granicus.if.org Git - postgresql/blob - src/backend/commands/trigger.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * trigger.c
   4  *        PostgreSQL TRIGGERs support code.
   5  *
   6  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * IDENTIFICATION
  10  *        $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.198 2006/01/05 10:07:45 petere Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #include "postgres.h"
  15
  16 #include "access/genam.h"
  17 #include "access/heapam.h"
  18 #include "access/xact.h"
  19 #include "catalog/catalog.h"
  20 #include "catalog/dependency.h"
  21 #include "catalog/indexing.h"
  22 #include "catalog/namespace.h"
  23 #include "catalog/pg_language.h"
  24 #include "catalog/pg_proc.h"
  25 #include "catalog/pg_trigger.h"
  26 #include "catalog/pg_type.h"
  27 #include "commands/defrem.h"
  28 #include "commands/trigger.h"
  29 #include "executor/executor.h"
  30 #include "executor/instrument.h"
  31 #include "miscadmin.h"
  32 #include "nodes/makefuncs.h"
  33 #include "parser/parse_func.h"
  34 #include "utils/acl.h"
  35 #include "utils/builtins.h"
  36 #include "utils/fmgroids.h"
  37 #include "utils/inval.h"
  38 #include "utils/lsyscache.h"
  39 #include "utils/memutils.h"
  40 #include "utils/syscache.h"
  41
  42
  43 static void InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx);
  44 static HeapTuple GetTupleForTrigger(EState *estate,
  45                                    ResultRelInfo *relinfo,
  46                                    ItemPointer tid,
  47                                    CommandId cid,
  48                                    TupleTableSlot **newSlot);
  49 static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata,
  50                                         int tgindx,
  51                                         FmgrInfo *finfo,
  52                                         Instrumentation *instr,
  53                                         MemoryContext per_tuple_context);
  54 static void AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event,
  55                                           bool row_trigger, HeapTuple oldtup, HeapTuple newtup);
  56
  57
  58 /*
  59  * Create a trigger.  Returns the OID of the created trigger.
  60  *
  61  * forConstraint, if true, says that this trigger is being created to
  62  * implement a constraint.      The caller will then be expected to make
  63  * a pg_depend entry linking the trigger to that constraint (and thereby
  64  * to the owning relation(s)).
  65  */
  66 Oid
  67 CreateTrigger(CreateTrigStmt *stmt, bool forConstraint)
  68 {
  69         int16           tgtype;
  70         int2vector *tgattr;
  71         Datum           values[Natts_pg_trigger];
  72         char            nulls[Natts_pg_trigger];
  73         Relation        rel;
  74         AclResult       aclresult;
  75         Relation        tgrel;
  76         SysScanDesc tgscan;
  77         ScanKeyData key;
  78         Relation        pgrel;
  79         HeapTuple       tuple;
  80         Oid                     fargtypes[1];   /* dummy */
  81         Oid                     funcoid;
  82         Oid                     funcrettype;
  83         Oid                     trigoid;
  84         int                     found = 0;
  85         int                     i;
  86         char            constrtrigname[NAMEDATALEN];
  87         char       *trigname;
  88         char       *constrname;
  89         Oid                     constrrelid = InvalidOid;
  90         ObjectAddress myself,
  91                                 referenced;
  92
  93         rel = heap_openrv(stmt->relation, AccessExclusiveLock);
  94
  95         if (stmt->constrrel != NULL)
  96                 constrrelid = RangeVarGetRelid(stmt->constrrel, false);
  97         else if (stmt->isconstraint)
  98         {
  99                 /*
 100                  * If this trigger is a constraint (and a foreign key one) then we
 101                  * really need a constrrelid.  Since we don't have one, we'll try to
 102                  * generate one from the argument information.
 103                  *
 104                  * This is really just a workaround for a long-ago pg_dump bug that
 105                  * omitted the FROM clause in dumped CREATE CONSTRAINT TRIGGER
 106                  * commands.  We don't want to bomb out completely here if we can't
 107                  * determine the correct relation, because that would prevent loading
 108                  * the dump file.  Instead, NOTICE here and ERROR in the trigger.
 109                  */
 110                 bool            needconstrrelid = false;
 111                 void       *elem = NULL;
 112
 113                 if (strncmp(strVal(lfirst(list_tail((stmt->funcname)))), "RI_FKey_check_", 14) == 0)
 114                 {
 115                         /* A trigger on FK table. */
 116                         needconstrrelid = true;
 117                         if (list_length(stmt->args) > RI_PK_RELNAME_ARGNO)
 118                                 elem = list_nth(stmt->args, RI_PK_RELNAME_ARGNO);
 119                 }
 120                 else if (strncmp(strVal(lfirst(list_tail((stmt->funcname)))), "RI_FKey_", 8) == 0)
 121                 {
 122                         /* A trigger on PK table. */
 123                         needconstrrelid = true;
 124                         if (list_length(stmt->args) > RI_FK_RELNAME_ARGNO)
 125                                 elem = list_nth(stmt->args, RI_FK_RELNAME_ARGNO);
 126                 }
 127                 if (elem != NULL)
 128                 {
 129                         RangeVar   *rel = makeRangeVar(NULL, strVal(elem));
 130
 131                         constrrelid = RangeVarGetRelid(rel, true);
 132                 }
 133                 if (needconstrrelid && constrrelid == InvalidOid)
 134                         ereport(NOTICE,
 135                                         (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 136                                          errmsg("could not determine referenced table for constraint \"%s\"",
 137                                                         stmt->trigname)));
 138         }
 139
 140         if (rel->rd_rel->relkind != RELKIND_RELATION)
 141                 ereport(ERROR,
 142                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 143                                  errmsg("\"%s\" is not a table",
 144                                                 RelationGetRelationName(rel))));
 145
 146         if (!allowSystemTableMods && IsSystemRelation(rel))
 147                 ereport(ERROR,
 148                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 149                                  errmsg("permission denied: \"%s\" is a system catalog",
 150                                                 RelationGetRelationName(rel))));
 151
 152         /* permission checks */
 153
 154         if (stmt->isconstraint)
 155         {
 156                 /* foreign key constraint trigger */
 157
 158                 aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
 159                                                                           ACL_REFERENCES);
 160                 if (aclresult != ACLCHECK_OK)
 161                         aclcheck_error(aclresult, ACL_KIND_CLASS,
 162                                                    RelationGetRelationName(rel));
 163                 if (constrrelid != InvalidOid)
 164                 {
 165                         aclresult = pg_class_aclcheck(constrrelid, GetUserId(),
 166                                                                                   ACL_REFERENCES);
 167                         if (aclresult != ACLCHECK_OK)
 168                                 aclcheck_error(aclresult, ACL_KIND_CLASS,
 169                                                            get_rel_name(constrrelid));
 170                 }
 171         }
 172         else
 173         {
 174                 /* real trigger */
 175                 aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
 176                                                                           ACL_TRIGGER);
 177                 if (aclresult != ACLCHECK_OK)
 178                         aclcheck_error(aclresult, ACL_KIND_CLASS,
 179                                                    RelationGetRelationName(rel));
 180         }
 181
 182         /*
 183          * Generate the trigger's OID now, so that we can use it in the name if
 184          * needed.
 185          */
 186         tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
 187
 188         trigoid = GetNewOid(tgrel);
 189
 190         /*
 191          * If trigger is an RI constraint, use specified trigger name as
 192          * constraint name and build a unique trigger name instead. This is mainly
 193          * for backwards compatibility with CREATE CONSTRAINT TRIGGER commands.
 194          */
 195         if (stmt->isconstraint)
 196         {
 197                 snprintf(constrtrigname, sizeof(constrtrigname),
 198                                  "RI_ConstraintTrigger_%u", trigoid);
 199                 trigname = constrtrigname;
 200                 constrname = stmt->trigname;
 201         }
 202         else
 203         {
 204                 trigname = stmt->trigname;
 205                 constrname = "";
 206         }
 207
 208         TRIGGER_CLEAR_TYPE(tgtype);
 209         if (stmt->before)
 210                 TRIGGER_SETT_BEFORE(tgtype);
 211         if (stmt->row)
 212                 TRIGGER_SETT_ROW(tgtype);
 213
 214         for (i = 0; stmt->actions[i]; i++)
 215         {
 216                 switch (stmt->actions[i])
 217                 {
 218                         case 'i':
 219                                 if (TRIGGER_FOR_INSERT(tgtype))
 220                                         ereport(ERROR,
 221                                                         (errcode(ERRCODE_SYNTAX_ERROR),
 222                                                          errmsg("multiple INSERT events specified")));
 223                                 TRIGGER_SETT_INSERT(tgtype);
 224                                 break;
 225                         case 'd':
 226                                 if (TRIGGER_FOR_DELETE(tgtype))
 227                                         ereport(ERROR,
 228                                                         (errcode(ERRCODE_SYNTAX_ERROR),
 229                                                          errmsg("multiple DELETE events specified")));
 230                                 TRIGGER_SETT_DELETE(tgtype);
 231                                 break;
 232                         case 'u':
 233                                 if (TRIGGER_FOR_UPDATE(tgtype))
 234                                         ereport(ERROR,
 235                                                         (errcode(ERRCODE_SYNTAX_ERROR),
 236                                                          errmsg("multiple UPDATE events specified")));
 237                                 TRIGGER_SETT_UPDATE(tgtype);
 238                                 break;
 239                         default:
 240                                 elog(ERROR, "unrecognized trigger event: %d",
 241                                          (int) stmt->actions[i]);
 242                                 break;
 243                 }
 244         }
 245
 246         /*
 247          * Scan pg_trigger for existing triggers on relation.  We do this mainly
 248          * because we must count them; a secondary benefit is to give a nice error
 249          * message if there's already a trigger of the same name. (The unique
 250          * index on tgrelid/tgname would complain anyway.)
 251          *
 252          * NOTE that this is cool only because we have AccessExclusiveLock on the
 253          * relation, so the trigger set won't be changing underneath us.
 254          */
 255         ScanKeyInit(&key,
 256                                 Anum_pg_trigger_tgrelid,
 257                                 BTEqualStrategyNumber, F_OIDEQ,
 258                                 ObjectIdGetDatum(RelationGetRelid(rel)));
 259         tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 260                                                                 SnapshotNow, 1, &key);
 261         while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
 262         {
 263                 Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
 264
 265                 if (namestrcmp(&(pg_trigger->tgname), trigname) == 0)
 266                         ereport(ERROR,
 267                                         (errcode(ERRCODE_DUPLICATE_OBJECT),
 268                                   errmsg("trigger \"%s\" for relation \"%s\" already exists",
 269                                                  trigname, stmt->relation->relname)));
 270                 found++;
 271         }
 272         systable_endscan(tgscan);
 273
 274         /*
 275          * Find and validate the trigger function.
 276          */
 277         funcoid = LookupFuncName(stmt->funcname, 0, fargtypes, false);
 278         funcrettype = get_func_rettype(funcoid);
 279         if (funcrettype != TRIGGEROID)
 280         {
 281                 /*
 282                  * We allow OPAQUE just so we can load old dump files.  When we see a
 283                  * trigger function declared OPAQUE, change it to TRIGGER.
 284                  */
 285                 if (funcrettype == OPAQUEOID)
 286                 {
 287                         ereport(WARNING,
 288                                         (errmsg("changing return type of function %s from \"opaque\" to \"trigger\"",
 289                                                         NameListToString(stmt->funcname))));
 290                         SetFunctionReturnType(funcoid, TRIGGEROID);
 291                 }
 292                 else
 293                         ereport(ERROR,
 294                                         (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 295                                          errmsg("function %s must return type \"trigger\"",
 296                                                         NameListToString(stmt->funcname))));
 297         }
 298
 299         /*
 300          * Build the new pg_trigger tuple.
 301          */
 302         MemSet(nulls, ' ', Natts_pg_trigger * sizeof(char));
 303
 304         values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel));
 305         values[Anum_pg_trigger_tgname - 1] = DirectFunctionCall1(namein,
 306                                                                                                   CStringGetDatum(trigname));
 307         values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid);
 308         values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype);
 309         values[Anum_pg_trigger_tgenabled - 1] = BoolGetDatum(true);
 310         values[Anum_pg_trigger_tgisconstraint - 1] = BoolGetDatum(stmt->isconstraint);
 311         values[Anum_pg_trigger_tgconstrname - 1] = DirectFunctionCall1(namein,
 312                                                                                                 CStringGetDatum(constrname));
 313         values[Anum_pg_trigger_tgconstrrelid - 1] = ObjectIdGetDatum(constrrelid);
 314         values[Anum_pg_trigger_tgdeferrable - 1] = BoolGetDatum(stmt->deferrable);
 315         values[Anum_pg_trigger_tginitdeferred - 1] = BoolGetDatum(stmt->initdeferred);
 316
 317         if (stmt->args)
 318         {
 319                 ListCell   *le;
 320                 char       *args;
 321                 int16           nargs = list_length(stmt->args);
 322                 int                     len = 0;
 323
 324                 foreach(le, stmt->args)
 325                 {
 326                         char       *ar = strVal(lfirst(le));
 327
 328                         len += strlen(ar) + 4;
 329                         for (; *ar; ar++)
 330                         {
 331                                 if (*ar == '\\')
 332                                         len++;
 333                         }
 334                 }
 335                 args = (char *) palloc(len + 1);
 336                 args[0] = '\0';
 337                 foreach(le, stmt->args)
 338                 {
 339                         char       *s = strVal(lfirst(le));
 340                         char       *d = args + strlen(args);
 341
 342                         while (*s)
 343                         {
 344                                 if (*s == '\\')
 345                                         *d++ = '\\';
 346                                 *d++ = *s++;
 347                         }
 348                         strcpy(d, "\\000");
 349                 }
 350                 values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs);
 351                 values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
 352                                                                                                           CStringGetDatum(args));
 353         }
 354         else
 355         {
 356                 values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0);
 357                 values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain,
 358                                                                                                                 CStringGetDatum(""));
 359         }
 360         /* tgattr is currently always a zero-length array */
 361         tgattr = buildint2vector(NULL, 0);
 362         values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr);
 363
 364         tuple = heap_formtuple(tgrel->rd_att, values, nulls);
 365
 366         /* force tuple to have the desired OID */
 367         HeapTupleSetOid(tuple, trigoid);
 368
 369         /*
 370          * Insert tuple into pg_trigger.
 371          */
 372         simple_heap_insert(tgrel, tuple);
 373
 374         CatalogUpdateIndexes(tgrel, tuple);
 375
 376         myself.classId = TriggerRelationId;
 377         myself.objectId = trigoid;
 378         myself.objectSubId = 0;
 379
 380         heap_freetuple(tuple);
 381         heap_close(tgrel, RowExclusiveLock);
 382
 383         pfree(DatumGetPointer(values[Anum_pg_trigger_tgname - 1]));
 384         pfree(DatumGetPointer(values[Anum_pg_trigger_tgargs - 1]));
 385
 386         /*
 387          * Update relation's pg_class entry.  Crucial side-effect: other backends
 388          * (and this one too!) are sent SI message to make them rebuild relcache
 389          * entries.
 390          */
 391         pgrel = heap_open(RelationRelationId, RowExclusiveLock);
 392         tuple = SearchSysCacheCopy(RELOID,
 393                                                            ObjectIdGetDatum(RelationGetRelid(rel)),
 394                                                            0, 0, 0);
 395         if (!HeapTupleIsValid(tuple))
 396                 elog(ERROR, "cache lookup failed for relation %u",
 397                          RelationGetRelid(rel));
 398
 399         ((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found + 1;
 400
 401         simple_heap_update(pgrel, &tuple->t_self, tuple);
 402
 403         CatalogUpdateIndexes(pgrel, tuple);
 404
 405         heap_freetuple(tuple);
 406         heap_close(pgrel, RowExclusiveLock);
 407
 408         /*
 409          * We used to try to update the rel's relcache entry here, but that's
 410          * fairly pointless since it will happen as a byproduct of the upcoming
 411          * CommandCounterIncrement...
 412          */
 413
 414         /*
 415          * Record dependencies for trigger.  Always place a normal dependency on
 416          * the function.  If we are doing this in response to an explicit CREATE
 417          * TRIGGER command, also make trigger be auto-dropped if its relation is
 418          * dropped or if the FK relation is dropped.  (Auto drop is compatible
 419          * with our pre-7.3 behavior.)  If the trigger is being made for a
 420          * constraint, we can skip the relation links; the dependency on the
 421          * constraint will indirectly depend on the relations.
 422          */
 423         referenced.classId = ProcedureRelationId;
 424         referenced.objectId = funcoid;
 425         referenced.objectSubId = 0;
 426         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 427
 428         if (!forConstraint)
 429         {
 430                 referenced.classId = RelationRelationId;
 431                 referenced.objectId = RelationGetRelid(rel);
 432                 referenced.objectSubId = 0;
 433                 recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
 434                 if (constrrelid != InvalidOid)
 435                 {
 436                         referenced.classId = RelationRelationId;
 437                         referenced.objectId = constrrelid;
 438                         referenced.objectSubId = 0;
 439                         recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
 440                 }
 441         }
 442
 443         /* Keep lock on target rel until end of xact */
 444         heap_close(rel, NoLock);
 445
 446         return trigoid;
 447 }
 448
 449 /*
 450  * DropTrigger - drop an individual trigger by name
 451  */
 452 void
 453 DropTrigger(Oid relid, const char *trigname, DropBehavior behavior)
 454 {
 455         Relation        tgrel;
 456         ScanKeyData skey[2];
 457         SysScanDesc tgscan;
 458         HeapTuple       tup;
 459         ObjectAddress object;
 460
 461         /*
 462          * Find the trigger, verify permissions, set up object address
 463          */
 464         tgrel = heap_open(TriggerRelationId, AccessShareLock);
 465
 466         ScanKeyInit(&skey[0],
 467                                 Anum_pg_trigger_tgrelid,
 468                                 BTEqualStrategyNumber, F_OIDEQ,
 469                                 ObjectIdGetDatum(relid));
 470
 471         ScanKeyInit(&skey[1],
 472                                 Anum_pg_trigger_tgname,
 473                                 BTEqualStrategyNumber, F_NAMEEQ,
 474                                 CStringGetDatum(trigname));
 475
 476         tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 477                                                                 SnapshotNow, 2, skey);
 478
 479         tup = systable_getnext(tgscan);
 480
 481         if (!HeapTupleIsValid(tup))
 482                 ereport(ERROR,
 483                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
 484                                  errmsg("trigger \"%s\" for table \"%s\" does not exist",
 485                                                 trigname, get_rel_name(relid))));
 486
 487         if (!pg_class_ownercheck(relid, GetUserId()))
 488                 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
 489                                            get_rel_name(relid));
 490
 491         object.classId = TriggerRelationId;
 492         object.objectId = HeapTupleGetOid(tup);
 493         object.objectSubId = 0;
 494
 495         systable_endscan(tgscan);
 496         heap_close(tgrel, AccessShareLock);
 497
 498         /*
 499          * Do the deletion
 500          */
 501         performDeletion(&object, behavior);
 502 }
 503
 504 /*
 505  * Guts of trigger deletion.
 506  */
 507 void
 508 RemoveTriggerById(Oid trigOid)
 509 {
 510         Relation        tgrel;
 511         SysScanDesc tgscan;
 512         ScanKeyData skey[1];
 513         HeapTuple       tup;
 514         Oid                     relid;
 515         Relation        rel;
 516         Relation        pgrel;
 517         HeapTuple       tuple;
 518         Form_pg_class classForm;
 519
 520         tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
 521
 522         /*
 523          * Find the trigger to delete.
 524          */
 525         ScanKeyInit(&skey[0],
 526                                 ObjectIdAttributeNumber,
 527                                 BTEqualStrategyNumber, F_OIDEQ,
 528                                 ObjectIdGetDatum(trigOid));
 529
 530         tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true,
 531                                                                 SnapshotNow, 1, skey);
 532
 533         tup = systable_getnext(tgscan);
 534         if (!HeapTupleIsValid(tup))
 535                 elog(ERROR, "could not find tuple for trigger %u", trigOid);
 536
 537         /*
 538          * Open and exclusive-lock the relation the trigger belongs to.
 539          */
 540         relid = ((Form_pg_trigger) GETSTRUCT(tup))->tgrelid;
 541
 542         rel = heap_open(relid, AccessExclusiveLock);
 543
 544         if (rel->rd_rel->relkind != RELKIND_RELATION)
 545                 ereport(ERROR,
 546                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 547                                  errmsg("\"%s\" is not a table",
 548                                                 RelationGetRelationName(rel))));
 549
 550         if (!allowSystemTableMods && IsSystemRelation(rel))
 551                 ereport(ERROR,
 552                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 553                                  errmsg("permission denied: \"%s\" is a system catalog",
 554                                                 RelationGetRelationName(rel))));
 555
 556         /*
 557          * Delete the pg_trigger tuple.
 558          */
 559         simple_heap_delete(tgrel, &tup->t_self);
 560
 561         systable_endscan(tgscan);
 562         heap_close(tgrel, RowExclusiveLock);
 563
 564         /*
 565          * Update relation's pg_class entry.  Crucial side-effect: other backends
 566          * (and this one too!) are sent SI message to make them rebuild relcache
 567          * entries.
 568          *
 569          * Note this is OK only because we have AccessExclusiveLock on the rel, so
 570          * no one else is creating/deleting triggers on this rel at the same time.
 571          */
 572         pgrel = heap_open(RelationRelationId, RowExclusiveLock);
 573         tuple = SearchSysCacheCopy(RELOID,
 574                                                            ObjectIdGetDatum(relid),
 575                                                            0, 0, 0);
 576         if (!HeapTupleIsValid(tuple))
 577                 elog(ERROR, "cache lookup failed for relation %u", relid);
 578         classForm = (Form_pg_class) GETSTRUCT(tuple);
 579
 580         if (classForm->reltriggers == 0)        /* should not happen */
 581                 elog(ERROR, "relation \"%s\" has reltriggers = 0",
 582                          RelationGetRelationName(rel));
 583         classForm->reltriggers--;
 584
 585         simple_heap_update(pgrel, &tuple->t_self, tuple);
 586
 587         CatalogUpdateIndexes(pgrel, tuple);
 588
 589         heap_freetuple(tuple);
 590
 591         heap_close(pgrel, RowExclusiveLock);
 592
 593         /* Keep lock on trigger's rel until end of xact */
 594         heap_close(rel, NoLock);
 595 }
 596
 597 /*
 598  *              renametrig              - changes the name of a trigger on a relation
 599  *
 600  *              trigger name is changed in trigger catalog.
 601  *              No record of the previous name is kept.
 602  *
 603  *              get proper relrelation from relation catalog (if not arg)
 604  *              scan trigger catalog
 605  *                              for name conflict (within rel)
 606  *                              for original trigger (if not arg)
 607  *              modify tgname in trigger tuple
 608  *              update row in catalog
 609  */
 610 void
 611 renametrig(Oid relid,
 612                    const char *oldname,
 613                    const char *newname)
 614 {
 615         Relation        targetrel;
 616         Relation        tgrel;
 617         HeapTuple       tuple;
 618         SysScanDesc tgscan;
 619         ScanKeyData key[2];
 620
 621         /*
 622          * Grab an exclusive lock on the target table, which we will NOT release
 623          * until end of transaction.
 624          */
 625         targetrel = heap_open(relid, AccessExclusiveLock);
 626
 627         /*
 628          * Scan pg_trigger twice for existing triggers on relation.  We do this in
 629          * order to ensure a trigger does not exist with newname (The unique index
 630          * on tgrelid/tgname would complain anyway) and to ensure a trigger does
 631          * exist with oldname.
 632          *
 633          * NOTE that this is cool only because we have AccessExclusiveLock on the
 634          * relation, so the trigger set won't be changing underneath us.
 635          */
 636         tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
 637
 638         /*
 639          * First pass -- look for name conflict
 640          */
 641         ScanKeyInit(&key[0],
 642                                 Anum_pg_trigger_tgrelid,
 643                                 BTEqualStrategyNumber, F_OIDEQ,
 644                                 ObjectIdGetDatum(relid));
 645         ScanKeyInit(&key[1],
 646                                 Anum_pg_trigger_tgname,
 647                                 BTEqualStrategyNumber, F_NAMEEQ,
 648                                 PointerGetDatum(newname));
 649         tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 650                                                                 SnapshotNow, 2, key);
 651         if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
 652                 ereport(ERROR,
 653                                 (errcode(ERRCODE_DUPLICATE_OBJECT),
 654                                  errmsg("trigger \"%s\" for relation \"%s\" already exists",
 655                                                 newname, RelationGetRelationName(targetrel))));
 656         systable_endscan(tgscan);
 657
 658         /*
 659          * Second pass -- look for trigger existing with oldname and update
 660          */
 661         ScanKeyInit(&key[0],
 662                                 Anum_pg_trigger_tgrelid,
 663                                 BTEqualStrategyNumber, F_OIDEQ,
 664                                 ObjectIdGetDatum(relid));
 665         ScanKeyInit(&key[1],
 666                                 Anum_pg_trigger_tgname,
 667                                 BTEqualStrategyNumber, F_NAMEEQ,
 668                                 PointerGetDatum(oldname));
 669         tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 670                                                                 SnapshotNow, 2, key);
 671         if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
 672         {
 673                 /*
 674                  * Update pg_trigger tuple with new tgname.
 675                  */
 676                 tuple = heap_copytuple(tuple);  /* need a modifiable copy */
 677
 678                 namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname, newname);
 679
 680                 simple_heap_update(tgrel, &tuple->t_self, tuple);
 681
 682                 /* keep system catalog indexes current */
 683                 CatalogUpdateIndexes(tgrel, tuple);
 684
 685                 /*
 686                  * Invalidate relation's relcache entry so that other backends (and
 687                  * this one too!) are sent SI message to make them rebuild relcache
 688                  * entries.  (Ideally this should happen automatically...)
 689                  */
 690                 CacheInvalidateRelcache(targetrel);
 691         }
 692         else
 693         {
 694                 ereport(ERROR,
 695                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
 696                                  errmsg("trigger \"%s\" for table \"%s\" does not exist",
 697                                                 oldname, RelationGetRelationName(targetrel))));
 698         }
 699
 700         systable_endscan(tgscan);
 701
 702         heap_close(tgrel, RowExclusiveLock);
 703
 704         /*
 705          * Close rel, but keep exclusive lock!
 706          */
 707         heap_close(targetrel, NoLock);
 708 }
 709
 710
 711 /*
 712  * EnableDisableTrigger()
 713  *
 714  *      Called by ALTER TABLE ENABLE/DISABLE TRIGGER
 715  *      to change 'tgenabled' flag for the specified trigger(s)
 716  *
 717  * rel: relation to process (caller must hold suitable lock on it)
 718  * tgname: trigger to process, or NULL to scan all triggers
 719  * enable: new value for tgenabled flag
 720  * skip_system: if true, skip "system" triggers (constraint triggers)
 721  *
 722  * Caller should have checked permissions for the table; here we also
 723  * enforce that superuser privilege is required to alter the state of
 724  * system triggers
 725  */
 726 void
 727 EnableDisableTrigger(Relation rel, const char *tgname,
 728                                          bool enable, bool skip_system)
 729 {
 730         Relation        tgrel;
 731         int                     nkeys;
 732         ScanKeyData keys[2];
 733         SysScanDesc tgscan;
 734         HeapTuple       tuple;
 735         bool            found;
 736         bool            changed;
 737
 738         /* Scan the relevant entries in pg_triggers */
 739         tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
 740
 741         ScanKeyInit(&keys[0],
 742                                 Anum_pg_trigger_tgrelid,
 743                                 BTEqualStrategyNumber, F_OIDEQ,
 744                                 ObjectIdGetDatum(RelationGetRelid(rel)));
 745         if (tgname)
 746         {
 747                 ScanKeyInit(&keys[1],
 748                                         Anum_pg_trigger_tgname,
 749                                         BTEqualStrategyNumber, F_NAMEEQ,
 750                                         CStringGetDatum(tgname));
 751                 nkeys = 2;
 752         }
 753         else
 754                 nkeys = 1;
 755
 756         tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 757                                                                 SnapshotNow, nkeys, keys);
 758
 759         found = changed = false;
 760
 761         while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
 762         {
 763                 Form_pg_trigger oldtrig = (Form_pg_trigger) GETSTRUCT(tuple);
 764
 765                 if (oldtrig->tgisconstraint)
 766                 {
 767                         /* system trigger ... ok to process? */
 768                         if (skip_system)
 769                                 continue;
 770                         if (!superuser())
 771                                 ereport(ERROR,
 772                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 773                                           errmsg("permission denied: \"%s\" is a system trigger",
 774                                                          NameStr(oldtrig->tgname))));
 775                 }
 776
 777                 found = true;
 778
 779                 if (oldtrig->tgenabled != enable)
 780                 {
 781                         /* need to change this one ... make a copy to scribble on */
 782                         HeapTuple       newtup = heap_copytuple(tuple);
 783                         Form_pg_trigger newtrig = (Form_pg_trigger) GETSTRUCT(newtup);
 784
 785                         newtrig->tgenabled = enable;
 786
 787                         simple_heap_update(tgrel, &newtup->t_self, newtup);
 788
 789                         /* Keep catalog indexes current */
 790                         CatalogUpdateIndexes(tgrel, newtup);
 791
 792                         heap_freetuple(newtup);
 793
 794                         changed = true;
 795                 }
 796         }
 797
 798         systable_endscan(tgscan);
 799
 800         heap_close(tgrel, RowExclusiveLock);
 801
 802         if (tgname && !found)
 803                 ereport(ERROR,
 804                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
 805                                  errmsg("trigger \"%s\" for table \"%s\" does not exist",
 806                                                 tgname, RelationGetRelationName(rel))));
 807
 808         /*
 809          * If we changed anything, broadcast a SI inval message to force each
 810          * backend (including our own!) to rebuild relation's relcache entry.
 811          * Otherwise they will fail to apply the change promptly.
 812          */
 813         if (changed)
 814                 CacheInvalidateRelcache(rel);
 815 }
 816
 817
 818 /*
 819  * Build trigger data to attach to the given relcache entry.
 820  *
 821  * Note that trigger data attached to a relcache entry must be stored in
 822  * CacheMemoryContext to ensure it survives as long as the relcache entry.
 823  * But we should be running in a less long-lived working context.  To avoid
 824  * leaking cache memory if this routine fails partway through, we build a
 825  * temporary TriggerDesc in working memory and then copy the completed
 826  * structure into cache memory.
 827  */
 828 void
 829 RelationBuildTriggers(Relation relation)
 830 {
 831         TriggerDesc *trigdesc;
 832         int                     ntrigs = relation->rd_rel->reltriggers;
 833         Trigger    *triggers;
 834         int                     found = 0;
 835         Relation        tgrel;
 836         ScanKeyData skey;
 837         SysScanDesc tgscan;
 838         HeapTuple       htup;
 839         MemoryContext oldContext;
 840
 841         Assert(ntrigs > 0);                     /* else I should not have been called */
 842
 843         triggers = (Trigger *) palloc(ntrigs * sizeof(Trigger));
 844
 845         /*
 846          * Note: since we scan the triggers using TriggerRelidNameIndexId, we will
 847          * be reading the triggers in name order, except possibly during
 848          * emergency-recovery operations (ie, IgnoreSystemIndexes). This in
 849          * turn ensures that triggers will be fired in name order.
 850          */
 851         ScanKeyInit(&skey,
 852                                 Anum_pg_trigger_tgrelid,
 853                                 BTEqualStrategyNumber, F_OIDEQ,
 854                                 ObjectIdGetDatum(RelationGetRelid(relation)));
 855
 856         tgrel = heap_open(TriggerRelationId, AccessShareLock);
 857         tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true,
 858                                                                 SnapshotNow, 1, &skey);
 859
 860         while (HeapTupleIsValid(htup = systable_getnext(tgscan)))
 861         {
 862                 Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
 863                 Trigger    *build;
 864
 865                 if (found >= ntrigs)
 866                         elog(ERROR, "too many trigger records found for relation \"%s\"",
 867                                  RelationGetRelationName(relation));
 868                 build = &(triggers[found]);
 869
 870                 build->tgoid = HeapTupleGetOid(htup);
 871                 build->tgname = DatumGetCString(DirectFunctionCall1(nameout,
 872                                                                                  NameGetDatum(&pg_trigger->tgname)));
 873                 build->tgfoid = pg_trigger->tgfoid;
 874                 build->tgtype = pg_trigger->tgtype;
 875                 build->tgenabled = pg_trigger->tgenabled;
 876                 build->tgisconstraint = pg_trigger->tgisconstraint;
 877                 build->tgconstrrelid = pg_trigger->tgconstrrelid;
 878                 build->tgdeferrable = pg_trigger->tgdeferrable;
 879                 build->tginitdeferred = pg_trigger->tginitdeferred;
 880                 build->tgnargs = pg_trigger->tgnargs;
 881                 /* tgattr is first var-width field, so OK to access directly */
 882                 build->tgnattr = pg_trigger->tgattr.dim1;
 883                 if (build->tgnattr > 0)
 884                 {
 885                         build->tgattr = (int2 *) palloc(build->tgnattr * sizeof(int2));
 886                         memcpy(build->tgattr, &(pg_trigger->tgattr.values),
 887                                    build->tgnattr * sizeof(int2));
 888                 }
 889                 else
 890                         build->tgattr = NULL;
 891                 if (build->tgnargs > 0)
 892                 {
 893                         bytea      *val;
 894                         bool            isnull;
 895                         char       *p;
 896                         int                     i;
 897
 898                         val = (bytea *)
 899                                 DatumGetPointer(fastgetattr(htup,
 900                                                                                         Anum_pg_trigger_tgargs,
 901                                                                                         tgrel->rd_att, &isnull));
 902                         if (isnull)
 903                                 elog(ERROR, "tgargs is null in trigger for relation \"%s\"",
 904                                          RelationGetRelationName(relation));
 905                         p = (char *) VARDATA(val);
 906                         build->tgargs = (char **) palloc(build->tgnargs * sizeof(char *));
 907                         for (i = 0; i < build->tgnargs; i++)
 908                         {
 909                                 build->tgargs[i] = pstrdup(p);
 910                                 p += strlen(p) + 1;
 911                         }
 912                 }
 913                 else
 914                         build->tgargs = NULL;
 915
 916                 found++;
 917         }
 918
 919         systable_endscan(tgscan);
 920         heap_close(tgrel, AccessShareLock);
 921
 922         if (found != ntrigs)
 923                 elog(ERROR, "%d trigger record(s) not found for relation \"%s\"",
 924                          ntrigs - found,
 925                          RelationGetRelationName(relation));
 926
 927         /* Build trigdesc */
 928         trigdesc = (TriggerDesc *) palloc0(sizeof(TriggerDesc));
 929         trigdesc->triggers = triggers;
 930         trigdesc->numtriggers = ntrigs;
 931         for (found = 0; found < ntrigs; found++)
 932                 InsertTrigger(trigdesc, &(triggers[found]), found);
 933
 934         /* Copy completed trigdesc into cache storage */
 935         oldContext = MemoryContextSwitchTo(CacheMemoryContext);
 936         relation->trigdesc = CopyTriggerDesc(trigdesc);
 937         MemoryContextSwitchTo(oldContext);
 938
 939         /* Release working memory */
 940         FreeTriggerDesc(trigdesc);
 941 }
 942
 943 /*
 944  * Insert the given trigger into the appropriate index list(s) for it
 945  *
 946  * To simplify storage management, we allocate each index list at the max
 947  * possible size (trigdesc->numtriggers) if it's used at all.  This does
 948  * not waste space permanently since we're only building a temporary
 949  * trigdesc at this point.
 950  */
 951 static void
 952 InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx)
 953 {
 954         uint16     *n;
 955         int               **t,
 956                           **tp;
 957
 958         if (TRIGGER_FOR_ROW(trigger->tgtype))
 959         {
 960                 /* ROW trigger */
 961                 if (TRIGGER_FOR_BEFORE(trigger->tgtype))
 962                 {
 963                         n = trigdesc->n_before_row;
 964                         t = trigdesc->tg_before_row;
 965                 }
 966                 else
 967                 {
 968                         n = trigdesc->n_after_row;
 969                         t = trigdesc->tg_after_row;
 970                 }
 971         }
 972         else
 973         {
 974                 /* STATEMENT trigger */
 975                 if (TRIGGER_FOR_BEFORE(trigger->tgtype))
 976                 {
 977                         n = trigdesc->n_before_statement;
 978                         t = trigdesc->tg_before_statement;
 979                 }
 980                 else
 981                 {
 982                         n = trigdesc->n_after_statement;
 983                         t = trigdesc->tg_after_statement;
 984                 }
 985         }
 986
 987         if (TRIGGER_FOR_INSERT(trigger->tgtype))
 988         {
 989                 tp = &(t[TRIGGER_EVENT_INSERT]);
 990                 if (*tp == NULL)
 991                         *tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
 992                 (*tp)[n[TRIGGER_EVENT_INSERT]] = indx;
 993                 (n[TRIGGER_EVENT_INSERT])++;
 994         }
 995
 996         if (TRIGGER_FOR_DELETE(trigger->tgtype))
 997         {
 998                 tp = &(t[TRIGGER_EVENT_DELETE]);
 999                 if (*tp == NULL)
1000                         *tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
1001                 (*tp)[n[TRIGGER_EVENT_DELETE]] = indx;
1002                 (n[TRIGGER_EVENT_DELETE])++;
1003         }
1004
1005         if (TRIGGER_FOR_UPDATE(trigger->tgtype))
1006         {
1007                 tp = &(t[TRIGGER_EVENT_UPDATE]);
1008                 if (*tp == NULL)
1009                         *tp = (int *) palloc(trigdesc->numtriggers * sizeof(int));
1010                 (*tp)[n[TRIGGER_EVENT_UPDATE]] = indx;
1011                 (n[TRIGGER_EVENT_UPDATE])++;
1012         }
1013 }
1014
1015 /*
1016  * Copy a TriggerDesc data structure.
1017  *
1018  * The copy is allocated in the current memory context.
1019  */
1020 TriggerDesc *
1021 CopyTriggerDesc(TriggerDesc *trigdesc)
1022 {
1023         TriggerDesc *newdesc;
1024         uint16     *n;
1025         int               **t,
1026                            *tnew;
1027         Trigger    *trigger;
1028         int                     i;
1029
1030         if (trigdesc == NULL || trigdesc->numtriggers <= 0)
1031                 return NULL;
1032
1033         newdesc = (TriggerDesc *) palloc(sizeof(TriggerDesc));
1034         memcpy(newdesc, trigdesc, sizeof(TriggerDesc));
1035
1036         trigger = (Trigger *) palloc(trigdesc->numtriggers * sizeof(Trigger));
1037         memcpy(trigger, trigdesc->triggers,
1038                    trigdesc->numtriggers * sizeof(Trigger));
1039         newdesc->triggers = trigger;
1040
1041         for (i = 0; i < trigdesc->numtriggers; i++)
1042         {
1043                 trigger->tgname = pstrdup(trigger->tgname);
1044                 if (trigger->tgnattr > 0)
1045                 {
1046                         int2       *newattr;
1047
1048                         newattr = (int2 *) palloc(trigger->tgnattr * sizeof(int2));
1049                         memcpy(newattr, trigger->tgattr,
1050                                    trigger->tgnattr * sizeof(int2));
1051                         trigger->tgattr = newattr;
1052                 }
1053                 if (trigger->tgnargs > 0)
1054                 {
1055                         char      **newargs;
1056                         int16           j;
1057
1058                         newargs = (char **) palloc(trigger->tgnargs * sizeof(char *));
1059                         for (j = 0; j < trigger->tgnargs; j++)
1060                                 newargs[j] = pstrdup(trigger->tgargs[j]);
1061                         trigger->tgargs = newargs;
1062                 }
1063                 trigger++;
1064         }
1065
1066         n = newdesc->n_before_statement;
1067         t = newdesc->tg_before_statement;
1068         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1069         {
1070                 if (n[i] > 0)
1071                 {
1072                         tnew = (int *) palloc(n[i] * sizeof(int));
1073                         memcpy(tnew, t[i], n[i] * sizeof(int));
1074                         t[i] = tnew;
1075                 }
1076                 else
1077                         t[i] = NULL;
1078         }
1079         n = newdesc->n_before_row;
1080         t = newdesc->tg_before_row;
1081         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1082         {
1083                 if (n[i] > 0)
1084                 {
1085                         tnew = (int *) palloc(n[i] * sizeof(int));
1086                         memcpy(tnew, t[i], n[i] * sizeof(int));
1087                         t[i] = tnew;
1088                 }
1089                 else
1090                         t[i] = NULL;
1091         }
1092         n = newdesc->n_after_row;
1093         t = newdesc->tg_after_row;
1094         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1095         {
1096                 if (n[i] > 0)
1097                 {
1098                         tnew = (int *) palloc(n[i] * sizeof(int));
1099                         memcpy(tnew, t[i], n[i] * sizeof(int));
1100                         t[i] = tnew;
1101                 }
1102                 else
1103                         t[i] = NULL;
1104         }
1105         n = newdesc->n_after_statement;
1106         t = newdesc->tg_after_statement;
1107         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1108         {
1109                 if (n[i] > 0)
1110                 {
1111                         tnew = (int *) palloc(n[i] * sizeof(int));
1112                         memcpy(tnew, t[i], n[i] * sizeof(int));
1113                         t[i] = tnew;
1114                 }
1115                 else
1116                         t[i] = NULL;
1117         }
1118
1119         return newdesc;
1120 }
1121
1122 /*
1123  * Free a TriggerDesc data structure.
1124  */
1125 void
1126 FreeTriggerDesc(TriggerDesc *trigdesc)
1127 {
1128         int               **t;
1129         Trigger    *trigger;
1130         int                     i;
1131
1132         if (trigdesc == NULL)
1133                 return;
1134
1135         t = trigdesc->tg_before_statement;
1136         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1137                 if (t[i] != NULL)
1138                         pfree(t[i]);
1139         t = trigdesc->tg_before_row;
1140         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1141                 if (t[i] != NULL)
1142                         pfree(t[i]);
1143         t = trigdesc->tg_after_row;
1144         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1145                 if (t[i] != NULL)
1146                         pfree(t[i]);
1147         t = trigdesc->tg_after_statement;
1148         for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++)
1149                 if (t[i] != NULL)
1150                         pfree(t[i]);
1151
1152         trigger = trigdesc->triggers;
1153         for (i = 0; i < trigdesc->numtriggers; i++)
1154         {
1155                 pfree(trigger->tgname);
1156                 if (trigger->tgnattr > 0)
1157                         pfree(trigger->tgattr);
1158                 if (trigger->tgnargs > 0)
1159                 {
1160                         while (--(trigger->tgnargs) >= 0)
1161                                 pfree(trigger->tgargs[trigger->tgnargs]);
1162                         pfree(trigger->tgargs);
1163                 }
1164                 trigger++;
1165         }
1166         pfree(trigdesc->triggers);
1167         pfree(trigdesc);
1168 }
1169
1170 /*
1171  * Compare two TriggerDesc structures for logical equality.
1172  */
1173 #ifdef NOT_USED
1174 bool
1175 equalTriggerDescs(TriggerDesc *trigdesc1, TriggerDesc *trigdesc2)
1176 {
1177         int                     i,
1178                                 j;
1179
1180         /*
1181          * We need not examine the "index" data, just the trigger array itself; if
1182          * we have the same triggers with the same types, the derived index data
1183          * should match.
1184          *
1185          * As of 7.3 we assume trigger set ordering is significant in the
1186          * comparison; so we just compare corresponding slots of the two sets.
1187          */
1188         if (trigdesc1 != NULL)
1189         {
1190                 if (trigdesc2 == NULL)
1191                         return false;
1192                 if (trigdesc1->numtriggers != trigdesc2->numtriggers)
1193                         return false;
1194                 for (i = 0; i < trigdesc1->numtriggers; i++)
1195                 {
1196                         Trigger    *trig1 = trigdesc1->triggers + i;
1197                         Trigger    *trig2 = trigdesc2->triggers + i;
1198
1199                         if (trig1->tgoid != trig2->tgoid)
1200                                 return false;
1201                         if (strcmp(trig1->tgname, trig2->tgname) != 0)
1202                                 return false;
1203                         if (trig1->tgfoid != trig2->tgfoid)
1204                                 return false;
1205                         if (trig1->tgtype != trig2->tgtype)
1206                                 return false;
1207                         if (trig1->tgenabled != trig2->tgenabled)
1208                                 return false;
1209                         if (trig1->tgisconstraint != trig2->tgisconstraint)
1210                                 return false;
1211                         if (trig1->tgconstrrelid != trig2->tgconstrrelid)
1212                                 return false;
1213                         if (trig1->tgdeferrable != trig2->tgdeferrable)
1214                                 return false;
1215                         if (trig1->tginitdeferred != trig2->tginitdeferred)
1216                                 return false;
1217                         if (trig1->tgnargs != trig2->tgnargs)
1218                                 return false;
1219                         if (trig1->tgnattr != trig2->tgnattr)
1220                                 return false;
1221                         if (trig1->tgnattr > 0 &&
1222                                 memcmp(trig1->tgattr, trig2->tgattr,
1223                                            trig1->tgnattr * sizeof(int2)) != 0)
1224                                 return false;
1225                         for (j = 0; j < trig1->tgnargs; j++)
1226                                 if (strcmp(trig1->tgargs[j], trig2->tgargs[j]) != 0)
1227                                         return false;
1228                 }
1229         }
1230         else if (trigdesc2 != NULL)
1231                 return false;
1232         return true;
1233 }
1234 #endif   /* NOT_USED */
1235
1236 /*
1237  * Call a trigger function.
1238  *
1239  *              trigdata: trigger descriptor.
1240  *              tgindx: trigger's index in finfo and instr arrays.
1241  *              finfo: array of cached trigger function call information.
1242  *              instr: optional array of EXPLAIN ANALYZE instrumentation state.
1243  *              per_tuple_context: memory context to execute the function in.
1244  *
1245  * Returns the tuple (or NULL) as returned by the function.
1246  */
1247 static HeapTuple
1248 ExecCallTriggerFunc(TriggerData *trigdata,
1249                                         int tgindx,
1250                                         FmgrInfo *finfo,
1251                                         Instrumentation *instr,
1252                                         MemoryContext per_tuple_context)
1253 {
1254         FunctionCallInfoData fcinfo;
1255         Datum           result;
1256         MemoryContext oldContext;
1257
1258         finfo += tgindx;
1259
1260         /*
1261          * We cache fmgr lookup info, to avoid making the lookup again on each
1262          * call.
1263          */
1264         if (finfo->fn_oid == InvalidOid)
1265                 fmgr_info(trigdata->tg_trigger->tgfoid, finfo);
1266
1267         Assert(finfo->fn_oid == trigdata->tg_trigger->tgfoid);
1268
1269         /*
1270          * If doing EXPLAIN ANALYZE, start charging time to this trigger.
1271          */
1272         if (instr)
1273                 InstrStartNode(instr + tgindx);
1274
1275         /*
1276          * Do the function evaluation in the per-tuple memory context, so that
1277          * leaked memory will be reclaimed once per tuple. Note in particular that
1278          * any new tuple created by the trigger function will live till the end of
1279          * the tuple cycle.
1280          */
1281         oldContext = MemoryContextSwitchTo(per_tuple_context);
1282
1283         /*
1284          * Call the function, passing no arguments but setting a context.
1285          */
1286         InitFunctionCallInfoData(fcinfo, finfo, 0, (Node *) trigdata, NULL);
1287
1288         result = FunctionCallInvoke(&fcinfo);
1289
1290         MemoryContextSwitchTo(oldContext);
1291
1292         /*
1293          * Trigger protocol allows function to return a null pointer, but NOT to
1294          * set the isnull result flag.
1295          */
1296         if (fcinfo.isnull)
1297                 ereport(ERROR,
1298                                 (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1299                                  errmsg("trigger function %u returned null value",
1300                                                 fcinfo.flinfo->fn_oid)));
1301
1302         /*
1303          * If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count
1304          * one "tuple returned" (really the number of firings).
1305          */
1306         if (instr)
1307                 InstrStopNode(instr + tgindx, true);
1308
1309         return (HeapTuple) DatumGetPointer(result);
1310 }
1311
1312 void
1313 ExecBSInsertTriggers(EState *estate, ResultRelInfo *relinfo)
1314 {
1315         TriggerDesc *trigdesc;
1316         int                     ntrigs;
1317         int                *tgindx;
1318         int                     i;
1319         TriggerData LocTriggerData;
1320
1321         trigdesc = relinfo->ri_TrigDesc;
1322
1323         if (trigdesc == NULL)
1324                 return;
1325
1326         ntrigs = trigdesc->n_before_statement[TRIGGER_EVENT_INSERT];
1327         tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_INSERT];
1328
1329         if (ntrigs == 0)
1330                 return;
1331
1332         LocTriggerData.type = T_TriggerData;
1333         LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
1334                 TRIGGER_EVENT_BEFORE;
1335         LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
1336         LocTriggerData.tg_trigtuple = NULL;
1337         LocTriggerData.tg_newtuple = NULL;
1338         LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
1339         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1340         for (i = 0; i < ntrigs; i++)
1341         {
1342                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
1343                 HeapTuple       newtuple;
1344
1345                 if (!trigger->tgenabled)
1346                         continue;
1347                 LocTriggerData.tg_trigger = trigger;
1348                 newtuple = ExecCallTriggerFunc(&LocTriggerData,
1349                                                                            tgindx[i],
1350                                                                            relinfo->ri_TrigFunctions,
1351                                                                            relinfo->ri_TrigInstrument,
1352                                                                            GetPerTupleMemoryContext(estate));
1353
1354                 if (newtuple)
1355                         ereport(ERROR,
1356                                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1357                                   errmsg("BEFORE STATEMENT trigger cannot return a value")));
1358         }
1359 }
1360
1361 void
1362 ExecASInsertTriggers(EState *estate, ResultRelInfo *relinfo)
1363 {
1364         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1365
1366         if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_INSERT] > 0)
1367                 AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT,
1368                                                           false, NULL, NULL);
1369 }
1370
1371 HeapTuple
1372 ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
1373                                          HeapTuple trigtuple)
1374 {
1375         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1376         int                     ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_INSERT];
1377         int                *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_INSERT];
1378         HeapTuple       newtuple = trigtuple;
1379         HeapTuple       oldtuple;
1380         TriggerData LocTriggerData;
1381         int                     i;
1382
1383         LocTriggerData.type = T_TriggerData;
1384         LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
1385                 TRIGGER_EVENT_ROW |
1386                 TRIGGER_EVENT_BEFORE;
1387         LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
1388         LocTriggerData.tg_newtuple = NULL;
1389         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1390         for (i = 0; i < ntrigs; i++)
1391         {
1392                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
1393
1394                 if (!trigger->tgenabled)
1395                         continue;
1396                 LocTriggerData.tg_trigtuple = oldtuple = newtuple;
1397                 LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
1398                 LocTriggerData.tg_trigger = trigger;
1399                 newtuple = ExecCallTriggerFunc(&LocTriggerData,
1400                                                                            tgindx[i],
1401                                                                            relinfo->ri_TrigFunctions,
1402                                                                            relinfo->ri_TrigInstrument,
1403                                                                            GetPerTupleMemoryContext(estate));
1404                 if (oldtuple != newtuple && oldtuple != trigtuple)
1405                         heap_freetuple(oldtuple);
1406                 if (newtuple == NULL)
1407                         break;
1408         }
1409         return newtuple;
1410 }
1411
1412 void
1413 ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo,
1414                                          HeapTuple trigtuple)
1415 {
1416         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1417
1418         if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0)
1419                 AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT,
1420                                                           true, NULL, trigtuple);
1421 }
1422
1423 void
1424 ExecBSDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
1425 {
1426         TriggerDesc *trigdesc;
1427         int                     ntrigs;
1428         int                *tgindx;
1429         int                     i;
1430         TriggerData LocTriggerData;
1431
1432         trigdesc = relinfo->ri_TrigDesc;
1433
1434         if (trigdesc == NULL)
1435                 return;
1436
1437         ntrigs = trigdesc->n_before_statement[TRIGGER_EVENT_DELETE];
1438         tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_DELETE];
1439
1440         if (ntrigs == 0)
1441                 return;
1442
1443         LocTriggerData.type = T_TriggerData;
1444         LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
1445                 TRIGGER_EVENT_BEFORE;
1446         LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
1447         LocTriggerData.tg_trigtuple = NULL;
1448         LocTriggerData.tg_newtuple = NULL;
1449         LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
1450         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1451         for (i = 0; i < ntrigs; i++)
1452         {
1453                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
1454                 HeapTuple       newtuple;
1455
1456                 if (!trigger->tgenabled)
1457                         continue;
1458                 LocTriggerData.tg_trigger = trigger;
1459                 newtuple = ExecCallTriggerFunc(&LocTriggerData,
1460                                                                            tgindx[i],
1461                                                                            relinfo->ri_TrigFunctions,
1462                                                                            relinfo->ri_TrigInstrument,
1463                                                                            GetPerTupleMemoryContext(estate));
1464
1465                 if (newtuple)
1466                         ereport(ERROR,
1467                                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1468                                   errmsg("BEFORE STATEMENT trigger cannot return a value")));
1469         }
1470 }
1471
1472 void
1473 ExecASDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
1474 {
1475         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1476
1477         if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_DELETE] > 0)
1478                 AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE,
1479                                                           false, NULL, NULL);
1480 }
1481
1482 bool
1483 ExecBRDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
1484                                          ItemPointer tupleid,
1485                                          CommandId cid)
1486 {
1487         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1488         int                     ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_DELETE];
1489         int                *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_DELETE];
1490         bool            result = true;
1491         TriggerData LocTriggerData;
1492         HeapTuple       trigtuple;
1493         HeapTuple       newtuple;
1494         TupleTableSlot *newSlot;
1495         int                     i;
1496
1497         trigtuple = GetTupleForTrigger(estate, relinfo, tupleid, cid, &newSlot);
1498         if (trigtuple == NULL)
1499                 return false;
1500
1501         LocTriggerData.type = T_TriggerData;
1502         LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
1503                 TRIGGER_EVENT_ROW |
1504                 TRIGGER_EVENT_BEFORE;
1505         LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
1506         LocTriggerData.tg_newtuple = NULL;
1507         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1508         for (i = 0; i < ntrigs; i++)
1509         {
1510                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
1511
1512                 if (!trigger->tgenabled)
1513                         continue;
1514                 LocTriggerData.tg_trigtuple = trigtuple;
1515                 LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
1516                 LocTriggerData.tg_trigger = trigger;
1517                 newtuple = ExecCallTriggerFunc(&LocTriggerData,
1518                                                                            tgindx[i],
1519                                                                            relinfo->ri_TrigFunctions,
1520                                                                            relinfo->ri_TrigInstrument,
1521                                                                            GetPerTupleMemoryContext(estate));
1522                 if (newtuple == NULL)
1523                 {
1524                         result = false;         /* tell caller to suppress delete */
1525                         break;
1526                 }
1527                 if (newtuple != trigtuple)
1528                         heap_freetuple(newtuple);
1529         }
1530         heap_freetuple(trigtuple);
1531
1532         return result;
1533 }
1534
1535 void
1536 ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
1537                                          ItemPointer tupleid)
1538 {
1539         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1540
1541         if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0)
1542         {
1543                 HeapTuple       trigtuple = GetTupleForTrigger(estate, relinfo,
1544                                                                                                    tupleid,
1545                                                                                                    (CommandId) 0,
1546                                                                                                    NULL);
1547
1548                 AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE,
1549                                                           true, trigtuple, NULL);
1550                 heap_freetuple(trigtuple);
1551         }
1552 }
1553
1554 void
1555 ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
1556 {
1557         TriggerDesc *trigdesc;
1558         int                     ntrigs;
1559         int                *tgindx;
1560         int                     i;
1561         TriggerData LocTriggerData;
1562
1563         trigdesc = relinfo->ri_TrigDesc;
1564
1565         if (trigdesc == NULL)
1566                 return;
1567
1568         ntrigs = trigdesc->n_before_statement[TRIGGER_EVENT_UPDATE];
1569         tgindx = trigdesc->tg_before_statement[TRIGGER_EVENT_UPDATE];
1570
1571         if (ntrigs == 0)
1572                 return;
1573
1574         LocTriggerData.type = T_TriggerData;
1575         LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
1576                 TRIGGER_EVENT_BEFORE;
1577         LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
1578         LocTriggerData.tg_trigtuple = NULL;
1579         LocTriggerData.tg_newtuple = NULL;
1580         LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
1581         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1582         for (i = 0; i < ntrigs; i++)
1583         {
1584                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
1585                 HeapTuple       newtuple;
1586
1587                 if (!trigger->tgenabled)
1588                         continue;
1589                 LocTriggerData.tg_trigger = trigger;
1590                 newtuple = ExecCallTriggerFunc(&LocTriggerData,
1591                                                                            tgindx[i],
1592                                                                            relinfo->ri_TrigFunctions,
1593                                                                            relinfo->ri_TrigInstrument,
1594                                                                            GetPerTupleMemoryContext(estate));
1595
1596                 if (newtuple)
1597                         ereport(ERROR,
1598                                         (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
1599                                   errmsg("BEFORE STATEMENT trigger cannot return a value")));
1600         }
1601 }
1602
1603 void
1604 ExecASUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
1605 {
1606         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1607
1608         if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_UPDATE] > 0)
1609                 AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE,
1610                                                           false, NULL, NULL);
1611 }
1612
1613 HeapTuple
1614 ExecBRUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
1615                                          ItemPointer tupleid, HeapTuple newtuple,
1616                                          CommandId cid)
1617 {
1618         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1619         int                     ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_UPDATE];
1620         int                *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_UPDATE];
1621         TriggerData LocTriggerData;
1622         HeapTuple       trigtuple;
1623         HeapTuple       oldtuple;
1624         HeapTuple       intuple = newtuple;
1625         TupleTableSlot *newSlot;
1626         int                     i;
1627
1628         trigtuple = GetTupleForTrigger(estate, relinfo, tupleid, cid, &newSlot);
1629         if (trigtuple == NULL)
1630                 return NULL;
1631
1632         /*
1633          * In READ COMMITTED isolation level it's possible that newtuple was
1634          * changed due to concurrent update.
1635          */
1636         if (newSlot != NULL)
1637                 intuple = newtuple = ExecRemoveJunk(estate->es_junkFilter, newSlot);
1638
1639         LocTriggerData.type = T_TriggerData;
1640         LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
1641                 TRIGGER_EVENT_ROW |
1642                 TRIGGER_EVENT_BEFORE;
1643         LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
1644         for (i = 0; i < ntrigs; i++)
1645         {
1646                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
1647
1648                 if (!trigger->tgenabled)
1649                         continue;
1650                 LocTriggerData.tg_trigtuple = trigtuple;
1651                 LocTriggerData.tg_newtuple = oldtuple = newtuple;
1652                 LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
1653                 LocTriggerData.tg_newtuplebuf = InvalidBuffer;
1654                 LocTriggerData.tg_trigger = trigger;
1655                 newtuple = ExecCallTriggerFunc(&LocTriggerData,
1656                                                                            tgindx[i],
1657                                                                            relinfo->ri_TrigFunctions,
1658                                                                            relinfo->ri_TrigInstrument,
1659                                                                            GetPerTupleMemoryContext(estate));
1660                 if (oldtuple != newtuple && oldtuple != intuple)
1661                         heap_freetuple(oldtuple);
1662                 if (newtuple == NULL)
1663                         break;
1664         }
1665         heap_freetuple(trigtuple);
1666         return newtuple;
1667 }
1668
1669 void
1670 ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
1671                                          ItemPointer tupleid, HeapTuple newtuple)
1672 {
1673         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
1674
1675         if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0)
1676         {
1677                 HeapTuple       trigtuple = GetTupleForTrigger(estate, relinfo,
1678                                                                                                    tupleid,
1679                                                                                                    (CommandId) 0,
1680                                                                                                    NULL);
1681
1682                 AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE,
1683                                                           true, trigtuple, newtuple);
1684                 heap_freetuple(trigtuple);
1685         }
1686 }
1687
1688
1689 static HeapTuple
1690 GetTupleForTrigger(EState *estate, ResultRelInfo *relinfo,
1691                                    ItemPointer tid, CommandId cid,
1692                                    TupleTableSlot **newSlot)
1693 {
1694         Relation        relation = relinfo->ri_RelationDesc;
1695         HeapTupleData tuple;
1696         HeapTuple       result;
1697         Buffer          buffer;
1698
1699         if (newSlot != NULL)
1700         {
1701                 HTSU_Result test;
1702                 ItemPointerData update_ctid;
1703                 TransactionId update_xmax;
1704
1705                 *newSlot = NULL;
1706
1707                 /*
1708                  * lock tuple for update
1709                  */
1710 ltrmark:;
1711                 tuple.t_self = *tid;
1712                 test = heap_lock_tuple(relation, &tuple, &buffer,
1713                                                            &update_ctid, &update_xmax, cid,
1714                                                            LockTupleExclusive, false);
1715                 switch (test)
1716                 {
1717                         case HeapTupleSelfUpdated:
1718                                 /* treat it as deleted; do not process */
1719                                 ReleaseBuffer(buffer);
1720                                 return NULL;
1721
1722                         case HeapTupleMayBeUpdated:
1723                                 break;
1724
1725                         case HeapTupleUpdated:
1726                                 ReleaseBuffer(buffer);
1727                                 if (IsXactIsoLevelSerializable)
1728                                         ereport(ERROR,
1729                                                         (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1730                                                          errmsg("could not serialize access due to concurrent update")));
1731                                 else if (!ItemPointerEquals(&update_ctid, &tuple.t_self))
1732                                 {
1733                                         /* it was updated, so look at the updated version */
1734                                         TupleTableSlot *epqslot;
1735
1736                                         epqslot = EvalPlanQual(estate,
1737                                                                                    relinfo->ri_RangeTableIndex,
1738                                                                                    &update_ctid,
1739                                                                                    update_xmax);
1740                                         if (!TupIsNull(epqslot))
1741                                         {
1742                                                 *tid = update_ctid;
1743                                                 *newSlot = epqslot;
1744                                                 goto ltrmark;
1745                                         }
1746                                 }
1747
1748                                 /*
1749                                  * if tuple was deleted or PlanQual failed for updated tuple -
1750                                  * we have not process this tuple!
1751                                  */
1752                                 return NULL;
1753
1754                         default:
1755                                 ReleaseBuffer(buffer);
1756                                 elog(ERROR, "unrecognized heap_lock_tuple status: %u", test);
1757                                 return NULL;    /* keep compiler quiet */
1758                 }
1759         }
1760         else
1761         {
1762                 PageHeader      dp;
1763                 ItemId          lp;
1764
1765                 buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
1766
1767                 dp = (PageHeader) BufferGetPage(buffer);
1768                 lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));
1769
1770                 Assert(ItemIdIsUsed(lp));
1771
1772                 tuple.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp);
1773                 tuple.t_len = ItemIdGetLength(lp);
1774                 tuple.t_self = *tid;
1775                 tuple.t_tableOid = RelationGetRelid(relation);
1776         }
1777
1778         result = heap_copytuple(&tuple);
1779         ReleaseBuffer(buffer);
1780
1781         return result;
1782 }
1783
1784
1785 /* ----------
1786  * After-trigger stuff
1787  *
1788  * The AfterTriggersData struct holds data about pending AFTER trigger events
1789  * during the current transaction tree.  (BEFORE triggers are fired
1790  * immediately so we don't need any persistent state about them.)  The struct
1791  * and most of its subsidiary data are kept in TopTransactionContext; however
1792  * the individual event records are kept in CurTransactionContext, so that
1793  * they will easily go away during subtransaction abort.
1794  *
1795  * Because the list of pending events can grow large, we go to some effort
1796  * to minimize memory consumption.      We do not use the generic List mechanism
1797  * but thread the events manually.
1798  *
1799  * XXX We need to be able to save the per-event data in a file if it grows too
1800  * large.
1801  * ----------
1802  */
1803
1804 /* Per-trigger SET CONSTRAINT status */
1805 typedef struct SetConstraintTriggerData
1806 {
1807         Oid                     sct_tgoid;
1808         bool            sct_tgisdeferred;
1809 } SetConstraintTriggerData;
1810
1811 typedef struct SetConstraintTriggerData *SetConstraintTrigger;
1812
1813 /*
1814  * SET CONSTRAINT intra-transaction status.
1815  *
1816  * We make this a single palloc'd object so it can be copied and freed easily.
1817  *
1818  * all_isset and all_isdeferred are used to keep track
1819  * of SET CONSTRAINTS ALL {DEFERRED, IMMEDIATE}.
1820  *
1821  * trigstates[] stores per-trigger tgisdeferred settings.
1822  */
1823 typedef struct SetConstraintStateData
1824 {
1825         bool            all_isset;
1826         bool            all_isdeferred;
1827         int                     numstates;              /* number of trigstates[] entries in use */
1828         int                     numalloc;               /* allocated size of trigstates[] */
1829         SetConstraintTriggerData trigstates[1];         /* VARIABLE LENGTH ARRAY */
1830 } SetConstraintStateData;
1831
1832 typedef SetConstraintStateData *SetConstraintState;
1833
1834
1835 /*
1836  * Per-trigger-event data
1837  *
1838  * Note: ate_firing_id is meaningful when either AFTER_TRIGGER_DONE
1839  * or AFTER_TRIGGER_IN_PROGRESS is set.  It indicates which trigger firing
1840  * cycle the trigger was or will be fired in.
1841  */
1842 typedef struct AfterTriggerEventData *AfterTriggerEvent;
1843
1844 typedef struct AfterTriggerEventData
1845 {
1846         AfterTriggerEvent ate_next; /* list link */
1847         TriggerEvent ate_event;         /* event type and status bits */
1848         CommandId       ate_firing_id;  /* ID for firing cycle */
1849         Oid                     ate_tgoid;              /* the trigger's ID */
1850         Oid                     ate_relid;              /* the relation it's on */
1851         ItemPointerData ate_oldctid;    /* specific tuple(s) involved */
1852         ItemPointerData ate_newctid;
1853 } AfterTriggerEventData;
1854
1855 /* A list of events */
1856 typedef struct AfterTriggerEventList
1857 {
1858         AfterTriggerEvent head;
1859         AfterTriggerEvent tail;
1860 } AfterTriggerEventList;
1861
1862
1863 /*
1864  * All per-transaction data for the AFTER TRIGGERS module.
1865  *
1866  * AfterTriggersData has the following fields:
1867  *
1868  * firing_counter is incremented for each call of afterTriggerInvokeEvents.
1869  * We mark firable events with the current firing cycle's ID so that we can
1870  * tell which ones to work on.  This ensures sane behavior if a trigger
1871  * function chooses to do SET CONSTRAINTS: the inner SET CONSTRAINTS will
1872  * only fire those events that weren't already scheduled for firing.
1873  *
1874  * state keeps track of the transaction-local effects of SET CONSTRAINTS.
1875  * This is saved and restored across failed subtransactions.
1876  *
1877  * events is the current list of deferred events.  This is global across
1878  * all subtransactions of the current transaction.      In a subtransaction
1879  * abort, we know that the events added by the subtransaction are at the
1880  * end of the list, so it is relatively easy to discard them.
1881  *
1882  * query_depth is the current depth of nested AfterTriggerBeginQuery calls
1883  * (-1 when the stack is empty).
1884  *
1885  * query_stack[query_depth] is a list of AFTER trigger events queued by the
1886  * current query (and the query_stack entries below it are lists of trigger
1887  * events queued by calling queries).  None of these are valid until the
1888  * matching AfterTriggerEndQuery call occurs.  At that point we fire
1889  * immediate-mode triggers, and append any deferred events to the main events
1890  * list.
1891  *
1892  * maxquerydepth is just the allocated length of query_stack.
1893  *
1894  * state_stack is a stack of pointers to saved copies of the SET CONSTRAINTS
1895  * state data; each subtransaction level that modifies that state first
1896  * saves a copy, which we use to restore the state if we abort.
1897  *
1898  * events_stack is a stack of copies of the events head/tail pointers,
1899  * which we use to restore those values during subtransaction abort.
1900  *
1901  * depth_stack is a stack of copies of subtransaction-start-time query_depth,
1902  * which we similarly use to clean up at subtransaction abort.
1903  *
1904  * firing_stack is a stack of copies of subtransaction-start-time
1905  * firing_counter.      We use this to recognize which deferred triggers were
1906  * fired (or marked for firing) within an aborted subtransaction.
1907  *
1908  * We use GetCurrentTransactionNestLevel() to determine the correct array
1909  * index in these stacks.  maxtransdepth is the number of allocated entries in
1910  * each stack.  (By not keeping our own stack pointer, we can avoid trouble
1911  * in cases where errors during subxact abort cause multiple invocations
1912  * of AfterTriggerEndSubXact() at the same nesting depth.)
1913  */
1914 typedef struct AfterTriggersData
1915 {
1916         CommandId       firing_counter; /* next firing ID to assign */
1917         SetConstraintState state;       /* the active S C state */
1918         AfterTriggerEventList events;           /* deferred-event list */
1919         int                     query_depth;    /* current query list index */
1920         AfterTriggerEventList *query_stack; /* events pending from each query */
1921         int                     maxquerydepth;  /* allocated len of above array */
1922
1923         /* these fields are just for resetting at subtrans abort: */
1924
1925         SetConstraintState *state_stack;        /* stacked S C states */
1926         AfterTriggerEventList *events_stack;            /* stacked list pointers */
1927         int                *depth_stack;        /* stacked query_depths */
1928         CommandId  *firing_stack;       /* stacked firing_counters */
1929         int                     maxtransdepth;  /* allocated len of above arrays */
1930 } AfterTriggersData;
1931
1932 typedef AfterTriggersData *AfterTriggers;
1933
1934 static AfterTriggers afterTriggers;
1935
1936
1937 static void AfterTriggerExecute(AfterTriggerEvent event,
1938                                         Relation rel, TriggerDesc *trigdesc,
1939                                         FmgrInfo *finfo,
1940                                         Instrumentation *instr,
1941                                         MemoryContext per_tuple_context);
1942 static SetConstraintState SetConstraintStateCreate(int numalloc);
1943 static SetConstraintState SetConstraintStateCopy(SetConstraintState state);
1944 static SetConstraintState SetConstraintStateAddItem(SetConstraintState state,
1945                                                   Oid tgoid, bool tgisdeferred);
1946
1947
1948 /* ----------
1949  * afterTriggerCheckState()
1950  *
1951  *      Returns true if the trigger identified by tgoid is actually
1952  *      in state DEFERRED.
1953  * ----------
1954  */
1955 static bool
1956 afterTriggerCheckState(Oid tgoid, TriggerEvent eventstate)
1957 {
1958         SetConstraintState state = afterTriggers->state;
1959         int                     i;
1960
1961         /*
1962          * For not-deferrable triggers (i.e. normal AFTER ROW triggers and
1963          * constraints declared NOT DEFERRABLE), the state is always false.
1964          */
1965         if ((eventstate & AFTER_TRIGGER_DEFERRABLE) == 0)
1966                 return false;
1967
1968         /*
1969          * Check if SET CONSTRAINTS has been executed for this specific trigger.
1970          */
1971         for (i = 0; i < state->numstates; i++)
1972         {
1973                 if (state->trigstates[i].sct_tgoid == tgoid)
1974                         return state->trigstates[i].sct_tgisdeferred;
1975         }
1976
1977         /*
1978          * Check if SET CONSTRAINTS ALL has been executed; if so use that.
1979          */
1980         if (state->all_isset)
1981                 return state->all_isdeferred;
1982
1983         /*
1984          * Otherwise return the default state for the trigger.
1985          */
1986         return ((eventstate & AFTER_TRIGGER_INITDEFERRED) != 0);
1987 }
1988
1989
1990 /* ----------
1991  * afterTriggerAddEvent()
1992  *
1993  *      Add a new trigger event to the current query's queue.
1994  * ----------
1995  */
1996 static void
1997 afterTriggerAddEvent(AfterTriggerEvent event)
1998 {
1999         AfterTriggerEventList *events;
2000
2001         Assert(event->ate_next == NULL);
2002
2003         /* Must be inside a query */
2004         Assert(afterTriggers->query_depth >= 0);
2005
2006         events = &afterTriggers->query_stack[afterTriggers->query_depth];
2007         if (events->tail == NULL)
2008         {
2009                 /* first list entry */
2010                 events->head = event;
2011                 events->tail = event;
2012         }
2013         else
2014         {
2015                 events->tail->ate_next = event;
2016                 events->tail = event;
2017         }
2018 }
2019
2020
2021 /* ----------
2022  * AfterTriggerExecute()
2023  *
2024  *      Fetch the required tuples back from the heap and fire one
2025  *      single trigger function.
2026  *
2027  *      Frequently, this will be fired many times in a row for triggers of
2028  *      a single relation.      Therefore, we cache the open relation and provide
2029  *      fmgr lookup cache space at the caller level.  (For triggers fired at
2030  *      the end of a query, we can even piggyback on the executor's state.)
2031  *
2032  *      event: event currently being fired.
2033  *      rel: open relation for event.
2034  *      trigdesc: working copy of rel's trigger info.
2035  *      finfo: array of fmgr lookup cache entries (one per trigger in trigdesc).
2036  *      instr: array of EXPLAIN ANALYZE instrumentation nodes (one per trigger),
2037  *              or NULL if no instrumentation is wanted.
2038  *      per_tuple_context: memory context to call trigger function in.
2039  * ----------
2040  */
2041 static void
2042 AfterTriggerExecute(AfterTriggerEvent event,
2043                                         Relation rel, TriggerDesc *trigdesc,
2044                                         FmgrInfo *finfo, Instrumentation *instr,
2045                                         MemoryContext per_tuple_context)
2046 {
2047         Oid                     tgoid = event->ate_tgoid;
2048         TriggerData LocTriggerData;
2049         HeapTupleData oldtuple;
2050         HeapTupleData newtuple;
2051         HeapTuple       rettuple;
2052         Buffer          oldbuffer = InvalidBuffer;
2053         Buffer          newbuffer = InvalidBuffer;
2054         int                     tgindx;
2055
2056         /*
2057          * Locate trigger in trigdesc.
2058          */
2059         LocTriggerData.tg_trigger = NULL;
2060         for (tgindx = 0; tgindx < trigdesc->numtriggers; tgindx++)
2061         {
2062                 if (trigdesc->triggers[tgindx].tgoid == tgoid)
2063                 {
2064                         LocTriggerData.tg_trigger = &(trigdesc->triggers[tgindx]);
2065                         break;
2066                 }
2067         }
2068         if (LocTriggerData.tg_trigger == NULL)
2069                 elog(ERROR, "could not find trigger %u", tgoid);
2070
2071         /*
2072          * If doing EXPLAIN ANALYZE, start charging time to this trigger. We want
2073          * to include time spent re-fetching tuples in the trigger cost.
2074          */
2075         if (instr)
2076                 InstrStartNode(instr + tgindx);
2077
2078         /*
2079          * Fetch the required OLD and NEW tuples.
2080          */
2081         if (ItemPointerIsValid(&(event->ate_oldctid)))
2082         {
2083                 ItemPointerCopy(&(event->ate_oldctid), &(oldtuple.t_self));
2084                 if (!heap_fetch(rel, SnapshotAny, &oldtuple, &oldbuffer, false, NULL))
2085                         elog(ERROR, "failed to fetch old tuple for AFTER trigger");
2086         }
2087
2088         if (ItemPointerIsValid(&(event->ate_newctid)))
2089         {
2090                 ItemPointerCopy(&(event->ate_newctid), &(newtuple.t_self));
2091                 if (!heap_fetch(rel, SnapshotAny, &newtuple, &newbuffer, false, NULL))
2092                         elog(ERROR, "failed to fetch new tuple for AFTER trigger");
2093         }
2094
2095         /*
2096          * Setup the trigger information
2097          */
2098         LocTriggerData.type = T_TriggerData;
2099         LocTriggerData.tg_event =
2100                 event->ate_event & (TRIGGER_EVENT_OPMASK | TRIGGER_EVENT_ROW);
2101         LocTriggerData.tg_relation = rel;
2102
2103         switch (event->ate_event & TRIGGER_EVENT_OPMASK)
2104         {
2105                 case TRIGGER_EVENT_INSERT:
2106                         LocTriggerData.tg_trigtuple = &newtuple;
2107                         LocTriggerData.tg_newtuple = NULL;
2108                         LocTriggerData.tg_trigtuplebuf = newbuffer;
2109                         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
2110                         break;
2111
2112                 case TRIGGER_EVENT_UPDATE:
2113                         LocTriggerData.tg_trigtuple = &oldtuple;
2114                         LocTriggerData.tg_newtuple = &newtuple;
2115                         LocTriggerData.tg_trigtuplebuf = oldbuffer;
2116                         LocTriggerData.tg_newtuplebuf = newbuffer;
2117                         break;
2118
2119                 case TRIGGER_EVENT_DELETE:
2120                         LocTriggerData.tg_trigtuple = &oldtuple;
2121                         LocTriggerData.tg_newtuple = NULL;
2122                         LocTriggerData.tg_trigtuplebuf = oldbuffer;
2123                         LocTriggerData.tg_newtuplebuf = InvalidBuffer;
2124                         break;
2125         }
2126
2127         MemoryContextReset(per_tuple_context);
2128
2129         /*
2130          * Call the trigger and throw away any possibly returned updated tuple.
2131          * (Don't let ExecCallTriggerFunc measure EXPLAIN time.)
2132          */
2133         rettuple = ExecCallTriggerFunc(&LocTriggerData,
2134                                                                    tgindx,
2135                                                                    finfo,
2136                                                                    NULL,
2137                                                                    per_tuple_context);
2138         if (rettuple != NULL && rettuple != &oldtuple && rettuple != &newtuple)
2139                 heap_freetuple(rettuple);
2140
2141         /*
2142          * Release buffers
2143          */
2144         if (oldbuffer != InvalidBuffer)
2145                 ReleaseBuffer(oldbuffer);
2146         if (newbuffer != InvalidBuffer)
2147                 ReleaseBuffer(newbuffer);
2148
2149         /*
2150          * If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count
2151          * one "tuple returned" (really the number of firings).
2152          */
2153         if (instr)
2154                 InstrStopNode(instr + tgindx, true);
2155 }
2156
2157
2158 /*
2159  * afterTriggerMarkEvents()
2160  *
2161  *      Scan the given event list for not yet invoked events.  Mark the ones
2162  *      that can be invoked now with the current firing ID.
2163  *
2164  *      If move_list isn't NULL, events that are not to be invoked now are
2165  *      removed from the given list and appended to move_list.
2166  *
2167  *      When immediate_only is TRUE, do not invoke currently-deferred triggers.
2168  *      (This will be FALSE only at main transaction exit.)
2169  *
2170  *      Returns TRUE if any invokable events were found.
2171  */
2172 static bool
2173 afterTriggerMarkEvents(AfterTriggerEventList *events,
2174                                            AfterTriggerEventList *move_list,
2175                                            bool immediate_only)
2176 {
2177         bool            found = false;
2178         AfterTriggerEvent event,
2179                                 prev_event;
2180
2181         prev_event = NULL;
2182         event = events->head;
2183
2184         while (event != NULL)
2185         {
2186                 bool            defer_it = false;
2187                 AfterTriggerEvent next_event;
2188
2189                 if (!(event->ate_event &
2190                           (AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS)))
2191                 {
2192                         /*
2193                          * This trigger hasn't been called or scheduled yet. Check if we
2194                          * should call it now.
2195                          */
2196                         if (immediate_only &&
2197                                 afterTriggerCheckState(event->ate_tgoid, event->ate_event))
2198                         {
2199                                 defer_it = true;
2200                         }
2201                         else
2202                         {
2203                                 /*
2204                                  * Mark it as to be fired in this firing cycle.
2205                                  */
2206                                 event->ate_firing_id = afterTriggers->firing_counter;
2207                                 event->ate_event |= AFTER_TRIGGER_IN_PROGRESS;
2208                                 found = true;
2209                         }
2210                 }
2211
2212                 /*
2213                  * If it's deferred, move it to move_list, if requested.
2214                  */
2215                 next_event = event->ate_next;
2216
2217                 if (defer_it && move_list != NULL)
2218                 {
2219                         /* Delink it from input list */
2220                         if (prev_event)
2221                                 prev_event->ate_next = next_event;
2222                         else
2223                                 events->head = next_event;
2224                         /* and add it to move_list */
2225                         event->ate_next = NULL;
2226                         if (move_list->tail == NULL)
2227                         {
2228                                 /* first list entry */
2229                                 move_list->head = event;
2230                                 move_list->tail = event;
2231                         }
2232                         else
2233                         {
2234                                 move_list->tail->ate_next = event;
2235                                 move_list->tail = event;
2236                         }
2237                 }
2238                 else
2239                 {
2240                         /* Keep it in input list */
2241                         prev_event = event;
2242                 }
2243
2244                 event = next_event;
2245         }
2246
2247         /* Update list tail pointer in case we moved tail event */
2248         events->tail = prev_event;
2249
2250         return found;
2251 }
2252
2253 /* ----------
2254  * afterTriggerInvokeEvents()
2255  *
2256  *      Scan the given event list for events that are marked as to be fired
2257  *      in the current firing cycle, and fire them.
2258  *
2259  *      If estate isn't NULL, then we expect that all the firable events are
2260  *      for triggers of the relations included in the estate's result relation
2261  *      array.  This allows us to re-use the estate's open relations and
2262  *      trigger cache info.  When estate is NULL, we have to find the relations
2263  *      the hard way.
2264  *
2265  *      When delete_ok is TRUE, it's okay to delete fully-processed events.
2266  *      The events list pointers are updated.
2267  * ----------
2268  */
2269 static void
2270 afterTriggerInvokeEvents(AfterTriggerEventList *events,
2271                                                  CommandId firing_id,
2272                                                  EState *estate,
2273                                                  bool delete_ok)
2274 {
2275         AfterTriggerEvent event,
2276                                 prev_event;
2277         MemoryContext per_tuple_context;
2278         Relation        rel = NULL;
2279         TriggerDesc *trigdesc = NULL;
2280         FmgrInfo   *finfo = NULL;
2281         Instrumentation *instr = NULL;
2282
2283         /* Make a per-tuple memory context for trigger function calls */
2284         per_tuple_context =
2285                 AllocSetContextCreate(CurrentMemoryContext,
2286                                                           "AfterTriggerTupleContext",
2287                                                           ALLOCSET_DEFAULT_MINSIZE,
2288                                                           ALLOCSET_DEFAULT_INITSIZE,
2289                                                           ALLOCSET_DEFAULT_MAXSIZE);
2290
2291         prev_event = NULL;
2292         event = events->head;
2293
2294         while (event != NULL)
2295         {
2296                 AfterTriggerEvent next_event;
2297
2298                 /*
2299                  * Is it one for me to fire?
2300                  */
2301                 if ((event->ate_event & AFTER_TRIGGER_IN_PROGRESS) &&
2302                         event->ate_firing_id == firing_id)
2303                 {
2304                         /*
2305                          * So let's fire it... but first, open the correct relation if
2306                          * this is not the same relation as before.
2307                          */
2308                         if (rel == NULL || rel->rd_id != event->ate_relid)
2309                         {
2310                                 if (estate)
2311                                 {
2312                                         /* Find target relation among estate's result rels */
2313                                         ResultRelInfo *rInfo;
2314                                         int                     nr;
2315
2316                                         rInfo = estate->es_result_relations;
2317                                         nr = estate->es_num_result_relations;
2318                                         while (nr > 0)
2319                                         {
2320                                                 if (rInfo->ri_RelationDesc->rd_id == event->ate_relid)
2321                                                         break;
2322                                                 rInfo++;
2323                                                 nr--;
2324                                         }
2325                                         if (nr <= 0)    /* should not happen */
2326                                                 elog(ERROR, "could not find relation %u among query result relations",
2327                                                          event->ate_relid);
2328                                         rel = rInfo->ri_RelationDesc;
2329                                         trigdesc = rInfo->ri_TrigDesc;
2330                                         finfo = rInfo->ri_TrigFunctions;
2331                                         instr = rInfo->ri_TrigInstrument;
2332                                 }
2333                                 else
2334                                 {
2335                                         /* Hard way: we manage the resources for ourselves */
2336                                         if (rel)
2337                                                 heap_close(rel, NoLock);
2338                                         if (trigdesc)
2339                                                 FreeTriggerDesc(trigdesc);
2340                                         if (finfo)
2341                                                 pfree(finfo);
2342                                         Assert(instr == NULL);          /* never used in this case */
2343
2344                                         /*
2345                                          * We assume that an appropriate lock is still held by the
2346                                          * executor, so grab no new lock here.
2347                                          */
2348                                         rel = heap_open(event->ate_relid, NoLock);
2349
2350                                         /*
2351                                          * Copy relation's trigger info so that we have a stable
2352                                          * copy no matter what the called triggers do.
2353                                          */
2354                                         trigdesc = CopyTriggerDesc(rel->trigdesc);
2355
2356                                         if (trigdesc == NULL)           /* should not happen */
2357                                                 elog(ERROR, "relation %u has no triggers",
2358                                                          event->ate_relid);
2359
2360                                         /*
2361                                          * Allocate space to cache fmgr lookup info for triggers.
2362                                          */
2363                                         finfo = (FmgrInfo *)
2364                                                 palloc0(trigdesc->numtriggers * sizeof(FmgrInfo));
2365
2366                                         /* Never any EXPLAIN info in this case */
2367                                 }
2368                         }
2369
2370                         /*
2371                          * Fire it.  Note that the AFTER_TRIGGER_IN_PROGRESS flag is still
2372                          * set, so recursive examinations of the event list won't try to
2373                          * re-fire it.
2374                          */
2375                         AfterTriggerExecute(event, rel, trigdesc, finfo, instr,
2376                                                                 per_tuple_context);
2377
2378                         /*
2379                          * Mark the event as done.
2380                          */
2381                         event->ate_event &= ~AFTER_TRIGGER_IN_PROGRESS;
2382                         event->ate_event |= AFTER_TRIGGER_DONE;
2383                 }
2384
2385                 /*
2386                  * If it's now done, throw it away, if allowed.
2387                  *
2388                  * NB: it's possible the trigger call above added more events to the
2389                  * queue, or that calls we will do later will want to add more, so we
2390                  * have to be careful about maintaining list validity at all points
2391                  * here.
2392                  */
2393                 next_event = event->ate_next;
2394
2395                 if ((event->ate_event & AFTER_TRIGGER_DONE) && delete_ok)
2396                 {
2397                         /* Delink it from list and free it */
2398                         if (prev_event)
2399                                 prev_event->ate_next = next_event;
2400                         else
2401                                 events->head = next_event;
2402                         pfree(event);
2403                 }
2404                 else
2405                 {
2406                         /* Keep it in list */
2407                         prev_event = event;
2408                 }
2409
2410                 event = next_event;
2411         }
2412
2413         /* Update list tail pointer in case we just deleted tail event */
2414         events->tail = prev_event;
2415
2416         /* Release working resources */
2417         if (!estate)
2418         {
2419                 if (rel)
2420                         heap_close(rel, NoLock);
2421                 if (trigdesc)
2422                         FreeTriggerDesc(trigdesc);
2423                 if (finfo)
2424                         pfree(finfo);
2425                 Assert(instr == NULL);  /* never used in this case */
2426         }
2427         MemoryContextDelete(per_tuple_context);
2428 }
2429
2430
2431 /* ----------
2432  * AfterTriggerBeginXact()
2433  *
2434  *      Called at transaction start (either BEGIN or implicit for single
2435  *      statement outside of transaction block).
2436  * ----------
2437  */
2438 void
2439 AfterTriggerBeginXact(void)
2440 {
2441         Assert(afterTriggers == NULL);
2442
2443         /*
2444          * Build empty after-trigger state structure
2445          */
2446         afterTriggers = (AfterTriggers)
2447                 MemoryContextAlloc(TopTransactionContext,
2448                                                    sizeof(AfterTriggersData));
2449
2450         afterTriggers->firing_counter = FirstCommandId;
2451         afterTriggers->state = SetConstraintStateCreate(8);
2452         afterTriggers->events.head = NULL;
2453         afterTriggers->events.tail = NULL;
2454         afterTriggers->query_depth = -1;
2455
2456         /* We initialize the query stack to a reasonable size */
2457         afterTriggers->query_stack = (AfterTriggerEventList *)
2458                 MemoryContextAlloc(TopTransactionContext,
2459                                                    8 * sizeof(AfterTriggerEventList));
2460         afterTriggers->maxquerydepth = 8;
2461
2462         /* Subtransaction stack is empty until/unless needed */
2463         afterTriggers->state_stack = NULL;
2464         afterTriggers->events_stack = NULL;
2465         afterTriggers->depth_stack = NULL;
2466         afterTriggers->firing_stack = NULL;
2467         afterTriggers->maxtransdepth = 0;
2468 }
2469
2470
2471 /* ----------
2472  * AfterTriggerBeginQuery()
2473  *
2474  *      Called just before we start processing a single query within a
2475  *      transaction (or subtransaction).  Set up to record AFTER trigger
2476  *      events queued by the query.  Note that it is allowed to have
2477  *      nested queries within a (sub)transaction.
2478  * ----------
2479  */
2480 void
2481 AfterTriggerBeginQuery(void)
2482 {
2483         /* Must be inside a transaction */
2484         Assert(afterTriggers != NULL);
2485
2486         /* Increase the query stack depth */
2487         afterTriggers->query_depth++;
2488
2489         /*
2490          * Allocate more space in the query stack if needed.
2491          */
2492         if (afterTriggers->query_depth >= afterTriggers->maxquerydepth)
2493         {
2494                 /* repalloc will keep the stack in the same context */
2495                 int                     new_alloc = afterTriggers->maxquerydepth * 2;
2496
2497                 afterTriggers->query_stack = (AfterTriggerEventList *)
2498                         repalloc(afterTriggers->query_stack,
2499                                          new_alloc * sizeof(AfterTriggerEventList));
2500                 afterTriggers->maxquerydepth = new_alloc;
2501         }
2502
2503         /* Initialize this query's list to empty */
2504         afterTriggers->query_stack[afterTriggers->query_depth].head = NULL;
2505         afterTriggers->query_stack[afterTriggers->query_depth].tail = NULL;
2506 }
2507
2508
2509 /* ----------
2510  * AfterTriggerEndQuery()
2511  *
2512  *      Called after one query has been completely processed. At this time
2513  *      we invoke all AFTER IMMEDIATE trigger events queued by the query, and
2514  *      transfer deferred trigger events to the global deferred-trigger list.
2515  *
2516  *      Note that this should be called just BEFORE closing down the executor
2517  *      with ExecutorEnd, because we make use of the EState's info about
2518  *      target relations.
2519  * ----------
2520  */
2521 void
2522 AfterTriggerEndQuery(EState *estate)
2523 {
2524         AfterTriggerEventList *events;
2525
2526         /* Must be inside a transaction */
2527         Assert(afterTriggers != NULL);
2528
2529         /* Must be inside a query, too */
2530         Assert(afterTriggers->query_depth >= 0);
2531
2532         /*
2533          * Process all immediate-mode triggers queued by the query, and move the
2534          * deferred ones to the main list of deferred events.
2535          *
2536          * Notice that we decide which ones will be fired, and put the deferred
2537          * ones on the main list, before anything is actually fired.  This ensures
2538          * reasonably sane behavior if a trigger function does SET CONSTRAINTS ...
2539          * IMMEDIATE: all events we have decided to defer will be available for it
2540          * to fire.
2541          *
2542          * If we find no firable events, we don't have to increment
2543          * firing_counter.
2544          */
2545         events = &afterTriggers->query_stack[afterTriggers->query_depth];
2546         if (afterTriggerMarkEvents(events, &afterTriggers->events, true))
2547         {
2548                 CommandId       firing_id = afterTriggers->firing_counter++;
2549
2550                 /* OK to delete the immediate events after processing them */
2551                 afterTriggerInvokeEvents(events, firing_id, estate, true);
2552         }
2553
2554         afterTriggers->query_depth--;
2555 }
2556
2557
2558 /* ----------
2559  * AfterTriggerFireDeferred()
2560  *
2561  *      Called just before the current transaction is committed. At this
2562  *      time we invoke all pending DEFERRED triggers.
2563  *
2564  *      It is possible for other modules to queue additional deferred triggers
2565  *      during pre-commit processing; therefore xact.c may have to call this
2566  *      multiple times.
2567  * ----------
2568  */
2569 void
2570 AfterTriggerFireDeferred(void)
2571 {
2572         AfterTriggerEventList *events;
2573
2574         /* Must be inside a transaction */
2575         Assert(afterTriggers != NULL);
2576
2577         /* ... but not inside a query */
2578         Assert(afterTriggers->query_depth == -1);
2579
2580         /*
2581          * If there are any triggers to fire, make sure we have set a snapshot for
2582          * them to use.  (Since PortalRunUtility doesn't set a snap for COMMIT, we
2583          * can't assume ActiveSnapshot is valid on entry.)
2584          */
2585         events = &afterTriggers->events;
2586         if (events->head != NULL)
2587                 ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
2588
2589         /*
2590          * Run all the remaining triggers.      Loop until they are all gone, just in
2591          * case some trigger queues more for us to do.
2592          */
2593         while (afterTriggerMarkEvents(events, NULL, false))
2594         {
2595                 CommandId       firing_id = afterTriggers->firing_counter++;
2596
2597                 afterTriggerInvokeEvents(events, firing_id, NULL, true);
2598         }
2599
2600         Assert(events->head == NULL);
2601 }
2602
2603
2604 /* ----------
2605  * AfterTriggerEndXact()
2606  *
2607  *      The current transaction is finishing.
2608  *
2609  *      Any unfired triggers are canceled so we simply throw
2610  *      away anything we know.
2611  *
2612  *      Note: it is possible for this to be called repeatedly in case of
2613  *      error during transaction abort; therefore, do not complain if
2614  *      already closed down.
2615  * ----------
2616  */
2617 void
2618 AfterTriggerEndXact(bool isCommit)
2619 {
2620         /*
2621          * Forget everything we know about AFTER triggers.
2622          *
2623          * Since all the info is in TopTransactionContext or children thereof, we
2624          * need do nothing special to reclaim memory.
2625          */
2626         afterTriggers = NULL;
2627 }
2628
2629 /*
2630  * AfterTriggerBeginSubXact()
2631  *
2632  *      Start a subtransaction.
2633  */
2634 void
2635 AfterTriggerBeginSubXact(void)
2636 {
2637         int                     my_level = GetCurrentTransactionNestLevel();
2638
2639         /*
2640          * Ignore call if the transaction is in aborted state.  (Probably
2641          * shouldn't happen?)
2642          */
2643         if (afterTriggers == NULL)
2644                 return;
2645
2646         /*
2647          * Allocate more space in the stacks if needed.
2648          */
2649         while (my_level >= afterTriggers->maxtransdepth)
2650         {
2651                 if (afterTriggers->maxtransdepth == 0)
2652                 {
2653                         MemoryContext old_cxt;
2654
2655                         old_cxt = MemoryContextSwitchTo(TopTransactionContext);
2656
2657 #define DEFTRIG_INITALLOC 8
2658                         afterTriggers->state_stack = (SetConstraintState *)
2659                                 palloc(DEFTRIG_INITALLOC * sizeof(SetConstraintState));
2660                         afterTriggers->events_stack = (AfterTriggerEventList *)
2661                                 palloc(DEFTRIG_INITALLOC * sizeof(AfterTriggerEventList));
2662                         afterTriggers->depth_stack = (int *)
2663                                 palloc(DEFTRIG_INITALLOC * sizeof(int));
2664                         afterTriggers->firing_stack = (CommandId *)
2665                                 palloc(DEFTRIG_INITALLOC * sizeof(CommandId));
2666                         afterTriggers->maxtransdepth = DEFTRIG_INITALLOC;
2667
2668                         MemoryContextSwitchTo(old_cxt);
2669                 }
2670                 else
2671                 {
2672                         /* repalloc will keep the stacks in the same context */
2673                         int                     new_alloc = afterTriggers->maxtransdepth * 2;
2674
2675                         afterTriggers->state_stack = (SetConstraintState *)
2676                                 repalloc(afterTriggers->state_stack,
2677                                                  new_alloc * sizeof(SetConstraintState));
2678                         afterTriggers->events_stack = (AfterTriggerEventList *)
2679                                 repalloc(afterTriggers->events_stack,
2680                                                  new_alloc * sizeof(AfterTriggerEventList));
2681                         afterTriggers->depth_stack = (int *)
2682                                 repalloc(afterTriggers->depth_stack,
2683                                                  new_alloc * sizeof(int));
2684                         afterTriggers->firing_stack = (CommandId *)
2685                                 repalloc(afterTriggers->firing_stack,
2686                                                  new_alloc * sizeof(CommandId));
2687                         afterTriggers->maxtransdepth = new_alloc;
2688                 }
2689         }
2690
2691         /*
2692          * Push the current information into the stack.  The SET CONSTRAINTS state
2693          * is not saved until/unless changed.
2694          */
2695         afterTriggers->state_stack[my_level] = NULL;
2696         afterTriggers->events_stack[my_level] = afterTriggers->events;
2697         afterTriggers->depth_stack[my_level] = afterTriggers->query_depth;
2698         afterTriggers->firing_stack[my_level] = afterTriggers->firing_counter;
2699 }
2700
2701 /*
2702  * AfterTriggerEndSubXact()
2703  *
2704  *      The current subtransaction is ending.
2705  */
2706 void
2707 AfterTriggerEndSubXact(bool isCommit)
2708 {
2709         int                     my_level = GetCurrentTransactionNestLevel();
2710         SetConstraintState state;
2711         AfterTriggerEvent event;
2712         CommandId       subxact_firing_id;
2713
2714         /*
2715          * Ignore call if the transaction is in aborted state.  (Probably
2716          * unneeded)
2717          */
2718         if (afterTriggers == NULL)
2719                 return;
2720
2721         /*
2722          * Pop the prior state if needed.
2723          */
2724         Assert(my_level < afterTriggers->maxtransdepth);
2725
2726         if (isCommit)
2727         {
2728                 /* If we saved a prior state, we don't need it anymore */
2729                 state = afterTriggers->state_stack[my_level];
2730                 if (state != NULL)
2731                         pfree(state);
2732                 /* this avoids double pfree if error later: */
2733                 afterTriggers->state_stack[my_level] = NULL;
2734                 Assert(afterTriggers->query_depth ==
2735                            afterTriggers->depth_stack[my_level]);
2736         }
2737         else
2738         {
2739                 /*
2740                  * Aborting --- restore the pointers from the stacks.
2741                  */
2742                 afterTriggers->events = afterTriggers->events_stack[my_level];
2743                 afterTriggers->query_depth = afterTriggers->depth_stack[my_level];
2744
2745                 /*
2746                  * Cleanup the tail of the list.
2747                  */
2748                 if (afterTriggers->events.tail != NULL)
2749                         afterTriggers->events.tail->ate_next = NULL;
2750
2751                 /*
2752                  * We don't need to free the subtransaction's items, since the
2753                  * CurTransactionContext will be reset shortly.
2754                  */
2755
2756                 /*
2757                  * Restore the trigger state.  If the saved state is NULL, then this
2758                  * subxact didn't save it, so it doesn't need restoring.
2759                  */
2760                 state = afterTriggers->state_stack[my_level];
2761                 if (state != NULL)
2762                 {
2763                         pfree(afterTriggers->state);
2764                         afterTriggers->state = state;
2765                 }
2766                 /* this avoids double pfree if error later: */
2767                 afterTriggers->state_stack[my_level] = NULL;
2768
2769                 /*
2770                  * Scan for any remaining deferred events that were marked DONE or IN
2771                  * PROGRESS by this subxact or a child, and un-mark them. We can
2772                  * recognize such events because they have a firing ID greater than or
2773                  * equal to the firing_counter value we saved at subtransaction start.
2774                  * (This essentially assumes that the current subxact includes all
2775                  * subxacts started after it.)
2776                  */
2777                 subxact_firing_id = afterTriggers->firing_stack[my_level];
2778                 for (event = afterTriggers->events.head;
2779                          event != NULL;
2780                          event = event->ate_next)
2781                 {
2782                         if (event->ate_event &
2783                                 (AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS))
2784                         {
2785                                 if (event->ate_firing_id >= subxact_firing_id)
2786                                         event->ate_event &=
2787                                                 ~(AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS);
2788                         }
2789                 }
2790         }
2791 }
2792
2793 /*
2794  * Create an empty SetConstraintState with room for numalloc trigstates
2795  */
2796 static SetConstraintState
2797 SetConstraintStateCreate(int numalloc)
2798 {
2799         SetConstraintState state;
2800
2801         /* Behave sanely with numalloc == 0 */
2802         if (numalloc <= 0)
2803                 numalloc = 1;
2804
2805         /*
2806          * We assume that zeroing will correctly initialize the state values.
2807          */
2808         state = (SetConstraintState)
2809                 MemoryContextAllocZero(TopTransactionContext,
2810                                                            sizeof(SetConstraintStateData) +
2811                                                    (numalloc - 1) *sizeof(SetConstraintTriggerData));
2812
2813         state->numalloc = numalloc;
2814
2815         return state;
2816 }
2817
2818 /*
2819  * Copy a SetConstraintState
2820  */
2821 static SetConstraintState
2822 SetConstraintStateCopy(SetConstraintState origstate)
2823 {
2824         SetConstraintState state;
2825
2826         state = SetConstraintStateCreate(origstate->numstates);
2827
2828         state->all_isset = origstate->all_isset;
2829         state->all_isdeferred = origstate->all_isdeferred;
2830         state->numstates = origstate->numstates;
2831         memcpy(state->trigstates, origstate->trigstates,
2832                    origstate->numstates * sizeof(SetConstraintTriggerData));
2833
2834         return state;
2835 }
2836
2837 /*
2838  * Add a per-trigger item to a SetConstraintState.      Returns possibly-changed
2839  * pointer to the state object (it will change if we have to repalloc).
2840  */
2841 static SetConstraintState
2842 SetConstraintStateAddItem(SetConstraintState state,
2843                                                   Oid tgoid, bool tgisdeferred)
2844 {
2845         if (state->numstates >= state->numalloc)
2846         {
2847                 int                     newalloc = state->numalloc * 2;
2848
2849                 newalloc = Max(newalloc, 8);    /* in case original has size 0 */
2850                 state = (SetConstraintState)
2851                         repalloc(state,
2852                                          sizeof(SetConstraintStateData) +
2853                                          (newalloc - 1) *sizeof(SetConstraintTriggerData));
2854                 state->numalloc = newalloc;
2855                 Assert(state->numstates < state->numalloc);
2856         }
2857
2858         state->trigstates[state->numstates].sct_tgoid = tgoid;
2859         state->trigstates[state->numstates].sct_tgisdeferred = tgisdeferred;
2860         state->numstates++;
2861
2862         return state;
2863 }
2864
2865 /* ----------
2866  * AfterTriggerSetState()
2867  *
2868  *      Execute the SET CONSTRAINTS ... utility command.
2869  * ----------
2870  */
2871 void
2872 AfterTriggerSetState(ConstraintsSetStmt *stmt)
2873 {
2874         int                     my_level = GetCurrentTransactionNestLevel();
2875
2876         /*
2877          * Ignore call if we aren't in a transaction.  (Shouldn't happen?)
2878          */
2879         if (afterTriggers == NULL)
2880                 return;
2881
2882         /*
2883          * If in a subtransaction, and we didn't save the current state already,
2884          * save it so it can be restored if the subtransaction aborts.
2885          */
2886         if (my_level > 1 &&
2887                 afterTriggers->state_stack[my_level] == NULL)
2888         {
2889                 afterTriggers->state_stack[my_level] =
2890                         SetConstraintStateCopy(afterTriggers->state);
2891         }
2892
2893         /*
2894          * Handle SET CONSTRAINTS ALL ...
2895          */
2896         if (stmt->constraints == NIL)
2897         {
2898                 /*
2899                  * Forget any previous SET CONSTRAINTS commands in this transaction.
2900                  */
2901                 afterTriggers->state->numstates = 0;
2902
2903                 /*
2904                  * Set the per-transaction ALL state to known.
2905                  */
2906                 afterTriggers->state->all_isset = true;
2907                 afterTriggers->state->all_isdeferred = stmt->deferred;
2908         }
2909         else
2910         {
2911                 Relation        tgrel;
2912                 ListCell   *l;
2913                 List       *oidlist = NIL;
2914
2915                 /* ----------
2916                  * Handle SET CONSTRAINTS constraint-name [, ...]
2917                  * First lookup all trigger Oid's for the constraint names.
2918                  * ----------
2919                  */
2920                 tgrel = heap_open(TriggerRelationId, AccessShareLock);
2921
2922                 foreach(l, stmt->constraints)
2923                 {
2924                         char       *cname = strVal(lfirst(l));
2925                         ScanKeyData skey;
2926                         SysScanDesc tgscan;
2927                         HeapTuple       htup;
2928                         bool            found;
2929
2930                         /*
2931                          * Check that only named constraints are set explicitly
2932                          */
2933                         if (strlen(cname) == 0)
2934                                 ereport(ERROR,
2935                                                 (errcode(ERRCODE_INVALID_NAME),
2936                                         errmsg("unnamed constraints cannot be set explicitly")));
2937
2938                         /*
2939                          * Setup to scan pg_trigger by tgconstrname ...
2940                          */
2941                         ScanKeyInit(&skey,
2942                                                 Anum_pg_trigger_tgconstrname,
2943                                                 BTEqualStrategyNumber, F_NAMEEQ,
2944                                                 PointerGetDatum(cname));
2945
2946                         tgscan = systable_beginscan(tgrel, TriggerConstrNameIndexId, true,
2947                                                                                 SnapshotNow, 1, &skey);
2948
2949                         /*
2950                          * ... and search for the constraint trigger row
2951                          */
2952                         found = false;
2953
2954                         while (HeapTupleIsValid(htup = systable_getnext(tgscan)))
2955                         {
2956                                 Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
2957
2958                                 /*
2959                                  * If we found some, check that they fit the deferrability but
2960                                  * skip referential action ones, since they are silently never
2961                                  * deferrable.
2962                                  */
2963                                 if (pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_UPD &&
2964                                         pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_DEL &&
2965                                         pg_trigger->tgfoid != F_RI_FKEY_CASCADE_UPD &&
2966                                         pg_trigger->tgfoid != F_RI_FKEY_CASCADE_DEL &&
2967                                         pg_trigger->tgfoid != F_RI_FKEY_SETNULL_UPD &&
2968                                         pg_trigger->tgfoid != F_RI_FKEY_SETNULL_DEL &&
2969                                         pg_trigger->tgfoid != F_RI_FKEY_SETDEFAULT_UPD &&
2970                                         pg_trigger->tgfoid != F_RI_FKEY_SETDEFAULT_DEL)
2971                                 {
2972                                         if (stmt->deferred && !pg_trigger->tgdeferrable)
2973                                                 ereport(ERROR,
2974                                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
2975                                                                  errmsg("constraint \"%s\" is not deferrable",
2976                                                                                 cname)));
2977                                         oidlist = lappend_oid(oidlist, HeapTupleGetOid(htup));
2978                                 }
2979                                 found = true;
2980                         }
2981
2982                         systable_endscan(tgscan);
2983
2984                         /*
2985                          * Not found ?
2986                          */
2987                         if (!found)
2988                                 ereport(ERROR,
2989                                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
2990                                                  errmsg("constraint \"%s\" does not exist",
2991                                                                 cname)));
2992                 }
2993                 heap_close(tgrel, AccessShareLock);
2994
2995                 /*
2996                  * Set the trigger states of individual triggers for this xact.
2997                  */
2998                 foreach(l, oidlist)
2999                 {
3000                         Oid                     tgoid = lfirst_oid(l);
3001                         SetConstraintState state = afterTriggers->state;
3002                         bool            found = false;
3003                         int                     i;
3004
3005                         for (i = 0; i < state->numstates; i++)
3006                         {
3007                                 if (state->trigstates[i].sct_tgoid == tgoid)
3008                                 {
3009                                         state->trigstates[i].sct_tgisdeferred = stmt->deferred;
3010                                         found = true;
3011                                         break;
3012                                 }
3013                         }
3014                         if (!found)
3015                         {
3016                                 afterTriggers->state =
3017                                         SetConstraintStateAddItem(state, tgoid, stmt->deferred);
3018                         }
3019                 }
3020         }
3021
3022         /*
3023          * SQL99 requires that when a constraint is set to IMMEDIATE, any deferred
3024          * checks against that constraint must be made when the SET CONSTRAINTS
3025          * command is executed -- i.e. the effects of the SET CONSTRAINTS command
3026          * apply retroactively.  We've updated the constraints state, so scan the
3027          * list of previously deferred events to fire any that have now become
3028          * immediate.
3029          *
3030          * Obviously, if this was SET ... DEFERRED then it can't have converted
3031          * any unfired events to immediate, so we need do nothing in that case.
3032          */
3033         if (!stmt->deferred)
3034         {
3035                 AfterTriggerEventList *events = &afterTriggers->events;
3036
3037                 if (afterTriggerMarkEvents(events, NULL, true))
3038                 {
3039                         CommandId       firing_id = afterTriggers->firing_counter++;
3040
3041                         /*
3042                          * We can delete fired events if we are at top transaction level,
3043                          * but we'd better not if inside a subtransaction, since the
3044                          * subtransaction could later get rolled back.
3045                          */
3046                         afterTriggerInvokeEvents(events, firing_id, NULL,
3047                                                                          !IsSubTransaction());
3048                 }
3049         }
3050 }
3051
3052
3053 /* ----------
3054  * AfterTriggerSaveEvent()
3055  *
3056  *      Called by ExecA[RS]...Triggers() to add the event to the queue.
3057  *
3058  *      NOTE: should be called only if we've determined that an event must
3059  *      be added to the queue.
3060  * ----------
3061  */
3062 static void
3063 AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger,
3064                                           HeapTuple oldtup, HeapTuple newtup)
3065 {
3066         Relation        rel = relinfo->ri_RelationDesc;
3067         TriggerDesc *trigdesc = relinfo->ri_TrigDesc;
3068         AfterTriggerEvent new_event;
3069         int                     i;
3070         int                     ntriggers;
3071         int                *tgindx;
3072         ItemPointerData oldctid;
3073         ItemPointerData newctid;
3074
3075         if (afterTriggers == NULL)
3076                 elog(ERROR, "AfterTriggerSaveEvent() called outside of transaction");
3077
3078         /*
3079          * Get the CTID's of OLD and NEW
3080          */
3081         if (oldtup != NULL)
3082                 ItemPointerCopy(&(oldtup->t_self), &(oldctid));
3083         else
3084                 ItemPointerSetInvalid(&(oldctid));
3085         if (newtup != NULL)
3086                 ItemPointerCopy(&(newtup->t_self), &(newctid));
3087         else
3088                 ItemPointerSetInvalid(&(newctid));
3089
3090         /*
3091          * Scan the appropriate set of triggers
3092          */
3093         if (row_trigger)
3094         {
3095                 ntriggers = trigdesc->n_after_row[event];
3096                 tgindx = trigdesc->tg_after_row[event];
3097         }
3098         else
3099         {
3100                 ntriggers = trigdesc->n_after_statement[event];
3101                 tgindx = trigdesc->tg_after_statement[event];
3102         }
3103
3104         for (i = 0; i < ntriggers; i++)
3105         {
3106                 Trigger    *trigger = &trigdesc->triggers[tgindx[i]];
3107
3108                 /* Ignore disabled triggers */
3109                 if (!trigger->tgenabled)
3110                         continue;
3111
3112                 /*
3113                  * If this is an UPDATE of a PK table or FK table that does not change
3114                  * the PK or FK respectively, we can skip queuing the event: there is
3115                  * no need to fire the trigger.
3116                  */
3117                 if ((event & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_UPDATE)
3118                 {
3119                         switch (RI_FKey_trigger_type(trigger->tgfoid))
3120                         {
3121                                 case RI_TRIGGER_PK:
3122                                         /* Update on PK table */
3123                                         if (RI_FKey_keyequal_upd_pk(trigger, rel, oldtup, newtup))
3124                                         {
3125                                                 /* key unchanged, so skip queuing this event */
3126                                                 continue;
3127                                         }
3128                                         break;
3129
3130                                 case RI_TRIGGER_FK:
3131
3132                                         /*
3133                                          * Update on FK table
3134                                          *
3135                                          * There is one exception when updating FK tables: if the
3136                                          * updated row was inserted by our own transaction and the
3137                                          * FK is deferred, we still need to fire the trigger. This
3138                                          * is because our UPDATE will invalidate the INSERT so the
3139                                          * end-of-transaction INSERT RI trigger will not do
3140                                          * anything, so we have to do the check for the UPDATE
3141                                          * anyway.
3142                                          */
3143                                         if (HeapTupleHeaderGetXmin(oldtup->t_data) !=
3144                                                 GetCurrentTransactionId() &&
3145                                                 RI_FKey_keyequal_upd_fk(trigger, rel, oldtup, newtup))
3146                                         {
3147                                                 continue;
3148                                         }
3149                                         break;
3150
3151                                 case RI_TRIGGER_NONE:
3152                                         /* Not an FK trigger */
3153                                         break;
3154                         }
3155                 }
3156
3157                 /*
3158                  * Create a new event.  We use the CurTransactionContext so the event
3159                  * will automatically go away if the subtransaction aborts.
3160                  */
3161                 new_event = (AfterTriggerEvent)
3162                         MemoryContextAlloc(CurTransactionContext,
3163                                                            sizeof(AfterTriggerEventData));
3164                 new_event->ate_next = NULL;
3165                 new_event->ate_event =
3166                         (event & TRIGGER_EVENT_OPMASK) |
3167                         (row_trigger ? TRIGGER_EVENT_ROW : 0) |
3168                         (trigger->tgdeferrable ? AFTER_TRIGGER_DEFERRABLE : 0) |
3169                         (trigger->tginitdeferred ? AFTER_TRIGGER_INITDEFERRED : 0);
3170                 new_event->ate_firing_id = 0;
3171                 new_event->ate_tgoid = trigger->tgoid;
3172                 new_event->ate_relid = rel->rd_id;
3173                 ItemPointerCopy(&oldctid, &(new_event->ate_oldctid));
3174                 ItemPointerCopy(&newctid, &(new_event->ate_newctid));
3175
3176                 /*
3177                  * Add the new event to the queue.
3178                  */
3179                 afterTriggerAddEvent(new_event);
3180         }
3181 }