Select Git revision
trigger.c 136.04 KiB
/*-------------------------------------------------------------------------
*
* trigger.c
* PostgreSQL TRIGGERs support code.
*
* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/commands/trigger.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/sysattr.h"
#include "access/htup_details.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "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_collate.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"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
/* GUC variables */
int SessionReplicationRole = SESSION_REPLICATION_ROLE_ORIGIN;
/* How many levels deep into trigger execution are we? */
static int MyTriggerDepth = 0;
#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 SetTriggerFlags(TriggerDesc *trigdesc, Trigger *trigger);
static HeapTuple GetTupleForTrigger(EState *estate,
EPQState *epqstate,
ResultRelInfo *relinfo,
ItemPointer tid,
LockTupleMode lockmode,
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);
/*
* 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, as well as ACL_EXECUTE on the trigger function. 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)
{
int16 tgtype;
int ncolumns;
int16 *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;
SysScanDesc tgscan;
ScanKeyData key;
Relation pgrel;
HeapTuple tuple;
Oid fargtypes[1]; /* dummy */ Oid funcoid;
Oid funcrettype;
Oid trigoid;
char internaltrigname[NAMEDATALEN];
char *trigname;
Oid constrrelid = InvalidOid;
ObjectAddress myself,
referenced;
rel = heap_openrv(stmt->relation, AccessExclusiveLock);
/*
* Triggers must be on tables or views, and there are additional
* relation-type-specific restrictions.
*/
if (rel->rd_rel->relkind == RELKIND_RELATION)
{
/* Tables can't have INSTEAD OF triggers */
if (stmt->timing != TRIGGER_TYPE_BEFORE &&
stmt->timing != TRIGGER_TYPE_AFTER)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a table",
RelationGetRelationName(rel)),
errdetail("Tables cannot have INSTEAD OF triggers.")));
}
else if (rel->rd_rel->relkind == RELKIND_VIEW)
{
/*
* Views can have INSTEAD OF triggers (which we check below are
* row-level), or statement-level BEFORE/AFTER triggers.
*/
if (stmt->timing != TRIGGER_TYPE_INSTEAD && stmt->row)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a view",
RelationGetRelationName(rel)),
errdetail("Views cannot have row-level BEFORE or AFTER triggers.")));
/* Disallow TRUNCATE triggers on VIEWs */
if (TRIGGER_FOR_TRUNCATE(stmt->events))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a view",
RelationGetRelationName(rel)),
errdetail("Views cannot have TRUNCATE triggers.")));
}
else
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or view",
RelationGetRelationName(rel))));
if (!allowSystemTableMods && IsSystemRelation(rel))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(rel))));
if (stmt->isconstraint && stmt->constrrel != NULL)
{
/*
* We must take a lock on the target relation to protect against
* concurrent drop. It's not clear that AccessShareLock is strong
* enough, but we certainly need at least that much... otherwise, we
* might end up creating a pg_constraint entry referencing a
* nonexistent table.
*/
constrrelid = RangeVarGetRelid(stmt->constrrel, AccessShareLock, 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->row)
TRIGGER_SETT_ROW(tgtype);
tgtype |= stmt->timing;
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")));
/* INSTEAD triggers must be row-level, and can't have WHEN or columns */
if (TRIGGER_FOR_INSTEAD(tgtype))
{
if (!TRIGGER_FOR_ROW(tgtype))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("INSTEAD OF triggers must be FOR EACH ROW")));
if (stmt->whenClause)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("INSTEAD OF triggers cannot have WHEN conditions")));
if (stmt->columns != NIL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("INSTEAD OF triggers cannot have column lists")));
}
/*
* Parse the WHEN clause, if any
*/
if (stmt->whenClause)
{
ParseState *pstate;
RangeTblEntry *rte;
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),
EXPR_KIND_TRIGGER_WHEN,
"WHEN");
/* we have to fix its collations too */
assign_expr_collations(pstate, whenClause);
/*
* 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_AGGREGATES,
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);
if (!isInternal)
{
aclresult = pg_proc_aclcheck(funcoid, GetUserId(), ACL_EXECUTE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_PROC,
NameListToString(stmt->funcname));
}
funcrettype = get_func_rettype(funcoid);
if (funcrettype != TRIGGEROID)
{
/*
* We allow OPAQUE just so we can load old dump files. When we see a
* trigger function declared OPAQUE, change it to TRIGGER.
*/
if (funcrettype == OPAQUEOID)
{
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,
true,
RelationGetRelid(rel),
NULL, /* no conkey */
0,
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 */
0, /* inhcount */
true, /* isnoinherit */
isInternal); /* is_internal */
}
/*
* 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);
/*
* 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
* 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 AccessExclusiveLock 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),
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,
CStringGetDatum(trigname));
values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid);
values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype);
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++)
{
if (*ar == '\\')
len++;
}
}
args = (char *) palloc(len + 1);
args[0] = '\0';
foreach(le, stmt->args)
{
char *s = strVal(lfirst(le));
char *d = args + strlen(args);
while (*s)
{
if (*s == '\\')
*d++ = '\\';
*d++ = *s++;
}
strcpy(d, "\\000");
}
values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs); values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
CStringGetDatum(args));
}
else
{
values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0);
values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
CStringGetDatum(""));
}
/* 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 = (int16 *) palloc(ncolumns * sizeof(int16));
foreach(cell, stmt->columns)
{
char *name = strVal(lfirst(cell));
int16 attnum;
int j;
/* Lookup column name. System columns are not allowed */
attnum = attnameAttNum(rel, name, false);
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
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]));
/*
* 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
* fairly pointless since it will happen as a byproduct of the upcoming
* CommandCounterIncrement...
*/
/*
* Record dependencies for trigger. Always place a normal dependency on
* the function.
*/
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
{
/*
* 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));
/*
* 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)
{
int i;
referenced.classId = RelationRelationId;
referenced.objectId = RelationGetRelid(rel);
for (i = 0; i < ncolumns; i++)
{
referenced.objectSubId = columns[i];
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
}
/*
* 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);
/* Post creation hook for new trigger */
InvokeObjectPostCreateHookArg(TriggerRelationId, trigoid, 0,
isInternal);
/* Keep lock on target rel until end of xact */
heap_close(rel, NoLock);
return trigoid;
}
/*
* 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_SIMPLE;
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_SIMPLE;
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_internal("%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_internal("%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_internal("%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;
fkcon->skip_validation = false;
fkcon->initially_valid = true;
/* ... and execute it */
ProcessUtility((Node *) atstmt,
"(generated ALTER TABLE ADD FOREIGN KEY command)",
NULL, None_Receiver, NULL, PROCESS_UTILITY_GENERATED);
/* 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 */
}
}
/*
* Guts of trigger deletion.
*/
void
RemoveTriggerById(Oid trigOid)
{
Relation tgrel;
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 exclusive-lock the relation the trigger belongs to.
*/
relid = ((Form_pg_trigger) GETSTRUCT(tup))->tgrelid;
rel = heap_open(relid, AccessExclusiveLock);
if (rel->rd_rel->relkind != RELKIND_RELATION &&
rel->rd_rel->relkind != RELKIND_VIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or view",
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);
}
/*
* get_trigger_oid - Look up a trigger by name to find its OID.
*
* If missing_ok is false, throw an error if trigger not found. If
* true, just return InvalidOid.
*/
Oid
get_trigger_oid(Oid relid, const char *trigname, bool missing_ok)
{
Relation tgrel;
ScanKeyData skey[2];
SysScanDesc tgscan;
HeapTuple tup;
Oid oid;
/*
* 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))
{
if (!missing_ok)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("trigger \"%s\" for table \"%s\" does not exist",
trigname, get_rel_name(relid))));
oid = InvalidOid;
}
else
{
oid = HeapTupleGetOid(tup);
}
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
return oid;
}
/*
* Perform permissions and integrity checks before acquiring a relation lock.
*/
static void
RangeVarCallbackForRenameTrigger(const RangeVar *rv, Oid relid, Oid oldrelid,
void *arg)
{
HeapTuple tuple;
Form_pg_class form;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
return; /* concurrently dropped */
form = (Form_pg_class) GETSTRUCT(tuple);
/* only tables and views can have triggers */
if (form->relkind != RELKIND_RELATION && form->relkind != RELKIND_VIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or view", rv->relname)));
/* you must own the table to rename one of its triggers */
if (!pg_class_ownercheck(relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, rv->relname);
if (!allowSystemTableMods && IsSystemClass(form))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
rv->relname)));
ReleaseSysCache(tuple);
}
/*
* 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
*/
Oid
renametrig(RenameStmt *stmt)
{
Oid tgoid;
Relation targetrel;
Relation tgrel;
HeapTuple tuple;
SysScanDesc tgscan;
ScanKeyData key[2];
Oid relid;
/*
* Look up name, check permissions, and acquire lock (which we will NOT
* release until end of transaction).
*/
relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
false, false,
RangeVarCallbackForRenameTrigger,
NULL);
/* Have lock already, so just need to build relcache entry. */
targetrel = relation_open(relid, NoLock);
/*
* 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(stmt->newname));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
SnapshotNow, 2, key);
if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("trigger \"%s\" for relation \"%s\" already exists",
stmt->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(stmt->subname));
tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
SnapshotNow, 2, key);
if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
{
tgoid = HeapTupleGetOid(tuple);
/*
* Update pg_trigger tuple with new tgname.
*/
tuple = heap_copytuple(tuple); /* need a modifiable copy */
namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname,
stmt->newname);
simple_heap_update(tgrel, &tuple->t_self, tuple);
/* keep system catalog indexes current */
CatalogUpdateIndexes(tgrel, tuple);
InvokeObjectPostAlterHook(TriggerRelationId,
HeapTupleGetOid(tuple), 0);
/*
* Invalidate relation's relcache entry so that other backends (and
* this one too!) are sent SI message to make them rebuild relcache
* entries. (Ideally this should happen automatically...)
*/
CacheInvalidateRelcache(targetrel);
}
else
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("trigger \"%s\" for table \"%s\" does not exist",
stmt->subname, RelationGetRelationName(targetrel))));
}
systable_endscan(tgscan);
heap_close(tgrel, RowExclusiveLock);
/*
* Close rel, but keep exclusive lock!
*/
relation_close(targetrel, NoLock);
return tgoid;
}
/*
* EnableDisableTrigger()
*
* Called by ALTER TABLE ENABLE/DISABLE [ REPLICA | ALWAYS ] TRIGGER
* 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, char fires_when, bool skip_system)
{
Relation tgrel;
int nkeys;
ScanKeyData keys[2];
SysScanDesc tgscan;
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),
errmsg("permission denied: \"%s\" is a system trigger",
NameStr(oldtrig->tgname))));
}
found = true;
if (oldtrig->tgenabled != fires_when)
{
/* need to change this one ... make a copy to scribble on */
HeapTuple newtup = heap_copytuple(tuple);
Form_pg_trigger newtrig = (Form_pg_trigger) GETSTRUCT(newtup);
newtrig->tgenabled = fires_when;
simple_heap_update(tgrel, &newtup->t_self, newtup);
/* Keep catalog indexes current */
CatalogUpdateIndexes(tgrel, newtup);
heap_freetuple(newtup);
changed = true;
}
InvokeObjectPostAlterHook(TriggerRelationId, HeapTupleGetOid(tuple), 0);
}
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;
SysScanDesc tgscan;
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;
/*
* Note: since we scan the triggers using TriggerRelidNameIndexId, we will
* be reading the triggers in name order, except possibly during
* emergency-recovery operations (ie, IgnoreSystemIndexes). This in turn
* ensures that triggers will be fired in name order.
*/
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,
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 = (int16 *) palloc(build->tgnattr * sizeof(int16));
memcpy(build->tgattr, &(pg_trigger->tgattr.values),
build->tgnattr * sizeof(int16));
}
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++)
SetTriggerFlags(trigdesc, &(triggers[i]));
/* Copy completed trigdesc into cache storage */
oldContext = MemoryContextSwitchTo(CacheMemoryContext);
relation->trigdesc = CopyTriggerDesc(trigdesc);
MemoryContextSwitchTo(oldContext);
/* Release working memory */
FreeTriggerDesc(trigdesc);
}
/*
* Update the TriggerDesc's hint flags to include the specified trigger
*/
static void
SetTriggerFlags(TriggerDesc *trigdesc, Trigger *trigger)
{
int16 tgtype = trigger->tgtype;
trigdesc->trig_insert_before_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_INSERT);
trigdesc->trig_insert_after_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_INSERT);
trigdesc->trig_insert_instead_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_INSERT);
trigdesc->trig_insert_before_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_INSERT);
trigdesc->trig_insert_after_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_INSERT);
trigdesc->trig_update_before_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_UPDATE);
trigdesc->trig_update_after_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_UPDATE);
trigdesc->trig_update_instead_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_UPDATE);
trigdesc->trig_update_before_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_UPDATE);
trigdesc->trig_update_after_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_UPDATE);
trigdesc->trig_delete_before_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_DELETE);
trigdesc->trig_delete_after_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_DELETE);
trigdesc->trig_delete_instead_row |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_DELETE);
trigdesc->trig_delete_before_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_DELETE);
trigdesc->trig_delete_after_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_DELETE);
/* there are no row-level truncate triggers */
trigdesc->trig_truncate_before_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_TRUNCATE);
trigdesc->trig_truncate_after_statement |=
TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_AFTER, TRIGGER_TYPE_TRUNCATE);
}
/*
* Copy a TriggerDesc data structure.
*
* The copy is allocated in the current memory context.
*/
TriggerDesc *
CopyTriggerDesc(TriggerDesc *trigdesc)
{
TriggerDesc *newdesc;
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)
{
int16 *newattr;
newattr = (int16 *) palloc(trigger->tgnattr * sizeof(int16));
memcpy(newattr, trigger->tgattr,
trigger->tgnattr * sizeof(int16));
trigger->tgattr = newattr;
}
if (trigger->tgnargs > 0)
{
char **newargs;
int16 j;
newargs = (char **) palloc(trigger->tgnargs * sizeof(char *));
for (j = 0; j < trigger->tgnargs; j++)
newargs[j] = pstrdup(trigger->tgargs[j]);
trigger->tgargs = newargs;
}
if (trigger->tgqual)
trigger->tgqual = pstrdup(trigger->tgqual);
trigger++;
}
return newdesc;
}
/* * Free a TriggerDesc data structure.
*/
void
FreeTriggerDesc(TriggerDesc *trigdesc)
{
Trigger *trigger;
int i;
if (trigdesc == NULL)
return;
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;
/*
* We need not examine the hint flags, just the trigger array itself; if
* we have the same triggers with the same types, the flags 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
* 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(int16)) != 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)
/* ok */ ;
else if (trig1->tgqual == NULL || trig2->tgqual == NULL)
return false;
else if (strcmp(trig1->tgqual, trig2->tgqual) != 0)
return false;
}
}
else if (trigdesc2 != NULL)
return false;
return true;
}
#endif /* NOT_USED */
/*
* Call a trigger function.
*
* trigdata: trigger descriptor.
* tgindx: trigger's index in finfo and instr arrays.
* finfo: array of cached trigger function call information.
* instr: optional array of EXPLAIN ANALYZE instrumentation state.
* per_tuple_context: memory context to execute the function in.
*
* Returns the tuple (or NULL) as returned by the function.
*/
static HeapTuple
ExecCallTriggerFunc(TriggerData *trigdata,
int tgindx,
FmgrInfo *finfo,
Instrumentation *instr,
MemoryContext per_tuple_context)
{
FunctionCallInfoData fcinfo;
PgStat_FunctionCallUsage fcusage;
Datum result;
MemoryContext oldContext;
finfo += tgindx;
/*
* We cache fmgr lookup info, to avoid making the lookup again on each
* call.
*/ if (finfo->fn_oid == InvalidOid)
fmgr_info(trigdata->tg_trigger->tgfoid, finfo);
Assert(finfo->fn_oid == trigdata->tg_trigger->tgfoid);
/*
* If doing EXPLAIN ANALYZE, start charging time to this trigger.
*/
if (instr)
InstrStartNode(instr + tgindx);
/*
* Do the function evaluation in the per-tuple memory context, so that
* leaked memory will be reclaimed once per tuple. Note in particular that
* any new tuple created by the trigger function will live till the end of
* the tuple cycle.
*/
oldContext = MemoryContextSwitchTo(per_tuple_context);
/*
* Call the function, passing no arguments but setting a context.
*/
InitFunctionCallInfoData(fcinfo, finfo, 0,
InvalidOid, (Node *) trigdata, NULL);
pgstat_init_function_usage(&fcinfo, &fcusage);
MyTriggerDepth++;
PG_TRY();
{
result = FunctionCallInvoke(&fcinfo);
}
PG_CATCH();
{
MyTriggerDepth--;
PG_RE_THROW();
}
PG_END_TRY();
MyTriggerDepth--;
pgstat_end_function_usage(&fcusage, true);
MemoryContextSwitchTo(oldContext);
/*
* Trigger protocol allows function to return a null pointer, but NOT to
* set the isnull result flag.
*/
if (fcinfo.isnull)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("trigger function %u returned null value",
fcinfo.flinfo->fn_oid)));
/*
* If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count
* one "tuple returned" (really the number of firings).
*/
if (instr)
InstrStopNode(instr + tgindx, 1);
return (HeapTuple) DatumGetPointer(result);
}
void
ExecBSInsertTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int i;
TriggerData LocTriggerData;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
if (!trigdesc->trig_insert_before_statement)
return;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
HeapTuple newtuple;
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_INSERT))
continue;
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, NULL))
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (newtuple)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("BEFORE STATEMENT trigger cannot return a value")));
}
}
void
ExecASInsertTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->trig_insert_after_statement)
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_INSERT,
false, NULL, NULL, NIL, NULL);
}
TupleTableSlot *
ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
TupleTableSlot *slot)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
HeapTuple slottuple = ExecMaterializeSlot(slot);
HeapTuple newtuple = slottuple;
HeapTuple oldtuple;
TriggerData LocTriggerData;
int i;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc; LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_ROW,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_INSERT))
continue;
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,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (oldtuple != newtuple && oldtuple != slottuple)
heap_freetuple(oldtuple);
if (newtuple == NULL)
return NULL; /* "do nothing" */
}
if (newtuple != slottuple)
{
/*
* Return the modified tuple using the es_trig_tuple_slot. We assume
* the tuple was allocated in per-tuple memory context, and therefore
* will go away by itself. The tuple table slot should not try to
* clear it.
*/
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
TupleDesc tupdesc = RelationGetDescr(relinfo->ri_RelationDesc);
if (newslot->tts_tupleDescriptor != tupdesc)
ExecSetSlotDescriptor(newslot, tupdesc);
ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
slot = newslot;
}
return slot;
}
void
ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo,
HeapTuple trigtuple, List *recheckIndexes)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->trig_insert_after_row)
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_INSERT,
true, NULL, trigtuple, recheckIndexes, NULL);
}
TupleTableSlot *
ExecIRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
TupleTableSlot *slot)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
HeapTuple slottuple = ExecMaterializeSlot(slot);
HeapTuple newtuple = slottuple;
HeapTuple oldtuple;
TriggerData LocTriggerData;
int i;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_INSTEAD;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_ROW,
TRIGGER_TYPE_INSTEAD,
TRIGGER_TYPE_INSERT))
continue;
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,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (oldtuple != newtuple && oldtuple != slottuple)
heap_freetuple(oldtuple);
if (newtuple == NULL)
return NULL; /* "do nothing" */
}
if (newtuple != slottuple)
{
/*
* Return the modified tuple using the es_trig_tuple_slot. We assume
* the tuple was allocated in per-tuple memory context, and therefore
* will go away by itself. The tuple table slot should not try to
* clear it.
*/
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
TupleDesc tupdesc = RelationGetDescr(relinfo->ri_RelationDesc);
if (newslot->tts_tupleDescriptor != tupdesc)
ExecSetSlotDescriptor(newslot, tupdesc);
ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
slot = newslot;
}
return slot;
}
void
ExecBSDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int i;
TriggerData LocTriggerData;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
if (!trigdesc->trig_delete_before_statement)
return;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
HeapTuple newtuple;
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_DELETE))
continue;
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, NULL))
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (newtuple)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("BEFORE STATEMENT trigger cannot return a value")));
}
}
void
ExecASDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->trig_delete_after_statement)
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;
bool result = true;
TriggerData LocTriggerData;
HeapTuple trigtuple;
HeapTuple newtuple;
TupleTableSlot *newSlot;
int i;
trigtuple = GetTupleForTrigger(estate, epqstate, relinfo, tupleid,
LockTupleExclusive, &newSlot);
if (trigtuple == NULL)
return false;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{ Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_ROW,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_DELETE))
continue;
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,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (newtuple == NULL)
{
result = false; /* tell caller to suppress delete */
break;
}
if (newtuple != trigtuple)
heap_freetuple(newtuple);
}
heap_freetuple(trigtuple);
return result;
}
void
ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->trig_delete_after_row)
{
HeapTuple trigtuple = GetTupleForTrigger(estate, NULL, relinfo,
tupleid, LockTupleExclusive,
NULL);
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_DELETE,
true, trigtuple, NULL, NIL, NULL);
heap_freetuple(trigtuple);
}
}
bool
ExecIRDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
HeapTuple trigtuple)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
TriggerData LocTriggerData;
HeapTuple rettuple;
int i;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_INSTEAD;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_ROW,
TRIGGER_TYPE_INSTEAD,
TRIGGER_TYPE_DELETE))
continue;
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, trigtuple, NULL))
continue;
LocTriggerData.tg_trigtuple = trigtuple;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
rettuple = ExecCallTriggerFunc(&LocTriggerData,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (rettuple == NULL)
return false; /* Delete was suppressed */
if (rettuple != trigtuple)
heap_freetuple(rettuple);
}
return true;
}
void
ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int i;
TriggerData LocTriggerData;
Bitmapset *modifiedCols;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
if (!trigdesc->trig_update_before_statement)
return;
modifiedCols = GetModifiedColumns(relinfo, estate);
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
HeapTuple newtuple;
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_UPDATE))
continue;
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
modifiedCols, NULL, NULL))
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (newtuple)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("BEFORE STATEMENT trigger cannot return a value")));
}
}
void
ExecASUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->trig_update_after_statement)
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_UPDATE,
false, NULL, NULL, NIL,
GetModifiedColumns(relinfo, estate));
}
TupleTableSlot *
ExecBRUpdateTriggers(EState *estate, EPQState *epqstate,
ResultRelInfo *relinfo,
ItemPointer tupleid, TupleTableSlot *slot)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
HeapTuple slottuple = ExecMaterializeSlot(slot);
HeapTuple newtuple = slottuple;
TriggerData LocTriggerData;
HeapTuple trigtuple;
HeapTuple oldtuple;
TupleTableSlot *newSlot;
int i;
Bitmapset *modifiedCols;
Bitmapset *keyCols;
LockTupleMode lockmode;
/*
* Compute lock mode to use. If columns that are part of the key have not
* been modified, then we can use a weaker lock, allowing for better
* concurrency.
*/
modifiedCols = GetModifiedColumns(relinfo, estate);
keyCols = RelationGetIndexAttrBitmap(relinfo->ri_RelationDesc, true);
if (bms_overlap(keyCols, modifiedCols))
lockmode = LockTupleExclusive;
else
lockmode = LockTupleNoKeyExclusive;
/* get a copy of the on-disk tuple we are planning to update */
trigtuple = GetTupleForTrigger(estate, epqstate, relinfo, tupleid,
lockmode, &newSlot);
if (trigtuple == NULL)
return NULL; /* cancel the update action */
/*
* In READ COMMITTED isolation level it's possible that target tuple was
* changed due to concurrent update. In that case we have a raw subplan
* output tuple in newSlot, and need to run it through the junk filter to
* produce an insertable tuple.
*
* Caution: more than likely, the passed-in slot is the same as the
* junkfilter's output slot, so we are clobbering the original value of
* slottuple by doing the filtering. This is OK since neither we nor our
* caller have any more interest in the prior contents of that slot.
*/
if (newSlot != NULL)
{
slot = ExecFilterJunk(relinfo->ri_junkFilter, newSlot);
slottuple = ExecMaterializeSlot(slot);
newtuple = slottuple; }
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_ROW,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_UPDATE))
continue;
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,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (oldtuple != newtuple && oldtuple != slottuple)
heap_freetuple(oldtuple);
if (newtuple == NULL)
{
heap_freetuple(trigtuple);
return NULL; /* "do nothing" */
}
}
heap_freetuple(trigtuple);
if (newtuple != slottuple)
{
/*
* Return the modified tuple using the es_trig_tuple_slot. We assume
* the tuple was allocated in per-tuple memory context, and therefore
* will go away by itself. The tuple table slot should not try to
* clear it.
*/
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
TupleDesc tupdesc = RelationGetDescr(relinfo->ri_RelationDesc);
if (newslot->tts_tupleDescriptor != tupdesc)
ExecSetSlotDescriptor(newslot, tupdesc);
ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
slot = newslot;
}
return slot;
}
void
ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
ItemPointer tupleid, HeapTuple newtuple,
List *recheckIndexes)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
if (trigdesc && trigdesc->trig_update_after_row)
{
HeapTuple trigtuple = GetTupleForTrigger(estate, NULL, relinfo, tupleid, LockTupleExclusive,
NULL);
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_UPDATE,
true, trigtuple, newtuple, recheckIndexes,
GetModifiedColumns(relinfo, estate));
heap_freetuple(trigtuple);
}
}
TupleTableSlot *
ExecIRUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
HeapTuple trigtuple, TupleTableSlot *slot)
{
TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
HeapTuple slottuple = ExecMaterializeSlot(slot);
HeapTuple newtuple = slottuple;
TriggerData LocTriggerData;
HeapTuple oldtuple;
int i;
LocTriggerData.type = T_TriggerData;
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_ROW |
TRIGGER_EVENT_INSTEAD;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_ROW,
TRIGGER_TYPE_INSTEAD,
TRIGGER_TYPE_UPDATE))
continue;
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, 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,
i,
relinfo->ri_TrigFunctions,
relinfo->ri_TrigInstrument,
GetPerTupleMemoryContext(estate));
if (oldtuple != newtuple && oldtuple != slottuple)
heap_freetuple(oldtuple);
if (newtuple == NULL)
return NULL; /* "do nothing" */
}
if (newtuple != slottuple)
{
/*
* Return the modified tuple using the es_trig_tuple_slot. We assume
* the tuple was allocated in per-tuple memory context, and therefore
* will go away by itself. The tuple table slot should not try to
* clear it.
*/
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
TupleDesc tupdesc = RelationGetDescr(relinfo->ri_RelationDesc);
if (newslot->tts_tupleDescriptor != tupdesc)
ExecSetSlotDescriptor(newslot, tupdesc);
ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
slot = newslot; }
return slot;
}
void
ExecBSTruncateTriggers(EState *estate, ResultRelInfo *relinfo)
{
TriggerDesc *trigdesc;
int i;
TriggerData LocTriggerData;
trigdesc = relinfo->ri_TrigDesc;
if (trigdesc == NULL)
return;
if (!trigdesc->trig_truncate_before_statement)
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 < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
HeapTuple newtuple;
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
TRIGGER_TYPE_STATEMENT,
TRIGGER_TYPE_BEFORE,
TRIGGER_TYPE_TRUNCATE))
continue;
if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event,
NULL, NULL, NULL))
continue;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
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->trig_truncate_after_statement)
AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_TRUNCATE,
false, NULL, NULL, NIL, NULL);
}
static HeapTuple
GetTupleForTrigger(EState *estate,
EPQState *epqstate,
ResultRelInfo *relinfo,
ItemPointer tid, LockTupleMode lockmode,
TupleTableSlot **newSlot)
{
Relation relation = relinfo->ri_RelationDesc;
HeapTupleData tuple;
HeapTuple result;
Buffer buffer;
if (newSlot != NULL)
{
HTSU_Result test;
HeapUpdateFailureData hufd;
*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,
estate->es_output_cid,
lockmode, false /* wait */,
false, &buffer, &hufd);
switch (test)
{
case HeapTupleSelfUpdated:
/*
* The target tuple was already updated or deleted by the
* current command, or by a later command in the current
* transaction. We ignore the tuple in the former case, and
* throw error in the latter case, for the same reasons
* enumerated in ExecUpdate and ExecDelete in
* nodeModifyTable.c.
*/
if (hufd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be updated was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
/* treat it as deleted; do not process */
ReleaseBuffer(buffer);
return NULL;
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
ReleaseBuffer(buffer);
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
if (!ItemPointerEquals(&hufd.ctid, &tuple.t_self))
{
/* it was updated, so look at the updated version */
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
epqstate,
relation,
relinfo->ri_RangeTableIndex,
lockmode,
&hufd.ctid,
hufd.xmax);
if (!TupIsNull(epqslot)) {
*tid = hufd.ctid;
*newSlot = epqslot;
/*
* EvalPlanQual already locked the tuple, but we
* 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;
}
}
/*
* if tuple was deleted or PlanQual failed for updated tuple -
* we must not process this tuple!
*/
return NULL;
default:
ReleaseBuffer(buffer);
elog(ERROR, "unrecognized heap_lock_tuple status: %u", test);
return NULL; /* keep compiler quiet */
}
}
else
{
Page page;
ItemId lp;
buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
/*
* Although we already know this tuple is valid, we must lock the
* buffer to ensure that no one has a buffer cleanup lock; otherwise
* they might move the tuple while we try to copy it. But we can
* release the lock before actually doing the heap_copytuple call,
* since holding pin is sufficient to prevent anyone from getting a
* cleanup lock they don't already hold.
*/
LockBuffer(buffer, BUFFER_LOCK_SHARE);
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);
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
}
result = heap_copytuple(&tuple);
ReleaseBuffer(buffer);
return result;
}
/*
* 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);
/*
* 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)
{
Node *tgqual;
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
tgqual = stringToNode(trigger->tgqual);
/* Change references to OLD and NEW to INNER_VAR and OUTER_VAR */ ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER_VAR, 0);
ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER_VAR, 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_newtup_slot == NULL)
{
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
estate->es_trig_newtup_slot = ExecInitExtraTupleSlot(estate);
MemoryContextSwitchTo(oldContext);
}
newslot = estate->es_trig_newtup_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_VAR/OUTER_VAR 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.
*
* all_isset and all_isdeferred are used to keep track
* of SET CONSTRAINTS ALL {DEFERRED, IMMEDIATE}.
*
* trigstates[] stores per-trigger tgisdeferred settings.
*/
typedef struct SetConstraintStateData
{
bool all_isset;
bool all_isdeferred;
int numstates; /* number of trigstates[] entries in use */
int numalloc; /* allocated size of trigstates[] */
SetConstraintTriggerData trigstates[1]; /* VARIABLE LENGTH ARRAY */
} SetConstraintStateData;
typedef SetConstraintStateData *SetConstraintState;
/*
* Per-trigger-event data
*
* 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
* tell which ones to work on. This ensures sane behavior if a trigger
* function chooses to do SET CONSTRAINTS: the inner SET CONSTRAINTS will
* only fire those events that weren't already scheduled for firing.
*
* state keeps track of the transaction-local effects of SET CONSTRAINTS.
* This is saved and restored across failed subtransactions.
*
* events is the current list of deferred events. This is global across
* all subtransactions of the current transaction. In a subtransaction
* abort, we know that the events added by the subtransaction are at the
* end of the list, so it is relatively easy to discard them. The event
* 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
* firing_counter. We use this to recognize which deferred triggers were
* fired (or marked for firing) within an aborted subtransaction.
*
* We use GetCurrentTransactionNestLevel() to determine the correct array
* index in these stacks. maxtransdepth is the number of allocated entries in
* each stack. (By not keeping our own stack pointer, we can avoid trouble
* in cases where errors during subxact abort cause multiple invocations
* of AfterTriggerEndSubXact() at the same nesting depth.)
*/
typedef struct AfterTriggersData
{
CommandId firing_counter; /* next firing ID to assign */
SetConstraintState state; /* the active S C state */
AfterTriggerEventList events; /* deferred-event list */
int query_depth; /* current query list index */
AfterTriggerEventList *query_stack; /* events pending from each query */
int maxquerydepth; /* allocated len of above array */
MemoryContext event_cxt; /* memory context for events, if any */
/* these fields are just for resetting at subtrans abort: */
SetConstraintState *state_stack; /* stacked S C states */
AfterTriggerEventList *events_stack; /* stacked list pointers */
int *depth_stack; /* stacked query_depths */
CommandId *firing_stack; /* stacked firing_counters */ int maxtransdepth; /* allocated len of above arrays */
} AfterTriggersData;
typedef AfterTriggersData *AfterTriggers;
static AfterTriggers afterTriggers;
static void AfterTriggerExecute(AfterTriggerEvent event,
Relation rel, TriggerDesc *trigdesc,
FmgrInfo *finfo,
Instrumentation *instr,
MemoryContext per_tuple_context);
static SetConstraintState SetConstraintStateCreate(int numalloc);
static SetConstraintState SetConstraintStateCopy(SetConstraintState state);
static SetConstraintState SetConstraintStateAddItem(SetConstraintState state,
Oid tgoid, bool tgisdeferred);
/* ----------
* afterTriggerCheckState()
*
* Returns true if the trigger event is actually in state DEFERRED.
* ----------
*/
static bool
afterTriggerCheckState(AfterTriggerShared evtshared)
{
Oid tgoid = evtshared->ats_tgoid;
SetConstraintState state = afterTriggers->state;
int i;
/*
* For not-deferrable triggers (i.e. normal AFTER ROW triggers and
* constraints declared NOT DEFERRABLE), the state is always false.
*/
if ((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;
/* events->tailfree is now out of sync, but we'll fix it below */
}
/*
* 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);
/*
* 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);
/*
* 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);
/*
* 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;
/*
* If it's last chunk, must sync event list's tailfree too. Note
* that delete_ok must NOT be passed as true if there could be
* stacked AfterTriggerEventList values pointing at this event
* list, since we'd fail to fix their copies of tailfree.
*/
if (chunk == events->tail)
events->tailfree = chunk->freeptr;
}
}
/* 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++;
/*
* Allocate more space in the query stack if needed.
*/
if (afterTriggers->query_depth >= afterTriggers->maxquerydepth)
{
/* repalloc will keep the stack in the same context */
int new_alloc = afterTriggers->maxquerydepth * 2;
afterTriggers->query_stack = (AfterTriggerEventList *)
repalloc(afterTriggers->query_stack,
new_alloc * sizeof(AfterTriggerEventList));
afterTriggers->maxquerydepth = new_alloc;
}
/* Initialize this query's list to empty */
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 must be called BEFORE closing down the executor
* with ExecutorEnd, because we make use of the EState's info about
* target relations. Normally it is called from ExecutorFinish.
* ----------
*/
void
AfterTriggerEndQuery(EState *estate)
{
AfterTriggerEventList *events;
/* Must be inside a transaction */
Assert(afterTriggers != NULL);
/* Must be inside a query, too */
Assert(afterTriggers->query_depth >= 0);
/*
* Process all immediate-mode triggers queued by the query, and move the
* deferred ones to the main list of deferred events.
*
* Notice that we decide which ones will be fired, and put the deferred
* ones on the main list, before anything is actually fired. This ensures
* reasonably sane behavior if a trigger function does SET CONSTRAINTS ...
* IMMEDIATE: all events we have decided to defer will be available for it
* to fire.
*
* We loop in case a trigger queues more events 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);
/*
* 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))
{ 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.
*
* 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();
/*
* 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 */
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;
}
}
/*
* 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;
/*
* 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]);
/*
* Restore the trigger state. If the saved state is NULL, then this
* subxact didn't save it, so it doesn't need restoring.
*/
state = afterTriggers->state_stack[my_level];
if (state != NULL)
{
pfree(afterTriggers->state);
afterTriggers->state = state;
}
/* this avoids double pfree if error later: */
afterTriggers->state_stack[my_level] = NULL;
/*
* Scan for any remaining deferred events that were marked DONE or IN
* PROGRESS by this subxact or a child, and un-mark them. We can
* recognize such events because they have a firing ID greater than or
* equal to the firing_counter value we saved at subtransaction start.
* (This essentially assumes that the current subxact includes all
* subxacts started after it.)
*/
subxact_firing_id = afterTriggers->firing_stack[my_level];
for_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) +
(numalloc - 1) *sizeof(SetConstraintTriggerData));
state->numalloc = numalloc;
return state;
}
/*
* Copy a SetConstraintState
*/
static SetConstraintState
SetConstraintStateCopy(SetConstraintState origstate)
{
SetConstraintState state;
state = SetConstraintStateCreate(origstate->numstates);
state->all_isset = origstate->all_isset;
state->all_isdeferred = origstate->all_isdeferred;
state->numstates = origstate->numstates;
memcpy(state->trigstates, origstate->trigstates,
origstate->numstates * sizeof(SetConstraintTriggerData));
return state;
}
/*
* Add a per-trigger item to a SetConstraintState. Returns possibly-changed
* pointer to the state object (it will change if we have to repalloc).
*/
static SetConstraintState
SetConstraintStateAddItem(SetConstraintState state,
Oid tgoid, bool tgisdeferred)
{
if (state->numstates >= state->numalloc)
{
int newalloc = state->numalloc * 2;
newalloc = Max(newalloc, 8); /* in case original has size 0 */
state = (SetConstraintState)
repalloc(state,
sizeof(SetConstraintStateData) +
(newalloc - 1) *sizeof(SetConstraintTriggerData));
state->numalloc = newalloc;
Assert(state->numstates < state->numalloc);
}
state->trigstates[state->numstates].sct_tgoid = tgoid;
state->trigstates[state->numstates].sct_tgisdeferred = tgisdeferred;
state->numstates++;
return state;
}
/* ----------
* AfterTriggerSetState()
*
* Execute the SET CONSTRAINTS ... utility command.
* ----------
*/
void
AfterTriggerSetState(ConstraintsSetStmt *stmt)
{
int my_level = GetCurrentTransactionNestLevel();
/*
* Ignore call if we aren't in a transaction. (Shouldn't happen?)
*/
if (afterTriggers == NULL)
return;
/*
* If in a subtransaction, and we didn't save the current state already,
* save it so it can be restored if the subtransaction aborts.
*/
if (my_level > 1 &&
afterTriggers->state_stack[my_level] == NULL)
{
afterTriggers->state_stack[my_level] =
SetConstraintStateCopy(afterTriggers->state);
}
/*
* Handle SET CONSTRAINTS ALL ...
*/
if (stmt->constraints == NIL)
{
/*
* Forget any previous SET CONSTRAINTS commands in this transaction.
*/
afterTriggers->state->numstates = 0;
/*
* Set the per-transaction ALL state to known.
*/
afterTriggers->state->all_isset = true;
afterTriggers->state->all_isdeferred = stmt->deferred;
}
else
{
Relation 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
* 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\"",
constraint->catalogname, constraint->schemaname,
constraint->relname)));
}
/*
* If we're given the schema name with the constraint, look only
* in that schema. If given a bare constraint name, use the
* search path to find the first matching constraint.
*/
if (constraint->schemaname)
{
Oid namespaceId = LookupExplicitNamespace(constraint->schemaname,
false);
namespacelist = list_make1_oid(namespaceId);
}
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);
/*
* 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);
}
}
}
/*
* 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))
{
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;
}
/*
* 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);
/*
* 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;
}
/*
* Also scan events queued by incomplete queries. This could only matter
* if TRUNCATE/etc is executed by a function or trigger within an updating
* query on the same relation, which is pretty perverse, but let's check. */
for (depth = 0; depth <= afterTriggers->query_depth; depth++)
{
for_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
* 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 tgtype_event;
int tgtype_level;
int i;
/*
* 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:
tgtype_event = TRIGGER_TYPE_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:
tgtype_event = TRIGGER_TYPE_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:
tgtype_event = TRIGGER_TYPE_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:
tgtype_event = TRIGGER_TYPE_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);
tgtype_event = 0; /* keep compiler quiet */
break;
}
tgtype_level = (row_trigger ? TRIGGER_TYPE_ROW : TRIGGER_TYPE_STATEMENT);
for (i = 0; i < trigdesc->numtriggers; i++)
{
Trigger *trigger = &trigdesc->triggers[i];
if (!TRIGGER_TYPE_MATCHES(trigger->tgtype,
tgtype_level,
TRIGGER_TYPE_AFTER,
tgtype_event))
continue; if (!TriggerEnabled(estate, relinfo, trigger, event,
modifiedCols, oldtup, newtup))
continue;
/*
* If the trigger is a foreign key enforcement trigger, there are
* certain cases where we can skip queueing the event because we can
* tell by inspection that the FK constraint will still pass.
*/
if (TRIGGER_FIRED_BY_UPDATE(event))
{
switch (RI_FKey_trigger_type(trigger->tgfoid))
{
case RI_TRIGGER_PK:
/* Update on trigger's PK table */
if (!RI_FKey_pk_upd_check_required(trigger, rel,
oldtup, newtup))
{
/* skip queuing this event */
continue;
}
break;
case RI_TRIGGER_FK:
/* Update on trigger's FK table */
if (!RI_FKey_fk_upd_check_required(trigger, rel,
oldtup, newtup))
{
/* skip queuing this event */
continue;
}
break;
case RI_TRIGGER_NONE:
/* Not an FK trigger */
break;
}
}
/*
* 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);
}
}
Datum
pg_trigger_depth(PG_FUNCTION_ARGS)
{ PG_RETURN_INT32(MyTriggerDepth);
}