/*------------------------------------------------------------------------- * * trigger.c * PostgreSQL TRIGGERs support code. * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/genam.h" #include "access/heapam.h" #include "catalog/catalog.h" #include "catalog/catname.h" #include "catalog/indexing.h" #include "catalog/pg_language.h" #include "catalog/pg_proc.h" #include "catalog/pg_trigger.h" #include "commands/comment.h" #include "commands/trigger.h" #include "executor/executor.h" #include "miscadmin.h" #include "utils/acl.h" #include "utils/builtins.h" #include "utils/inval.h" #include "utils/syscache.h" #include "utils/tqual.h" DLLIMPORT TriggerData *CurrentTriggerData = NULL; void RelationBuildTriggers(Relation relation); void FreeTriggerDesc(Relation relation); static void DescribeTrigger(TriggerDesc *trigdesc, Trigger *trigger); static HeapTuple GetTupleForTrigger(EState *estate, ItemPointer tid, TupleTableSlot **newSlot); extern GlobalMemory CacheCxt; void CreateTrigger(CreateTrigStmt *stmt) { int16 tgtype; int16 tgattr[FUNC_MAX_ARGS] = {0}; Datum values[Natts_pg_trigger]; char nulls[Natts_pg_trigger]; Relation rel; Relation tgrel; HeapScanDesc tgscan; ScanKeyData key; Relation pgrel; HeapTuple tuple; Relation idescs[Num_pg_trigger_indices]; Relation ridescs[Num_pg_class_indices]; MemoryContext oldcxt; Oid fargtypes[FUNC_MAX_ARGS]; int found = 0; int i; char constrtrigname[NAMEDATALEN]; char *constrname = ""; Oid constrrelid = 0; if (!allowSystemTableMods && IsSystemRelationName(stmt->relname)) elog(ERROR, "CreateTrigger: can't create trigger for system relation %s", stmt->relname); #ifndef NO_SECURITY if (!pg_ownercheck(GetPgUserName(), stmt->relname, RELNAME)) elog(ERROR, "%s: %s", stmt->relname, aclcheck_error_strings[ACLCHECK_NOT_OWNER]); #endif /* ---------- * If trigger is a constraint, user trigger name as constraint * name and build a unique trigger name instead. * ---------- */ if (stmt->isconstraint) { constrname = stmt->trigname; stmt->trigname = constrtrigname; sprintf(constrtrigname, "RI_ConstraintTrigger_%d", newoid()); if (strcmp(stmt->constrrelname, "") == 0) constrrelid = 0; else { rel = heap_openr(stmt->constrrelname, NoLock); if (rel == NULL) elog(ERROR, "table \"%s\" does not exist", stmt->constrrelname); constrrelid = rel->rd_id; heap_close(rel, NoLock); } } rel = heap_openr(stmt->relname, AccessExclusiveLock); TRIGGER_CLEAR_TYPE(tgtype); if (stmt->before) TRIGGER_SETT_BEFORE(tgtype); if (stmt->row) TRIGGER_SETT_ROW(tgtype); else elog(ERROR, "CreateTrigger: STATEMENT triggers are unimplemented, yet"); for (i = 0; i < 3 && stmt->actions[i]; i++) { switch (stmt->actions[i]) { case 'i': if (TRIGGER_FOR_INSERT(tgtype)) elog(ERROR, "CreateTrigger: double INSERT event specified"); TRIGGER_SETT_INSERT(tgtype); break; case 'd': if (TRIGGER_FOR_DELETE(tgtype)) elog(ERROR, "CreateTrigger: double DELETE event specified"); TRIGGER_SETT_DELETE(tgtype); break; case 'u': if (TRIGGER_FOR_UPDATE(tgtype)) elog(ERROR, "CreateTrigger: double UPDATE event specified"); TRIGGER_SETT_UPDATE(tgtype); break; default: elog(ERROR, "CreateTrigger: unknown event specified"); break; } } /* Scan pg_trigger */ tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgrelid, F_OIDEQ, RelationGetRelid(rel)); tgscan = heap_beginscan(tgrel, 0, SnapshotNow, 1, &key); while (HeapTupleIsValid(tuple = heap_getnext(tgscan, 0))) { Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); if (namestrcmp(&(pg_trigger->tgname), stmt->trigname) == 0) elog(ERROR, "CreateTrigger: trigger %s already defined on relation %s", stmt->trigname, stmt->relname); else found++; } heap_endscan(tgscan); MemSet(fargtypes, 0, FUNC_MAX_ARGS * sizeof(Oid)); tuple = SearchSysCacheTuple(PROCNAME, PointerGetDatum(stmt->funcname), Int32GetDatum(0), PointerGetDatum(fargtypes), 0); if (!HeapTupleIsValid(tuple) || ((Form_pg_proc) GETSTRUCT(tuple))->pronargs != 0) elog(ERROR, "CreateTrigger: function %s() does not exist", stmt->funcname); if (((Form_pg_proc) GETSTRUCT(tuple))->prorettype != 0) elog(ERROR, "CreateTrigger: function %s() must return OPAQUE", stmt->funcname); if (((Form_pg_proc) GETSTRUCT(tuple))->prolang != ClanguageId && ((Form_pg_proc) GETSTRUCT(tuple))->prolang != INTERNALlanguageId) { HeapTuple langTup; langTup = SearchSysCacheTuple(LANGOID, ObjectIdGetDatum(((Form_pg_proc) GETSTRUCT(tuple))->prolang), 0, 0, 0); if (!HeapTupleIsValid(langTup)) elog(ERROR, "CreateTrigger: cache lookup for PL failed"); if (((Form_pg_language) GETSTRUCT(langTup))->lanispl == false) elog(ERROR, "CreateTrigger: only builtin, C and PL functions are supported"); } MemSet(nulls, ' ', Natts_pg_trigger * sizeof(char)); values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel)); values[Anum_pg_trigger_tgname - 1] = NameGetDatum(namein(stmt->trigname)); values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(tuple->t_data->t_oid); values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype); values[Anum_pg_trigger_tgenabled - 1] = true; values[Anum_pg_trigger_tgisconstraint - 1] = stmt->isconstraint; values[Anum_pg_trigger_tgconstrname - 1] = PointerGetDatum(constrname);; values[Anum_pg_trigger_tgconstrrelid - 1] = constrrelid; values[Anum_pg_trigger_tgdeferrable - 1] = stmt->deferrable; values[Anum_pg_trigger_tginitdeferred - 1] = stmt->initdeferred; if (stmt->args) { List *le; char *args; int16 nargs = length(stmt->args); int len = 0; foreach(le, stmt->args) { char *ar = (char *) lfirst(le); len += strlen(ar) + VARHDRSZ; for (; *ar; ar++) { if (*ar == '\\') len++; } } args = (char *) palloc(len + 1); args[0] = 0; foreach(le, stmt->args) { char *s = (char *) lfirst(le); char *d = args + strlen(args); while (*s) { if (*s == '\\') *d++ = '\\'; *d++ = *s++; } *d = 0; strcat(args, "\\000"); } values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs); values[Anum_pg_trigger_tgargs - 1] = PointerGetDatum(byteain(args)); } else { values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0); values[Anum_pg_trigger_tgargs - 1] = PointerGetDatum(byteain("")); } values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr); tuple = heap_formtuple(tgrel->rd_att, values, nulls); heap_insert(tgrel, tuple); CatalogOpenIndices(Num_pg_trigger_indices, Name_pg_trigger_indices, idescs); CatalogIndexInsert(idescs, Num_pg_trigger_indices, tgrel, tuple); CatalogCloseIndices(Num_pg_trigger_indices, idescs); heap_freetuple(tuple); heap_close(tgrel, RowExclusiveLock); pfree(DatumGetPointer(values[Anum_pg_trigger_tgname - 1])); pfree(DatumGetPointer(values[Anum_pg_trigger_tgargs - 1])); /* update pg_class */ pgrel = heap_openr(RelationRelationName, RowExclusiveLock); tuple = SearchSysCacheTupleCopy(RELNAME, PointerGetDatum(stmt->relname), 0, 0, 0); if (!HeapTupleIsValid(tuple)) elog(ERROR, "CreateTrigger: relation %s not found in pg_class", stmt->relname); ((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found + 1; RelationInvalidateHeapTuple(pgrel, tuple); heap_update(pgrel, &tuple->t_self, tuple, NULL); CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs); CatalogIndexInsert(ridescs, Num_pg_class_indices, pgrel, tuple); CatalogCloseIndices(Num_pg_class_indices, ridescs); heap_freetuple(tuple); heap_close(pgrel, RowExclusiveLock); CommandCounterIncrement(); oldcxt = MemoryContextSwitchTo((MemoryContext) CacheCxt); FreeTriggerDesc(rel); rel->rd_rel->reltriggers = found + 1; RelationBuildTriggers(rel); MemoryContextSwitchTo(oldcxt); /* Keep lock on target rel until end of xact */ heap_close(rel, NoLock); } void DropTrigger(DropTrigStmt *stmt) { Relation rel; Relation tgrel; HeapScanDesc tgscan; ScanKeyData key; Relation pgrel; HeapTuple tuple; Relation ridescs[Num_pg_class_indices]; MemoryContext oldcxt; int found = 0; int tgfound = 0; #ifndef NO_SECURITY if (!pg_ownercheck(GetPgUserName(), stmt->relname, RELNAME)) elog(ERROR, "%s: %s", stmt->relname, aclcheck_error_strings[ACLCHECK_NOT_OWNER]); #endif rel = heap_openr(stmt->relname, AccessExclusiveLock); tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgrelid, F_OIDEQ, RelationGetRelid(rel)); tgscan = heap_beginscan(tgrel, 0, SnapshotNow, 1, &key); while (HeapTupleIsValid(tuple = heap_getnext(tgscan, 0))) { Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); if (namestrcmp(&(pg_trigger->tgname), stmt->trigname) == 0) { /*** Delete any comments associated with this trigger ***/ DeleteComments(tuple->t_data->t_oid); heap_delete(tgrel, &tuple->t_self, NULL); tgfound++; } else found++; } if (tgfound == 0) elog(ERROR, "DropTrigger: there is no trigger %s on relation %s", stmt->trigname, stmt->relname); if (tgfound > 1) elog(NOTICE, "DropTrigger: found (and deleted) %d triggers %s on relation %s", tgfound, stmt->trigname, stmt->relname); heap_endscan(tgscan); heap_close(tgrel, RowExclusiveLock); /* update pg_class */ pgrel = heap_openr(RelationRelationName, RowExclusiveLock); tuple = SearchSysCacheTupleCopy(RELNAME, PointerGetDatum(stmt->relname), 0, 0, 0); if (!HeapTupleIsValid(tuple)) elog(ERROR, "DropTrigger: relation %s not found in pg_class", stmt->relname); ((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found; RelationInvalidateHeapTuple(pgrel, tuple); heap_update(pgrel, &tuple->t_self, tuple, NULL); CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs); CatalogIndexInsert(ridescs, Num_pg_class_indices, pgrel, tuple); CatalogCloseIndices(Num_pg_class_indices, ridescs); heap_freetuple(tuple); heap_close(pgrel, RowExclusiveLock); CommandCounterIncrement(); oldcxt = MemoryContextSwitchTo((MemoryContext) CacheCxt); FreeTriggerDesc(rel); rel->rd_rel->reltriggers = found; if (found > 0) RelationBuildTriggers(rel); MemoryContextSwitchTo(oldcxt); /* Keep lock on target rel until end of xact */ heap_close(rel, NoLock); } void RelationRemoveTriggers(Relation rel) { Relation tgrel; HeapScanDesc tgscan; ScanKeyData key; HeapTuple tup; Form_pg_trigger pg_trigger; tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgrelid, F_OIDEQ, RelationGetRelid(rel)); tgscan = heap_beginscan(tgrel, 0, SnapshotNow, 1, &key); while (HeapTupleIsValid(tup = heap_getnext(tgscan, 0))) { /*** Delete any comments associated with this trigger ***/ DeleteComments(tup->t_data->t_oid); heap_delete(tgrel, &tup->t_self, NULL); } heap_endscan(tgscan); /* ---------- * Also drop all constraint triggers referencing this relation * ---------- */ ScanKeyEntryInitialize(&key, 0, Anum_pg_trigger_tgconstrrelid, F_OIDEQ, RelationGetRelid(rel)); tgscan = heap_beginscan(tgrel, 0, SnapshotNow, 1, &key); while (HeapTupleIsValid(tup = heap_getnext(tgscan, 0))) { Relation refrel; DropTrigStmt stmt; pg_trigger = (Form_pg_trigger) GETSTRUCT(tup); refrel = heap_open(pg_trigger->tgrelid, NoLock); stmt.relname = pstrdup(RelationGetRelationName(refrel)); stmt.trigname = nameout(&pg_trigger->tgname); elog(NOTICE, "DROP TABLE implicitly drops referential integrity trigger from table \"%s\"", stmt.relname); DropTrigger(&stmt); pfree(stmt.relname); pfree(stmt.trigname); heap_close(refrel, NoLock); } heap_endscan(tgscan); heap_close(tgrel, RowExclusiveLock); } void RelationBuildTriggers(Relation relation) { TriggerDesc *trigdesc = (TriggerDesc *) palloc(sizeof(TriggerDesc)); int ntrigs = relation->rd_rel->reltriggers; Trigger *triggers = NULL; Trigger *build; Relation tgrel; Form_pg_trigger pg_trigger; Relation irel; ScanKeyData skey; HeapTupleData tuple; IndexScanDesc sd; RetrieveIndexResult indexRes; Buffer buffer; struct varlena *val; bool isnull; int found; MemSet(trigdesc, 0, sizeof(TriggerDesc)); ScanKeyEntryInitialize(&skey, (bits16) 0x0, (AttrNumber) 1, (RegProcedure) F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation))); tgrel = heap_openr(TriggerRelationName, AccessShareLock); irel = index_openr(TriggerRelidIndex); sd = index_beginscan(irel, false, 1, &skey); for (found = 0;;) { indexRes = index_getnext(sd, ForwardScanDirection); if (!indexRes) break; tuple.t_self = indexRes->heap_iptr; heap_fetch(tgrel, SnapshotNow, &tuple, &buffer); pfree(indexRes); if (!tuple.t_data) continue; if (found == ntrigs) elog(ERROR, "RelationBuildTriggers: unexpected record found for rel %.*s", NAMEDATALEN, RelationGetRelationName(relation)); pg_trigger = (Form_pg_trigger) GETSTRUCT(&tuple); if (triggers == NULL) triggers = (Trigger *) palloc(sizeof(Trigger)); else triggers = (Trigger *) repalloc(triggers, (found + 1) * sizeof(Trigger)); build = &(triggers[found]); build->tgoid = tuple.t_data->t_oid; build->tgname = nameout(&pg_trigger->tgname); build->tgfoid = pg_trigger->tgfoid; build->tgfunc.fn_addr = NULL; build->tgtype = pg_trigger->tgtype; build->tgenabled = pg_trigger->tgenabled; build->tgisconstraint = pg_trigger->tgisconstraint; build->tgdeferrable = pg_trigger->tgdeferrable; build->tginitdeferred = pg_trigger->tginitdeferred; build->tgnargs = pg_trigger->tgnargs; memcpy(build->tgattr, &(pg_trigger->tgattr), FUNC_MAX_ARGS * sizeof(int16)); val = (struct varlena *) fastgetattr(&tuple, Anum_pg_trigger_tgargs, tgrel->rd_att, &isnull); if (isnull) elog(ERROR, "RelationBuildTriggers: tgargs IS NULL for rel %.*s", NAMEDATALEN, RelationGetRelationName(relation)); if (build->tgnargs > 0) { char *p; int i; val = (struct varlena *) fastgetattr(&tuple, Anum_pg_trigger_tgargs, tgrel->rd_att, &isnull); if (isnull) elog(ERROR, "RelationBuildTriggers: tgargs IS NULL for rel %.*s", NAMEDATALEN, RelationGetRelationName(relation)); p = (char *) VARDATA(val); build->tgargs = (char **) palloc(build->tgnargs * sizeof(char *)); for (i = 0; i < build->tgnargs; i++) { build->tgargs[i] = (char *) palloc(strlen(p) + 1); strcpy(build->tgargs[i], p); p += strlen(p) + 1; } } else build->tgargs = NULL; found++; ReleaseBuffer(buffer); } if (found < ntrigs) elog(ERROR, "RelationBuildTriggers: %d record not found for rel %.*s", ntrigs - found, NAMEDATALEN, RelationGetRelationName(relation)); index_endscan(sd); index_close(irel); heap_close(tgrel, AccessShareLock); /* Build trigdesc */ trigdesc->triggers = triggers; for (found = 0; found < ntrigs; found++) { build = &(triggers[found]); DescribeTrigger(trigdesc, build); } relation->trigdesc = trigdesc; } void FreeTriggerDesc(Relation relation) { TriggerDesc *trigdesc = relation->trigdesc; Trigger ***t; Trigger *trigger; int i; if (trigdesc == NULL) return; t = trigdesc->tg_before_statement; for (i = 0; i < 3; i++) if (t[i] != NULL) pfree(t[i]); t = trigdesc->tg_before_row; for (i = 0; i < 3; i++) if (t[i] != NULL) pfree(t[i]); t = trigdesc->tg_after_row; for (i = 0; i < 3; i++) if (t[i] != NULL) pfree(t[i]); t = trigdesc->tg_after_statement; for (i = 0; i < 3; i++) if (t[i] != NULL) pfree(t[i]); trigger = trigdesc->triggers; for (i = 0; i < relation->rd_rel->reltriggers; i++) { pfree(trigger->tgname); if (trigger->tgnargs > 0) { while (--(trigger->tgnargs) >= 0) pfree(trigger->tgargs[trigger->tgnargs]); pfree(trigger->tgargs); } trigger++; } pfree(trigdesc->triggers); pfree(trigdesc); relation->trigdesc = NULL; return; } static void DescribeTrigger(TriggerDesc *trigdesc, Trigger *trigger) { uint16 *n; Trigger ***t, ***tp; if (TRIGGER_FOR_ROW(trigger->tgtype)) /* Is ROW/STATEMENT * trigger */ { if (TRIGGER_FOR_BEFORE(trigger->tgtype)) { n = trigdesc->n_before_row; t = trigdesc->tg_before_row; } else { n = trigdesc->n_after_row; t = trigdesc->tg_after_row; } } else /* STATEMENT (NI) */ { if (TRIGGER_FOR_BEFORE(trigger->tgtype)) { n = trigdesc->n_before_statement; t = trigdesc->tg_before_statement; } else { n = trigdesc->n_after_statement; t = trigdesc->tg_after_statement; } } if (TRIGGER_FOR_INSERT(trigger->tgtype)) { tp = &(t[TRIGGER_EVENT_INSERT]); if (*tp == NULL) *tp = (Trigger **) palloc(sizeof(Trigger *)); else *tp = (Trigger **) repalloc(*tp, (n[TRIGGER_EVENT_INSERT] + 1) * sizeof(Trigger *)); (*tp)[n[TRIGGER_EVENT_INSERT]] = trigger; (n[TRIGGER_EVENT_INSERT])++; } if (TRIGGER_FOR_DELETE(trigger->tgtype)) { tp = &(t[TRIGGER_EVENT_DELETE]); if (*tp == NULL) *tp = (Trigger **) palloc(sizeof(Trigger *)); else *tp = (Trigger **) repalloc(*tp, (n[TRIGGER_EVENT_DELETE] + 1) * sizeof(Trigger *)); (*tp)[n[TRIGGER_EVENT_DELETE]] = trigger; (n[TRIGGER_EVENT_DELETE])++; } if (TRIGGER_FOR_UPDATE(trigger->tgtype)) { tp = &(t[TRIGGER_EVENT_UPDATE]); if (*tp == NULL) *tp = (Trigger **) palloc(sizeof(Trigger *)); else *tp = (Trigger **) repalloc(*tp, (n[TRIGGER_EVENT_UPDATE] + 1) * sizeof(Trigger *)); (*tp)[n[TRIGGER_EVENT_UPDATE]] = trigger; (n[TRIGGER_EVENT_UPDATE])++; } } static HeapTuple ExecCallTriggerFunc(Trigger *trigger) { if (trigger->tgfunc.fn_addr == NULL) fmgr_info(trigger->tgfoid, &trigger->tgfunc); if (trigger->tgfunc.fn_plhandler != NULL) { return (HeapTuple) (*(trigger->tgfunc.fn_plhandler)) (&trigger->tgfunc); } return (HeapTuple) ((*fmgr_faddr(&trigger->tgfunc)) ()); } HeapTuple ExecBRInsertTriggers(Relation rel, HeapTuple trigtuple) { TriggerData *SaveTriggerData; int ntrigs = rel->trigdesc->n_before_row[TRIGGER_EVENT_INSERT]; Trigger **trigger = rel->trigdesc->tg_before_row[TRIGGER_EVENT_INSERT]; HeapTuple newtuple = trigtuple; HeapTuple oldtuple; int i; SaveTriggerData = (TriggerData *) palloc(sizeof(TriggerData)); SaveTriggerData->tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; SaveTriggerData->tg_relation = rel; SaveTriggerData->tg_newtuple = NULL; for (i = 0; i < ntrigs; i++) { if (!trigger[i]->tgenabled) continue; CurrentTriggerData = SaveTriggerData; CurrentTriggerData->tg_trigtuple = oldtuple = newtuple; CurrentTriggerData->tg_trigger = trigger[i]; newtuple = ExecCallTriggerFunc(trigger[i]); if (newtuple == NULL) break; else if (oldtuple != newtuple && oldtuple != trigtuple) heap_freetuple(oldtuple); } CurrentTriggerData = NULL; pfree(SaveTriggerData); return newtuple; } void ExecARInsertTriggers(Relation rel, HeapTuple trigtuple) { DeferredTriggerSaveEvent(rel, TRIGGER_EVENT_INSERT, NULL, trigtuple); return; } bool ExecBRDeleteTriggers(EState *estate, ItemPointer tupleid) { Relation rel = estate->es_result_relation_info->ri_RelationDesc; TriggerData *SaveTriggerData; int ntrigs = rel->trigdesc->n_before_row[TRIGGER_EVENT_DELETE]; Trigger **trigger = rel->trigdesc->tg_before_row[TRIGGER_EVENT_DELETE]; HeapTuple trigtuple; HeapTuple newtuple = NULL; TupleTableSlot *newSlot; int i; trigtuple = GetTupleForTrigger(estate, tupleid, &newSlot); if (trigtuple == NULL) return false; SaveTriggerData = (TriggerData *) palloc(sizeof(TriggerData)); SaveTriggerData->tg_event = TRIGGER_EVENT_DELETE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; SaveTriggerData->tg_relation = rel; SaveTriggerData->tg_newtuple = NULL; for (i = 0; i < ntrigs; i++) { if (!trigger[i]->tgenabled) continue; CurrentTriggerData = SaveTriggerData; CurrentTriggerData->tg_trigtuple = trigtuple; CurrentTriggerData->tg_trigger = trigger[i]; newtuple = ExecCallTriggerFunc(trigger[i]); if (newtuple == NULL) break; if (newtuple != trigtuple) heap_freetuple(newtuple); } CurrentTriggerData = NULL; pfree(SaveTriggerData); heap_freetuple(trigtuple); return (newtuple == NULL) ? false : true; } void ExecARDeleteTriggers(EState *estate, ItemPointer tupleid) { Relation rel = estate->es_result_relation_info->ri_RelationDesc; HeapTuple trigtuple = GetTupleForTrigger(estate, tupleid, NULL); DeferredTriggerSaveEvent(rel, TRIGGER_EVENT_DELETE, trigtuple, NULL); return; } HeapTuple ExecBRUpdateTriggers(EState *estate, ItemPointer tupleid, HeapTuple newtuple) { Relation rel = estate->es_result_relation_info->ri_RelationDesc; TriggerData *SaveTriggerData; int ntrigs = rel->trigdesc->n_before_row[TRIGGER_EVENT_UPDATE]; Trigger **trigger = rel->trigdesc->tg_before_row[TRIGGER_EVENT_UPDATE]; HeapTuple trigtuple; HeapTuple oldtuple; HeapTuple intuple = newtuple; TupleTableSlot *newSlot; int i; trigtuple = GetTupleForTrigger(estate, tupleid, &newSlot); if (trigtuple == NULL) return NULL; /* * In READ COMMITTED isolevel it's possible that newtuple was changed * due to concurrent update. */ if (newSlot != NULL) intuple = newtuple = ExecRemoveJunk(estate->es_junkFilter, newSlot); SaveTriggerData = (TriggerData *) palloc(sizeof(TriggerData)); SaveTriggerData->tg_event = TRIGGER_EVENT_UPDATE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; SaveTriggerData->tg_relation = rel; for (i = 0; i < ntrigs; i++) { if (!trigger[i]->tgenabled) continue; CurrentTriggerData = SaveTriggerData; CurrentTriggerData->tg_trigtuple = trigtuple; CurrentTriggerData->tg_newtuple = oldtuple = newtuple; CurrentTriggerData->tg_trigger = trigger[i]; newtuple = ExecCallTriggerFunc(trigger[i]); if (newtuple == NULL) break; else if (oldtuple != newtuple && oldtuple != intuple) heap_freetuple(oldtuple); } CurrentTriggerData = NULL; pfree(SaveTriggerData); heap_freetuple(trigtuple); return newtuple; } void ExecARUpdateTriggers(EState *estate, ItemPointer tupleid, HeapTuple newtuple) { Relation rel = estate->es_result_relation_info->ri_RelationDesc; HeapTuple trigtuple = GetTupleForTrigger(estate, tupleid, NULL); DeferredTriggerSaveEvent(rel, TRIGGER_EVENT_UPDATE, trigtuple, newtuple); return; } extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti, ItemPointer tid); static HeapTuple GetTupleForTrigger(EState *estate, ItemPointer tid, TupleTableSlot **newSlot) { Relation relation = estate->es_result_relation_info->ri_RelationDesc; HeapTupleData tuple; HeapTuple result; Buffer buffer; if (newSlot != NULL) { int test; /* * mark tuple for update */ *newSlot = NULL; tuple.t_self = *tid; ltrmark:; test = heap_mark4update(relation, &tuple, &buffer); switch (test) { case HeapTupleSelfUpdated: ReleaseBuffer(buffer); return (NULL); case HeapTupleMayBeUpdated: break; case HeapTupleUpdated: ReleaseBuffer(buffer); if (XactIsoLevel == XACT_SERIALIZABLE) elog(ERROR, "Can't serialize access due to concurrent update"); else if (!(ItemPointerEquals(&(tuple.t_self), tid))) { TupleTableSlot *epqslot = EvalPlanQual(estate, estate->es_result_relation_info->ri_RangeTableIndex, &(tuple.t_self)); if (!(TupIsNull(epqslot))) { *tid = tuple.t_self; *newSlot = epqslot; goto ltrmark; } } /* * if tuple was deleted or PlanQual failed for updated * tuple - we have not process this tuple! */ return (NULL); default: ReleaseBuffer(buffer); elog(ERROR, "Unknown status %u from heap_mark4update", test); return (NULL); } } else { PageHeader dp; ItemId lp; buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid)); if (!BufferIsValid(buffer)) elog(ERROR, "GetTupleForTrigger: failed ReadBuffer"); dp = (PageHeader) BufferGetPage(buffer); lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid)); Assert(ItemIdIsUsed(lp)); tuple.t_datamcxt = NULL; tuple.t_data = (HeapTupleHeader) PageGetItem((Page) dp, lp); tuple.t_len = ItemIdGetLength(lp); tuple.t_self = *tid; } result = heap_copytuple(&tuple); ReleaseBuffer(buffer); return result; } /* ---------- * Deferred trigger stuff * ---------- */ /* ---------- * Internal data to the deferred trigger mechanism is held * during entire session in a global memor created at startup and * over statements/commands in a separate global memory which * is created at transaction start and destroyed at transaction * end. * ---------- */ static GlobalMemory deftrig_gcxt = NULL; static GlobalMemory deftrig_cxt = NULL; /* ---------- * Global data that tells which triggers are actually in * state IMMEDIATE or DEFERRED. * ---------- */ static bool deftrig_dfl_all_isset = false; static bool deftrig_dfl_all_isdeferred = false; static List *deftrig_dfl_trigstates = NIL; static bool deftrig_all_isset; static bool deftrig_all_isdeferred; static List *deftrig_trigstates; /* ---------- * The list of events during the entire transaction. * * XXX This must finally be held in a file because of the huge * number of events that could occur in the real world. * ---------- */ static int deftrig_n_events; static List *deftrig_events; /* ---------- * deferredTriggerCheckState() * * Returns true if the trigger identified by tgoid is actually * in state DEFERRED. * ---------- */ static bool deferredTriggerCheckState(Oid tgoid, int32 itemstate) { MemoryContext oldcxt; List *sl; DeferredTriggerStatus trigstate; /* ---------- * Not deferrable triggers (i.e. normal AFTER ROW triggers * and constraints declared NOT DEFERRABLE, the state is * allways false. * ---------- */ if ((itemstate & TRIGGER_DEFERRED_DEFERRABLE) == 0) return false; /* ---------- * Lookup if we know an individual state for this trigger * ---------- */ foreach (sl, deftrig_trigstates) { trigstate = (DeferredTriggerStatus) lfirst(sl); if (trigstate->dts_tgoid == tgoid) return trigstate->dts_tgisdeferred; } /* ---------- * No individual state known - so if the user issued a * SET CONSTRAINT ALL ..., we return that instead of the * triggers default state. * ---------- */ if (deftrig_all_isset) return deftrig_all_isdeferred; /* ---------- * No ALL state known either, remember the default state * as the current and return that. * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_cxt); trigstate = (DeferredTriggerStatus) palloc(sizeof(DeferredTriggerStatusData)); trigstate->dts_tgoid = tgoid; trigstate->dts_tgisdeferred = ((itemstate & TRIGGER_DEFERRED_INITDEFERRED) != 0); deftrig_trigstates = lappend(deftrig_trigstates, trigstate); MemoryContextSwitchTo(oldcxt); return trigstate->dts_tgisdeferred; } /* ---------- * deferredTriggerAddEvent() * * Add a new trigger event to the queue. * ---------- */ static void deferredTriggerAddEvent(DeferredTriggerEvent event) { deftrig_events = lappend(deftrig_events, event); deftrig_n_events++; return; } /* ---------- * deferredTriggerGetPreviousEvent() * * Backward scan the eventlist to find the event a given OLD tuple * resulted from in the same transaction. * ---------- */ static DeferredTriggerEvent deferredTriggerGetPreviousEvent(Oid relid, ItemPointer ctid) { DeferredTriggerEvent previous; int n; for (n = deftrig_n_events - 1; n >= 0; n--) { previous = (DeferredTriggerEvent) nth(n, deftrig_events); if (previous->dte_relid != relid) continue; if (previous->dte_event & TRIGGER_DEFERRED_CANCELED) continue; if (ItemPointerGetBlockNumber(ctid) == ItemPointerGetBlockNumber(&(previous->dte_newctid)) && ItemPointerGetOffsetNumber(ctid) == ItemPointerGetOffsetNumber(&(previous->dte_newctid))) return previous; } elog(ERROR, "deferredTriggerGetPreviousEvent(): event for tuple %s not found", tidout(ctid)); return NULL; } /* ---------- * deferredTriggerExecute() * * Fetch the required tuples back from the heap and fire one * single trigger function. * ---------- */ static void deferredTriggerExecute(DeferredTriggerEvent event, int itemno) { Relation rel; TriggerData SaveTriggerData; HeapTupleData oldtuple; HeapTupleData newtuple; HeapTuple rettuple; Buffer oldbuffer; Buffer newbuffer; /* ---------- * Open the heap and fetch the required OLD and NEW tuples. * ---------- */ rel = heap_open(event->dte_relid, NoLock); if (ItemPointerIsValid(&(event->dte_oldctid))) { ItemPointerCopy(&(event->dte_oldctid), &(oldtuple.t_self)); heap_fetch(rel, SnapshotAny, &oldtuple, &oldbuffer); if (!oldtuple.t_data) elog(ERROR, "deferredTriggerExecute(): failed to fetch old tuple"); } if (ItemPointerIsValid(&(event->dte_newctid))) { ItemPointerCopy(&(event->dte_newctid), &(newtuple.t_self)); heap_fetch(rel, SnapshotAny, &newtuple, &newbuffer); if (!newtuple.t_data) elog(ERROR, "deferredTriggerExecute(): failed to fetch new tuple"); } /* ---------- * Setup the trigger information * ---------- */ SaveTriggerData.tg_event = (event->dte_event & TRIGGER_EVENT_OPMASK) | TRIGGER_EVENT_ROW; SaveTriggerData.tg_relation = rel; switch (event->dte_event & TRIGGER_EVENT_OPMASK) { case TRIGGER_EVENT_INSERT: SaveTriggerData.tg_trigtuple = &newtuple; SaveTriggerData.tg_newtuple = NULL; SaveTriggerData.tg_trigger = rel->trigdesc->tg_after_row[TRIGGER_EVENT_INSERT][itemno]; break; case TRIGGER_EVENT_UPDATE: SaveTriggerData.tg_trigtuple = &oldtuple; SaveTriggerData.tg_newtuple = &newtuple; SaveTriggerData.tg_trigger = rel->trigdesc->tg_after_row[TRIGGER_EVENT_UPDATE][itemno]; break; case TRIGGER_EVENT_DELETE: SaveTriggerData.tg_trigtuple = &oldtuple; SaveTriggerData.tg_newtuple = NULL; SaveTriggerData.tg_trigger = rel->trigdesc->tg_after_row[TRIGGER_EVENT_DELETE][itemno]; break; default: } /* ---------- * Call the trigger and throw away an eventually returned * updated tuple. * ---------- */ CurrentTriggerData = &SaveTriggerData; rettuple = ExecCallTriggerFunc(SaveTriggerData.tg_trigger); CurrentTriggerData = NULL; if (rettuple != NULL && rettuple != &oldtuple && rettuple != &newtuple) heap_freetuple(rettuple); /* ---------- * Might have been a referential integrity constraint trigger. * Reset the snapshot overriding flag. * ---------- */ ReferentialIntegritySnapshotOverride = false; /* ---------- * Release buffers and close the relation * ---------- */ if (ItemPointerIsValid(&(event->dte_oldctid))) ReleaseBuffer(oldbuffer); if (ItemPointerIsValid(&(event->dte_newctid))) ReleaseBuffer(newbuffer); heap_close(rel, NoLock); return; } /* ---------- * deferredTriggerInvokeEvents() * * Scan the event queue for not yet invoked triggers. Check if they * should be invoked now and do so. * ---------- */ static void deferredTriggerInvokeEvents(bool immediate_only) { List *el; DeferredTriggerEvent event; int still_deferred_ones; int eventno = -1; int i; /* ---------- * For now we process all events - to speedup transaction blocks * we need to remember the actual end of the queue at EndQuery * and process only events that are newer. On state changes we * simply reset the position to the beginning of the queue and * process all events once with the new states when the * SET CONSTRAINTS ... command finishes and calls EndQuery. * ---------- */ foreach (el, deftrig_events) { eventno++; /* ---------- * Get the event and check if it is completely done. * ---------- */ event = (DeferredTriggerEvent) lfirst(el); if (event->dte_event & (TRIGGER_DEFERRED_DONE | TRIGGER_DEFERRED_CANCELED)) continue; /* ---------- * Check each trigger item in the event. * ---------- */ still_deferred_ones = false; for (i = 0; i < event->dte_n_items; i++) { if (event->dte_item[i].dti_state & TRIGGER_DEFERRED_DONE) continue; /* ---------- * This trigger item hasn't been called yet. Check if * we should call it now. * ---------- */ if (immediate_only && deferredTriggerCheckState( event->dte_item[i].dti_tgoid, event->dte_item[i].dti_state)) { still_deferred_ones = true; continue; } /* ---------- * So let's fire it... * ---------- */ deferredTriggerExecute(event, i); event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE; } /* ---------- * Remember in the event itself if all trigger items are * done. * ---------- */ if (!still_deferred_ones) event->dte_event |= TRIGGER_DEFERRED_DONE; } } /* ---------- * DeferredTriggerInit() * * Initialize the deferred trigger mechanism. This is called during * backend startup and is guaranteed to be before the first of all * transactions. * ---------- */ int DeferredTriggerInit(void) { deftrig_gcxt = CreateGlobalMemory("DeferredTriggerSession"); return 0; } /* ---------- * DeferredTriggerBeginXact() * * Called at transaction start (either BEGIN or implicit for single * statement outside of transaction block). * ---------- */ void DeferredTriggerBeginXact(void) { MemoryContext oldcxt; List *l; DeferredTriggerStatus dflstat; DeferredTriggerStatus stat; if (deftrig_cxt != NULL) elog(FATAL, "DeferredTriggerBeginXact() called while inside transaction"); /* ---------- * Create the per transaction memory context and copy all states * from the per session context to here. * ---------- */ deftrig_cxt = CreateGlobalMemory("DeferredTriggerXact"); oldcxt = MemoryContextSwitchTo((MemoryContext)deftrig_cxt); deftrig_all_isset = deftrig_dfl_all_isset; deftrig_all_isdeferred = deftrig_dfl_all_isdeferred; deftrig_trigstates = NIL; foreach (l, deftrig_dfl_trigstates) { dflstat = (DeferredTriggerStatus) lfirst(l); stat = (DeferredTriggerStatus) palloc(sizeof(DeferredTriggerStatusData)); stat->dts_tgoid = dflstat->dts_tgoid; stat->dts_tgisdeferred = dflstat->dts_tgisdeferred; deftrig_trigstates = lappend(deftrig_trigstates, stat); } MemoryContextSwitchTo(oldcxt); deftrig_n_events = 0; deftrig_events = NIL; } /* ---------- * DeferredTriggerEndQuery() * * Called after one query sent down by the user has completely been * processed. At this time we invoke all outstanding IMMEDIATE triggers. * ---------- */ void DeferredTriggerEndQuery(void) { /* ---------- * Ignore call if we aren't in a transaction. * ---------- */ if (deftrig_cxt == NULL) return; deferredTriggerInvokeEvents(true); } /* ---------- * DeferredTriggerEndXact() * * Called just before the current transaction is committed. At this * time we invoke all DEFERRED triggers and tidy up. * ---------- */ void DeferredTriggerEndXact(void) { /* ---------- * Ignore call if we aren't in a transaction. * ---------- */ if (deftrig_cxt == NULL) return; deferredTriggerInvokeEvents(false); GlobalMemoryDestroy(deftrig_cxt); deftrig_cxt = NULL; } /* ---------- * DeferredTriggerAbortXact() * * The current transaction has entered the abort state. * All outstanding triggers are canceled so we simply throw * away anything we know. * ---------- */ void DeferredTriggerAbortXact(void) { /* ---------- * Ignore call if we aren't in a transaction. * ---------- */ if (deftrig_cxt == NULL) return; GlobalMemoryDestroy(deftrig_cxt); deftrig_cxt = NULL; } /* ---------- * DeferredTriggerSetState() * * Called for the users SET CONSTRAINTS ... utility command. * ---------- */ void DeferredTriggerSetState(ConstraintsSetStmt *stmt) { Relation tgrel; Relation irel; List *l; List *ls; List *lnext; List *loid = NIL; MemoryContext oldcxt; bool found; DeferredTriggerStatus state; /* ---------- * Handle SET CONSTRAINTS ALL ... * ---------- */ if (stmt->constraints == NIL) { if (!IsTransactionBlock()) { /* ---------- * ... outside of a transaction block * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_gcxt); /* ---------- * Drop all information about individual trigger states per * session. * ---------- */ l = deftrig_dfl_trigstates; while (l != NIL) { lnext = lnext(l); pfree(lfirst(l)); pfree(l); l = lnext; } deftrig_dfl_trigstates = NIL; /* ---------- * Set the session ALL state to known. * ---------- */ deftrig_dfl_all_isset = true; deftrig_dfl_all_isdeferred = stmt->deferred; MemoryContextSwitchTo(oldcxt); return; } else { /* ---------- * ... inside of a transaction block * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_cxt); /* ---------- * Drop all information about individual trigger states per * transaction. * ---------- */ l = deftrig_trigstates; while (l != NIL) { lnext = lnext(l); pfree(lfirst(l)); pfree(l); l = lnext; } deftrig_trigstates = NIL; /* ---------- * Set the per transaction ALL state to known. * ---------- */ deftrig_all_isset = true; deftrig_all_isdeferred = stmt->deferred; MemoryContextSwitchTo(oldcxt); return; } } /* ---------- * Handle SET CONSTRAINTS constraint-name [, ...] * First lookup all trigger Oid's for the constraint names. * ---------- */ tgrel = heap_openr(TriggerRelationName, AccessShareLock); irel = index_openr(TriggerConstrNameIndex); foreach (l, stmt->constraints) { ScanKeyData skey; HeapTupleData tuple; IndexScanDesc sd; RetrieveIndexResult indexRes; Buffer buffer; Form_pg_trigger pg_trigger; Oid constr_oid; /* ---------- * Check that only named constraints are set explicitly * ---------- */ if (strcmp((char *)lfirst(l), "") == 0) elog(ERROR, "unnamed constraints cannot be set explicitly"); /* ---------- * Setup to scan pg_trigger by tgconstrname ... * ---------- */ ScanKeyEntryInitialize(&skey, (bits16) 0x0, (AttrNumber) 1, (RegProcedure) F_NAMEEQ, PointerGetDatum((char *)lfirst(l))); sd = index_beginscan(irel, false, 1, &skey); /* ---------- * ... and search for the constraint trigger row * ---------- */ found = false; for (;;) { indexRes = index_getnext(sd, ForwardScanDirection); if (!indexRes) break; tuple.t_self = indexRes->heap_iptr; heap_fetch(tgrel, SnapshotNow, &tuple, &buffer); pfree(indexRes); if (!tuple.t_data) { ReleaseBuffer(buffer); continue; } /* ---------- * If we found some, check that they fit the deferrability * ---------- */ pg_trigger = (Form_pg_trigger) GETSTRUCT(&tuple); if (stmt->deferred & !pg_trigger->tgdeferrable) elog(ERROR, "Constraint '%s' is not deferrable", (char *)lfirst(l)); constr_oid = tuple.t_data->t_oid; loid = lappend(loid, (Node *)constr_oid); found = true; ReleaseBuffer(buffer); } /* ---------- * Not found ? * ---------- */ if (!found) elog(ERROR, "Constraint '%s' does not exist", (char *)lfirst(l)); index_endscan(sd); } index_close(irel); heap_close(tgrel, AccessShareLock); if (!IsTransactionBlock()) { /* ---------- * Outside of a transaction block set the trigger * states of individual triggers on session level. * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_gcxt); foreach (l, loid) { found = false; foreach (ls, deftrig_dfl_trigstates) { state = (DeferredTriggerStatus) lfirst(ls); if (state->dts_tgoid == (Oid) lfirst(l)) { state->dts_tgisdeferred = stmt->deferred; found = true; break; } } if (!found) { state = (DeferredTriggerStatus) palloc(sizeof(DeferredTriggerStatusData)); state->dts_tgoid = (Oid) lfirst(l); state->dts_tgisdeferred = stmt->deferred; deftrig_dfl_trigstates = lappend(deftrig_dfl_trigstates, state); } } MemoryContextSwitchTo(oldcxt); return; } else { /* ---------- * Inside of a transaction block set the trigger * states of individual triggers on transaction level. * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_cxt); foreach (l, loid) { found = false; foreach (ls, deftrig_trigstates) { state = (DeferredTriggerStatus) lfirst(ls); if (state->dts_tgoid == (Oid) lfirst(l)) { state->dts_tgisdeferred = stmt->deferred; found = true; break; } } if (!found) { state = (DeferredTriggerStatus) palloc(sizeof(DeferredTriggerStatusData)); state->dts_tgoid = (Oid) lfirst(l); state->dts_tgisdeferred = stmt->deferred; deftrig_trigstates = lappend(deftrig_trigstates, state); } } MemoryContextSwitchTo(oldcxt); return; } } /* ---------- * DeferredTriggerSaveEvent() * * Called by ExecAR...Triggers() to add the event to the queue. * ---------- */ void DeferredTriggerSaveEvent(Relation rel, int event, HeapTuple oldtup, HeapTuple newtup) { MemoryContext oldcxt; DeferredTriggerEvent new_event; DeferredTriggerEvent prev_event; int new_size; int i; int ntriggers; Trigger **triggers; ItemPointerData oldctid; ItemPointerData newctid; TriggerData SaveTriggerData; if (deftrig_cxt == NULL) elog(ERROR, "DeferredTriggerSaveEvent() called outside of transaction"); /* ---------- * Check if we're interested in this row at all * ---------- */ if (rel->trigdesc->n_after_row[TRIGGER_EVENT_INSERT] == 0 && rel->trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] == 0 && rel->trigdesc->n_after_row[TRIGGER_EVENT_DELETE] == 0 && rel->trigdesc->n_before_row[TRIGGER_EVENT_INSERT] == 0 && rel->trigdesc->n_before_row[TRIGGER_EVENT_UPDATE] == 0 && rel->trigdesc->n_before_row[TRIGGER_EVENT_DELETE] == 0) return; /* ---------- * Get the CTID's of OLD and NEW * ---------- */ if (oldtup != NULL) ItemPointerCopy(&(oldtup->t_self), &(oldctid)); else ItemPointerSetInvalid(&(oldctid)); if (newtup != NULL) ItemPointerCopy(&(newtup->t_self), &(newctid)); else ItemPointerSetInvalid(&(newctid)); /* ---------- * Create a new event * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_cxt); ntriggers = rel->trigdesc->n_after_row[event]; triggers = rel->trigdesc->tg_after_row[event]; new_size = sizeof(DeferredTriggerEventData) + ntriggers * sizeof(DeferredTriggerEventItem); new_event = (DeferredTriggerEvent) palloc(new_size); new_event->dte_event = event & TRIGGER_EVENT_OPMASK; new_event->dte_relid = rel->rd_id; ItemPointerCopy(&oldctid, &(new_event->dte_oldctid)); ItemPointerCopy(&newctid, &(new_event->dte_newctid)); new_event->dte_n_items = ntriggers; new_event->dte_item[ntriggers].dti_state = new_size; for (i = 0; i < ntriggers; i++) { new_event->dte_item[i].dti_tgoid = triggers[i]->tgoid; new_event->dte_item[i].dti_state = ((triggers[i]->tgdeferrable) ? TRIGGER_DEFERRED_DEFERRABLE : 0) | ((triggers[i]->tginitdeferred) ? TRIGGER_DEFERRED_INITDEFERRED : 0) | ((rel->trigdesc->n_before_row[event] > 0) ? TRIGGER_DEFERRED_HAS_BEFORE : 0); } MemoryContextSwitchTo(oldcxt); switch (event & TRIGGER_EVENT_OPMASK) { case TRIGGER_EVENT_INSERT: new_event->dte_event |= TRIGGER_DEFERRED_ROW_INSERTED; new_event->dte_event |= TRIGGER_DEFERRED_KEY_CHANGED; break; case TRIGGER_EVENT_UPDATE: /* ---------- * On UPDATE check if the tuple updated has been inserted * or a foreign referenced key value that's changing now * has been updated once before in this transaction. * ---------- */ if (oldtup->t_data->t_xmin != GetCurrentTransactionId()) prev_event = NULL; else prev_event = deferredTriggerGetPreviousEvent(rel->rd_id, &oldctid); /* ---------- * Now check if one of the referenced keys is changed. * ---------- */ for (i = 0; i < ntriggers; i++) { bool is_ri_trigger; bool key_unchanged; /* ---------- * We are interested in RI_FKEY triggers only. * ---------- */ switch (triggers[i]->tgfoid) { case F_RI_FKEY_NOACTION_UPD: is_ri_trigger = true; new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE; break; case F_RI_FKEY_CASCADE_UPD: case F_RI_FKEY_RESTRICT_UPD: case F_RI_FKEY_SETNULL_UPD: case F_RI_FKEY_SETDEFAULT_UPD: is_ri_trigger = true; break; default: is_ri_trigger = false; break; } if (!is_ri_trigger) continue; SaveTriggerData.tg_event = TRIGGER_EVENT_UPDATE; SaveTriggerData.tg_relation = rel; SaveTriggerData.tg_trigtuple = oldtup; SaveTriggerData.tg_newtuple = newtup; SaveTriggerData.tg_trigger = triggers[i]; CurrentTriggerData = &SaveTriggerData; key_unchanged = RI_FKey_keyequal_upd(); CurrentTriggerData = NULL; if (key_unchanged) { /* ---------- * The key hasn't changed, so no need later to invoke * the trigger at all. But remember other states from * the possible earlier event. * ---------- */ new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE; if (prev_event) { if (prev_event->dte_event & TRIGGER_DEFERRED_ROW_INSERTED) { /* ---------- * This is a row inserted during our transaction. * So any key value is considered changed. * ---------- */ new_event->dte_event |= TRIGGER_DEFERRED_ROW_INSERTED; new_event->dte_event |= TRIGGER_DEFERRED_KEY_CHANGED; new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_KEY_CHANGED; } else { /* ---------- * This is a row, previously updated. So * if this key has been changed before, we * still remember that it happened. * ---------- */ if (prev_event->dte_item[i].dti_state & TRIGGER_DEFERRED_KEY_CHANGED) { new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_KEY_CHANGED; new_event->dte_event |= TRIGGER_DEFERRED_KEY_CHANGED; } } } } else { /* ---------- * Bomb out if this key has been changed before. * Otherwise remember that we do so. * ---------- */ if (prev_event) { if (prev_event->dte_event & TRIGGER_DEFERRED_ROW_INSERTED) elog(ERROR, "triggered data change violation " "on relation \"%s\"", nameout(&(rel->rd_rel->relname))); if (prev_event->dte_item[i].dti_state & TRIGGER_DEFERRED_KEY_CHANGED) elog(ERROR, "triggered data change violation " "on relation \"%s\"", nameout(&(rel->rd_rel->relname))); } /* ---------- * This is the first change to this key, so let * it happen. * ---------- */ new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_KEY_CHANGED; new_event->dte_event |= TRIGGER_DEFERRED_KEY_CHANGED; } } break; case TRIGGER_EVENT_DELETE: /* ---------- * On DELETE check if the tuple deleted has been inserted * or a possibly referenced key value has changed in this * transaction. * ---------- */ if (oldtup->t_data->t_xmin != GetCurrentTransactionId()) break; /* ---------- * Look at the previous event to the same tuple. * ---------- */ prev_event = deferredTriggerGetPreviousEvent(rel->rd_id, &oldctid); if (prev_event->dte_event & TRIGGER_DEFERRED_KEY_CHANGED) elog(ERROR, "triggered data change violation " "on relation \"%s\"", nameout(&(rel->rd_rel->relname))); break; } /* ---------- * Anything's fine up to here. Add the new event to the queue. * ---------- */ oldcxt = MemoryContextSwitchTo((MemoryContext) deftrig_cxt); deferredTriggerAddEvent(new_event); MemoryContextSwitchTo(oldcxt); return; }