(pstate, var->location)));
if (TRIGGER_FOR_DELETE(tgtype))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("DELETE trigger's WHEN condition cannot reference NEW values"),
parser_errposition(pstate, var->location)));
if (var->varattno < 0 && TRIGGER_FOR_BEFORE(tgtype))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("BEFORE trigger's WHEN condition cannot reference NEW system columns"),
parser_errposition(pstate, var->location)));
break;
default:
/* can't happen without add_missing_from, so just elog */
elog(ERROR, "trigger WHEN condition cannot contain references to other relations");
break;
}
}
/* we'll need the rtable for recordDependencyOnExpr */
whenRtable = pstate->p_rtable;
qual = nodeToString(whenClause);
free_parsestate(pstate);
}
else
{
whenClause = NULL;
whenRtable = NIL;
qual = NULL;
}
/*
* Find and validate the trigger function.
*/
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))));
}
/*
* If the command is a user-entered CREATE CONSTRAINT TRIGGER command that
* references one of the built-in RI_FKey trigger functions, assume it is
* from a dump of a pre-7.3 foreign key constraint, and take steps to
* convert this legacy representation into a regular foreign key
* constraint. Ugly, but necessary for loading old dump files.
*/
if (stmt->isconstraint && !isInternal &&
list_length(stmt->args) >= 6 &&
(list_length(stmt->args) % 2) == 0 &&
RI_FKey_trigger_type(funcoid) != RI_TRIGGER_NONE)
{
/* Keep lock on target rel until end of xact */
heap_close(rel, NoLock);
ConvertTriggerToFK(stmt, funcoid);
return InvalidOid;
}
/*
* If it's a user-entered CREATE CONSTRAINT TRIGGER command, make a
* corresponding pg_constraint entry.
*/
if (stmt->isconstraint && !OidIsValid(constraintOid))
{
/* Internal callers should have made their own constraints */
Assert(!isInternal);
constraintOid = CreateConstraintEntry(stmt->trigname,
RelationGetNamespace(rel),
CONSTRAINT_TRIGGER,
stmt->deferrable,
stmt->initdeferred,
RelationGetRelid(rel),
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NULL, /* no conkey */
0,
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InvalidOid, /* no domain */
InvalidOid, /* no index */
InvalidOid, /* no foreign key */
NULL,
NULL,
NULL,
NULL,
0,
' ',
' ',
' ',
NULL, /* no exclusion */
NULL, /* no check constraint */
NULL,
NULL,
true, /* islocal */
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0); /* inhcount */
}
/*
* Generate the trigger's OID now, so that we can use it in the name if
* needed.
*/
tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
trigoid = GetNewOid(tgrel);
/*
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* If trigger is internally generated, modify the provided trigger name to
* ensure uniqueness by appending the trigger OID. (Callers will usually
* supply a simple constant trigger name in these cases.)
*/
if (isInternal)
{
snprintf(internaltrigname, sizeof(internaltrigname),
"%s_%u", stmt->trigname, trigoid);
trigname = internaltrigname;
}
else
{
/* user-defined trigger; use the specified trigger name as-is */
trigname = stmt->trigname;
}
/*
* Scan pg_trigger for existing triggers on relation. We do this only to
* give a nice error message if there's already a trigger of the same
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* name. (The unique index on tgrelid/tgname would complain anyway.) We
* can skip this for internally generated triggers, since the name
* modification above should be sufficient.
*
* NOTE that this is cool only because we have ShareRowExclusiveLock on the
* relation, so the trigger set won't be changing underneath us.
*/
if (!isInternal)
{
ScanKeyInit(&key,
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, 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),
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errmsg("trigger \"%s\" for relation \"%s\" already exists",
trigname, stmt->relation->relname)));
}
systable_endscan(tgscan);
}
/*
* Build the new pg_trigger tuple.
*/
memset(nulls, false, sizeof(nulls));
values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel));
values[Anum_pg_trigger_tgname - 1] = DirectFunctionCall1(namein,
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CStringGetDatum(trigname));
values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid);
values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype);
Changes pg_trigger and extend pg_rewrite in order to allow triggers and rules to be defined with different, per session controllable, behaviors for replication purposes. This will allow replication systems like Slony-I and, as has been stated on pgsql-hackers, other products to control the firing mechanism of triggers and rewrite rules without modifying the system catalog directly. The firing mechanisms are controlled by a new superuser-only GUC variable, session_replication_role, together with a change to pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both columns are a single char data type now (tgenabled was a bool before). The possible values in these attributes are: 'O' - Trigger/Rule fires when session_replication_role is "origin" (default) or "local". This is the default behavior. 'D' - Trigger/Rule is disabled and fires never 'A' - Trigger/Rule fires always regardless of the setting of session_replication_role 'R' - Trigger/Rule fires when session_replication_role is "replica" The GUC variable can only be changed as long as the system does not have any cached query plans. This will prevent changing the session role and accidentally executing stored procedures or functions that have plans cached that expand to the wrong query set due to differences in the rule firing semantics. The SQL syntax for changing a triggers/rules firing semantics is ALTER TABLE <tabname> <when> TRIGGER|RULE <name>; <when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE psql's \d command as well as pg_dump are extended in a backward compatible fashion. Jan
2007-03-20 00:38:32 +01:00
values[Anum_pg_trigger_tgenabled - 1] = CharGetDatum(TRIGGER_FIRES_ON_ORIGIN);
values[Anum_pg_trigger_tgisinternal - 1] = BoolGetDatum(isInternal);
values[Anum_pg_trigger_tgconstrrelid - 1] = ObjectIdGetDatum(constrrelid);
values[Anum_pg_trigger_tgconstrindid - 1] = ObjectIdGetDatum(indexOid);
values[Anum_pg_trigger_tgconstraint - 1] = ObjectIdGetDatum(constraintOid);
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++)
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{
if (*ar == '\\')
len++;
}
}
args = (char *) palloc(len + 1);
args[0] = '\0';
foreach(le, stmt->args)
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{
char *s = strVal(lfirst(le));
char *d = args + strlen(args);
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while (*s)
{
if (*s == '\\')
*d++ = '\\';
*d++ = *s++;
}
strcpy(d, "\\000");
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}
values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs);
values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
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CStringGetDatum(args));
}
else
{
values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0);
values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
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CStringGetDatum(""));
}
/* build column number array if it's a column-specific trigger */
ncolumns = list_length(stmt->columns);
if (ncolumns == 0)
columns = NULL;
else
{
ListCell *cell;
int i = 0;
columns = (int2 *) palloc(ncolumns * sizeof(int2));
foreach(cell, stmt->columns)
{
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char *name = strVal(lfirst(cell));
int2 attnum;
int j;
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/* Lookup column name. System columns are not allowed */
attnum = attnameAttNum(rel, name, false);
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
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errmsg("column \"%s\" of relation \"%s\" does not exist",
name, RelationGetRelationName(rel))));
/* Check for duplicates */
for (j = i - 1; j >= 0; j--)
{
if (columns[j] == attnum)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column \"%s\" specified more than once",
name)));
}
columns[i++] = attnum;
}
}
tgattr = buildint2vector(columns, ncolumns);
values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr);
/* set tgqual if trigger has WHEN clause */
if (qual)
values[Anum_pg_trigger_tgqual - 1] = CStringGetTextDatum(qual);
else
nulls[Anum_pg_trigger_tgqual - 1] = true;
tuple = heap_form_tuple(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);
heap_freetuple(tuple);
heap_close(tgrel, RowExclusiveLock);
pfree(DatumGetPointer(values[Anum_pg_trigger_tgname - 1]));
pfree(DatumGetPointer(values[Anum_pg_trigger_tgargs - 1]));
pfree(DatumGetPointer(values[Anum_pg_trigger_tgattr - 1]));
/*
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* 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);
tuple = SearchSysCacheCopy1(RELOID,
ObjectIdGetDatum(RelationGetRelid(rel)));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u",
RelationGetRelid(rel));
((Form_pg_class) GETSTRUCT(tuple))->relhastriggers = true;
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
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* fairly pointless since it will happen as a byproduct of the upcoming
* CommandCounterIncrement...
*/
/*
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* Record dependencies for trigger. Always place a normal dependency on
* the function.
*/
myself.classId = TriggerRelationId;
myself.objectId = trigoid;
myself.objectSubId = 0;
referenced.classId = ProcedureRelationId;
referenced.objectId = funcoid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
if (isInternal && OidIsValid(constraintOid))
{
/*
* Internally-generated trigger for a constraint, so make it an
* internal dependency of the constraint. We can skip depending on
* the relation(s), as there'll be an indirect dependency via the
* constraint.
*/
referenced.classId = ConstraintRelationId;
referenced.objectId = constraintOid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
}
else
{
/*
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* User CREATE TRIGGER, so place dependencies. We 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.)
*/
referenced.classId = RelationRelationId;
referenced.objectId = RelationGetRelid(rel);
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
if (OidIsValid(constrrelid))
{
referenced.classId = RelationRelationId;
referenced.objectId = constrrelid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
}
/* Not possible to have an index dependency in this case */
Assert(!OidIsValid(indexOid));
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/*
* If it's a user-specified constraint trigger, make the constraint
* internally dependent on the trigger instead of vice versa.
*/
if (OidIsValid(constraintOid))
{
referenced.classId = ConstraintRelationId;
referenced.objectId = constraintOid;
referenced.objectSubId = 0;
recordDependencyOn(&referenced, &myself, DEPENDENCY_INTERNAL);
}
}
/* If column-specific trigger, add normal dependencies on columns */
if (columns != NULL)
{
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int i;
referenced.classId = RelationRelationId;
referenced.objectId = RelationGetRelid(rel);
for (i = 0; i < ncolumns; i++)
{
referenced.objectSubId = columns[i];
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
}
/*
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* If it has a WHEN clause, add dependencies on objects mentioned in the
* expression (eg, functions, as well as any columns used).
*/
if (whenClause != NULL)
recordDependencyOnExpr(&myself, whenClause, whenRtable,
DEPENDENCY_NORMAL);
/* Keep lock on target rel until end of xact */
heap_close(rel, NoLock);
return trigoid;
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}
/*
* Convert legacy (pre-7.3) CREATE CONSTRAINT TRIGGER commands into
* full-fledged foreign key constraints.
*
* The conversion is complex because a pre-7.3 foreign key involved three
* separate triggers, which were reported separately in dumps. While the
* single trigger on the referencing table adds no new information, we need
* to know the trigger functions of both of the triggers on the referenced
* table to build the constraint declaration. Also, due to lack of proper
* dependency checking pre-7.3, it is possible that the source database had
* an incomplete set of triggers resulting in an only partially enforced
* FK constraint. (This would happen if one of the tables had been dropped
* and re-created, but only if the DB had been affected by a 7.0 pg_dump bug
* that caused loss of tgconstrrelid information.) We choose to translate to
* an FK constraint only when we've seen all three triggers of a set. This is
* implemented by storing unmatched items in a list in TopMemoryContext.
* We match triggers together by comparing the trigger arguments (which
* include constraint name, table and column names, so should be good enough).
*/
typedef struct
{
List *args; /* list of (T_String) Values or NIL */
Oid funcoids[3]; /* OIDs of trigger functions */
/* The three function OIDs are stored in the order update, delete, child */
} OldTriggerInfo;
static void
ConvertTriggerToFK(CreateTrigStmt *stmt, Oid funcoid)
{
static List *info_list = NIL;
static const char *const funcdescr[3] = {
gettext_noop("Found referenced table's UPDATE trigger."),
gettext_noop("Found referenced table's DELETE trigger."),
gettext_noop("Found referencing table's trigger.")
};
char *constr_name;
char *fk_table_name;
char *pk_table_name;
char fk_matchtype = FKCONSTR_MATCH_UNSPECIFIED;
List *fk_attrs = NIL;
List *pk_attrs = NIL;
StringInfoData buf;
int funcnum;
OldTriggerInfo *info = NULL;
ListCell *l;
int i;
/* Parse out the trigger arguments */
constr_name = strVal(linitial(stmt->args));
fk_table_name = strVal(lsecond(stmt->args));
pk_table_name = strVal(lthird(stmt->args));
i = 0;
foreach(l, stmt->args)
{
Value *arg = (Value *) lfirst(l);
i++;
if (i < 4) /* skip constraint and table names */
continue;
if (i == 4) /* handle match type */
{
if (strcmp(strVal(arg), "FULL") == 0)
fk_matchtype = FKCONSTR_MATCH_FULL;
else
fk_matchtype = FKCONSTR_MATCH_UNSPECIFIED;
continue;
}
if (i % 2)
fk_attrs = lappend(fk_attrs, arg);
else
pk_attrs = lappend(pk_attrs, arg);
}
/* Prepare description of constraint for use in messages */
initStringInfo(&buf);
appendStringInfo(&buf, "FOREIGN KEY %s(",
quote_identifier(fk_table_name));
i = 0;
foreach(l, fk_attrs)
{
Value *arg = (Value *) lfirst(l);
if (i++ > 0)
appendStringInfoChar(&buf, ',');
appendStringInfoString(&buf, quote_identifier(strVal(arg)));
}
appendStringInfo(&buf, ") REFERENCES %s(",
quote_identifier(pk_table_name));
i = 0;
foreach(l, pk_attrs)
{
Value *arg = (Value *) lfirst(l);
if (i++ > 0)
appendStringInfoChar(&buf, ',');
appendStringInfoString(&buf, quote_identifier(strVal(arg)));
}
appendStringInfoChar(&buf, ')');
/* Identify class of trigger --- update, delete, or referencing-table */
switch (funcoid)
{
case F_RI_FKEY_CASCADE_UPD:
case F_RI_FKEY_RESTRICT_UPD:
case F_RI_FKEY_SETNULL_UPD:
case F_RI_FKEY_SETDEFAULT_UPD:
case F_RI_FKEY_NOACTION_UPD:
funcnum = 0;
break;
case F_RI_FKEY_CASCADE_DEL:
case F_RI_FKEY_RESTRICT_DEL:
case F_RI_FKEY_SETNULL_DEL:
case F_RI_FKEY_SETDEFAULT_DEL:
case F_RI_FKEY_NOACTION_DEL:
funcnum = 1;
break;
default:
funcnum = 2;
break;
}
/* See if we have a match to this trigger */
foreach(l, info_list)
{
info = (OldTriggerInfo *) lfirst(l);
if (info->funcoids[funcnum] == InvalidOid &&
equal(info->args, stmt->args))
{
info->funcoids[funcnum] = funcoid;
break;
}
}
if (l == NULL)
{
/* First trigger of set, so create a new list entry */
MemoryContext oldContext;
ereport(NOTICE,
(errmsg("ignoring incomplete trigger group for constraint \"%s\" %s",
constr_name, buf.data),
errdetail("%s", _(funcdescr[funcnum]))));
oldContext = MemoryContextSwitchTo(TopMemoryContext);
info = (OldTriggerInfo *) palloc0(sizeof(OldTriggerInfo));
info->args = copyObject(stmt->args);
info->funcoids[funcnum] = funcoid;
info_list = lappend(info_list, info);
MemoryContextSwitchTo(oldContext);
}
else if (info->funcoids[0] == InvalidOid ||
info->funcoids[1] == InvalidOid ||
info->funcoids[2] == InvalidOid)
{
/* Second trigger of set */
ereport(NOTICE,
(errmsg("ignoring incomplete trigger group for constraint \"%s\" %s",
constr_name, buf.data),
errdetail("%s", _(funcdescr[funcnum]))));
}
else
{
/* OK, we have a set, so make the FK constraint ALTER TABLE cmd */
AlterTableStmt *atstmt = makeNode(AlterTableStmt);
AlterTableCmd *atcmd = makeNode(AlterTableCmd);
Constraint *fkcon = makeNode(Constraint);
ereport(NOTICE,
(errmsg("converting trigger group into constraint \"%s\" %s",
constr_name, buf.data),
errdetail("%s", _(funcdescr[funcnum]))));
fkcon->contype = CONSTR_FOREIGN;
fkcon->location = -1;
if (funcnum == 2)
{
/* This trigger is on the FK table */
atstmt->relation = stmt->relation;
if (stmt->constrrel)
fkcon->pktable = stmt->constrrel;
else
{
/* Work around ancient pg_dump bug that omitted constrrel */
fkcon->pktable = makeRangeVar(NULL, pk_table_name, -1);
}
}
else
{
/* This trigger is on the PK table */
fkcon->pktable = stmt->relation;
if (stmt->constrrel)
atstmt->relation = stmt->constrrel;
else
{
/* Work around ancient pg_dump bug that omitted constrrel */
atstmt->relation = makeRangeVar(NULL, fk_table_name, -1);
}
}
atstmt->cmds = list_make1(atcmd);
atstmt->relkind = OBJECT_TABLE;
atcmd->subtype = AT_AddConstraint;
atcmd->def = (Node *) fkcon;
if (strcmp(constr_name, "<unnamed>") == 0)
fkcon->conname = NULL;
else
fkcon->conname = constr_name;
fkcon->fk_attrs = fk_attrs;
fkcon->pk_attrs = pk_attrs;
fkcon->fk_matchtype = fk_matchtype;
switch (info->funcoids[0])
{
case F_RI_FKEY_NOACTION_UPD:
fkcon->fk_upd_action = FKCONSTR_ACTION_NOACTION;
break;
case F_RI_FKEY_CASCADE_UPD:
fkcon->fk_upd_action = FKCONSTR_ACTION_CASCADE;
break;
case F_RI_FKEY_RESTRICT_UPD:
fkcon->fk_upd_action = FKCONSTR_ACTION_RESTRICT;
break;
case F_RI_FKEY_SETNULL_UPD:
fkcon->fk_upd_action = FKCONSTR_ACTION_SETNULL;
break;
case F_RI_FKEY_SETDEFAULT_UPD:
fkcon->fk_upd_action = FKCONSTR_ACTION_SETDEFAULT;
break;
default:
/* can't get here because of earlier checks */
elog(ERROR, "confused about RI update function");
}
switch (info->funcoids[1])
{
case F_RI_FKEY_NOACTION_DEL:
fkcon->fk_del_action = FKCONSTR_ACTION_NOACTION;
break;
case F_RI_FKEY_CASCADE_DEL:
fkcon->fk_del_action = FKCONSTR_ACTION_CASCADE;
break;
case F_RI_FKEY_RESTRICT_DEL:
fkcon->fk_del_action = FKCONSTR_ACTION_RESTRICT;
break;
case F_RI_FKEY_SETNULL_DEL:
fkcon->fk_del_action = FKCONSTR_ACTION_SETNULL;
break;
case F_RI_FKEY_SETDEFAULT_DEL:
fkcon->fk_del_action = FKCONSTR_ACTION_SETDEFAULT;
break;
default:
/* can't get here because of earlier checks */
elog(ERROR, "confused about RI delete function");
}
fkcon->deferrable = stmt->deferrable;
fkcon->initdeferred = stmt->initdeferred;
/* ... and execute it */
ProcessUtility((Node *) atstmt,
"(generated ALTER TABLE ADD FOREIGN KEY command)",
NULL, false, None_Receiver, NULL);
/* Remove the matched item from the list */
info_list = list_delete_ptr(info_list, info);
pfree(info);
/* We leak the copied args ... not worth worrying about */
}
}
/*
* DropTrigger - drop an individual trigger by name
*/
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void
DropTrigger(Oid relid, const char *trigname, DropBehavior behavior,
bool missing_ok)
{
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Relation tgrel;
ScanKeyData skey[2];
SysScanDesc tgscan;
HeapTuple tup;
ObjectAddress object;
/*
* Find the trigger, verify permissions, set up object address
*/
tgrel = heap_open(TriggerRelationId, 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, TriggerRelidNameIndexId, true,
SnapshotNow, 2, skey);
tup = systable_getnext(tgscan);
if (!HeapTupleIsValid(tup))
{
2006-10-04 02:30:14 +02:00
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 */
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
return;
}
if (!pg_class_ownercheck(relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
get_rel_name(relid));
object.classId = TriggerRelationId;
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)
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{
Relation tgrel;
2002-09-04 22:31:48 +02:00
SysScanDesc tgscan;
ScanKeyData skey[1];
HeapTuple tup;
Oid relid;
Relation rel;
tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
/*
* Find the trigger to delete.
*/
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(trigOid));
tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true,
SnapshotNow, 1, skey);
tup = systable_getnext(tgscan);
if (!HeapTupleIsValid(tup))
elog(ERROR, "could not find tuple for trigger %u", trigOid);
/*
* Open and lock the relation the trigger belongs to. As in
* CreateTrigger, this is sufficient to lock out all operations that
* could fire or add triggers; but it would need to be revisited if
* we had ON SELECT triggers.
*/
relid = ((Form_pg_trigger) GETSTRUCT(tup))->tgrelid;
rel = heap_open(relid, ShareRowExclusiveLock);
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);
/*
* We do not bother to try to determine whether any other triggers remain,
* which would be needed in order to decide whether it's safe to clear the
* relation's relhastriggers. (In any case, there might be a concurrent
* process adding new triggers.) Instead, just force a relcache inval to
* make other backends (and this one too!) rebuild their relcache entries.
* There's no great harm in leaving relhastriggers true even if there are
* no triggers left.
*/
CacheInvalidateRelcache(rel);
/* Keep lock on trigger's rel until end of xact */
heap_close(rel, NoLock);
1997-08-31 13:40:13 +02:00
}
/*
* 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;
2002-09-04 22:31:48 +02:00
SysScanDesc tgscan;
ScanKeyData key[2];
/*
2005-10-15 04:49:52 +02:00
* Grab an exclusive lock on the target table, which we will NOT release
* until end of transaction.
*/
targetrel = heap_open(relid, AccessExclusiveLock);
/*
2005-10-15 04:49:52 +02:00
* 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
*/
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, TriggerRelidNameIndexId, true,
SnapshotNow, 2, key);
if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
2005-10-15 04:49:52 +02:00
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, TriggerRelidNameIndexId, true,
SnapshotNow, 2, key);
if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
{
/*
* Update pg_trigger tuple with new tgname.
*/
2002-09-04 22:31:48 +02:00
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);
/*
2005-10-15 04:49:52 +02:00
* 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),
2004-08-29 07:07:03 +02:00
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);
}
/*
* EnableDisableTrigger()
*
* Called by ALTER TABLE ENABLE/DISABLE [ REPLICA | ALWAYS ] TRIGGER
Changes pg_trigger and extend pg_rewrite in order to allow triggers and rules to be defined with different, per session controllable, behaviors for replication purposes. This will allow replication systems like Slony-I and, as has been stated on pgsql-hackers, other products to control the firing mechanism of triggers and rewrite rules without modifying the system catalog directly. The firing mechanisms are controlled by a new superuser-only GUC variable, session_replication_role, together with a change to pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both columns are a single char data type now (tgenabled was a bool before). The possible values in these attributes are: 'O' - Trigger/Rule fires when session_replication_role is "origin" (default) or "local". This is the default behavior. 'D' - Trigger/Rule is disabled and fires never 'A' - Trigger/Rule fires always regardless of the setting of session_replication_role 'R' - Trigger/Rule fires when session_replication_role is "replica" The GUC variable can only be changed as long as the system does not have any cached query plans. This will prevent changing the session role and accidentally executing stored procedures or functions that have plans cached that expand to the wrong query set due to differences in the rule firing semantics. The SQL syntax for changing a triggers/rules firing semantics is ALTER TABLE <tabname> <when> TRIGGER|RULE <name>; <when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE psql's \d command as well as pg_dump are extended in a backward compatible fashion. Jan
2007-03-20 00:38:32 +01:00
* to change 'tgenabled' field 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
* fires_when: new value for tgenabled field. In addition to generic
* enablement/disablement, this also defines when the trigger
* should be fired in session replication roles.
* 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,
Changes pg_trigger and extend pg_rewrite in order to allow triggers and rules to be defined with different, per session controllable, behaviors for replication purposes. This will allow replication systems like Slony-I and, as has been stated on pgsql-hackers, other products to control the firing mechanism of triggers and rewrite rules without modifying the system catalog directly. The firing mechanisms are controlled by a new superuser-only GUC variable, session_replication_role, together with a change to pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both columns are a single char data type now (tgenabled was a bool before). The possible values in these attributes are: 'O' - Trigger/Rule fires when session_replication_role is "origin" (default) or "local". This is the default behavior. 'D' - Trigger/Rule is disabled and fires never 'A' - Trigger/Rule fires always regardless of the setting of session_replication_role 'R' - Trigger/Rule fires when session_replication_role is "replica" The GUC variable can only be changed as long as the system does not have any cached query plans. This will prevent changing the session role and accidentally executing stored procedures or functions that have plans cached that expand to the wrong query set due to differences in the rule firing semantics. The SQL syntax for changing a triggers/rules firing semantics is ALTER TABLE <tabname> <when> TRIGGER|RULE <name>; <when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE psql's \d command as well as pg_dump are extended in a backward compatible fashion. Jan
2007-03-20 00:38:32 +01:00
char fires_when, bool skip_system)
{
2005-10-15 04:49:52 +02:00
Relation tgrel;
int nkeys;
ScanKeyData keys[2];
SysScanDesc tgscan;
2005-10-15 04:49:52 +02:00
HeapTuple tuple;
bool found;
bool changed;
/* Scan the relevant entries in pg_triggers */
tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
ScanKeyInit(&keys[0],
Anum_pg_trigger_tgrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
if (tgname)
{
ScanKeyInit(&keys[1],
Anum_pg_trigger_tgname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(tgname));
nkeys = 2;
}
else
nkeys = 1;
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
SnapshotNow, nkeys, keys);
found = changed = false;
while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
{
Form_pg_trigger oldtrig = (Form_pg_trigger) GETSTRUCT(tuple);
if (oldtrig->tgisinternal)
{
/* system trigger ... ok to process? */
if (skip_system)
continue;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
2005-10-15 04:49:52 +02:00
errmsg("permission denied: \"%s\" is a system trigger",
NameStr(oldtrig->tgname))));
}
found = true;
Changes pg_trigger and extend pg_rewrite in order to allow triggers and rules to be defined with different, per session controllable, behaviors for replication purposes. This will allow replication systems like Slony-I and, as has been stated on pgsql-hackers, other products to control the firing mechanism of triggers and rewrite rules without modifying the system catalog directly. The firing mechanisms are controlled by a new superuser-only GUC variable, session_replication_role, together with a change to pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both columns are a single char data type now (tgenabled was a bool before). The possible values in these attributes are: 'O' - Trigger/Rule fires when session_replication_role is "origin" (default) or "local". This is the default behavior. 'D' - Trigger/Rule is disabled and fires never 'A' - Trigger/Rule fires always regardless of the setting of session_replication_role 'R' - Trigger/Rule fires when session_replication_role is "replica" The GUC variable can only be changed as long as the system does not have any cached query plans. This will prevent changing the session role and accidentally executing stored procedures or functions that have plans cached that expand to the wrong query set due to differences in the rule firing semantics. The SQL syntax for changing a triggers/rules firing semantics is ALTER TABLE <tabname> <when> TRIGGER|RULE <name>; <when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE psql's \d command as well as pg_dump are extended in a backward compatible fashion. Jan
2007-03-20 00:38:32 +01:00
if (oldtrig->tgenabled != fires_when)
{
/* need to change this one ... make a copy to scribble on */
2005-10-15 04:49:52 +02:00
HeapTuple newtup = heap_copytuple(tuple);
Form_pg_trigger newtrig = (Form_pg_trigger) GETSTRUCT(newtup);
Changes pg_trigger and extend pg_rewrite in order to allow triggers and rules to be defined with different, per session controllable, behaviors for replication purposes. This will allow replication systems like Slony-I and, as has been stated on pgsql-hackers, other products to control the firing mechanism of triggers and rewrite rules without modifying the system catalog directly. The firing mechanisms are controlled by a new superuser-only GUC variable, session_replication_role, together with a change to pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both columns are a single char data type now (tgenabled was a bool before). The possible values in these attributes are: 'O' - Trigger/Rule fires when session_replication_role is "origin" (default) or "local". This is the default behavior. 'D' - Trigger/Rule is disabled and fires never 'A' - Trigger/Rule fires always regardless of the setting of session_replication_role 'R' - Trigger/Rule fires when session_replication_role is "replica" The GUC variable can only be changed as long as the system does not have any cached query plans. This will prevent changing the session role and accidentally executing stored procedures or functions that have plans cached that expand to the wrong query set due to differences in the rule firing semantics. The SQL syntax for changing a triggers/rules firing semantics is ALTER TABLE <tabname> <when> TRIGGER|RULE <name>; <when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE psql's \d command as well as pg_dump are extended in a backward compatible fashion. Jan
2007-03-20 00:38:32 +01:00
newtrig->tgenabled = fires_when;
simple_heap_update(tgrel, &newtup->t_self, newtup);
/* Keep catalog indexes current */
CatalogUpdateIndexes(tgrel, newtup);
heap_freetuple(newtup);
changed = true;
}
}
systable_endscan(tgscan);
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 numtrigs;
int maxtrigs;
Trigger *triggers;
Relation tgrel;
ScanKeyData skey;
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SysScanDesc tgscan;
2000-02-18 10:30:20 +01:00
HeapTuple htup;
MemoryContext oldContext;
int i;
/*
* Allocate a working array to hold the triggers (the array is extended if
* necessary)
*/
maxtrigs = 16;
triggers = (Trigger *) palloc(maxtrigs * sizeof(Trigger));
numtrigs = 0;
/*
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* Note: since we scan the triggers using TriggerRelidNameIndexId, we will
* be reading the triggers in name order, except possibly during
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* emergency-recovery operations (ie, IgnoreSystemIndexes). 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_open(TriggerRelationId, AccessShareLock);
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
SnapshotNow, 1, &skey);
while (HeapTupleIsValid(htup = systable_getnext(tgscan)))
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
Trigger *build;
Datum datum;
bool isnull;
if (numtrigs >= maxtrigs)
{
maxtrigs *= 2;
triggers = (Trigger *) repalloc(triggers, maxtrigs * sizeof(Trigger));
}
build = &(triggers[numtrigs]);
build->tgoid = HeapTupleGetOid(htup);
build->tgname = DatumGetCString(DirectFunctionCall1(nameout,
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NameGetDatum(&pg_trigger->tgname)));
build->tgfoid = pg_trigger->tgfoid;
build->tgtype = pg_trigger->tgtype;
build->tgenabled = pg_trigger->tgenabled;
build->tgisinternal = pg_trigger->tgisinternal;
build->tgconstrrelid = pg_trigger->tgconstrrelid;
build->tgconstrindid = pg_trigger->tgconstrindid;
build->tgconstraint = pg_trigger->tgconstraint;
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;
char *p;
val = DatumGetByteaP(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;
datum = fastgetattr(htup, Anum_pg_trigger_tgqual,
tgrel->rd_att, &isnull);
if (!isnull)
build->tgqual = TextDatumGetCString(datum);
else
build->tgqual = NULL;
numtrigs++;
}
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
/* There might not be any triggers */
if (numtrigs == 0)
{
pfree(triggers);
return;
}
/* Build trigdesc */
trigdesc = (TriggerDesc *) palloc0(sizeof(TriggerDesc));
trigdesc->triggers = triggers;
trigdesc->numtriggers = numtrigs;
for (i = 0; i < numtrigs; i++)
InsertTrigger(trigdesc, &(triggers[i]), i);
/* Copy completed trigdesc into cache storage */
oldContext = MemoryContextSwitchTo(CacheMemoryContext);
relation->trigdesc = CopyTriggerDesc(trigdesc);
MemoryContextSwitchTo(oldContext);
/* Release working memory */
FreeTriggerDesc(trigdesc);
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}
/*
* 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.
*/
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static void
InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx)
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{
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])++;
}
if (TRIGGER_FOR_TRUNCATE(trigger->tgtype))
{
tp = &(t[TRIGGER_EVENT_TRUNCATE]);
if (*tp == NULL)
*tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
(*tp)[n[TRIGGER_EVENT_TRUNCATE]] = indx;
(n[TRIGGER_EVENT_TRUNCATE])++;
}
}
/*
* 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)
{
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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;
}
if (trigger->tgqual)
trigger->tgqual = pstrdup(trigger->tgqual);
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);
}
if (trigger->tgqual)
pfree(trigger->tgqual);
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;
/*
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* 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.
*
* Note: comparing the stringToNode forms of the WHEN clauses means that
2010-02-26 03:01:40 +01:00
* parse column locations will affect the result. This is okay as long as
* this function is only used for detecting exact equality, as for example
* in checking for staleness of a cache entry.
*/
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->tgisinternal != trig2->tgisinternal)
return false;
if (trig1->tgconstrrelid != trig2->tgconstrrelid)
return false;
if (trig1->tgconstrindid != trig2->tgconstrindid)
return false;
if (trig1->tgconstraint != trig2->tgconstraint)
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;
if (trig1->tgqual == NULL && trig2->tgqual == NULL)
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/* ok */ ;
else if (trig1->tgqual == NULL || trig2->tgqual == NULL)
return false;
else if (strcmp(trig1->tgqual, trig2->tgqual) != 0)
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return false;
}
}
else if (trigdesc2 != NULL)
return false;
return true;
}
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#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.
*/
static HeapTuple
ExecCallTriggerFunc(TriggerData *trigdata,
int tgindx,
FmgrInfo *finfo,
Instrumentation *instr,
MemoryContext per_tuple_context)
{
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FunctionCallInfoData fcinfo;
PgStat_FunctionCallUsage fcusage;
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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);
/*
2001-03-22 05:01:46 +01:00
* Do the function evaluation in the per-tuple memory context, so that
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* 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);
pgstat_init_function_usage(&fcinfo, &fcusage);
result = FunctionCallInvoke(&fcinfo);
pgstat_end_function_usage(&fcusage, true);
MemoryContextSwitchTo(oldContext);
/*
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* 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)));
/*
2005-10-15 04:49:52 +02:00
* 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)
{
2003-08-04 02:43:34 +02:00
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 |
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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 (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, NULL))
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),
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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(estate, relinfo, TRIGGER_EVENT_INSERT,
false, NULL, NULL, NIL, 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];
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HeapTuple newtuple = trigtuple;
HeapTuple oldtuple;
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TriggerData LocTriggerData;
int i;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
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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 (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, newtuple))
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;
}
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return newtuple;
}
void
ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo,
HeapTuple trigtuple, List *recheckIndexes)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0)
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_INSERT,
true, NULL, trigtuple, recheckIndexes, NULL);
}
void
ExecBSDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
{
2003-08-04 02:43:34 +02:00
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 |
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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 (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, NULL))
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),
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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(estate, relinfo, TRIGGER_EVENT_DELETE,
false, NULL, NULL, NIL, NULL);
}
bool
ExecBRDeleteTriggers(EState *estate, EPQState *epqstate,
ResultRelInfo *relinfo,
ItemPointer tupleid)
{
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;
1999-05-25 18:15:34 +02:00
HeapTuple trigtuple;
HeapTuple newtuple;
TupleTableSlot *newSlot;
1999-05-25 18:15:34 +02:00
int i;
trigtuple = GetTupleForTrigger(estate, epqstate, relinfo, tupleid,
&newSlot);
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if (trigtuple == NULL)
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return false;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
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TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1997-09-11 09:24:37 +02:00
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, trigtuple, NULL))
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));
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if (newtuple == NULL)
{
result = false; /* tell caller to suppress delete */
1997-09-11 09:24:37 +02:00
break;
}
if (newtuple != trigtuple)
heap_freetuple(newtuple);
1997-09-11 09:24:37 +02:00
}
heap_freetuple(trigtuple);
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return result;
}
void
ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1997-09-11 09:24:37 +02:00
if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0)
{
HeapTuple trigtuple = GetTupleForTrigger(estate, NULL, relinfo,
tupleid, NULL);
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_DELETE,
true, trigtuple, NULL, NIL, NULL);
heap_freetuple(trigtuple);
}
}
void
ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
{
2003-08-04 02:43:34 +02:00
TriggerDesc *trigdesc;
int ntrigs;
int *tgindx;
int i;
TriggerData LocTriggerData;
2010-02-26 03:01:40 +01:00
Bitmapset *modifiedCols;
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;
modifiedCols = GetModifiedColumns(relinfo, estate);
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
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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 (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
modifiedCols, NULL, NULL))
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),
2005-10-15 04:49:52 +02:00
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(estate, relinfo, TRIGGER_EVENT_UPDATE,
false, NULL, NULL, NIL,
GetModifiedColumns(relinfo, estate));
}
HeapTuple
ExecBRUpdateTriggers(EState *estate, EPQState *epqstate,
ResultRelInfo *relinfo,
ItemPointer tupleid, HeapTuple newtuple)
{
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;
1999-05-25 18:15:34 +02:00
HeapTuple trigtuple;
HeapTuple oldtuple;
HeapTuple intuple = newtuple;
TupleTableSlot *newSlot;
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int i;
2010-02-26 03:01:40 +01:00
Bitmapset *modifiedCols;
trigtuple = GetTupleForTrigger(estate, epqstate, relinfo, tupleid,
&newSlot);
1997-09-11 09:24:37 +02:00
if (trigtuple == NULL)
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return NULL;
1997-09-11 09:24:37 +02:00
/*
* In READ COMMITTED isolation level it's possible that newtuple was
* changed due to concurrent update. In that case we have a raw subplan
* output tuple and need to run it through the junk filter.
*/
if (newSlot != NULL)
intuple = newtuple = ExecRemoveJunk(relinfo->ri_junkFilter, newSlot);
modifiedCols = GetModifiedColumns(relinfo, estate);
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
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TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
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for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
modifiedCols, trigtuple, newtuple))
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);
1997-09-11 09:24:37 +02:00
if (newtuple == NULL)
break;
}
heap_freetuple(trigtuple);
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return newtuple;
}
void
ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid, HeapTuple newtuple,
List *recheckIndexes)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0)
{
HeapTuple trigtuple = GetTupleForTrigger(estate, NULL, relinfo,
tupleid, NULL);
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_UPDATE,
true, trigtuple, newtuple, recheckIndexes,
GetModifiedColumns(relinfo, estate));
heap_freetuple(trigtuple);
}
}
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void
ExecBSTruncateTriggers(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_TRUNCATE];
tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_TRUNCATE];
if (ntrigs == 0)
return;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_TRUNCATE |
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 (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, NULL))
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
ExecASTruncateTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_TRUNCATE] > 0)
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_TRUNCATE,
false, NULL, NULL, NIL, NULL);
}
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static HeapTuple
GetTupleForTrigger(EState *estate,
EPQState *epqstate,
ResultRelInfo *relinfo,
ItemPointer tid,
TupleTableSlot **newSlot)
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{
Relation relation = relinfo->ri_RelationDesc;
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HeapTupleData tuple;
HeapTuple result;
Buffer buffer;
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if (newSlot != NULL)
{
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HTSU_Result test;
ItemPointerData update_ctid;
TransactionId update_xmax;
*newSlot = NULL;
/* caller must pass an epqstate if EvalPlanQual is possible */
Assert(epqstate != NULL);
/*
* lock tuple for update
*/
ltrmark:;
tuple.t_self = *tid;
test = heap_lock_tuple(relation, &tuple, &buffer,
&update_ctid, &update_xmax,
estate->es_output_cid,
LockTupleExclusive, false);
switch (test)
{
case HeapTupleSelfUpdated:
/* treat it as deleted; do not process */
ReleaseBuffer(buffer);
return NULL;
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case HeapTupleMayBeUpdated:
break;
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case HeapTupleUpdated:
ReleaseBuffer(buffer);
if (IsXactIsoLevelSerializable)
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
if (!ItemPointerEquals(&update_ctid, &tuple.t_self))
{
/* it was updated, so look at the updated version */
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
epqstate,
relation,
relinfo->ri_RangeTableIndex,
&update_ctid,
update_xmax);
if (!TupIsNull(epqslot))
{
*tid = update_ctid;
*newSlot = epqslot;
/*
* EvalPlanQual already locked the tuple, but we
2010-02-26 03:01:40 +01:00
* re-call heap_lock_tuple anyway as an easy way of
* re-fetching the correct tuple. Speed is hardly a
* criterion in this path anyhow.
*/
goto ltrmark;
}
}
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/*
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* if tuple was deleted or PlanQual failed for updated tuple -
* we must not process this tuple!
*/
return NULL;
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default:
ReleaseBuffer(buffer);
elog(ERROR, "unrecognized heap_lock_tuple status: %u", test);
return NULL; /* keep compiler quiet */
}
}
else
{
Page page;
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ItemId lp;
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buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
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page = BufferGetPage(buffer);
lp = PageGetItemId(page, ItemPointerGetOffsetNumber(tid));
Assert(ItemIdIsNormal(lp));
tuple.t_data = (HeapTupleHeader) PageGetItem(page, lp);
tuple.t_len = ItemIdGetLength(lp);
tuple.t_self = *tid;
tuple.t_tableOid = RelationGetRelid(relation);
1997-09-11 09:24:37 +02:00
}
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result = heap_copytuple(&tuple);
ReleaseBuffer(buffer);
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1998-11-27 20:52:36 +01:00
return result;
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}
/*
* Is trigger enabled to fire?
*/
static bool
TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
Trigger *trigger, TriggerEvent event,
Bitmapset *modifiedCols,
HeapTuple oldtup, HeapTuple newtup)
{
/* Check replication-role-dependent enable state */
if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA)
{
if (trigger->tgenabled == TRIGGER_FIRES_ON_ORIGIN ||
trigger->tgenabled == TRIGGER_DISABLED)
return false;
}
else /* ORIGIN or LOCAL role */
{
if (trigger->tgenabled == TRIGGER_FIRES_ON_REPLICA ||
trigger->tgenabled == TRIGGER_DISABLED)
return false;
}
/*
* Check for column-specific trigger (only possible for UPDATE, and in
* fact we *must* ignore tgattr for other event types)
*/
if (trigger->tgnattr > 0 && TRIGGER_FIRED_BY_UPDATE(event))
{
int i;
bool modified;
modified = false;
for (i = 0; i < trigger->tgnattr; i++)
{
if (bms_is_member(trigger->tgattr[i] - FirstLowInvalidHeapAttributeNumber,
modifiedCols))
{
modified = true;
break;
}
}
if (!modified)
return false;
}
/* Check for WHEN clause */
if (trigger->tgqual)
{
TupleDesc tupdesc = RelationGetDescr(relinfo->ri_RelationDesc);
List **predicate;
ExprContext *econtext;
TupleTableSlot *oldslot = NULL;
TupleTableSlot *newslot = NULL;
MemoryContext oldContext;
int i;
Assert(estate != NULL);
/*
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* trigger is an element of relinfo->ri_TrigDesc->triggers[]; find the
* matching element of relinfo->ri_TrigWhenExprs[]
*/
i = trigger - relinfo->ri_TrigDesc->triggers;
predicate = &relinfo->ri_TrigWhenExprs[i];
/*
* If first time through for this WHEN expression, build expression
* nodetrees for it. Keep them in the per-query memory context so
* they'll survive throughout the query.
*/
if (*predicate == NIL)
{
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Node *tgqual;
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
tgqual = stringToNode(trigger->tgqual);
/* Change references to OLD and NEW to INNER and OUTER */
ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER, 0);
ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER, 0);
/* ExecQual wants implicit-AND form */
tgqual = (Node *) make_ands_implicit((Expr *) tgqual);
*predicate = (List *) ExecPrepareExpr((Expr *) tgqual, estate);
MemoryContextSwitchTo(oldContext);
}
/*
* We will use the EState's per-tuple context for evaluating WHEN
* expressions (creating it if it's not already there).
*/
econtext = GetPerTupleExprContext(estate);
/*
* Put OLD and NEW tuples into tupleslots for expression evaluation.
* These slots can be shared across the whole estate, but be careful
* that they have the current resultrel's tupdesc.
*/
if (HeapTupleIsValid(oldtup))
{
if (estate->es_trig_oldtup_slot == NULL)
{
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
estate->es_trig_oldtup_slot = ExecInitExtraTupleSlot(estate);
MemoryContextSwitchTo(oldContext);
}
oldslot = estate->es_trig_oldtup_slot;
if (oldslot->tts_tupleDescriptor != tupdesc)
ExecSetSlotDescriptor(oldslot, tupdesc);
ExecStoreTuple(oldtup, oldslot, InvalidBuffer, false);
}
if (HeapTupleIsValid(newtup))
{
if (estate->es_trig_tuple_slot == NULL)
{
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
estate->es_trig_tuple_slot = ExecInitExtraTupleSlot(estate);
MemoryContextSwitchTo(oldContext);
}
newslot = estate->es_trig_tuple_slot;
if (newslot->tts_tupleDescriptor != tupdesc)
ExecSetSlotDescriptor(newslot, tupdesc);
ExecStoreTuple(newtup, newslot, InvalidBuffer, false);
}
/*
* Finally evaluate the expression, making the old and/or new tuples
* available as INNER/OUTER respectively.
*/
econtext->ecxt_innertuple = oldslot;
econtext->ecxt_outertuple = newslot;
if (!ExecQual(*predicate, econtext, false))
return false;
}
return true;
}
/* ----------
* 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 a separate sub-context. This is
* done mainly so that it's easy to tell from a memory context dump how much
* space is being eaten by trigger events.
*
* Because the list of pending events can grow large, we go to some
* considerable effort to minimize per-event memory consumption. The event
* records are grouped into chunks and common data for similar events in the
* same chunk is only stored once.
*
* 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.
2003-08-04 02:43:34 +02:00
*
* 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
{
2004-08-29 07:07:03 +02:00
bool all_isset;
bool all_isdeferred;
int numstates; /* number of trigstates[] entries in use */
int numalloc; /* allocated size of trigstates[] */
2005-10-15 04:49:52 +02:00
SetConstraintTriggerData trigstates[1]; /* VARIABLE LENGTH ARRAY */
} SetConstraintStateData;
typedef SetConstraintStateData *SetConstraintState;
/*
* Per-trigger-event data
*
* The actual per-event data, AfterTriggerEventData, includes DONE/IN_PROGRESS
* status bits and one or two tuple CTIDs. Each event record also has an
* associated AfterTriggerSharedData that is shared across all instances
* of similar events within a "chunk".
*
* We arrange not to waste storage on ate_ctid2 for non-update events.
* We could go further and not store either ctid for statement-level triggers,
* but that seems unlikely to be worth the trouble.
*
* Note: ats_firing_id is initially zero and is set to something else when
* AFTER_TRIGGER_IN_PROGRESS is set. It indicates which trigger firing
* cycle the trigger will be fired in (or was fired in, if DONE is set).
* Although this is mutable state, we can keep it in AfterTriggerSharedData
* because all instances of the same type of event in a given event list will
* be fired at the same time, if they were queued between the same firing
* cycles. So we need only ensure that ats_firing_id is zero when attaching
* a new event to an existing AfterTriggerSharedData record.
*/
typedef uint32 TriggerFlags;
#define AFTER_TRIGGER_OFFSET 0x0FFFFFFF /* must be low-order
* bits */
#define AFTER_TRIGGER_2CTIDS 0x10000000
#define AFTER_TRIGGER_DONE 0x20000000
#define AFTER_TRIGGER_IN_PROGRESS 0x40000000
typedef struct AfterTriggerSharedData *AfterTriggerShared;
typedef struct AfterTriggerSharedData
{
TriggerEvent ats_event; /* event type indicator, see trigger.h */
Oid ats_tgoid; /* the trigger's ID */
Oid ats_relid; /* the relation it's on */
CommandId ats_firing_id; /* ID for firing cycle */
} AfterTriggerSharedData;
typedef struct AfterTriggerEventData *AfterTriggerEvent;
typedef struct AfterTriggerEventData
{
TriggerFlags ate_flags; /* status bits and offset to shared data */
ItemPointerData ate_ctid1; /* inserted, deleted, or old updated tuple */
ItemPointerData ate_ctid2; /* new updated tuple */
} AfterTriggerEventData;
/* This struct must exactly match the one above except for not having ctid2 */
typedef struct AfterTriggerEventDataOneCtid
{
TriggerFlags ate_flags; /* status bits and offset to shared data */
ItemPointerData ate_ctid1; /* inserted, deleted, or old updated tuple */
} AfterTriggerEventDataOneCtid;
#define SizeofTriggerEvent(evt) \
(((evt)->ate_flags & AFTER_TRIGGER_2CTIDS) ? \
sizeof(AfterTriggerEventData) : sizeof(AfterTriggerEventDataOneCtid))
#define GetTriggerSharedData(evt) \
((AfterTriggerShared) ((char *) (evt) + ((evt)->ate_flags & AFTER_TRIGGER_OFFSET)))
/*
* To avoid palloc overhead, we keep trigger events in arrays in successively-
* larger chunks (a slightly more sophisticated version of an expansible
* array). The space between CHUNK_DATA_START and freeptr is occupied by
* AfterTriggerEventData records; the space between endfree and endptr is
* occupied by AfterTriggerSharedData records.
*/
typedef struct AfterTriggerEventChunk
{
struct AfterTriggerEventChunk *next; /* list link */
char *freeptr; /* start of free space in chunk */
char *endfree; /* end of free space in chunk */
char *endptr; /* end of chunk */
/* event data follows here */
} AfterTriggerEventChunk;
#define CHUNK_DATA_START(cptr) ((char *) (cptr) + MAXALIGN(sizeof(AfterTriggerEventChunk)))
/* A list of events */
typedef struct AfterTriggerEventList
{
AfterTriggerEventChunk *head;
AfterTriggerEventChunk *tail;
char *tailfree; /* freeptr of tail chunk */
} AfterTriggerEventList;
/* Macros to help in iterating over a list of events */
#define for_each_chunk(cptr, evtlist) \
for (cptr = (evtlist).head; cptr != NULL; cptr = cptr->next)
#define for_each_event(eptr, cptr) \
for (eptr = (AfterTriggerEvent) CHUNK_DATA_START(cptr); \
(char *) eptr < (cptr)->freeptr; \
eptr = (AfterTriggerEvent) (((char *) eptr) + SizeofTriggerEvent(eptr)))
/* Use this if no special per-chunk processing is needed */
#define for_each_event_chunk(eptr, cptr, evtlist) \
for_each_chunk(cptr, evtlist) for_each_event(eptr, cptr)
/*
* 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
2005-10-15 04:49:52 +02:00
* 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
2005-10-15 04:49:52 +02:00
* 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
* list chunks themselves are stored in event_cxt.
*
* 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
2005-10-15 04:49:52 +02:00
* 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
2005-10-15 04:49:52 +02:00
* 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
{
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CommandId firing_counter; /* next firing ID to assign */
SetConstraintState state; /* the active S C state */
AfterTriggerEventList events; /* deferred-event list */
2005-10-15 04:49:52 +02:00
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; /* memory context for events, if any */
/* these fields are just for resetting at subtrans abort: */
SetConstraintState *state_stack; /* stacked S C states */
2005-10-15 04:49:52 +02:00
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,
2005-10-15 04:49:52 +02:00
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,
2005-10-15 04:49:52 +02:00
Oid tgoid, bool tgisdeferred);
/* ----------
* afterTriggerCheckState()
*
* Returns true if the trigger event is actually in state DEFERRED.
* ----------
*/
static bool
afterTriggerCheckState(AfterTriggerShared evtshared)
{
Oid tgoid = evtshared->ats_tgoid;
SetConstraintState state = afterTriggers->state;
2004-08-29 07:07:03 +02:00
int i;
/*
* For not-deferrable triggers (i.e. normal AFTER ROW triggers and
* constraints declared NOT DEFERRABLE), the state is always false.
*/
if ((evtshared->ats_event & 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 ((evtshared->ats_event & AFTER_TRIGGER_INITDEFERRED) != 0);
}
/* ----------
* afterTriggerAddEvent()
*
* Add a new trigger event to the specified queue.
* The passed-in event data is copied.
* ----------
*/
static void
afterTriggerAddEvent(AfterTriggerEventList *events,
AfterTriggerEvent event, AfterTriggerShared evtshared)
{
Size eventsize = SizeofTriggerEvent(event);
Size needed = eventsize + sizeof(AfterTriggerSharedData);
AfterTriggerEventChunk *chunk;
AfterTriggerShared newshared;
AfterTriggerEvent newevent;
/*
* If empty list or not enough room in the tail chunk, make a new chunk.
* We assume here that a new shared record will always be needed.
*/
chunk = events->tail;
if (chunk == NULL ||
chunk->endfree - chunk->freeptr < needed)
{
Size chunksize;
/* Create event context if we didn't already */
if (afterTriggers->event_cxt == NULL)
afterTriggers->event_cxt =
AllocSetContextCreate(TopTransactionContext,
"AfterTriggerEvents",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* Chunk size starts at 1KB and is allowed to increase up to 1MB.
* These numbers are fairly arbitrary, though there is a hard limit at
* AFTER_TRIGGER_OFFSET; else we couldn't link event records to their
* shared records using the available space in ate_flags. Another
* constraint is that if the chunk size gets too huge, the search loop
* below would get slow given a (not too common) usage pattern with
* many distinct event types in a chunk. Therefore, we double the
* preceding chunk size only if there weren't too many shared records
* in the preceding chunk; otherwise we halve it. This gives us some
* ability to adapt to the actual usage pattern of the current query
* while still having large chunk sizes in typical usage. All chunk
* sizes used should be MAXALIGN multiples, to ensure that the shared
* records will be aligned safely.
*/
#define MIN_CHUNK_SIZE 1024
#define MAX_CHUNK_SIZE (1024*1024)
#if MAX_CHUNK_SIZE > (AFTER_TRIGGER_OFFSET+1)
#error MAX_CHUNK_SIZE must not exceed AFTER_TRIGGER_OFFSET
#endif
if (chunk == NULL)
chunksize = MIN_CHUNK_SIZE;
else
{
/* preceding chunk size... */
chunksize = chunk->endptr - (char *) chunk;
/* check number of shared records in preceding chunk */
if ((chunk->endptr - chunk->endfree) <=
(100 * sizeof(AfterTriggerSharedData)))
chunksize *= 2; /* okay, double it */
else
chunksize /= 2; /* too many shared records */
chunksize = Min(chunksize, MAX_CHUNK_SIZE);
}
chunk = MemoryContextAlloc(afterTriggers->event_cxt, chunksize);
chunk->next = NULL;
chunk->freeptr = CHUNK_DATA_START(chunk);
chunk->endptr = chunk->endfree = (char *) chunk + chunksize;
Assert(chunk->endfree - chunk->freeptr >= needed);
if (events->head == NULL)
events->head = chunk;
else
events->tail->next = chunk;
events->tail = chunk;
}
/*
* Try to locate a matching shared-data record already in the chunk. If
* none, make a new one.
*/
for (newshared = ((AfterTriggerShared) chunk->endptr) - 1;
(char *) newshared >= chunk->endfree;
newshared--)
{
if (newshared->ats_tgoid == evtshared->ats_tgoid &&
newshared->ats_relid == evtshared->ats_relid &&
newshared->ats_event == evtshared->ats_event &&
newshared->ats_firing_id == 0)
break;
}
if ((char *) newshared < chunk->endfree)
{
*newshared = *evtshared;
newshared->ats_firing_id = 0; /* just to be sure */
chunk->endfree = (char *) newshared;
}
/* Insert the data */
newevent = (AfterTriggerEvent) chunk->freeptr;
memcpy(newevent, event, eventsize);
/* ... and link the new event to its shared record */
newevent->ate_flags &= ~AFTER_TRIGGER_OFFSET;
newevent->ate_flags |= (char *) newshared - (char *) newevent;
chunk->freeptr += eventsize;
events->tailfree = chunk->freeptr;
}
/* ----------
* afterTriggerFreeEventList()
*
* Free all the event storage in the given list.
* ----------
*/
static void
afterTriggerFreeEventList(AfterTriggerEventList *events)
{
AfterTriggerEventChunk *chunk;
AfterTriggerEventChunk *next_chunk;
for (chunk = events->head; chunk != NULL; chunk = next_chunk)
{
next_chunk = chunk->next;
pfree(chunk);
}
events->head = NULL;
events->tail = NULL;
events->tailfree = NULL;
}
/* ----------
* afterTriggerRestoreEventList()
*
* Restore an event list to its prior length, removing all the events
* added since it had the value old_events.
* ----------
*/
static void
afterTriggerRestoreEventList(AfterTriggerEventList *events,
const AfterTriggerEventList *old_events)
{
AfterTriggerEventChunk *chunk;
AfterTriggerEventChunk *next_chunk;
if (old_events->tail == NULL)
{
/* restoring to a completely empty state, so free everything */
afterTriggerFreeEventList(events);
}
else
{
*events = *old_events;
/* free any chunks after the last one we want to keep */
for (chunk = events->tail->next; chunk != NULL; chunk = next_chunk)
{
next_chunk = chunk->next;
pfree(chunk);
}
/* and clean up the tail chunk to be the right length */
events->tail->next = NULL;
events->tail->freeptr = events->tailfree;
/*
* We don't make any effort to remove now-unused shared data records.
* They might still be useful, anyway.
*/
}
}
/* ----------
* 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)
{
AfterTriggerShared evtshared = GetTriggerSharedData(event);
Oid tgoid = evtshared->ats_tgoid;
TriggerData LocTriggerData;
HeapTupleData tuple1;
HeapTupleData tuple2;
HeapTuple rettuple;
Buffer buffer1 = InvalidBuffer;
Buffer buffer2 = 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);
/*
2005-10-15 04:49:52 +02:00
* 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 tuple(s).
*/
if (ItemPointerIsValid(&(event->ate_ctid1)))
{
ItemPointerCopy(&(event->ate_ctid1), &(tuple1.t_self));
if (!heap_fetch(rel, SnapshotAny, &tuple1, &buffer1, false, NULL))
elog(ERROR, "failed to fetch tuple1 for AFTER trigger");
LocTriggerData.tg_trigtuple = &tuple1;
LocTriggerData.tg_trigtuplebuf = buffer1;
}
else
{
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
}
/* don't touch ctid2 if not there */
if ((event->ate_flags & AFTER_TRIGGER_2CTIDS) &&
ItemPointerIsValid(&(event->ate_ctid2)))
{
ItemPointerCopy(&(event->ate_ctid2), &(tuple2.t_self));
if (!heap_fetch(rel, SnapshotAny, &tuple2, &buffer2, false, NULL))
elog(ERROR, "failed to fetch tuple2 for AFTER trigger");
LocTriggerData.tg_newtuple = &tuple2;
LocTriggerData.tg_newtuplebuf = buffer2;
}
else
{
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
}
/*
* Setup the remaining trigger information
*/
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event =
evtshared->ats_event & (TRIGGER_EVENT_OPMASK | TRIGGER_EVENT_ROW);
LocTriggerData.tg_relation = rel;
MemoryContextReset(per_tuple_context);
/*
2005-10-15 04:49:52 +02:00
* 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 != &tuple1 && rettuple != &tuple2)
heap_freetuple(rettuple);
/*
* Release buffers
*/
if (buffer1 != InvalidBuffer)
ReleaseBuffer(buffer1);
if (buffer2 != InvalidBuffer)
ReleaseBuffer(buffer2);
/*
2005-10-15 04:49:52 +02:00
* 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
* transferred 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;
AfterTriggerEventChunk *chunk;
for_each_event_chunk(event, chunk, *events)
{
AfterTriggerShared evtshared = GetTriggerSharedData(event);
bool defer_it = false;
if (!(event->ate_flags &
(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(evtshared))
{
defer_it = true;
}
else
{
/*
* Mark it as to be fired in this firing cycle.
*/
evtshared->ats_firing_id = afterTriggers->firing_counter;
event->ate_flags |= AFTER_TRIGGER_IN_PROGRESS;
found = true;
}
}
/*
* If it's deferred, move it to move_list, if requested.
*/
if (defer_it && move_list != NULL)
{
/* add it to move_list */
afterTriggerAddEvent(move_list, event, evtshared);
/* mark original copy "done" so we don't do it again */
event->ate_flags |= AFTER_TRIGGER_DONE;
}
}
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, we use its result relation info to avoid repeated
* openings and closing of trigger target relations. If it is NULL, we
* make one locally to cache the info in case there are multiple trigger
* events per rel.
*
* When delete_ok is TRUE, it's safe to delete fully-processed events.
* (We are not very tense about that: we simply reset a chunk to be empty
* if all its events got fired. The objective here is just to avoid useless
* rescanning of events when a trigger queues new events during transaction
* end, so it's not necessary to worry much about the case where only
* some events are fired.)
*
* Returns TRUE if no unfired events remain in the list (this allows us
* to avoid repeating afterTriggerMarkEvents).
*/
static bool
afterTriggerInvokeEvents(AfterTriggerEventList *events,
CommandId firing_id,
EState *estate,
bool delete_ok)
{
bool all_fired = true;
AfterTriggerEventChunk *chunk;
MemoryContext per_tuple_context;
bool local_estate = false;
Relation rel = NULL;
TriggerDesc *trigdesc = NULL;
FmgrInfo *finfo = NULL;
Instrumentation *instr = NULL;
/* Make a local EState if need be */
if (estate == NULL)
{
estate = CreateExecutorState();
local_estate = true;
}
/* 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);
for_each_chunk(chunk, *events)
{
AfterTriggerEvent event;
bool all_fired_in_chunk = true;
for_each_event(event, chunk)
{
AfterTriggerShared evtshared = GetTriggerSharedData(event);
/*
* Is it one for me to fire?
*/
if ((event->ate_flags & AFTER_TRIGGER_IN_PROGRESS) &&
evtshared->ats_firing_id == firing_id)
{
/*
* So let's fire it... but first, find the correct relation if
* this is not the same relation as before.
*/
if (rel == NULL || RelationGetRelid(rel) != evtshared->ats_relid)
{
ResultRelInfo *rInfo;
rInfo = ExecGetTriggerResultRel(estate, evtshared->ats_relid);
rel = rInfo->ri_RelationDesc;
trigdesc = rInfo->ri_TrigDesc;
finfo = rInfo->ri_TrigFunctions;
instr = rInfo->ri_TrigInstrument;
if (trigdesc == NULL) /* should not happen */
elog(ERROR, "relation %u has no triggers",
evtshared->ats_relid);
}
/*
* 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_flags &= ~AFTER_TRIGGER_IN_PROGRESS;
event->ate_flags |= AFTER_TRIGGER_DONE;
}
else if (!(event->ate_flags & AFTER_TRIGGER_DONE))
{
/* something remains to be done */
all_fired = all_fired_in_chunk = false;
}
}
/* Clear the chunk if delete_ok and nothing left of interest */
if (delete_ok && all_fired_in_chunk)
{
chunk->freeptr = CHUNK_DATA_START(chunk);
chunk->endfree = chunk->endptr;
}
}
/* Release working resources */
MemoryContextDelete(per_tuple_context);
if (local_estate)
{
ListCell *l;
foreach(l, estate->es_trig_target_relations)
{
ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);
/* Close indices and then the relation itself */
ExecCloseIndices(resultRelInfo);
heap_close(resultRelInfo->ri_RelationDesc, NoLock);
}
FreeExecutorState(estate);
}
return all_fired;
}
/* ----------
* 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 = (CommandId) 1; /* mustn't be 0 */
afterTriggers->state = SetConstraintStateCreate(8);
afterTriggers->events.head = NULL;
afterTriggers->events.tail = NULL;
afterTriggers->events.tailfree = 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->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)
{
AfterTriggerEventList *events;
/* Must be inside a transaction */
Assert(afterTriggers != NULL);
/* Increase the query stack depth */
afterTriggers->query_depth++;
2003-08-04 02:43:34 +02:00
/*
* Allocate more space in the query stack if needed.
*/
if (afterTriggers->query_depth >= afterTriggers->maxquerydepth)
{
/* repalloc will keep the stack in the same context */
2005-10-15 04:49:52 +02:00
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 */
events = &afterTriggers->query_stack[afterTriggers->query_depth];
events->head = NULL;
events->tail = NULL;
events->tailfree = 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);
/*
2005-10-15 04:49:52 +02:00
* 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
2005-10-15 04:49:52 +02:00
* 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 at the same query level
* (is that even possible?). Be careful here: firing a trigger could
* result in query_stack being repalloc'd, so we can't save its address
* across afterTriggerInvokeEvents calls.
*
* If we find no firable events, we don't have to increment
* firing_counter.
*/
for (;;)
{
events = &afterTriggers->query_stack[afterTriggers->query_depth];
if (afterTriggerMarkEvents(events, &afterTriggers->events, true))
{
CommandId firing_id = afterTriggers->firing_counter++;
/* OK to delete the immediate events after processing them */
if (afterTriggerInvokeEvents(events, firing_id, estate, true))
break; /* all fired */
}
else
break;
}
/* Release query-local storage for events */
afterTriggerFreeEventList(&afterTriggers->query_stack[afterTriggers->query_depth]);
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;
bool snap_pushed = false;
/* Must be inside a transaction */
Assert(afterTriggers != NULL);
/* ... but not inside a query */
Assert(afterTriggers->query_depth == -1);
/*
2005-10-15 04:49:52 +02:00
* 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)
{
PushActiveSnapshot(GetTransactionSnapshot());
snap_pushed = true;
}
/*
* 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))
{
2005-10-15 04:49:52 +02:00
CommandId firing_id = afterTriggers->firing_counter++;
if (afterTriggerInvokeEvents(events, firing_id, NULL, true))
break; /* all fired */
}
/*
* We don't bother freeing the event list, since it will go away anyway
* (and more efficiently than via pfree) in AfterTriggerEndXact.
*/
if (snap_pushed)
PopActiveSnapshot();
}
/* ----------
* 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.
*
2004-08-29 07:07:03 +02:00
* 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!
*/
if (afterTriggers && afterTriggers->event_cxt)
MemoryContextDelete(afterTriggers->event_cxt);
afterTriggers = NULL;
}
/*
* AfterTriggerBeginSubXact()
*
* Start a subtransaction.
*/
void
AfterTriggerBeginSubXact(void)
{
int my_level = GetCurrentTransactionNestLevel();
/*
2005-10-15 04:49:52 +02:00
* 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->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 */
2005-10-15 04:49:52 +02:00
int new_alloc = afterTriggers->maxtransdepth * 2;
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;
}
}
/*
2005-10-15 04:49:52 +02:00
* 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->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;
AfterTriggerEventChunk *chunk;
CommandId subxact_firing_id;
/*
2005-10-15 04:49:52 +02:00
* Ignore call if the transaction is in aborted state. (Probably
* unneeded)
*/
if (afterTriggers == NULL)
return;
/*
* Pop the prior state if needed.
*/
if (isCommit)
{
Assert(my_level < afterTriggers->maxtransdepth);
/* 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]);
}
else
{
/*
* Aborting. It is possible subxact start failed before calling
* AfterTriggerBeginSubXact, in which case we mustn't risk touching
* stack levels that aren't there.
*/
if (my_level >= afterTriggers->maxtransdepth)
return;
/*
* Release any event lists from queries being aborted, and restore
* query_depth to its pre-subxact value.
*/
while (afterTriggers->query_depth > afterTriggers->depth_stack[my_level])
{
afterTriggerFreeEventList(&afterTriggers->query_stack[afterTriggers->query_depth]);
afterTriggers->query_depth--;
}
Assert(afterTriggers->query_depth ==
afterTriggers->depth_stack[my_level]);
/*
* Restore the global deferred-event list to its former length,
* discarding any events queued by the subxact.
*/
afterTriggerRestoreEventList(&afterTriggers->events,
&afterTriggers->events_stack[my_level]);
/*
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* 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;
/*
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* 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_each_event_chunk(event, chunk, afterTriggers->events)
{
AfterTriggerShared evtshared = GetTriggerSharedData(event);
if (event->ate_flags &
(AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS))
{
if (evtshared->ats_firing_id >= subxact_firing_id)
event->ate_flags &=
~(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) +
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(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;
}
/*
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* 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)
{
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int newalloc = state->numalloc * 2;
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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;
/*
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* 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 conrel;
Relation tgrel;
List *conoidlist = NIL;
List *tgoidlist = NIL;
ListCell *lc;
/*
* Handle SET CONSTRAINTS constraint-name [, ...]
*
* First, identify all the named constraints and make a list of their
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* OIDs. Since, unlike the SQL spec, we allow multiple constraints of
* the same name within a schema, the specifications are not
* necessarily unique. Our strategy is to target all matching
* constraints within the first search-path schema that has any
* matches, but disregard matches in schemas beyond the first match.
* (This is a bit odd but it's the historical behavior.)
*/
conrel = heap_open(ConstraintRelationId, AccessShareLock);
foreach(lc, stmt->constraints)
{
RangeVar *constraint = lfirst(lc);
bool found;
List *namespacelist;
ListCell *nslc;
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\"",
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constraint->catalogname, constraint->schemaname,
constraint->relname)));
}
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/*
* If we're given the schema name with the constraint, look only
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* in that schema. If given a bare constraint name, use the
* search path to find the first matching constraint.
*/
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if (constraint->schemaname)
{
Oid namespaceId = LookupExplicitNamespace(constraint->schemaname);
namespacelist = list_make1_oid(namespaceId);
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}
else
{
namespacelist = fetch_search_path(true);
}
found = false;
foreach(nslc, namespacelist)
{
Oid namespaceId = lfirst_oid(nslc);
SysScanDesc conscan;
ScanKeyData skey[2];
HeapTuple tup;
ScanKeyInit(&skey[0],
Anum_pg_constraint_conname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(constraint->relname));
ScanKeyInit(&skey[1],
Anum_pg_constraint_connamespace,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(namespaceId));
conscan = systable_beginscan(conrel, ConstraintNameNspIndexId,
true, SnapshotNow, 2, skey);
while (HeapTupleIsValid(tup = systable_getnext(conscan)))
{
Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tup);
if (con->condeferrable)
conoidlist = lappend_oid(conoidlist,
HeapTupleGetOid(tup));
else if (stmt->deferred)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" is not deferrable",
constraint->relname)));
found = true;
}
systable_endscan(conscan);
/*
* Once we've found a matching constraint we do not search
* later parts of the search path.
*/
if (found)
break;
}
list_free(namespacelist);
/*
* Not found ?
*/
if (!found)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" does not exist",
constraint->relname)));
}
heap_close(conrel, AccessShareLock);
/*
* Now, locate the trigger(s) implementing each of these constraints,
* and make a list of their OIDs.
*/
tgrel = heap_open(TriggerRelationId, AccessShareLock);
foreach(lc, conoidlist)
{
Oid conoid = lfirst_oid(lc);
bool found;
ScanKeyData skey;
SysScanDesc tgscan;
HeapTuple htup;
found = false;
ScanKeyInit(&skey,
Anum_pg_trigger_tgconstraint,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(conoid));
tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
SnapshotNow, 1, &skey);
while (HeapTupleIsValid(htup = systable_getnext(tgscan)))
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
/*
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* Silently skip triggers that are marked as non-deferrable in
* pg_trigger. This is not an error condition, since a
* deferrable RI constraint may have some non-deferrable
* actions.
*/
if (pg_trigger->tgdeferrable)
tgoidlist = lappend_oid(tgoidlist,
HeapTupleGetOid(htup));
found = true;
}
systable_endscan(tgscan);
/* Safety check: a deferrable constraint should have triggers */
if (!found)
elog(ERROR, "no triggers found for constraint with OID %u",
conoid);
}
heap_close(tgrel, AccessShareLock);
/*
* Now we can set the trigger states of individual triggers for this
* xact.
*/
foreach(lc, tgoidlist)
{
Oid tgoid = lfirst_oid(lc);
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);
}
}
}
/*
2005-10-15 04:49:52 +02:00
* 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;
bool snapshot_set = false;
while (afterTriggerMarkEvents(events, NULL, true))
{
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CommandId firing_id = afterTriggers->firing_counter++;
/*
* Make sure a snapshot has been established in case trigger
* functions need one. Note that we avoid setting a snapshot if
* we don't find at least one trigger that has to be fired now.
* This is so that BEGIN; SET CONSTRAINTS ...; SET TRANSACTION
* ISOLATION LEVEL SERIALIZABLE; ... works properly. (If we are
* at the start of a transaction it's not possible for any trigger
* events to be queued yet.)
*/
if (!snapshot_set)
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
2005-10-15 04:49:52 +02:00
* 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.
*/
if (afterTriggerInvokeEvents(events, firing_id, NULL,
!IsSubTransaction()))
break; /* all fired */
}
if (snapshot_set)
PopActiveSnapshot();
}
}
/* ----------
* 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;
AfterTriggerEventChunk *chunk;
int depth;
/* No-op if we aren't in a transaction. (Shouldn't happen?) */
if (afterTriggers == NULL)
return false;
/* Scan queued events */
for_each_event_chunk(event, chunk, afterTriggers->events)
{
AfterTriggerShared evtshared = GetTriggerSharedData(event);
/*
2006-10-04 02:30:14 +02:00
* 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_flags & AFTER_TRIGGER_DONE)
continue;
if (evtshared->ats_relid == relid)
return true;
}
/*
2006-10-04 02:30:14 +02:00
* Also scan events queued by incomplete queries. This could only matter
* if TRUNCATE/etc is executed by a function or trigger within an updating
2006-10-04 02:30:14 +02:00
* query on the same relation, which is pretty perverse, but let's check.
*/
for (depth = 0; depth <= afterTriggers->query_depth; depth++)
{
for_each_event_chunk(event, chunk, afterTriggers->query_stack[depth])
{
AfterTriggerShared evtshared = GetTriggerSharedData(event);
if (event->ate_flags & AFTER_TRIGGER_DONE)
continue;
if (evtshared->ats_relid == relid)
return true;
}
}
return false;
}
/* ----------
* AfterTriggerSaveEvent()
*
* Called by ExecA[RS]...Triggers() to queue up the triggers that should
* be fired for an event.
*
* NOTE: this is called whenever there are any triggers associated with
2010-02-26 03:01:40 +01:00
* the event (even if they are disabled). This function decides which
* triggers actually need to be queued.
* ----------
*/
static void
AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo,
int event, bool row_trigger,
HeapTuple oldtup, HeapTuple newtup,
List *recheckIndexes, Bitmapset *modifiedCols)
{
Relation rel = relinfo->ri_RelationDesc;
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
AfterTriggerEventData new_event;
AfterTriggerSharedData new_shared;
int i;
int ntriggers;
int *tgindx;
/*
2010-02-26 03:01:40 +01:00
* Check state. We use normal tests not Asserts because it is possible to
* reach here in the wrong state given misconfigured RI triggers, in
* particular deferring a cascade action trigger.
*/
if (afterTriggers == NULL)
elog(ERROR, "AfterTriggerSaveEvent() called outside of transaction");
if (afterTriggers->query_depth < 0)
elog(ERROR, "AfterTriggerSaveEvent() called outside of query");
/*
* Validate the event code and collect the associated tuple CTIDs.
*
* The event code will be used both as a bitmask and an array offset, so
* validation is important to make sure we don't walk off the edge of our
* arrays.
*/
new_event.ate_flags = 0;
switch (event)
{
case TRIGGER_EVENT_INSERT:
if (row_trigger)
{
Assert(oldtup == NULL);
Assert(newtup != NULL);
ItemPointerCopy(&(newtup->t_self), &(new_event.ate_ctid1));
ItemPointerSetInvalid(&(new_event.ate_ctid2));
}
else
{
Assert(oldtup == NULL);
Assert(newtup == NULL);
ItemPointerSetInvalid(&(new_event.ate_ctid1));
ItemPointerSetInvalid(&(new_event.ate_ctid2));
}
break;
case TRIGGER_EVENT_DELETE:
if (row_trigger)
{
Assert(oldtup != NULL);
Assert(newtup == NULL);
ItemPointerCopy(&(oldtup->t_self), &(new_event.ate_ctid1));
ItemPointerSetInvalid(&(new_event.ate_ctid2));
}
else
{
Assert(oldtup == NULL);
Assert(newtup == NULL);
ItemPointerSetInvalid(&(new_event.ate_ctid1));
ItemPointerSetInvalid(&(new_event.ate_ctid2));
}
break;
case TRIGGER_EVENT_UPDATE:
if (row_trigger)
{
Assert(oldtup != NULL);
Assert(newtup != NULL);
ItemPointerCopy(&(oldtup->t_self), &(new_event.ate_ctid1));
ItemPointerCopy(&(newtup->t_self), &(new_event.ate_ctid2));
new_event.ate_flags |= AFTER_TRIGGER_2CTIDS;
}
else
{
Assert(oldtup == NULL);
Assert(newtup == NULL);
ItemPointerSetInvalid(&(new_event.ate_ctid1));
ItemPointerSetInvalid(&(new_event.ate_ctid2));
}
break;
case TRIGGER_EVENT_TRUNCATE:
Assert(oldtup == NULL);
Assert(newtup == NULL);
ItemPointerSetInvalid(&(new_event.ate_ctid1));
ItemPointerSetInvalid(&(new_event.ate_ctid2));
break;
default:
elog(ERROR, "invalid after-trigger event code: %d", event);
break;
}
/*
* 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++)
{
2003-08-04 02:43:34 +02:00
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
if (!TriggerEnabled(estate, relinfo, trigger, event,
modifiedCols, oldtup, newtup))
continue;
/*
2005-10-15 04:49:52 +02:00
* 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 (TRIGGER_FIRED_BY_UPDATE(event))
{
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:
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/*
* Update on FK table
*
2005-10-15 04:49:52 +02:00
* 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;
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case RI_TRIGGER_NONE:
/* Not an FK trigger */
break;
}
}
/*
2010-02-26 03:01:40 +01:00
* If the trigger is a deferred unique constraint check trigger, only
* queue it if the unique constraint was potentially violated, which
* we know from index insertion time.
*/
if (trigger->tgfoid == F_UNIQUE_KEY_RECHECK)
{
if (!list_member_oid(recheckIndexes, trigger->tgconstrindid))
continue; /* Uniqueness definitely not violated */
}
/*
* Fill in event structure and add it to the current query's queue.
*/
new_shared.ats_event =
(event & TRIGGER_EVENT_OPMASK) |
(row_trigger ? TRIGGER_EVENT_ROW : 0) |
(trigger->tgdeferrable ? AFTER_TRIGGER_DEFERRABLE : 0) |
(trigger->tginitdeferred ? AFTER_TRIGGER_INITDEFERRED : 0);
new_shared.ats_tgoid = trigger->tgoid;
new_shared.ats_relid = RelationGetRelid(rel);
new_shared.ats_firing_id = 0;
afterTriggerAddEvent(&afterTriggers->query_stack[afterTriggers->query_depth],
&new_event, &new_shared);
}
}