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Diffstat (limited to 'src/backend/commands/trigger.c')
| -rw-r--r-- | src/backend/commands/trigger.c | 2163 |
1 files changed, 0 insertions, 2163 deletions
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c deleted file mode 100644 index 18484372ed5..00000000000 --- a/src/backend/commands/trigger.c +++ /dev/null @@ -1,2163 +0,0 @@ -/*------------------------------------------------------------------------- - * - * trigger.c - * PostgreSQL TRIGGERs support code. - * - * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.120 2002/06/20 20:29:27 momjian Exp $ - * - *------------------------------------------------------------------------- - */ -#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/namespace.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 "parser/parse_func.h" -#include "utils/acl.h" -#include "utils/builtins.h" -#include "utils/fmgroids.h" -#include "utils/inval.h" -#include "utils/lsyscache.h" -#include "utils/syscache.h" - - -static void InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx); -static HeapTuple GetTupleForTrigger(EState *estate, - ResultRelInfo *relinfo, - ItemPointer tid, - TupleTableSlot **newSlot); -static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata, - FmgrInfo *finfo, - MemoryContext per_tuple_context); -static void DeferredTriggerSaveEvent(ResultRelInfo *relinfo, int event, - HeapTuple oldtup, HeapTuple newtup); -static void DeferredTriggerExecute(DeferredTriggerEvent event, int itemno, - Relation rel, FmgrInfo *finfo, - MemoryContext per_tuple_context); - - -void -CreateTrigger(CreateTrigStmt *stmt) -{ - int16 tgtype; - int16 tgattr[FUNC_MAX_ARGS]; - Datum values[Natts_pg_trigger]; - char nulls[Natts_pg_trigger]; - Relation rel; - AclResult aclresult; - Relation tgrel; - SysScanDesc tgscan; - ScanKeyData key; - Relation pgrel; - HeapTuple tuple; - Relation idescs[Num_pg_trigger_indices]; - Relation ridescs[Num_pg_class_indices]; - Oid fargtypes[FUNC_MAX_ARGS]; - Oid funcoid; - Oid funclang; - int found = 0; - int i; - char constrtrigname[NAMEDATALEN]; - char *constrname = ""; - Oid constrrelid = InvalidOid; - - rel = heap_openrv(stmt->relation, AccessExclusiveLock); - - if (rel->rd_rel->relkind != RELKIND_RELATION) - elog(ERROR, "CreateTrigger: relation \"%s\" is not a table", - stmt->relation->relname); - - if (!allowSystemTableMods && IsSystemRelation(rel)) - elog(ERROR, "CreateTrigger: can't create trigger for system relation %s", - stmt->relation->relname); - - aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(), - stmt->isconstraint ? ACL_REFERENCES : ACL_TRIGGER); - if (aclresult != ACLCHECK_OK) - aclcheck_error(aclresult, RelationGetRelationName(rel)); - - /* - * If trigger is an RI constraint, use trigger name as constraint name - * and build a unique trigger name instead. - */ - if (stmt->isconstraint) - { - constrname = stmt->trigname; - snprintf(constrtrigname, sizeof(constrtrigname), - "RI_ConstraintTrigger_%u", newoid()); - stmt->trigname = constrtrigname; - - if (stmt->constrrel != NULL) - constrrelid = RangeVarGetRelid(stmt->constrrel, false); - else - constrrelid = InvalidOid; - } - - 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 for existing triggers on relation. We do this mainly - * because we must count them; a secondary benefit is to give a nice - * error message if there's already a trigger of the same name. (The - * unique index on tgrelid/tgname would complain anyway.) - * - * NOTE that this is cool only because we have AccessExclusiveLock on the - * relation, so the trigger set won't be changing underneath us. - */ - tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - ScanKeyEntryInitialize(&key, 0, - Anum_pg_trigger_tgrelid, - F_OIDEQ, - ObjectIdGetDatum(RelationGetRelid(rel))); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, - SnapshotNow, 1, &key); - while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) - { - Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); - - if (namestrcmp(&(pg_trigger->tgname), stmt->trigname) == 0) - elog(ERROR, "CreateTrigger: trigger %s already defined on relation %s", - stmt->trigname, stmt->relation->relname); - found++; - } - systable_endscan(tgscan); - - /* - * Find and validate the trigger function. - */ - MemSet(fargtypes, 0, FUNC_MAX_ARGS * sizeof(Oid)); - funcoid = LookupFuncName(stmt->funcname, 0, fargtypes); - if (!OidIsValid(funcoid)) - elog(ERROR, "CreateTrigger: function %s() does not exist", - NameListToString(stmt->funcname)); - tuple = SearchSysCache(PROCOID, - ObjectIdGetDatum(funcoid), - 0, 0, 0); - if (!HeapTupleIsValid(tuple)) - elog(ERROR, "CreateTrigger: function %s() does not exist", - NameListToString(stmt->funcname)); - if (((Form_pg_proc) GETSTRUCT(tuple))->prorettype != 0) - elog(ERROR, "CreateTrigger: function %s() must return OPAQUE", - NameListToString(stmt->funcname)); - funclang = ((Form_pg_proc) GETSTRUCT(tuple))->prolang; - ReleaseSysCache(tuple); - - if (funclang != ClanguageId && funclang != INTERNALlanguageId) - { - HeapTuple langTup; - - langTup = SearchSysCache(LANGOID, - ObjectIdGetDatum(funclang), - 0, 0, 0); - if (!HeapTupleIsValid(langTup)) - elog(ERROR, "CreateTrigger: cache lookup for language %u failed", - funclang); - if (((Form_pg_language) GETSTRUCT(langTup))->lanispl == false) - elog(ERROR, "CreateTrigger: only internal, C and PL functions are supported"); - ReleaseSysCache(langTup); - } - - /* - * Build the new pg_trigger tuple. - */ - MemSet(nulls, ' ', Natts_pg_trigger * sizeof(char)); - - values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel)); - values[Anum_pg_trigger_tgname - 1] = DirectFunctionCall1(namein, - CStringGetDatum(stmt->trigname)); - values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid); - values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype); - values[Anum_pg_trigger_tgenabled - 1] = BoolGetDatum(true); - values[Anum_pg_trigger_tgisconstraint - 1] = BoolGetDatum(stmt->isconstraint); - values[Anum_pg_trigger_tgconstrname - 1] = PointerGetDatum(constrname); - values[Anum_pg_trigger_tgconstrrelid - 1] = ObjectIdGetDatum(constrrelid); - values[Anum_pg_trigger_tgdeferrable - 1] = BoolGetDatum(stmt->deferrable); - values[Anum_pg_trigger_tginitdeferred - 1] = BoolGetDatum(stmt->initdeferred); - - if (stmt->args) - { - List *le; - char *args; - int16 nargs = length(stmt->args); - int len = 0; - - foreach(le, stmt->args) - { - char *ar = ((Value *) lfirst(le))->val.str; - - len += strlen(ar) + 4; - for (; *ar; ar++) - { - if (*ar == '\\') - len++; - } - } - args = (char *) palloc(len + 1); - args[0] = '\0'; - foreach(le, stmt->args) - { - char *s = ((Value *) lfirst(le))->val.str; - char *d = args + strlen(args); - - while (*s) - { - if (*s == '\\') - *d++ = '\\'; - *d++ = *s++; - } - strcpy(d, "\\000"); - } - values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs); - values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain, - CStringGetDatum(args)); - } - else - { - values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0); - values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain, - CStringGetDatum("")); - } - MemSet(tgattr, 0, FUNC_MAX_ARGS * sizeof(int16)); - values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr); - - tuple = heap_formtuple(tgrel->rd_att, values, nulls); - - /* - * Insert tuple into pg_trigger. - */ - simple_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 relation's pg_class entry. Crucial side-effect: other - * backends (and this one too!) are sent SI message to make them - * rebuild relcache entries. - */ - pgrel = heap_openr(RelationRelationName, RowExclusiveLock); - tuple = SearchSysCacheCopy(RELOID, - ObjectIdGetDatum(RelationGetRelid(rel)), - 0, 0, 0); - if (!HeapTupleIsValid(tuple)) - elog(ERROR, "CreateTrigger: relation %s not found in pg_class", - stmt->relation->relname); - - ((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found + 1; - simple_heap_update(pgrel, &tuple->t_self, tuple); - 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); - - /* - * We used to try to update the rel's relcache entry here, but that's - * fairly pointless since it will happen as a byproduct of the - * upcoming CommandCounterIncrement... - */ - - /* Keep lock on target rel until end of xact */ - heap_close(rel, NoLock); -} - -/* - * DropTrigger - drop an individual trigger by name - */ -void -DropTrigger(Oid relid, const char *trigname) -{ - Relation rel; - Relation tgrel; - SysScanDesc tgscan; - ScanKeyData key; - Relation pgrel; - HeapTuple tuple; - Relation ridescs[Num_pg_class_indices]; - int remaining = 0; - int found = 0; - - rel = heap_open(relid, AccessExclusiveLock); - - if (rel->rd_rel->relkind != RELKIND_RELATION) - elog(ERROR, "DropTrigger: relation \"%s\" is not a table", - RelationGetRelationName(rel)); - - if (!allowSystemTableMods && IsSystemRelation(rel)) - elog(ERROR, "DropTrigger: can't drop trigger for system relation %s", - RelationGetRelationName(rel)); - - if (!pg_class_ownercheck(relid, GetUserId())) - aclcheck_error(ACLCHECK_NOT_OWNER, RelationGetRelationName(rel)); - - /* - * Search pg_trigger, delete target trigger, count remaining triggers - * for relation. (Although we could fetch and delete the target - * trigger directly, we'd still have to scan the remaining triggers, - * so we may as well do both in one indexscan.) - * - * Note this is OK only because we have AccessExclusiveLock on the rel, - * so no one else is creating/deleting triggers on this rel at the same - * time. - */ - tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - ScanKeyEntryInitialize(&key, 0, - Anum_pg_trigger_tgrelid, - F_OIDEQ, - ObjectIdGetDatum(relid)); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, - SnapshotNow, 1, &key); - while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) - { - Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); - - if (namestrcmp(&(pg_trigger->tgname), trigname) == 0) - { - /* Delete any comments associated with this trigger */ - DeleteComments(tuple->t_data->t_oid, RelationGetRelid(tgrel)); - - simple_heap_delete(tgrel, &tuple->t_self); - found++; - } - else - remaining++; - } - systable_endscan(tgscan); - heap_close(tgrel, RowExclusiveLock); - - if (found == 0) - elog(ERROR, "DropTrigger: there is no trigger %s on relation %s", - trigname, RelationGetRelationName(rel)); - if (found > 1) /* shouldn't happen */ - elog(NOTICE, "DropTrigger: found (and deleted) %d triggers %s on relation %s", - found, trigname, RelationGetRelationName(rel)); - - /* - * Update relation's pg_class entry. Crucial side-effect: other - * backends (and this one too!) are sent SI message to make them - * rebuild relcache entries. - */ - pgrel = heap_openr(RelationRelationName, RowExclusiveLock); - tuple = SearchSysCacheCopy(RELOID, - ObjectIdGetDatum(relid), - 0, 0, 0); - if (!HeapTupleIsValid(tuple)) - elog(ERROR, "DropTrigger: relation %s not found in pg_class", - RelationGetRelationName(rel)); - - ((Form_pg_class) GETSTRUCT(tuple))->reltriggers = remaining; - simple_heap_update(pgrel, &tuple->t_self, tuple); - 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); - - /* Keep lock on target rel until end of xact */ - heap_close(rel, NoLock); -} - -/* - * Remove all triggers for a relation that's being deleted. - */ -void -RelationRemoveTriggers(Relation rel) -{ - Relation tgrel; - SysScanDesc tgscan; - ScanKeyData key; - HeapTuple tup; - bool found = false; - - tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - ScanKeyEntryInitialize(&key, 0, - Anum_pg_trigger_tgrelid, - F_OIDEQ, - ObjectIdGetDatum(RelationGetRelid(rel))); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, - SnapshotNow, 1, &key); - - while (HeapTupleIsValid(tup = systable_getnext(tgscan))) - { - /* Delete any comments associated with this trigger */ - DeleteComments(tup->t_data->t_oid, RelationGetRelid(tgrel)); - - simple_heap_delete(tgrel, &tup->t_self); - - found = true; - } - - systable_endscan(tgscan); - - /* - * If we deleted any triggers, must update pg_class entry and advance - * command counter to make the updated entry visible. This is fairly - * annoying, since we'e just going to drop the durn thing later, but - * it's necessary to have a consistent state in case we do - * CommandCounterIncrement() below --- if RelationBuildTriggers() - * runs, it will complain otherwise. Perhaps RelationBuildTriggers() - * shouldn't be so picky... - */ - if (found) - { - Relation pgrel; - Relation ridescs[Num_pg_class_indices]; - - pgrel = heap_openr(RelationRelationName, RowExclusiveLock); - tup = SearchSysCacheCopy(RELOID, - ObjectIdGetDatum(RelationGetRelid(rel)), - 0, 0, 0); - if (!HeapTupleIsValid(tup)) - elog(ERROR, "RelationRemoveTriggers: relation %u not found in pg_class", - RelationGetRelid(rel)); - - ((Form_pg_class) GETSTRUCT(tup))->reltriggers = 0; - simple_heap_update(pgrel, &tup->t_self, tup); - CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs); - CatalogIndexInsert(ridescs, Num_pg_class_indices, pgrel, tup); - CatalogCloseIndices(Num_pg_class_indices, ridescs); - heap_freetuple(tup); - heap_close(pgrel, RowExclusiveLock); - CommandCounterIncrement(); - } - - /* - * Also drop all constraint triggers referencing this relation - */ - ScanKeyEntryInitialize(&key, 0, - Anum_pg_trigger_tgconstrrelid, - F_OIDEQ, - ObjectIdGetDatum(RelationGetRelid(rel))); - tgscan = systable_beginscan(tgrel, TriggerConstrRelidIndex, true, - SnapshotNow, 1, &key); - - while (HeapTupleIsValid(tup = systable_getnext(tgscan))) - { - Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tup); - - elog(NOTICE, "DROP TABLE implicitly drops referential integrity trigger from table \"%s\"", - get_rel_name(pg_trigger->tgrelid)); - - DropTrigger(pg_trigger->tgrelid, NameStr(pg_trigger->tgname)); - - /* - * Need to do a command counter increment here to show up new - * pg_class.reltriggers in the next loop iteration (in case there - * are multiple referential integrity action triggers for the same - * FK table defined on the PK table). - */ - CommandCounterIncrement(); - } - systable_endscan(tgscan); - - heap_close(tgrel, RowExclusiveLock); -} - -/* - * renametrig - changes the name of a trigger on a relation - * - * trigger name is changed in trigger catalog. - * No record of the previous name is kept. - * - * get proper relrelation from relation catalog (if not arg) - * scan trigger catalog - * for name conflict (within rel) - * for original trigger (if not arg) - * modify tgname in trigger tuple - * update row in catalog - */ -void -renametrig(Oid relid, - const char *oldname, - const char *newname) -{ - Relation targetrel; - Relation tgrel; - HeapTuple tuple; - SysScanDesc tgscan; - ScanKeyData key[2]; - Relation idescs[Num_pg_trigger_indices]; - - /* - * Grab an exclusive lock on the target table, which we will NOT - * release until end of transaction. - */ - targetrel = heap_open(relid, AccessExclusiveLock); - - /* - * Scan pg_trigger twice for existing triggers on relation. We do this in - * order to ensure a trigger does not exist with newname (The unique index - * on tgrelid/tgname would complain anyway) and to ensure a trigger does - * exist with oldname. - * - * NOTE that this is cool only because we have AccessExclusiveLock on the - * relation, so the trigger set won't be changing underneath us. - */ - tgrel = heap_openr(TriggerRelationName, RowExclusiveLock); - - /* - * First pass -- look for name conflict - */ - ScanKeyEntryInitialize(&key[0], 0, - Anum_pg_trigger_tgrelid, - F_OIDEQ, - ObjectIdGetDatum(relid)); - ScanKeyEntryInitialize(&key[1], 0, - Anum_pg_trigger_tgname, - F_NAMEEQ, - PointerGetDatum(newname)); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, - SnapshotNow, 2, key); - if (HeapTupleIsValid(tuple = systable_getnext(tgscan))) - elog(ERROR, "renametrig: trigger %s already defined on relation %s", - newname, RelationGetRelationName(targetrel)); - systable_endscan(tgscan); - - /* - * Second pass -- look for trigger existing with oldname and update - */ - ScanKeyEntryInitialize(&key[0], 0, - Anum_pg_trigger_tgrelid, - F_OIDEQ, - ObjectIdGetDatum(relid)); - ScanKeyEntryInitialize(&key[1], 0, - Anum_pg_trigger_tgname, - F_NAMEEQ, - PointerGetDatum(oldname)); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, - SnapshotNow, 2, key); - if (HeapTupleIsValid(tuple = systable_getnext(tgscan))) - { - /* - * Update pg_trigger tuple with new tgname. - */ - tuple = heap_copytuple(tuple); /* need a modifiable copy */ - - namestrcpy(&((Form_pg_trigger) GETSTRUCT(tuple))->tgname, newname); - - simple_heap_update(tgrel, &tuple->t_self, tuple); - - /* - * keep system catalog indices current - */ - CatalogOpenIndices(Num_pg_trigger_indices, Name_pg_trigger_indices, idescs); - CatalogIndexInsert(idescs, Num_pg_trigger_indices, tgrel, tuple); - CatalogCloseIndices(Num_pg_trigger_indices, idescs); - - /* - * Invalidate relation's relcache entry so that other backends (and - * this one too!) are sent SI message to make them rebuild relcache - * entries. (Ideally this should happen automatically...) - */ - CacheInvalidateRelcache(relid); - } - else - { - elog(ERROR, "renametrig: trigger %s not defined on relation %s", - oldname, RelationGetRelationName(targetrel)); - } - - systable_endscan(tgscan); - - heap_close(tgrel, RowExclusiveLock); - - /* - * Close rel, but keep exclusive lock! - */ - heap_close(targetrel, NoLock); -} - -/* - * Build trigger data to attach to the given relcache entry. - * - * Note that trigger data must be allocated in CacheMemoryContext - * to ensure it survives as long as the relcache entry. But we - * are probably running in a less long-lived working context. - */ -void -RelationBuildTriggers(Relation relation) -{ - TriggerDesc *trigdesc; - int ntrigs = relation->rd_rel->reltriggers; - Trigger *triggers; - int found = 0; - Relation tgrel; - ScanKeyData skey; - SysScanDesc tgscan; - HeapTuple htup; - struct varlena *val; - bool isnull; - - triggers = (Trigger *) MemoryContextAlloc(CacheMemoryContext, - ntrigs * sizeof(Trigger)); - - /* - * Note: since we scan the triggers using TriggerRelidNameIndex, - * we will be reading the triggers in name order, except possibly - * during emergency-recovery operations (ie, IsIgnoringSystemIndexes). - * This in turn ensures that triggers will be fired in name order. - */ - ScanKeyEntryInitialize(&skey, - (bits16) 0x0, - (AttrNumber) Anum_pg_trigger_tgrelid, - (RegProcedure) F_OIDEQ, - ObjectIdGetDatum(RelationGetRelid(relation))); - - tgrel = heap_openr(TriggerRelationName, AccessShareLock); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true, - SnapshotNow, 1, &skey); - - while (HeapTupleIsValid(htup = systable_getnext(tgscan))) - { - Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup); - Trigger *build; - - if (found >= ntrigs) - elog(ERROR, "RelationBuildTriggers: unexpected record found for rel %s", - RelationGetRelationName(relation)); - build = &(triggers[found]); - - build->tgoid = htup->t_data->t_oid; - build->tgname = MemoryContextStrdup(CacheMemoryContext, - DatumGetCString(DirectFunctionCall1(nameout, - NameGetDatum(&pg_trigger->tgname)))); - build->tgfoid = pg_trigger->tgfoid; - build->tgtype = pg_trigger->tgtype; - build->tgenabled = pg_trigger->tgenabled; - build->tgisconstraint = pg_trigger->tgisconstraint; - build->tgconstrrelid = pg_trigger->tgconstrrelid; - build->tgdeferrable = pg_trigger->tgdeferrable; - build->tginitdeferred = pg_trigger->tginitdeferred; - build->tgnargs = pg_trigger->tgnargs; - memcpy(build->tgattr, &(pg_trigger->tgattr), - FUNC_MAX_ARGS * sizeof(int16)); - if (build->tgnargs > 0) - { - char *p; - int i; - - val = (struct varlena *) fastgetattr(htup, - Anum_pg_trigger_tgargs, - tgrel->rd_att, &isnull); - if (isnull) - elog(ERROR, "RelationBuildTriggers: tgargs IS NULL for rel %s", - RelationGetRelationName(relation)); - p = (char *) VARDATA(val); - build->tgargs = (char **) - MemoryContextAlloc(CacheMemoryContext, - build->tgnargs * sizeof(char *)); - for (i = 0; i < build->tgnargs; i++) - { - build->tgargs[i] = MemoryContextStrdup(CacheMemoryContext, - p); - p += strlen(p) + 1; - } - } - else - build->tgargs = NULL; - - found++; - } - - systable_endscan(tgscan); - heap_close(tgrel, AccessShareLock); - - if (found != ntrigs) - elog(ERROR, "RelationBuildTriggers: %d record(s) not found for rel %s", - ntrigs - found, - RelationGetRelationName(relation)); - - /* Build trigdesc */ - trigdesc = (TriggerDesc *) MemoryContextAlloc(CacheMemoryContext, - sizeof(TriggerDesc)); - MemSet(trigdesc, 0, sizeof(TriggerDesc)); - trigdesc->triggers = triggers; - trigdesc->numtriggers = ntrigs; - for (found = 0; found < ntrigs; found++) - InsertTrigger(trigdesc, &(triggers[found]), found); - - relation->trigdesc = trigdesc; -} - -/* Insert the given trigger into the appropriate index list(s) for it */ -static void -InsertTrigger(TriggerDesc *trigdesc, Trigger *trigger, int indx) -{ - uint16 *n; - int **t, - **tp; - - if (TRIGGER_FOR_ROW(trigger->tgtype)) - { - /* ROW trigger */ - if (TRIGGER_FOR_BEFORE(trigger->tgtype)) - { - n = trigdesc->n_before_row; - t = trigdesc->tg_before_row; - } - else - { - n = trigdesc->n_after_row; - t = trigdesc->tg_after_row; - } - } - else - { - /* STATEMENT trigger */ - if (TRIGGER_FOR_BEFORE(trigger->tgtype)) - { - n = trigdesc->n_before_statement; - t = trigdesc->tg_before_statement; - } - else - { - n = trigdesc->n_after_statement; - t = trigdesc->tg_after_statement; - } - } - - if (TRIGGER_FOR_INSERT(trigger->tgtype)) - { - tp = &(t[TRIGGER_EVENT_INSERT]); - if (*tp == NULL) - *tp = (int *) MemoryContextAlloc(CacheMemoryContext, - sizeof(int)); - else - *tp = (int *) repalloc(*tp, (n[TRIGGER_EVENT_INSERT] + 1) * - sizeof(int)); - (*tp)[n[TRIGGER_EVENT_INSERT]] = indx; - (n[TRIGGER_EVENT_INSERT])++; - } - - if (TRIGGER_FOR_DELETE(trigger->tgtype)) - { - tp = &(t[TRIGGER_EVENT_DELETE]); - if (*tp == NULL) - *tp = (int *) MemoryContextAlloc(CacheMemoryContext, - sizeof(int)); - else - *tp = (int *) repalloc(*tp, (n[TRIGGER_EVENT_DELETE] + 1) * - sizeof(int)); - (*tp)[n[TRIGGER_EVENT_DELETE]] = indx; - (n[TRIGGER_EVENT_DELETE])++; - } - - if (TRIGGER_FOR_UPDATE(trigger->tgtype)) - { - tp = &(t[TRIGGER_EVENT_UPDATE]); - if (*tp == NULL) - *tp = (int *) MemoryContextAlloc(CacheMemoryContext, - sizeof(int)); - else - *tp = (int *) repalloc(*tp, (n[TRIGGER_EVENT_UPDATE] + 1) * - sizeof(int)); - (*tp)[n[TRIGGER_EVENT_UPDATE]] = indx; - (n[TRIGGER_EVENT_UPDATE])++; - } -} - -void -FreeTriggerDesc(TriggerDesc *trigdesc) -{ - int **t; - Trigger *trigger; - int i; - - if (trigdesc == NULL) - return; - - t = trigdesc->tg_before_statement; - for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++) - if (t[i] != NULL) - pfree(t[i]); - t = trigdesc->tg_before_row; - for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++) - if (t[i] != NULL) - pfree(t[i]); - t = trigdesc->tg_after_row; - for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++) - if (t[i] != NULL) - pfree(t[i]); - t = trigdesc->tg_after_statement; - for (i = 0; i < TRIGGER_NUM_EVENT_CLASSES; i++) - if (t[i] != NULL) - pfree(t[i]); - - trigger = trigdesc->triggers; - for (i = 0; i < trigdesc->numtriggers; i++) - { - pfree(trigger->tgname); - if (trigger->tgnargs > 0) - { - while (--(trigger->tgnargs) >= 0) - pfree(trigger->tgargs[trigger->tgnargs]); - pfree(trigger->tgargs); - } - trigger++; - } - pfree(trigdesc->triggers); - pfree(trigdesc); -} - -bool -equalTriggerDescs(TriggerDesc *trigdesc1, TriggerDesc *trigdesc2) -{ - int i, - j; - - /* - * We need not examine the "index" data, just the trigger array - * itself; if we have the same triggers with the same types, the - * derived index data should match. - * - * As of 7.3 we assume trigger set ordering is significant in the - * comparison; so we just compare corresponding slots of the two sets. - */ - if (trigdesc1 != NULL) - { - if (trigdesc2 == NULL) - return false; - if (trigdesc1->numtriggers != trigdesc2->numtriggers) - return false; - for (i = 0; i < trigdesc1->numtriggers; i++) - { - Trigger *trig1 = trigdesc1->triggers + i; - Trigger *trig2 = trigdesc2->triggers + i; - - if (trig1->tgoid != trig2->tgoid) - return false; - if (strcmp(trig1->tgname, trig2->tgname) != 0) - return false; - if (trig1->tgfoid != trig2->tgfoid) - return false; - if (trig1->tgtype != trig2->tgtype) - return false; - if (trig1->tgenabled != trig2->tgenabled) - return false; - if (trig1->tgisconstraint != trig2->tgisconstraint) - return false; - if (trig1->tgconstrrelid != trig2->tgconstrrelid) - return false; - if (trig1->tgdeferrable != trig2->tgdeferrable) - return false; - if (trig1->tginitdeferred != trig2->tginitdeferred) - return false; - if (trig1->tgnargs != trig2->tgnargs) - return false; - if (memcmp(trig1->tgattr, trig2->tgattr, - sizeof(trig1->tgattr)) != 0) - return false; - for (j = 0; j < trig1->tgnargs; j++) - if (strcmp(trig1->tgargs[j], trig2->tgargs[j]) != 0) - return false; - } - } - else if (trigdesc2 != NULL) - return false; - return true; -} - -/* - * Call a trigger function. - * - * trigdata: trigger descriptor. - * finfo: possibly-cached call info for the function. - * per_tuple_context: memory context to execute the function in. - * - * Returns the tuple (or NULL) as returned by the function. - */ -static HeapTuple -ExecCallTriggerFunc(TriggerData *trigdata, - FmgrInfo *finfo, - MemoryContext per_tuple_context) -{ - FunctionCallInfoData fcinfo; - Datum result; - MemoryContext oldContext; - - /* - * We cache fmgr lookup info, to avoid making the lookup again on each - * call. - */ - if (finfo->fn_oid == InvalidOid) - fmgr_info(trigdata->tg_trigger->tgfoid, finfo); - - Assert(finfo->fn_oid == trigdata->tg_trigger->tgfoid); - - /* - * Do the function evaluation in the per-tuple memory context, so that - * leaked memory will be reclaimed once per tuple. Note in particular - * that any new tuple created by the trigger function will live till - * the end of the tuple cycle. - */ - oldContext = MemoryContextSwitchTo(per_tuple_context); - - /* - * Call the function, passing no arguments but setting a context. - */ - MemSet(&fcinfo, 0, sizeof(fcinfo)); - - fcinfo.flinfo = finfo; - fcinfo.context = (Node *) trigdata; - - result = FunctionCallInvoke(&fcinfo); - - MemoryContextSwitchTo(oldContext); - - /* - * Trigger protocol allows function to return a null pointer, but NOT - * to set the isnull result flag. - */ - if (fcinfo.isnull) - elog(ERROR, "ExecCallTriggerFunc: function %u returned NULL", - fcinfo.flinfo->fn_oid); - - return (HeapTuple) DatumGetPointer(result); -} - -HeapTuple -ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo, - HeapTuple trigtuple) -{ - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - int ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_INSERT]; - int *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_INSERT]; - HeapTuple newtuple = trigtuple; - HeapTuple oldtuple; - TriggerData LocTriggerData; - int i; - - /* Allocate cache space for fmgr lookup info, if not done yet */ - if (relinfo->ri_TrigFunctions == NULL) - { - relinfo->ri_TrigFunctions = (FmgrInfo *) - palloc(trigdesc->numtriggers * sizeof(FmgrInfo)); - MemSet(relinfo->ri_TrigFunctions, 0, - trigdesc->numtriggers * sizeof(FmgrInfo)); - } - - LocTriggerData.type = T_TriggerData; - LocTriggerData.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; - LocTriggerData.tg_relation = relinfo->ri_RelationDesc; - LocTriggerData.tg_newtuple = NULL; - for (i = 0; i < ntrigs; i++) - { - Trigger *trigger = &trigdesc->triggers[tgindx[i]]; - - if (!trigger->tgenabled) - continue; - LocTriggerData.tg_trigtuple = oldtuple = newtuple; - LocTriggerData.tg_trigger = trigger; - newtuple = ExecCallTriggerFunc(&LocTriggerData, - relinfo->ri_TrigFunctions + tgindx[i], - GetPerTupleMemoryContext(estate)); - if (oldtuple != newtuple && oldtuple != trigtuple) - heap_freetuple(oldtuple); - if (newtuple == NULL) - break; - } - return newtuple; -} - -void -ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo, - HeapTuple trigtuple) -{ - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - - if (trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0) - DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT, - NULL, trigtuple); -} - -bool -ExecBRDeleteTriggers(EState *estate, ResultRelInfo *relinfo, - ItemPointer tupleid) -{ - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - int ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_DELETE]; - int *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_DELETE]; - TriggerData LocTriggerData; - HeapTuple trigtuple; - HeapTuple newtuple = NULL; - TupleTableSlot *newSlot; - int i; - - trigtuple = GetTupleForTrigger(estate, relinfo, tupleid, &newSlot); - if (trigtuple == NULL) - return false; - - /* Allocate cache space for fmgr lookup info, if not done yet */ - if (relinfo->ri_TrigFunctions == NULL) - { - relinfo->ri_TrigFunctions = (FmgrInfo *) - palloc(trigdesc->numtriggers * sizeof(FmgrInfo)); - MemSet(relinfo->ri_TrigFunctions, 0, - trigdesc->numtriggers * sizeof(FmgrInfo)); - } - - LocTriggerData.type = T_TriggerData; - LocTriggerData.tg_event = TRIGGER_EVENT_DELETE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; - LocTriggerData.tg_relation = relinfo->ri_RelationDesc; - LocTriggerData.tg_newtuple = NULL; - for (i = 0; i < ntrigs; i++) - { - Trigger *trigger = &trigdesc->triggers[tgindx[i]]; - - if (!trigger->tgenabled) - continue; - LocTriggerData.tg_trigtuple = trigtuple; - LocTriggerData.tg_trigger = trigger; - newtuple = ExecCallTriggerFunc(&LocTriggerData, - relinfo->ri_TrigFunctions + tgindx[i], - GetPerTupleMemoryContext(estate)); - if (newtuple == NULL) - break; - if (newtuple != trigtuple) - heap_freetuple(newtuple); - } - heap_freetuple(trigtuple); - - return (newtuple == NULL) ? false : true; -} - -void -ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo, - ItemPointer tupleid) -{ - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - - if (trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0) - { - HeapTuple trigtuple = GetTupleForTrigger(estate, relinfo, - tupleid, NULL); - - DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE, - trigtuple, NULL); - heap_freetuple(trigtuple); - } -} - -HeapTuple -ExecBRUpdateTriggers(EState *estate, ResultRelInfo *relinfo, - ItemPointer tupleid, HeapTuple newtuple) -{ - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - int ntrigs = trigdesc->n_before_row[TRIGGER_EVENT_UPDATE]; - int *tgindx = trigdesc->tg_before_row[TRIGGER_EVENT_UPDATE]; - TriggerData LocTriggerData; - HeapTuple trigtuple; - HeapTuple oldtuple; - HeapTuple intuple = newtuple; - TupleTableSlot *newSlot; - int i; - - trigtuple = GetTupleForTrigger(estate, relinfo, 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); - - /* Allocate cache space for fmgr lookup info, if not done yet */ - if (relinfo->ri_TrigFunctions == NULL) - { - relinfo->ri_TrigFunctions = (FmgrInfo *) - palloc(trigdesc->numtriggers * sizeof(FmgrInfo)); - MemSet(relinfo->ri_TrigFunctions, 0, - trigdesc->numtriggers * sizeof(FmgrInfo)); - } - - LocTriggerData.type = T_TriggerData; - LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; - LocTriggerData.tg_relation = relinfo->ri_RelationDesc; - for (i = 0; i < ntrigs; i++) - { - Trigger *trigger = &trigdesc->triggers[tgindx[i]]; - - if (!trigger->tgenabled) - continue; - LocTriggerData.tg_trigtuple = trigtuple; - LocTriggerData.tg_newtuple = oldtuple = newtuple; - LocTriggerData.tg_trigger = trigger; - newtuple = ExecCallTriggerFunc(&LocTriggerData, - relinfo->ri_TrigFunctions + tgindx[i], - GetPerTupleMemoryContext(estate)); - if (oldtuple != newtuple && oldtuple != intuple) - heap_freetuple(oldtuple); - if (newtuple == NULL) - break; - } - heap_freetuple(trigtuple); - return newtuple; -} - -void -ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo, - ItemPointer tupleid, HeapTuple newtuple) -{ - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - - if (trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0) - { - HeapTuple trigtuple = GetTupleForTrigger(estate, relinfo, - tupleid, NULL); - - DeferredTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE, - trigtuple, newtuple); - heap_freetuple(trigtuple); - } -} - - -static HeapTuple -GetTupleForTrigger(EState *estate, ResultRelInfo *relinfo, - ItemPointer tid, TupleTableSlot **newSlot) -{ - Relation relation = relinfo->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, - GetCurrentCommandId()); - 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, - relinfo->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 context created at startup and - * over statements/commands in a separate context which - * is created at transaction start and destroyed at transaction end. - * ---------- - */ -static MemoryContext deftrig_gcxt = NULL; -static MemoryContext 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 pending deferred trigger events during the current transaction. - * - * deftrig_events is the head, deftrig_event_tail is the last entry. - * Because this can grow pretty large, we don't use separate List nodes, - * but instead thread the list through the dte_next fields of the member - * nodes. Saves just a few bytes per entry, but that adds up. - * - * XXX Need to be able to shove this data out to a file if it grows too - * large... - * ---------- - */ -static DeferredTriggerEvent deftrig_events; -static DeferredTriggerEvent deftrig_event_tail; - - -/* ---------- - * 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(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) -{ - /* - * Since the event list could grow quite long, we keep track of the - * list tail and append there, rather than just doing a stupid - * "lappend". This avoids O(N^2) behavior for large numbers of events. - */ - event->dte_next = NULL; - if (deftrig_event_tail == NULL) - { - /* first list entry */ - deftrig_events = event; - deftrig_event_tail = event; - } - else - { - deftrig_event_tail->dte_next = event; - deftrig_event_tail = event; - } -} - - -/* ---------- - * DeferredTriggerExecute() - * - * Fetch the required tuples back from the heap and fire one - * single trigger function. - * - * Frequently, this will be fired many times in a row for triggers of - * a single relation. Therefore, we cache the open relation and provide - * fmgr lookup cache space at the caller level. - * - * event: event currently being fired. - * itemno: item within event currently being fired. - * rel: open relation for event. - * finfo: array of fmgr lookup cache entries (one per trigger of relation). - * per_tuple_context: memory context to call trigger function in. - * ---------- - */ -static void -DeferredTriggerExecute(DeferredTriggerEvent event, int itemno, - Relation rel, FmgrInfo *finfo, - MemoryContext per_tuple_context) -{ - Oid tgoid = event->dte_item[itemno].dti_tgoid; - TriggerDesc *trigdesc = rel->trigdesc; - TriggerData LocTriggerData; - HeapTupleData oldtuple; - HeapTupleData newtuple; - HeapTuple rettuple; - Buffer oldbuffer; - Buffer newbuffer; - int tgindx; - - /* - * Fetch the required OLD and NEW tuples. - */ - if (ItemPointerIsValid(&(event->dte_oldctid))) - { - ItemPointerCopy(&(event->dte_oldctid), &(oldtuple.t_self)); - if (!heap_fetch(rel, SnapshotAny, &oldtuple, &oldbuffer, false, NULL)) - elog(ERROR, "DeferredTriggerExecute: failed to fetch old tuple"); - } - - if (ItemPointerIsValid(&(event->dte_newctid))) - { - ItemPointerCopy(&(event->dte_newctid), &(newtuple.t_self)); - if (!heap_fetch(rel, SnapshotAny, &newtuple, &newbuffer, false, NULL)) - elog(ERROR, "DeferredTriggerExecute: failed to fetch new tuple"); - } - - /* - * Setup the trigger information - */ - LocTriggerData.type = T_TriggerData; - LocTriggerData.tg_event = (event->dte_event & TRIGGER_EVENT_OPMASK) | - TRIGGER_EVENT_ROW; - LocTriggerData.tg_relation = rel; - - LocTriggerData.tg_trigger = NULL; - for (tgindx = 0; tgindx < trigdesc->numtriggers; tgindx++) - { - if (trigdesc->triggers[tgindx].tgoid == tgoid) - { - LocTriggerData.tg_trigger = &(trigdesc->triggers[tgindx]); - break; - } - } - if (LocTriggerData.tg_trigger == NULL) - elog(ERROR, "DeferredTriggerExecute: can't find trigger %u", tgoid); - - switch (event->dte_event & TRIGGER_EVENT_OPMASK) - { - case TRIGGER_EVENT_INSERT: - LocTriggerData.tg_trigtuple = &newtuple; - LocTriggerData.tg_newtuple = NULL; - break; - - case TRIGGER_EVENT_UPDATE: - LocTriggerData.tg_trigtuple = &oldtuple; - LocTriggerData.tg_newtuple = &newtuple; - break; - - case TRIGGER_EVENT_DELETE: - LocTriggerData.tg_trigtuple = &oldtuple; - LocTriggerData.tg_newtuple = NULL; - break; - } - - /* - * Call the trigger and throw away an eventually returned updated - * tuple. - */ - rettuple = ExecCallTriggerFunc(&LocTriggerData, - finfo + tgindx, - per_tuple_context); - 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 - */ - if (ItemPointerIsValid(&(event->dte_oldctid))) - ReleaseBuffer(oldbuffer); - if (ItemPointerIsValid(&(event->dte_newctid))) - ReleaseBuffer(newbuffer); -} - - -/* ---------- - * 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) -{ - DeferredTriggerEvent event, - prev_event = NULL; - MemoryContext per_tuple_context; - Relation rel = NULL; - FmgrInfo *finfo = NULL; - - /* - * If immediate_only is true, we remove fully-processed events from - * the event queue to recycle space. If immediate_only is false, - * we are going to discard the whole event queue on return anyway, - * so no need to bother with "retail" pfree's. - * - * In a scenario with many commands in a transaction and many - * deferred-to-end-of-transaction triggers, it could get annoying - * to rescan all the deferred triggers at each command end. - * To speed this up, we could remember the actual end of the queue at - * EndQuery and examine only events that are newer. On state changes - * we simply reset the saved position to the beginning of the queue - * and process all events once with the new states. - */ - - /* Make a per-tuple memory context for trigger function calls */ - per_tuple_context = - AllocSetContextCreate(CurrentMemoryContext, - "DeferredTriggerTupleContext", - ALLOCSET_DEFAULT_MINSIZE, - ALLOCSET_DEFAULT_INITSIZE, - ALLOCSET_DEFAULT_MAXSIZE); - - event = deftrig_events; - while (event != NULL) - { - bool still_deferred_ones = false; - DeferredTriggerEvent next_event; - int i; - - /* - * Check if event is already completely done. - */ - if (! (event->dte_event & (TRIGGER_DEFERRED_DONE | - TRIGGER_DEFERRED_CANCELED))) - { - MemoryContextReset(per_tuple_context); - - /* - * Check each trigger item in the event. - */ - 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... but first, open the correct relation - * if this is not the same relation as before. - */ - if (rel == NULL || rel->rd_id != event->dte_relid) - { - if (rel) - heap_close(rel, NoLock); - if (finfo) - pfree(finfo); - - /* - * We assume that an appropriate lock is still held by the - * executor, so grab no new lock here. - */ - rel = heap_open(event->dte_relid, NoLock); - - /* - * Allocate space to cache fmgr lookup info for triggers - * of this relation. - */ - finfo = (FmgrInfo *) - palloc(rel->trigdesc->numtriggers * sizeof(FmgrInfo)); - MemSet(finfo, 0, - rel->trigdesc->numtriggers * sizeof(FmgrInfo)); - } - - DeferredTriggerExecute(event, i, rel, finfo, - per_tuple_context); - - event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE; - } /* end loop over items within event */ - } - - /* - * If it's now completely done, throw it away. - * - * NB: it's possible the trigger calls above added more events to the - * queue, or that calls we will do later will want to add more, - * so we have to be careful about maintaining list validity here. - */ - next_event = event->dte_next; - - if (still_deferred_ones) - { - /* Not done, keep in list */ - prev_event = event; - } - else - { - /* Done */ - if (immediate_only) - { - /* delink it from list and free it */ - if (prev_event) - prev_event->dte_next = next_event; - else - deftrig_events = next_event; - pfree(event); - } - else - { - /* - * We will clean up later, but just for paranoia's sake, - * mark the event done. - */ - event->dte_event |= TRIGGER_DEFERRED_DONE; - } - } - - event = next_event; - } - - /* Update list tail pointer in case we just deleted tail event */ - deftrig_event_tail = prev_event; - - /* Release working resources */ - if (rel) - heap_close(rel, NoLock); - if (finfo) - pfree(finfo); - MemoryContextDelete(per_tuple_context); -} - - -/* ---------- - * DeferredTriggerInit() - * - * Initialize the deferred trigger mechanism. This is called during - * backend startup and is guaranteed to be before the first of all - * transactions. - * ---------- - */ -void -DeferredTriggerInit(void) -{ - /* - * Since this context will never be reset, give it a minsize of 0. - * This avoids using any memory if the session never stores anything. - */ - deftrig_gcxt = AllocSetContextCreate(TopMemoryContext, - "DeferredTriggerSession", - 0, - ALLOCSET_DEFAULT_INITSIZE, - ALLOCSET_DEFAULT_MAXSIZE); -} - - -/* ---------- - * 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(ERROR, - "DeferredTriggerBeginXact() called while inside transaction"); - - /* - * Create the per transaction memory context and copy all states from - * the per session context to here. Set the minsize to 0 to avoid - * wasting memory if there is no deferred trigger data. - */ - deftrig_cxt = AllocSetContextCreate(TopTransactionContext, - "DeferredTriggerXact", - 0, - ALLOCSET_DEFAULT_INITSIZE, - ALLOCSET_DEFAULT_MAXSIZE); - oldcxt = MemoryContextSwitchTo(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_events = NULL; - deftrig_event_tail = NULL; -} - - -/* ---------- - * 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); - - MemoryContextDelete(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; - - MemoryContextDelete(deftrig_cxt); - deftrig_cxt = NULL; -} - - -/* ---------- - * DeferredTriggerSetState() - * - * Called for the users SET CONSTRAINTS ... utility command. - * ---------- - */ -void -DeferredTriggerSetState(ConstraintsSetStmt *stmt) -{ - Relation tgrel; - List *l; - List *ls; - List *loid = NIL; - MemoryContext oldcxt; - bool found; - DeferredTriggerStatus state; - - /* - * Handle SET CONSTRAINTS ALL ... - */ - if (stmt->constraints == NIL) - { - if (!IsTransactionBlock()) - { - /* - * ... outside of a transaction block - * - * Drop all information about individual trigger states per - * session. - */ - l = deftrig_dfl_trigstates; - while (l != NIL) - { - List *next = lnext(l); - - pfree(lfirst(l)); - pfree(l); - l = next; - } - deftrig_dfl_trigstates = NIL; - - /* - * Set the session ALL state to known. - */ - deftrig_dfl_all_isset = true; - deftrig_dfl_all_isdeferred = stmt->deferred; - - return; - } - else - { - /* - * ... inside of a transaction block - * - * Drop all information about individual trigger states per - * transaction. - */ - l = deftrig_trigstates; - while (l != NIL) - { - List *next = lnext(l); - - pfree(lfirst(l)); - pfree(l); - l = next; - } - deftrig_trigstates = NIL; - - /* - * Set the per transaction ALL state to known. - */ - deftrig_all_isset = true; - deftrig_all_isdeferred = stmt->deferred; - - return; - } - } - - /* ---------- - * Handle SET CONSTRAINTS constraint-name [, ...] - * First lookup all trigger Oid's for the constraint names. - * ---------- - */ - tgrel = heap_openr(TriggerRelationName, AccessShareLock); - - foreach(l, stmt->constraints) - { - char *cname = strVal(lfirst(l)); - ScanKeyData skey; - SysScanDesc tgscan; - HeapTuple htup; - - /* - * Check that only named constraints are set explicitly - */ - if (strlen(cname) == 0) - elog(ERROR, "unnamed constraints cannot be set explicitly"); - - /* - * Setup to scan pg_trigger by tgconstrname ... - */ - ScanKeyEntryInitialize(&skey, - (bits16) 0x0, - (AttrNumber) Anum_pg_trigger_tgconstrname, - (RegProcedure) F_NAMEEQ, - PointerGetDatum(cname)); - - tgscan = systable_beginscan(tgrel, TriggerConstrNameIndex, true, - SnapshotNow, 1, &skey); - - /* - * ... and search for the constraint trigger row - */ - found = false; - - while (HeapTupleIsValid(htup = systable_getnext(tgscan))) - { - Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup); - Oid constr_oid; - - /* - * If we found some, check that they fit the deferrability but - * skip ON <event> RESTRICT ones, since they are silently - * never deferrable. - */ - if (stmt->deferred && !pg_trigger->tgdeferrable && - pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_UPD && - pg_trigger->tgfoid != F_RI_FKEY_RESTRICT_DEL) - elog(ERROR, "Constraint '%s' is not deferrable", - cname); - - constr_oid = htup->t_data->t_oid; - loid = lappendi(loid, constr_oid); - found = true; - } - - systable_endscan(tgscan); - - /* - * Not found ? - */ - if (!found) - elog(ERROR, "Constraint '%s' does not exist", cname); - } - heap_close(tgrel, AccessShareLock); - - if (!IsTransactionBlock()) - { - /* - * Outside of a transaction block set the trigger states of - * individual triggers on session level. - */ - oldcxt = MemoryContextSwitchTo(deftrig_gcxt); - - foreach(l, loid) - { - found = false; - foreach(ls, deftrig_dfl_trigstates) - { - state = (DeferredTriggerStatus) lfirst(ls); - if (state->dts_tgoid == (Oid) lfirsti(l)) - { - state->dts_tgisdeferred = stmt->deferred; - found = true; - break; - } - } - if (!found) - { - state = (DeferredTriggerStatus) - palloc(sizeof(DeferredTriggerStatusData)); - state->dts_tgoid = (Oid) lfirsti(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(deftrig_cxt); - - foreach(l, loid) - { - found = false; - foreach(ls, deftrig_trigstates) - { - state = (DeferredTriggerStatus) lfirst(ls); - if (state->dts_tgoid == (Oid) lfirsti(l)) - { - state->dts_tgisdeferred = stmt->deferred; - found = true; - break; - } - } - if (!found) - { - state = (DeferredTriggerStatus) - palloc(sizeof(DeferredTriggerStatusData)); - state->dts_tgoid = (Oid) lfirsti(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. - * - * NOTE: should be called only if we've determined that an event must - * be added to the queue. - * ---------- - */ -static void -DeferredTriggerSaveEvent(ResultRelInfo *relinfo, int event, - HeapTuple oldtup, HeapTuple newtup) -{ - Relation rel = relinfo->ri_RelationDesc; - TriggerDesc *trigdesc = relinfo->ri_TrigDesc; - MemoryContext oldcxt; - DeferredTriggerEvent new_event; - int new_size; - int i; - int ntriggers; - int *tgindx; - ItemPointerData oldctid; - ItemPointerData newctid; - TriggerData LocTriggerData; - - if (deftrig_cxt == NULL) - elog(ERROR, - "DeferredTriggerSaveEvent() called outside of transaction"); - - /* - * Get the CTID's of OLD and NEW - */ - if (oldtup != NULL) - ItemPointerCopy(&(oldtup->t_self), &(oldctid)); - else - ItemPointerSetInvalid(&(oldctid)); - if (newtup != NULL) - ItemPointerCopy(&(newtup->t_self), &(newctid)); - else - ItemPointerSetInvalid(&(newctid)); - - /* - * Create a new event - */ - oldcxt = MemoryContextSwitchTo(deftrig_cxt); - - ntriggers = trigdesc->n_after_row[event]; - tgindx = trigdesc->tg_after_row[event]; - new_size = offsetof(DeferredTriggerEventData, dte_item[0]) + - ntriggers * sizeof(DeferredTriggerEventItem); - - new_event = (DeferredTriggerEvent) palloc(new_size); - new_event->dte_next = NULL; - 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; - for (i = 0; i < ntriggers; i++) - { - Trigger *trigger = &trigdesc->triggers[tgindx[i]]; - - new_event->dte_item[i].dti_tgoid = trigger->tgoid; - new_event->dte_item[i].dti_state = - ((trigger->tgdeferrable) ? - TRIGGER_DEFERRED_DEFERRABLE : 0) | - ((trigger->tginitdeferred) ? - TRIGGER_DEFERRED_INITDEFERRED : 0) | - ((trigdesc->n_before_row[event] > 0) ? - TRIGGER_DEFERRED_HAS_BEFORE : 0); - } - - MemoryContextSwitchTo(oldcxt); - - switch (event & TRIGGER_EVENT_OPMASK) - { - case TRIGGER_EVENT_INSERT: - /* nothing to do */ - break; - - case TRIGGER_EVENT_UPDATE: - /* - * Check if one of the referenced keys is changed. - */ - for (i = 0; i < ntriggers; i++) - { - Trigger *trigger = &trigdesc->triggers[tgindx[i]]; - bool is_ri_trigger; - bool key_unchanged; - - /* - * We are interested in RI_FKEY triggers only. - */ - switch (trigger->tgfoid) - { - case F_RI_FKEY_NOACTION_UPD: - 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; - - LocTriggerData.type = T_TriggerData; - LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE; - LocTriggerData.tg_relation = rel; - LocTriggerData.tg_trigtuple = oldtup; - LocTriggerData.tg_newtuple = newtup; - LocTriggerData.tg_trigger = trigger; - - key_unchanged = RI_FKey_keyequal_upd(&LocTriggerData); - - if (key_unchanged) - { - /* - * The key hasn't changed, so no need later to invoke - * the trigger at all. - */ - new_event->dte_item[i].dti_state |= TRIGGER_DEFERRED_DONE; - } - } - - break; - - case TRIGGER_EVENT_DELETE: - /* nothing to do */ - break; - } - - /* - * Add the new event to the queue. - */ - deferredTriggerAddEvent(new_event); -} |