/*------------------------------------------------------------------------- * * trigger.c * PostgreSQL TRIGGERs support code. * * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION * src/backend/commands/trigger.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/genam.h" #include "access/htup_details.h" #include "access/relation.h" #include "access/sysattr.h" #include "access/table.h" #include "access/tableam.h" #include "access/xact.h" #include "catalog/catalog.h" #include "catalog/dependency.h" #include "catalog/indexing.h" #include "catalog/objectaccess.h" #include "catalog/partition.h" #include "catalog/pg_constraint.h" #include "catalog/pg_inherits.h" #include "catalog/pg_proc.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" #include "commands/dbcommands.h" #include "commands/trigger.h" #include "executor/executor.h" #include "miscadmin.h" #include "nodes/bitmapset.h" #include "nodes/makefuncs.h" #include "optimizer/optimizer.h" #include "parser/parse_clause.h" #include "parser/parse_collate.h" #include "parser/parse_func.h" #include "parser/parse_relation.h" #include "partitioning/partdesc.h" #include "pgstat.h" #include "rewrite/rewriteManip.h" #include "storage/lmgr.h" #include "utils/acl.h" #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/guc_hooks.h" #include "utils/inval.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/plancache.h" #include "utils/rel.h" #include "utils/snapmgr.h" #include "utils/syscache.h" #include "utils/tuplestore.h" /* GUC variables */ int SessionReplicationRole = SESSION_REPLICATION_ROLE_ORIGIN; /* How many levels deep into trigger execution are we? */ static int MyTriggerDepth = 0; /* Local function prototypes */ static void renametrig_internal(Relation tgrel, Relation targetrel, HeapTuple trigtup, const char *newname, const char *expected_name); static void renametrig_partition(Relation tgrel, Oid partitionId, Oid parentTriggerOid, const char *newname, const char *expected_name); static void SetTriggerFlags(TriggerDesc *trigdesc, Trigger *trigger); static bool GetTupleForTrigger(EState *estate, EPQState *epqstate, ResultRelInfo *relinfo, ItemPointer tid, LockTupleMode lockmode, TupleTableSlot *oldslot, TupleTableSlot **epqslot, TM_Result *tmresultp, TM_FailureData *tmfdp); static bool TriggerEnabled(EState *estate, ResultRelInfo *relinfo, Trigger *trigger, TriggerEvent event, Bitmapset *modifiedCols, TupleTableSlot *oldslot, TupleTableSlot *newslot); static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata, int tgindx, FmgrInfo *finfo, Instrumentation *instr, MemoryContext per_tuple_context); static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo, ResultRelInfo *src_partinfo, ResultRelInfo *dst_partinfo, int event, bool row_trigger, TupleTableSlot *oldslot, TupleTableSlot *newslot, List *recheckIndexes, Bitmapset *modifiedCols, TransitionCaptureState *transition_capture, bool is_crosspart_update); static void AfterTriggerEnlargeQueryState(void); static bool before_stmt_triggers_fired(Oid relid, CmdType cmdType); /* * Create a trigger. Returns the address of the created trigger. * * queryString is the source text of the CREATE TRIGGER command. * This must be supplied if a whenClause is specified, else it can be NULL. * * relOid, if nonzero, is the relation on which the trigger should be * created. If zero, the name provided in the statement will be looked up. * * refRelOid, if nonzero, is the relation to which the constraint trigger * refers. If zero, the constraint relation name provided in the statement * will be looked up as needed. * * constraintOid, if nonzero, says that this trigger is being created * internally to implement that constraint. A suitable pg_depend entry will * be made to link the trigger to that constraint. constraintOid is zero when * executing a user-entered CREATE TRIGGER command. (For CREATE CONSTRAINT * TRIGGER, we build a pg_constraint entry internally.) * * indexOid, if nonzero, is the OID of an index associated with the constraint. * We do nothing with this except store it into pg_trigger.tgconstrindid; * but when creating a trigger for a deferrable unique constraint on a * partitioned table, its children are looked up. Note we don't cope with * invalid indexes in that case. * * funcoid, if nonzero, is the OID of the function to invoke. When this is * given, stmt->funcname is ignored. * * parentTriggerOid, if nonzero, is a trigger that begets this one; so that * if that trigger is dropped, this one should be too. There are two cases * when a nonzero value is passed for this: 1) when this function recurses to * create the trigger on partitions, 2) when creating child foreign key * triggers; see CreateFKCheckTrigger() and createForeignKeyActionTriggers(). * * If whenClause is passed, it is an already-transformed expression for * WHEN. In this case, we ignore any that may come in stmt->whenClause. * * If isInternal is true then this is an internally-generated trigger. * This argument sets the tgisinternal field of the pg_trigger entry, and * if true causes us to modify the given trigger name to ensure uniqueness. * * When isInternal is not true we require ACL_TRIGGER permissions on the * relation, as well as ACL_EXECUTE on the trigger function. For internal * triggers the caller must apply any required permission checks. * * When called on partitioned tables, this function recurses to create the * trigger on all the partitions, except if isInternal is true, in which * case caller is expected to execute recursion on its own. in_partition * indicates such a recursive call; outside callers should pass "false" * (but see CloneRowTriggersToPartition). */ ObjectAddress CreateTrigger(CreateTrigStmt *stmt, const char *queryString, Oid relOid, Oid refRelOid, Oid constraintOid, Oid indexOid, Oid funcoid, Oid parentTriggerOid, Node *whenClause, bool isInternal, bool in_partition) { return CreateTriggerFiringOn(stmt, queryString, relOid, refRelOid, constraintOid, indexOid, funcoid, parentTriggerOid, whenClause, isInternal, in_partition, TRIGGER_FIRES_ON_ORIGIN); } /* * Like the above; additionally the firing condition * (always/origin/replica/disabled) can be specified. */ ObjectAddress CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString, Oid relOid, Oid refRelOid, Oid constraintOid, Oid indexOid, Oid funcoid, Oid parentTriggerOid, Node *whenClause, bool isInternal, bool in_partition, char trigger_fires_when) { int16 tgtype; int ncolumns; int16 *columns; int2vector *tgattr; List *whenRtable; char *qual; Datum values[Natts_pg_trigger]; bool nulls[Natts_pg_trigger]; Relation rel; AclResult aclresult; Relation tgrel; Relation pgrel; HeapTuple tuple = NULL; Oid funcrettype; Oid trigoid = InvalidOid; char internaltrigname[NAMEDATALEN]; char *trigname; Oid constrrelid = InvalidOid; ObjectAddress myself, referenced; char *oldtablename = NULL; char *newtablename = NULL; bool partition_recurse; bool trigger_exists = false; Oid existing_constraint_oid = InvalidOid; bool existing_isInternal = false; bool existing_isClone = false; if (OidIsValid(relOid)) rel = table_open(relOid, ShareRowExclusiveLock); else rel = table_openrv(stmt->relation, ShareRowExclusiveLock); /* * Triggers must be on tables or views, and there are additional * relation-type-specific restrictions. */ if (rel->rd_rel->relkind == RELKIND_RELATION) { /* Tables can't have INSTEAD OF triggers */ if (stmt->timing != TRIGGER_TYPE_BEFORE && stmt->timing != TRIGGER_TYPE_AFTER) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a table", RelationGetRelationName(rel)), errdetail("Tables cannot have INSTEAD OF triggers."))); } else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { /* Partitioned tables can't have INSTEAD OF triggers */ if (stmt->timing != TRIGGER_TYPE_BEFORE && stmt->timing != TRIGGER_TYPE_AFTER) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a table", RelationGetRelationName(rel)), errdetail("Tables cannot have INSTEAD OF triggers."))); /* * FOR EACH ROW triggers have further restrictions */ if (stmt->row) { /* * Disallow use of transition tables. * * Note that we have another restriction about transition tables * in partitions; search for 'has_superclass' below for an * explanation. The check here is just to protect from the fact * that if we allowed it here, the creation would succeed for a * partitioned table with no partitions, but would be blocked by * the other restriction when the first partition was created, * which is very unfriendly behavior. */ if (stmt->transitionRels != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("\"%s\" is a partitioned table", RelationGetRelationName(rel)), errdetail("ROW triggers with transition tables are not supported on partitioned tables."))); } } else if (rel->rd_rel->relkind == RELKIND_VIEW) { /* * Views can have INSTEAD OF triggers (which we check below are * row-level), or statement-level BEFORE/AFTER triggers. */ if (stmt->timing != TRIGGER_TYPE_INSTEAD && stmt->row) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a view", RelationGetRelationName(rel)), errdetail("Views cannot have row-level BEFORE or AFTER triggers."))); /* Disallow TRUNCATE triggers on VIEWs */ if (TRIGGER_FOR_TRUNCATE(stmt->events)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a view", RelationGetRelationName(rel)), errdetail("Views cannot have TRUNCATE triggers."))); } else if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { if (stmt->timing != TRIGGER_TYPE_BEFORE && stmt->timing != TRIGGER_TYPE_AFTER) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a foreign table", RelationGetRelationName(rel)), errdetail("Foreign tables cannot have INSTEAD OF triggers."))); /* * We disallow constraint triggers to protect the assumption that * triggers on FKs can't be deferred. See notes with AfterTriggers * data structures, below. */ if (stmt->isconstraint) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a foreign table", RelationGetRelationName(rel)), errdetail("Foreign tables cannot have constraint triggers."))); } else ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("relation \"%s\" cannot have triggers", RelationGetRelationName(rel)), errdetail_relkind_not_supported(rel->rd_rel->relkind))); if (!allowSystemTableMods && IsSystemRelation(rel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(rel)))); if (stmt->isconstraint) { /* * We must take a lock on the target relation to protect against * concurrent drop. It's not clear that AccessShareLock is strong * enough, but we certainly need at least that much... otherwise, we * might end up creating a pg_constraint entry referencing a * nonexistent table. */ if (OidIsValid(refRelOid)) { LockRelationOid(refRelOid, AccessShareLock); constrrelid = refRelOid; } else if (stmt->constrrel != NULL) constrrelid = RangeVarGetRelid(stmt->constrrel, AccessShareLock, false); } /* permission checks */ if (!isInternal) { aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(), ACL_TRIGGER); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind), RelationGetRelationName(rel)); if (OidIsValid(constrrelid)) { aclresult = pg_class_aclcheck(constrrelid, GetUserId(), ACL_TRIGGER); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, get_relkind_objtype(get_rel_relkind(constrrelid)), get_rel_name(constrrelid)); } } /* * When called on a partitioned table to create a FOR EACH ROW trigger * that's not internal, we create one trigger for each partition, too. * * For that, we'd better hold lock on all of them ahead of time. */ partition_recurse = !isInternal && stmt->row && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE; if (partition_recurse) list_free(find_all_inheritors(RelationGetRelid(rel), ShareRowExclusiveLock, NULL)); /* Compute tgtype */ TRIGGER_CLEAR_TYPE(tgtype); if (stmt->row) TRIGGER_SETT_ROW(tgtype); tgtype |= stmt->timing; tgtype |= stmt->events; /* Disallow ROW-level TRUNCATE triggers */ if (TRIGGER_FOR_ROW(tgtype) && TRIGGER_FOR_TRUNCATE(tgtype)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("TRUNCATE FOR EACH ROW triggers are not supported"))); /* INSTEAD triggers must be row-level, and can't have WHEN or columns */ if (TRIGGER_FOR_INSTEAD(tgtype)) { if (!TRIGGER_FOR_ROW(tgtype)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("INSTEAD OF triggers must be FOR EACH ROW"))); if (stmt->whenClause) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("INSTEAD OF triggers cannot have WHEN conditions"))); if (stmt->columns != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("INSTEAD OF triggers cannot have column lists"))); } /* * We don't yet support naming ROW transition variables, but the parser * recognizes the syntax so we can give a nicer message here. * * Per standard, REFERENCING TABLE names are only allowed on AFTER * triggers. Per standard, REFERENCING ROW names are not allowed with FOR * EACH STATEMENT. Per standard, each OLD/NEW, ROW/TABLE permutation is * only allowed once. Per standard, OLD may not be specified when * creating a trigger only for INSERT, and NEW may not be specified when * creating a trigger only for DELETE. * * Notice that the standard allows an AFTER ... FOR EACH ROW trigger to * reference both ROW and TABLE transition data. */ if (stmt->transitionRels != NIL) { List *varList = stmt->transitionRels; ListCell *lc; foreach(lc, varList) { TriggerTransition *tt = lfirst_node(TriggerTransition, lc); if (!(tt->isTable)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ROW variable naming in the REFERENCING clause is not supported"), errhint("Use OLD TABLE or NEW TABLE for naming transition tables."))); /* * Because of the above test, we omit further ROW-related testing * below. If we later allow naming OLD and NEW ROW variables, * adjustments will be needed below. */ if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a foreign table", RelationGetRelationName(rel)), errdetail("Triggers on foreign tables cannot have transition tables."))); if (rel->rd_rel->relkind == RELKIND_VIEW) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a view", RelationGetRelationName(rel)), errdetail("Triggers on views cannot have transition tables."))); /* * We currently don't allow row-level triggers with transition * tables on partition or inheritance children. Such triggers * would somehow need to see tuples converted to the format of the * table they're attached to, and it's not clear which subset of * tuples each child should see. See also the prohibitions in * ATExecAttachPartition() and ATExecAddInherit(). */ if (TRIGGER_FOR_ROW(tgtype) && has_superclass(rel->rd_id)) { /* Use appropriate error message. */ if (rel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ROW triggers with transition tables are not supported on partitions"))); else ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ROW triggers with transition tables are not supported on inheritance children"))); } if (stmt->timing != TRIGGER_TYPE_AFTER) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("transition table name can only be specified for an AFTER trigger"))); if (TRIGGER_FOR_TRUNCATE(tgtype)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("TRUNCATE triggers with transition tables are not supported"))); /* * We currently don't allow multi-event triggers ("INSERT OR * UPDATE") with transition tables, because it's not clear how to * handle INSERT ... ON CONFLICT statements which can fire both * INSERT and UPDATE triggers. We show the inserted tuples to * INSERT triggers and the updated tuples to UPDATE triggers, but * it's not yet clear what INSERT OR UPDATE trigger should see. * This restriction could be lifted if we can decide on the right * semantics in a later release. */ if (((TRIGGER_FOR_INSERT(tgtype) ? 1 : 0) + (TRIGGER_FOR_UPDATE(tgtype) ? 1 : 0) + (TRIGGER_FOR_DELETE(tgtype) ? 1 : 0)) != 1) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("transition tables cannot be specified for triggers with more than one event"))); /* * We currently don't allow column-specific triggers with * transition tables. Per spec, that seems to require * accumulating separate transition tables for each combination of * columns, which is a lot of work for a rather marginal feature. */ if (stmt->columns != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("transition tables cannot be specified for triggers with column lists"))); /* * We disallow constraint triggers with transition tables, to * protect the assumption that such triggers can't be deferred. * See notes with AfterTriggers data structures, below. * * Currently this is enforced by the grammar, so just Assert here. */ Assert(!stmt->isconstraint); if (tt->isNew) { if (!(TRIGGER_FOR_INSERT(tgtype) || TRIGGER_FOR_UPDATE(tgtype))) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("NEW TABLE can only be specified for an INSERT or UPDATE trigger"))); if (newtablename != NULL) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("NEW TABLE cannot be specified multiple times"))); newtablename = tt->name; } else { if (!(TRIGGER_FOR_DELETE(tgtype) || TRIGGER_FOR_UPDATE(tgtype))) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("OLD TABLE can only be specified for a DELETE or UPDATE trigger"))); if (oldtablename != NULL) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("OLD TABLE cannot be specified multiple times"))); oldtablename = tt->name; } } if (newtablename != NULL && oldtablename != NULL && strcmp(newtablename, oldtablename) == 0) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("OLD TABLE name and NEW TABLE name cannot be the same"))); } /* * Parse the WHEN clause, if any and we weren't passed an already * transformed one. * * Note that as a side effect, we fill whenRtable when parsing. If we got * an already parsed clause, this does not occur, which is what we want -- * no point in adding redundant dependencies below. */ if (!whenClause && stmt->whenClause) { ParseState *pstate; ParseNamespaceItem *nsitem; List *varList; ListCell *lc; /* Set up a pstate to parse with */ pstate = make_parsestate(NULL); pstate->p_sourcetext = queryString; /* * Set up nsitems for OLD and NEW references. * * 'OLD' must always have varno equal to 1 and 'NEW' equal to 2. */ nsitem = addRangeTableEntryForRelation(pstate, rel, AccessShareLock, makeAlias("old", NIL), false, false); addNSItemToQuery(pstate, nsitem, false, true, true); nsitem = addRangeTableEntryForRelation(pstate, rel, AccessShareLock, makeAlias("new", NIL), false, false); addNSItemToQuery(pstate, nsitem, false, true, true); /* Transform expression. Copy to be sure we don't modify original */ whenClause = transformWhereClause(pstate, copyObject(stmt->whenClause), EXPR_KIND_TRIGGER_WHEN, "WHEN"); /* we have to fix its collations too */ assign_expr_collations(pstate, whenClause); /* * Check for disallowed references to OLD/NEW. * * NB: pull_var_clause is okay here only because we don't allow * subselects in WHEN clauses; it would fail to examine the contents * of subselects. */ varList = pull_var_clause(whenClause, 0); foreach(lc, varList) { Var *var = (Var *) lfirst(lc); switch (var->varno) { case PRS2_OLD_VARNO: if (!TRIGGER_FOR_ROW(tgtype)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("statement trigger's WHEN condition cannot reference column values"), parser_errposition(pstate, var->location))); if (TRIGGER_FOR_INSERT(tgtype)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("INSERT trigger's WHEN condition cannot reference OLD values"), parser_errposition(pstate, var->location))); /* system columns are okay here */ break; case PRS2_NEW_VARNO: if (!TRIGGER_FOR_ROW(tgtype)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("statement trigger's WHEN condition cannot reference column values"), parser_errposition(pstate, var->location))); if (TRIGGER_FOR_DELETE(tgtype)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("DELETE trigger's WHEN condition cannot reference NEW values"), parser_errposition(pstate, var->location))); if (var->varattno < 0 && TRIGGER_FOR_BEFORE(tgtype)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("BEFORE trigger's WHEN condition cannot reference NEW system columns"), parser_errposition(pstate, var->location))); if (TRIGGER_FOR_BEFORE(tgtype) && var->varattno == 0 && RelationGetDescr(rel)->constr && RelationGetDescr(rel)->constr->has_generated_stored) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("BEFORE trigger's WHEN condition cannot reference NEW generated columns"), errdetail("A whole-row reference is used and the table contains generated columns."), parser_errposition(pstate, var->location))); if (TRIGGER_FOR_BEFORE(tgtype) && var->varattno > 0 && TupleDescAttr(RelationGetDescr(rel), var->varattno - 1)->attgenerated) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("BEFORE trigger's WHEN condition cannot reference NEW generated columns"), errdetail("Column \"%s\" is a generated column.", NameStr(TupleDescAttr(RelationGetDescr(rel), var->varattno - 1)->attname)), parser_errposition(pstate, var->location))); break; default: /* can't happen without add_missing_from, so just elog */ elog(ERROR, "trigger WHEN condition cannot contain references to other relations"); break; } } /* we'll need the rtable for recordDependencyOnExpr */ whenRtable = pstate->p_rtable; qual = nodeToString(whenClause); free_parsestate(pstate); } else if (!whenClause) { whenClause = NULL; whenRtable = NIL; qual = NULL; } else { qual = nodeToString(whenClause); whenRtable = NIL; } /* * Find and validate the trigger function. */ if (!OidIsValid(funcoid)) funcoid = LookupFuncName(stmt->funcname, 0, NULL, false); if (!isInternal) { aclresult = object_aclcheck(ProcedureRelationId, funcoid, GetUserId(), ACL_EXECUTE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_FUNCTION, NameListToString(stmt->funcname)); } funcrettype = get_func_rettype(funcoid); if (funcrettype != TRIGGEROID) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("function %s must return type %s", NameListToString(stmt->funcname), "trigger"))); /* * Scan pg_trigger to see if there is already a trigger of the same name. * Skip this for internally generated triggers, since we'll modify the * name to be unique below. * * NOTE that this is cool only because we have ShareRowExclusiveLock on * the relation, so the trigger set won't be changing underneath us. */ tgrel = table_open(TriggerRelationId, RowExclusiveLock); if (!isInternal) { ScanKeyData skeys[2]; SysScanDesc tgscan; ScanKeyInit(&skeys[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&skeys[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(stmt->trigname)); tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, skeys); /* There should be at most one matching tuple */ if (HeapTupleIsValid(tuple = systable_getnext(tgscan))) { Form_pg_trigger oldtrigger = (Form_pg_trigger) GETSTRUCT(tuple); trigoid = oldtrigger->oid; existing_constraint_oid = oldtrigger->tgconstraint; existing_isInternal = oldtrigger->tgisinternal; existing_isClone = OidIsValid(oldtrigger->tgparentid); trigger_exists = true; /* copy the tuple to use in CatalogTupleUpdate() */ tuple = heap_copytuple(tuple); } systable_endscan(tgscan); } if (!trigger_exists) { /* Generate the OID for the new trigger. */ trigoid = GetNewOidWithIndex(tgrel, TriggerOidIndexId, Anum_pg_trigger_oid); } else { /* * If OR REPLACE was specified, we'll replace the old trigger; * otherwise complain about the duplicate name. */ if (!stmt->replace) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("trigger \"%s\" for relation \"%s\" already exists", stmt->trigname, RelationGetRelationName(rel)))); /* * An internal trigger or a child trigger (isClone) cannot be replaced * by a user-defined trigger. However, skip this test when * in_partition, because then we're recursing from a partitioned table * and the check was made at the parent level. */ if ((existing_isInternal || existing_isClone) && !isInternal && !in_partition) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("trigger \"%s\" for relation \"%s\" is an internal or a child trigger", stmt->trigname, RelationGetRelationName(rel)))); /* * It is not allowed to replace with a constraint trigger; gram.y * should have enforced this already. */ Assert(!stmt->isconstraint); /* * It is not allowed to replace an existing constraint trigger, * either. (The reason for these restrictions is partly that it seems * difficult to deal with pending trigger events in such cases, and * partly that the command might imply changing the constraint's * properties as well, which doesn't seem nice.) */ if (OidIsValid(existing_constraint_oid)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("trigger \"%s\" for relation \"%s\" is a constraint trigger", stmt->trigname, RelationGetRelationName(rel)))); } /* * If it's a user-entered CREATE CONSTRAINT TRIGGER command, make a * corresponding pg_constraint entry. */ if (stmt->isconstraint && !OidIsValid(constraintOid)) { /* Internal callers should have made their own constraints */ Assert(!isInternal); constraintOid = CreateConstraintEntry(stmt->trigname, RelationGetNamespace(rel), CONSTRAINT_TRIGGER, stmt->deferrable, stmt->initdeferred, true, InvalidOid, /* no parent */ RelationGetRelid(rel), NULL, /* no conkey */ 0, 0, InvalidOid, /* no domain */ InvalidOid, /* no index */ InvalidOid, /* no foreign key */ NULL, NULL, NULL, NULL, 0, ' ', ' ', NULL, 0, ' ', NULL, /* no exclusion */ NULL, /* no check constraint */ NULL, true, /* islocal */ 0, /* inhcount */ true, /* noinherit */ false, /* conperiod */ isInternal); /* is_internal */ } /* * If trigger is internally generated, modify the provided trigger name to * ensure uniqueness by appending the trigger OID. (Callers will usually * supply a simple constant trigger name in these cases.) */ if (isInternal) { snprintf(internaltrigname, sizeof(internaltrigname), "%s_%u", stmt->trigname, trigoid); trigname = internaltrigname; } else { /* user-defined trigger; use the specified trigger name as-is */ trigname = stmt->trigname; } /* * Build the new pg_trigger tuple. */ memset(nulls, false, sizeof(nulls)); values[Anum_pg_trigger_oid - 1] = ObjectIdGetDatum(trigoid); values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel)); values[Anum_pg_trigger_tgparentid - 1] = ObjectIdGetDatum(parentTriggerOid); values[Anum_pg_trigger_tgname - 1] = DirectFunctionCall1(namein, CStringGetDatum(trigname)); values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid); values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype); values[Anum_pg_trigger_tgenabled - 1] = trigger_fires_when; values[Anum_pg_trigger_tgisinternal - 1] = BoolGetDatum(isInternal); values[Anum_pg_trigger_tgconstrrelid - 1] = ObjectIdGetDatum(constrrelid); values[Anum_pg_trigger_tgconstrindid - 1] = ObjectIdGetDatum(indexOid); values[Anum_pg_trigger_tgconstraint - 1] = ObjectIdGetDatum(constraintOid); values[Anum_pg_trigger_tgdeferrable - 1] = BoolGetDatum(stmt->deferrable); values[Anum_pg_trigger_tginitdeferred - 1] = BoolGetDatum(stmt->initdeferred); if (stmt->args) { ListCell *le; char *args; int16 nargs = list_length(stmt->args); int len = 0; foreach(le, stmt->args) { char *ar = strVal(lfirst(le)); len += strlen(ar) + 4; for (; *ar; ar++) { if (*ar == '\\') len++; } } args = (char *) palloc(len + 1); args[0] = '\0'; foreach(le, stmt->args) { char *s = strVal(lfirst(le)); char *d = args + strlen(args); while (*s) { if (*s == '\\') *d++ = '\\'; *d++ = *s++; } strcpy(d, "\\000"); } values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(nargs); values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain, CStringGetDatum(args)); } else { values[Anum_pg_trigger_tgnargs - 1] = Int16GetDatum(0); values[Anum_pg_trigger_tgargs - 1] = DirectFunctionCall1(byteain, CStringGetDatum("")); } /* build column number array if it's a column-specific trigger */ ncolumns = list_length(stmt->columns); if (ncolumns == 0) columns = NULL; else { ListCell *cell; int i = 0; columns = (int16 *) palloc(ncolumns * sizeof(int16)); foreach(cell, stmt->columns) { char *name = strVal(lfirst(cell)); int16 attnum; int j; /* Lookup column name. System columns are not allowed */ attnum = attnameAttNum(rel, name, false); if (attnum == InvalidAttrNumber) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", name, RelationGetRelationName(rel)))); /* Check for duplicates */ for (j = i - 1; j >= 0; j--) { if (columns[j] == attnum) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" specified more than once", name))); } columns[i++] = attnum; } } tgattr = buildint2vector(columns, ncolumns); values[Anum_pg_trigger_tgattr - 1] = PointerGetDatum(tgattr); /* set tgqual if trigger has WHEN clause */ if (qual) values[Anum_pg_trigger_tgqual - 1] = CStringGetTextDatum(qual); else nulls[Anum_pg_trigger_tgqual - 1] = true; if (oldtablename) values[Anum_pg_trigger_tgoldtable - 1] = DirectFunctionCall1(namein, CStringGetDatum(oldtablename)); else nulls[Anum_pg_trigger_tgoldtable - 1] = true; if (newtablename) values[Anum_pg_trigger_tgnewtable - 1] = DirectFunctionCall1(namein, CStringGetDatum(newtablename)); else nulls[Anum_pg_trigger_tgnewtable - 1] = true; /* * Insert or replace tuple in pg_trigger. */ if (!trigger_exists) { tuple = heap_form_tuple(tgrel->rd_att, values, nulls); CatalogTupleInsert(tgrel, tuple); } else { HeapTuple newtup; newtup = heap_form_tuple(tgrel->rd_att, values, nulls); CatalogTupleUpdate(tgrel, &tuple->t_self, newtup); heap_freetuple(newtup); } heap_freetuple(tuple); /* free either original or new tuple */ table_close(tgrel, RowExclusiveLock); pfree(DatumGetPointer(values[Anum_pg_trigger_tgname - 1])); pfree(DatumGetPointer(values[Anum_pg_trigger_tgargs - 1])); pfree(DatumGetPointer(values[Anum_pg_trigger_tgattr - 1])); if (oldtablename) pfree(DatumGetPointer(values[Anum_pg_trigger_tgoldtable - 1])); if (newtablename) pfree(DatumGetPointer(values[Anum_pg_trigger_tgnewtable - 1])); /* * Update relation's pg_class entry; if necessary; and if not, send an SI * message to make other backends (and this one) rebuild relcache entries. */ pgrel = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(RelationGetRelid(rel))); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", RelationGetRelid(rel)); if (!((Form_pg_class) GETSTRUCT(tuple))->relhastriggers) { ((Form_pg_class) GETSTRUCT(tuple))->relhastriggers = true; CatalogTupleUpdate(pgrel, &tuple->t_self, tuple); CommandCounterIncrement(); } else CacheInvalidateRelcacheByTuple(tuple); heap_freetuple(tuple); table_close(pgrel, RowExclusiveLock); /* * If we're replacing a trigger, flush all the old dependencies before * recording new ones. */ if (trigger_exists) deleteDependencyRecordsFor(TriggerRelationId, trigoid, true); /* * Record dependencies for trigger. Always place a normal dependency on * the function. */ myself.classId = TriggerRelationId; myself.objectId = trigoid; myself.objectSubId = 0; referenced.classId = ProcedureRelationId; referenced.objectId = funcoid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL); if (isInternal && OidIsValid(constraintOid)) { /* * Internally-generated trigger for a constraint, so make it an * internal dependency of the constraint. We can skip depending on * the relation(s), as there'll be an indirect dependency via the * constraint. */ referenced.classId = ConstraintRelationId; referenced.objectId = constraintOid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL); } else { /* * User CREATE TRIGGER, so place dependencies. We make trigger be * auto-dropped if its relation is dropped or if the FK relation is * dropped. (Auto drop is compatible with our pre-7.3 behavior.) */ referenced.classId = RelationRelationId; referenced.objectId = RelationGetRelid(rel); referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO); if (OidIsValid(constrrelid)) { referenced.classId = RelationRelationId; referenced.objectId = constrrelid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO); } /* Not possible to have an index dependency in this case */ Assert(!OidIsValid(indexOid)); /* * If it's a user-specified constraint trigger, make the constraint * internally dependent on the trigger instead of vice versa. */ if (OidIsValid(constraintOid)) { referenced.classId = ConstraintRelationId; referenced.objectId = constraintOid; referenced.objectSubId = 0; recordDependencyOn(&referenced, &myself, DEPENDENCY_INTERNAL); } /* * If it's a partition trigger, create the partition dependencies. */ if (OidIsValid(parentTriggerOid)) { ObjectAddressSet(referenced, TriggerRelationId, parentTriggerOid); recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_PRI); ObjectAddressSet(referenced, RelationRelationId, RelationGetRelid(rel)); recordDependencyOn(&myself, &referenced, DEPENDENCY_PARTITION_SEC); } } /* If column-specific trigger, add normal dependencies on columns */ if (columns != NULL) { int i; referenced.classId = RelationRelationId; referenced.objectId = RelationGetRelid(rel); for (i = 0; i < ncolumns; i++) { referenced.objectSubId = columns[i]; recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL); } } /* * If it has a WHEN clause, add dependencies on objects mentioned in the * expression (eg, functions, as well as any columns used). */ if (whenRtable != NIL) recordDependencyOnExpr(&myself, whenClause, whenRtable, DEPENDENCY_NORMAL); /* Post creation hook for new trigger */ InvokeObjectPostCreateHookArg(TriggerRelationId, trigoid, 0, isInternal); /* * Lastly, create the trigger on child relations, if needed. */ if (partition_recurse) { PartitionDesc partdesc = RelationGetPartitionDesc(rel, true); int i; MemoryContext oldcxt, perChildCxt; perChildCxt = AllocSetContextCreate(CurrentMemoryContext, "part trig clone", ALLOCSET_SMALL_SIZES); /* * We don't currently expect to be called with a valid indexOid. If * that ever changes then we'll need to write code here to find the * corresponding child index. */ Assert(!OidIsValid(indexOid)); oldcxt = MemoryContextSwitchTo(perChildCxt); /* Iterate to create the trigger on each existing partition */ for (i = 0; i < partdesc->nparts; i++) { CreateTrigStmt *childStmt; Relation childTbl; Node *qual; childTbl = table_open(partdesc->oids[i], ShareRowExclusiveLock); /* * Initialize our fabricated parse node by copying the original * one, then resetting fields that we pass separately. */ childStmt = (CreateTrigStmt *) copyObject(stmt); childStmt->funcname = NIL; childStmt->whenClause = NULL; /* If there is a WHEN clause, create a modified copy of it */ qual = copyObject(whenClause); qual = (Node *) map_partition_varattnos((List *) qual, PRS2_OLD_VARNO, childTbl, rel); qual = (Node *) map_partition_varattnos((List *) qual, PRS2_NEW_VARNO, childTbl, rel); CreateTriggerFiringOn(childStmt, queryString, partdesc->oids[i], refRelOid, InvalidOid, InvalidOid, funcoid, trigoid, qual, isInternal, true, trigger_fires_when); table_close(childTbl, NoLock); MemoryContextReset(perChildCxt); } MemoryContextSwitchTo(oldcxt); MemoryContextDelete(perChildCxt); } /* Keep lock on target rel until end of xact */ table_close(rel, NoLock); return myself; } /* * TriggerSetParentTrigger * Set a partition's trigger as child of its parent trigger, * or remove the linkage if parentTrigId is InvalidOid. * * This updates the constraint's pg_trigger row to show it as inherited, and * adds PARTITION dependencies to prevent the trigger from being deleted * on its own. Alternatively, reverse that. */ void TriggerSetParentTrigger(Relation trigRel, Oid childTrigId, Oid parentTrigId, Oid childTableId) { SysScanDesc tgscan; ScanKeyData skey[1]; Form_pg_trigger trigForm; HeapTuple tuple, newtup; ObjectAddress depender; ObjectAddress referenced; /* * Find the trigger to delete. */ ScanKeyInit(&skey[0], Anum_pg_trigger_oid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(childTrigId)); tgscan = systable_beginscan(trigRel, TriggerOidIndexId, true, NULL, 1, skey); tuple = systable_getnext(tgscan); if (!HeapTupleIsValid(tuple)) elog(ERROR, "could not find tuple for trigger %u", childTrigId); newtup = heap_copytuple(tuple); trigForm = (Form_pg_trigger) GETSTRUCT(newtup); if (OidIsValid(parentTrigId)) { /* don't allow setting parent for a constraint that already has one */ if (OidIsValid(trigForm->tgparentid)) elog(ERROR, "trigger %u already has a parent trigger", childTrigId); trigForm->tgparentid = parentTrigId; CatalogTupleUpdate(trigRel, &tuple->t_self, newtup); ObjectAddressSet(depender, TriggerRelationId, childTrigId); ObjectAddressSet(referenced, TriggerRelationId, parentTrigId); recordDependencyOn(&depender, &referenced, DEPENDENCY_PARTITION_PRI); ObjectAddressSet(referenced, RelationRelationId, childTableId); recordDependencyOn(&depender, &referenced, DEPENDENCY_PARTITION_SEC); } else { trigForm->tgparentid = InvalidOid; CatalogTupleUpdate(trigRel, &tuple->t_self, newtup); deleteDependencyRecordsForClass(TriggerRelationId, childTrigId, TriggerRelationId, DEPENDENCY_PARTITION_PRI); deleteDependencyRecordsForClass(TriggerRelationId, childTrigId, RelationRelationId, DEPENDENCY_PARTITION_SEC); } heap_freetuple(newtup); systable_endscan(tgscan); } /* * Guts of trigger deletion. */ void RemoveTriggerById(Oid trigOid) { Relation tgrel; SysScanDesc tgscan; ScanKeyData skey[1]; HeapTuple tup; Oid relid; Relation rel; tgrel = table_open(TriggerRelationId, RowExclusiveLock); /* * Find the trigger to delete. */ ScanKeyInit(&skey[0], Anum_pg_trigger_oid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(trigOid)); tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true, NULL, 1, skey); tup = systable_getnext(tgscan); if (!HeapTupleIsValid(tup)) elog(ERROR, "could not find tuple for trigger %u", trigOid); /* * Open and exclusive-lock the relation the trigger belongs to. */ relid = ((Form_pg_trigger) GETSTRUCT(tup))->tgrelid; rel = table_open(relid, AccessExclusiveLock); if (rel->rd_rel->relkind != RELKIND_RELATION && rel->rd_rel->relkind != RELKIND_VIEW && rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE && rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("relation \"%s\" cannot have triggers", RelationGetRelationName(rel)), errdetail_relkind_not_supported(rel->rd_rel->relkind))); if (!allowSystemTableMods && IsSystemRelation(rel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(rel)))); /* * Delete the pg_trigger tuple. */ CatalogTupleDelete(tgrel, &tup->t_self); systable_endscan(tgscan); table_close(tgrel, RowExclusiveLock); /* * We do not bother to try to determine whether any other triggers remain, * which would be needed in order to decide whether it's safe to clear the * relation's relhastriggers. (In any case, there might be a concurrent * process adding new triggers.) Instead, just force a relcache inval to * make other backends (and this one too!) rebuild their relcache entries. * There's no great harm in leaving relhastriggers true even if there are * no triggers left. */ CacheInvalidateRelcache(rel); /* Keep lock on trigger's rel until end of xact */ table_close(rel, NoLock); } /* * get_trigger_oid - Look up a trigger by name to find its OID. * * If missing_ok is false, throw an error if trigger not found. If * true, just return InvalidOid. */ Oid get_trigger_oid(Oid relid, const char *trigname, bool missing_ok) { Relation tgrel; ScanKeyData skey[2]; SysScanDesc tgscan; HeapTuple tup; Oid oid; /* * Find the trigger, verify permissions, set up object address */ tgrel = table_open(TriggerRelationId, AccessShareLock); ScanKeyInit(&skey[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid)); ScanKeyInit(&skey[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(trigname)); tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, skey); tup = systable_getnext(tgscan); if (!HeapTupleIsValid(tup)) { if (!missing_ok) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("trigger \"%s\" for table \"%s\" does not exist", trigname, get_rel_name(relid)))); oid = InvalidOid; } else { oid = ((Form_pg_trigger) GETSTRUCT(tup))->oid; } systable_endscan(tgscan); table_close(tgrel, AccessShareLock); return oid; } /* * Perform permissions and integrity checks before acquiring a relation lock. */ static void RangeVarCallbackForRenameTrigger(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg) { HeapTuple tuple; Form_pg_class form; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped */ form = (Form_pg_class) GETSTRUCT(tuple); /* only tables and views can have triggers */ if (form->relkind != RELKIND_RELATION && form->relkind != RELKIND_VIEW && form->relkind != RELKIND_FOREIGN_TABLE && form->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("relation \"%s\" cannot have triggers", rv->relname), errdetail_relkind_not_supported(form->relkind))); /* you must own the table to rename one of its triggers */ if (!object_ownercheck(RelationRelationId, relid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)), rv->relname); if (!allowSystemTableMods && IsSystemClass(relid, form)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", rv->relname))); ReleaseSysCache(tuple); } /* * renametrig - changes the name of a trigger on a relation * * trigger name is changed in trigger catalog. * No record of the previous name is kept. * * get proper relrelation from relation catalog (if not arg) * scan trigger catalog * for name conflict (within rel) * for original trigger (if not arg) * modify tgname in trigger tuple * update row in catalog */ ObjectAddress renametrig(RenameStmt *stmt) { Oid tgoid; Relation targetrel; Relation tgrel; HeapTuple tuple; SysScanDesc tgscan; ScanKeyData key[2]; Oid relid; ObjectAddress address; /* * Look up name, check permissions, and acquire lock (which we will NOT * release until end of transaction). */ relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, 0, RangeVarCallbackForRenameTrigger, NULL); /* Have lock already, so just need to build relcache entry. */ targetrel = relation_open(relid, NoLock); /* * On partitioned tables, this operation recurses to partitions. Lock all * tables upfront. */ if (targetrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) (void) find_all_inheritors(relid, AccessExclusiveLock, NULL); tgrel = table_open(TriggerRelationId, RowExclusiveLock); /* * Search for the trigger to modify. */ ScanKeyInit(&key[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid)); ScanKeyInit(&key[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, PointerGetDatum(stmt->subname)); tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, key); if (HeapTupleIsValid(tuple = systable_getnext(tgscan))) { Form_pg_trigger trigform; trigform = (Form_pg_trigger) GETSTRUCT(tuple); tgoid = trigform->oid; /* * If the trigger descends from a trigger on a parent partitioned * table, reject the rename. We don't allow a trigger in a partition * to differ in name from that of its parent: that would lead to an * inconsistency that pg_dump would not reproduce. */ if (OidIsValid(trigform->tgparentid)) ereport(ERROR, errmsg("cannot rename trigger \"%s\" on table \"%s\"", stmt->subname, RelationGetRelationName(targetrel)), errhint("Rename the trigger on the partitioned table \"%s\" instead.", get_rel_name(get_partition_parent(relid, false)))); /* Rename the trigger on this relation ... */ renametrig_internal(tgrel, targetrel, tuple, stmt->newname, stmt->subname); /* ... and if it is partitioned, recurse to its partitions */ if (targetrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { PartitionDesc partdesc = RelationGetPartitionDesc(targetrel, true); for (int i = 0; i < partdesc->nparts; i++) { Oid partitionId = partdesc->oids[i]; renametrig_partition(tgrel, partitionId, trigform->oid, stmt->newname, stmt->subname); } } } else { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("trigger \"%s\" for table \"%s\" does not exist", stmt->subname, RelationGetRelationName(targetrel)))); } ObjectAddressSet(address, TriggerRelationId, tgoid); systable_endscan(tgscan); table_close(tgrel, RowExclusiveLock); /* * Close rel, but keep exclusive lock! */ relation_close(targetrel, NoLock); return address; } /* * Subroutine for renametrig -- perform the actual work of renaming one * trigger on one table. * * If the trigger has a name different from the expected one, raise a * NOTICE about it. */ static void renametrig_internal(Relation tgrel, Relation targetrel, HeapTuple trigtup, const char *newname, const char *expected_name) { HeapTuple tuple; Form_pg_trigger tgform; ScanKeyData key[2]; SysScanDesc tgscan; /* If the trigger already has the new name, nothing to do. */ tgform = (Form_pg_trigger) GETSTRUCT(trigtup); if (strcmp(NameStr(tgform->tgname), newname) == 0) return; /* * Before actually trying the rename, search for triggers with the same * name. The update would fail with an ugly message in that case, and it * is better to throw a nicer error. */ ScanKeyInit(&key[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(targetrel))); ScanKeyInit(&key[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, PointerGetDatum(newname)); tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, key); if (HeapTupleIsValid(tuple = systable_getnext(tgscan))) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("trigger \"%s\" for relation \"%s\" already exists", newname, RelationGetRelationName(targetrel)))); systable_endscan(tgscan); /* * The target name is free; update the existing pg_trigger tuple with it. */ tuple = heap_copytuple(trigtup); /* need a modifiable copy */ tgform = (Form_pg_trigger) GETSTRUCT(tuple); /* * If the trigger has a name different from what we expected, let the user * know. (We can proceed anyway, since we must have reached here following * a tgparentid link.) */ if (strcmp(NameStr(tgform->tgname), expected_name) != 0) ereport(NOTICE, errmsg("renamed trigger \"%s\" on relation \"%s\"", NameStr(tgform->tgname), RelationGetRelationName(targetrel))); namestrcpy(&tgform->tgname, newname); CatalogTupleUpdate(tgrel, &tuple->t_self, tuple); InvokeObjectPostAlterHook(TriggerRelationId, tgform->oid, 0); /* * Invalidate relation's relcache entry so that other backends (and this * one too!) are sent SI message to make them rebuild relcache entries. * (Ideally this should happen automatically...) */ CacheInvalidateRelcache(targetrel); } /* * Subroutine for renametrig -- Helper for recursing to partitions when * renaming triggers on a partitioned table. */ static void renametrig_partition(Relation tgrel, Oid partitionId, Oid parentTriggerOid, const char *newname, const char *expected_name) { SysScanDesc tgscan; ScanKeyData key; HeapTuple tuple; /* * Given a relation and the OID of a trigger on parent relation, find the * corresponding trigger in the child and rename that trigger to the given * name. */ ScanKeyInit(&key, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(partitionId)); tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 1, &key); while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) { Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tuple); Relation partitionRel; if (tgform->tgparentid != parentTriggerOid) continue; /* not our trigger */ partitionRel = table_open(partitionId, NoLock); /* Rename the trigger on this partition */ renametrig_internal(tgrel, partitionRel, tuple, newname, expected_name); /* And if this relation is partitioned, recurse to its partitions */ if (partitionRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { PartitionDesc partdesc = RelationGetPartitionDesc(partitionRel, true); for (int i = 0; i < partdesc->nparts; i++) { Oid partoid = partdesc->oids[i]; renametrig_partition(tgrel, partoid, tgform->oid, newname, NameStr(tgform->tgname)); } } table_close(partitionRel, NoLock); /* There should be at most one matching tuple */ break; } systable_endscan(tgscan); } /* * EnableDisableTrigger() * * Called by ALTER TABLE ENABLE/DISABLE [ REPLICA | ALWAYS ] TRIGGER * to change 'tgenabled' field for the specified trigger(s) * * rel: relation to process (caller must hold suitable lock on it) * tgname: name of trigger to process, or NULL to scan all triggers * tgparent: if not zero, process only triggers with this tgparentid * fires_when: new value for tgenabled field. In addition to generic * enablement/disablement, this also defines when the trigger * should be fired in session replication roles. * skip_system: if true, skip "system" triggers (constraint triggers) * recurse: if true, recurse to partitions * * Caller should have checked permissions for the table; here we also * enforce that superuser privilege is required to alter the state of * system triggers */ void EnableDisableTrigger(Relation rel, const char *tgname, Oid tgparent, char fires_when, bool skip_system, bool recurse, LOCKMODE lockmode) { Relation tgrel; int nkeys; ScanKeyData keys[2]; SysScanDesc tgscan; HeapTuple tuple; bool found; bool changed; /* Scan the relevant entries in pg_triggers */ tgrel = table_open(TriggerRelationId, RowExclusiveLock); ScanKeyInit(&keys[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); if (tgname) { ScanKeyInit(&keys[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(tgname)); nkeys = 2; } else nkeys = 1; tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, nkeys, keys); found = changed = false; while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) { Form_pg_trigger oldtrig = (Form_pg_trigger) GETSTRUCT(tuple); if (OidIsValid(tgparent) && tgparent != oldtrig->tgparentid) continue; if (oldtrig->tgisinternal) { /* system trigger ... ok to process? */ if (skip_system) continue; if (!superuser()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system trigger", NameStr(oldtrig->tgname)))); } found = true; if (oldtrig->tgenabled != fires_when) { /* need to change this one ... make a copy to scribble on */ HeapTuple newtup = heap_copytuple(tuple); Form_pg_trigger newtrig = (Form_pg_trigger) GETSTRUCT(newtup); newtrig->tgenabled = fires_when; CatalogTupleUpdate(tgrel, &newtup->t_self, newtup); heap_freetuple(newtup); changed = true; } /* * When altering FOR EACH ROW triggers on a partitioned table, do the * same on the partitions as well, unless ONLY is specified. * * Note that we recurse even if we didn't change the trigger above, * because the partitions' copy of the trigger may have a different * value of tgenabled than the parent's trigger and thus might need to * be changed. */ if (recurse && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && (TRIGGER_FOR_ROW(oldtrig->tgtype))) { PartitionDesc partdesc = RelationGetPartitionDesc(rel, true); int i; for (i = 0; i < partdesc->nparts; i++) { Relation part; part = relation_open(partdesc->oids[i], lockmode); /* Match on child triggers' tgparentid, not their name */ EnableDisableTrigger(part, NULL, oldtrig->oid, fires_when, skip_system, recurse, lockmode); table_close(part, NoLock); /* keep lock till commit */ } } InvokeObjectPostAlterHook(TriggerRelationId, oldtrig->oid, 0); } systable_endscan(tgscan); table_close(tgrel, RowExclusiveLock); if (tgname && !found) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("trigger \"%s\" for table \"%s\" does not exist", tgname, RelationGetRelationName(rel)))); /* * If we changed anything, broadcast a SI inval message to force each * backend (including our own!) to rebuild relation's relcache entry. * Otherwise they will fail to apply the change promptly. */ if (changed) CacheInvalidateRelcache(rel); } /* * Build trigger data to attach to the given relcache entry. * * Note that trigger data attached to a relcache entry must be stored in * CacheMemoryContext to ensure it survives as long as the relcache entry. * But we should be running in a less long-lived working context. To avoid * leaking cache memory if this routine fails partway through, we build a * temporary TriggerDesc in working memory and then copy the completed * structure into cache memory. */ void RelationBuildTriggers(Relation relation) { TriggerDesc *trigdesc; int numtrigs; int maxtrigs; Trigger *triggers; Relation tgrel; ScanKeyData skey; SysScanDesc tgscan; HeapTuple htup; MemoryContext oldContext; int i; /* * Allocate a working array to hold the triggers (the array is extended if * necessary) */ maxtrigs = 16; triggers = (Trigger *) palloc(maxtrigs * sizeof(Trigger)); numtrigs = 0; /* * Note: since we scan the triggers using TriggerRelidNameIndexId, we will * be reading the triggers in name order, except possibly during * emergency-recovery operations (ie, IgnoreSystemIndexes). This in turn * ensures that triggers will be fired in name order. */ ScanKeyInit(&skey, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation))); tgrel = table_open(TriggerRelationId, AccessShareLock); tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 1, &skey); while (HeapTupleIsValid(htup = systable_getnext(tgscan))) { Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup); Trigger *build; Datum datum; bool isnull; if (numtrigs >= maxtrigs) { maxtrigs *= 2; triggers = (Trigger *) repalloc(triggers, maxtrigs * sizeof(Trigger)); } build = &(triggers[numtrigs]); build->tgoid = pg_trigger->oid; build->tgname = DatumGetCString(DirectFunctionCall1(nameout, NameGetDatum(&pg_trigger->tgname))); build->tgfoid = pg_trigger->tgfoid; build->tgtype = pg_trigger->tgtype; build->tgenabled = pg_trigger->tgenabled; build->tgisinternal = pg_trigger->tgisinternal; build->tgisclone = OidIsValid(pg_trigger->tgparentid); build->tgconstrrelid = pg_trigger->tgconstrrelid; build->tgconstrindid = pg_trigger->tgconstrindid; build->tgconstraint = pg_trigger->tgconstraint; build->tgdeferrable = pg_trigger->tgdeferrable; build->tginitdeferred = pg_trigger->tginitdeferred; build->tgnargs = pg_trigger->tgnargs; /* tgattr is first var-width field, so OK to access directly */ build->tgnattr = pg_trigger->tgattr.dim1; if (build->tgnattr > 0) { build->tgattr = (int16 *) palloc(build->tgnattr * sizeof(int16)); memcpy(build->tgattr, &(pg_trigger->tgattr.values), build->tgnattr * sizeof(int16)); } else build->tgattr = NULL; if (build->tgnargs > 0) { bytea *val; char *p; val = DatumGetByteaPP(fastgetattr(htup, Anum_pg_trigger_tgargs, tgrel->rd_att, &isnull)); if (isnull) elog(ERROR, "tgargs is null in trigger for relation \"%s\"", RelationGetRelationName(relation)); p = (char *) VARDATA_ANY(val); build->tgargs = (char **) palloc(build->tgnargs * sizeof(char *)); for (i = 0; i < build->tgnargs; i++) { build->tgargs[i] = pstrdup(p); p += strlen(p) + 1; } } else build->tgargs = NULL; datum = fastgetattr(htup, Anum_pg_trigger_tgoldtable, tgrel->rd_att, &isnull); if (!isnull) build->tgoldtable = DatumGetCString(DirectFunctionCall1(nameout, datum)); else build->tgoldtable = NULL; datum = fastgetattr(htup, Anum_pg_trigger_tgnewtable, tgrel->rd_att, &isnull); if (!isnull) build->tgnewtable = DatumGetCString(DirectFunctionCall1(nameout, datum)); else build->tgnewtable = NULL; datum = fastgetattr(htup, Anum_pg_trigger_tgqual, tgrel->rd_att, &isnull); if (!isnull) build->tgqual = TextDatumGetCString(datum); else build->tgqual = NULL; numtrigs++; } systable_endscan(tgscan); table_close(tgrel, AccessShareLock); /* There might not be any triggers */ if (numtrigs == 0) { pfree(triggers); return; } /* Build trigdesc */ trigdesc = (TriggerDesc *) palloc0(sizeof(TriggerDesc)); trigdesc->triggers = triggers; trigdesc->numtriggers = numtrigs; for (i = 0; i < numtrigs; i++) SetTriggerFlags(trigdesc, &(triggers[i])); /* Copy completed trigdesc into cache storage */ oldContext = MemoryContextSwitchTo(CacheMemoryContext); relation->trigdesc = CopyTriggerDesc(trigdesc); MemoryContextSwitchTo(oldContext); /* Release working memory */ FreeTriggerDesc(trigdesc); } /* * Update the TriggerDesc's hint flags to include the specified trigger */ static void SetTriggerFlags(TriggerDesc *trigdesc, Trigger *trigger) { int16 tgtype = trigger->tgtype; trigdesc->trig_insert_before_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_INSERT); trigdesc->trig_insert_after_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_INSERT); trigdesc->trig_insert_instead_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_INSERT); trigdesc->trig_insert_before_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_INSERT); trigdesc->trig_insert_after_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_INSERT); trigdesc->trig_update_before_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_UPDATE); trigdesc->trig_update_after_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_UPDATE); trigdesc->trig_update_instead_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_UPDATE); trigdesc->trig_update_before_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_UPDATE); trigdesc->trig_update_after_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_UPDATE); trigdesc->trig_delete_before_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_DELETE); trigdesc->trig_delete_after_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_DELETE); trigdesc->trig_delete_instead_row |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_DELETE); trigdesc->trig_delete_before_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_DELETE); trigdesc->trig_delete_after_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_DELETE); /* there are no row-level truncate triggers */ trigdesc->trig_truncate_before_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_TRUNCATE); trigdesc->trig_truncate_after_statement |= TRIGGER_TYPE_MATCHES(tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_AFTER, TRIGGER_TYPE_TRUNCATE); trigdesc->trig_insert_new_table |= (TRIGGER_FOR_INSERT(tgtype) && TRIGGER_USES_TRANSITION_TABLE(trigger->tgnewtable)); trigdesc->trig_update_old_table |= (TRIGGER_FOR_UPDATE(tgtype) && TRIGGER_USES_TRANSITION_TABLE(trigger->tgoldtable)); trigdesc->trig_update_new_table |= (TRIGGER_FOR_UPDATE(tgtype) && TRIGGER_USES_TRANSITION_TABLE(trigger->tgnewtable)); trigdesc->trig_delete_old_table |= (TRIGGER_FOR_DELETE(tgtype) && TRIGGER_USES_TRANSITION_TABLE(trigger->tgoldtable)); } /* * Copy a TriggerDesc data structure. * * The copy is allocated in the current memory context. */ TriggerDesc * CopyTriggerDesc(TriggerDesc *trigdesc) { TriggerDesc *newdesc; Trigger *trigger; int i; if (trigdesc == NULL || trigdesc->numtriggers <= 0) return NULL; newdesc = (TriggerDesc *) palloc(sizeof(TriggerDesc)); memcpy(newdesc, trigdesc, sizeof(TriggerDesc)); trigger = (Trigger *) palloc(trigdesc->numtriggers * sizeof(Trigger)); memcpy(trigger, trigdesc->triggers, trigdesc->numtriggers * sizeof(Trigger)); newdesc->triggers = trigger; for (i = 0; i < trigdesc->numtriggers; i++) { trigger->tgname = pstrdup(trigger->tgname); if (trigger->tgnattr > 0) { int16 *newattr; newattr = (int16 *) palloc(trigger->tgnattr * sizeof(int16)); memcpy(newattr, trigger->tgattr, trigger->tgnattr * sizeof(int16)); trigger->tgattr = newattr; } if (trigger->tgnargs > 0) { char **newargs; int16 j; newargs = (char **) palloc(trigger->tgnargs * sizeof(char *)); for (j = 0; j < trigger->tgnargs; j++) newargs[j] = pstrdup(trigger->tgargs[j]); trigger->tgargs = newargs; } if (trigger->tgqual) trigger->tgqual = pstrdup(trigger->tgqual); if (trigger->tgoldtable) trigger->tgoldtable = pstrdup(trigger->tgoldtable); if (trigger->tgnewtable) trigger->tgnewtable = pstrdup(trigger->tgnewtable); trigger++; } return newdesc; } /* * Free a TriggerDesc data structure. */ void FreeTriggerDesc(TriggerDesc *trigdesc) { Trigger *trigger; int i; if (trigdesc == NULL) return; trigger = trigdesc->triggers; for (i = 0; i < trigdesc->numtriggers; i++) { pfree(trigger->tgname); if (trigger->tgnattr > 0) pfree(trigger->tgattr); if (trigger->tgnargs > 0) { while (--(trigger->tgnargs) >= 0) pfree(trigger->tgargs[trigger->tgnargs]); pfree(trigger->tgargs); } if (trigger->tgqual) pfree(trigger->tgqual); if (trigger->tgoldtable) pfree(trigger->tgoldtable); if (trigger->tgnewtable) pfree(trigger->tgnewtable); trigger++; } pfree(trigdesc->triggers); pfree(trigdesc); } /* * Compare two TriggerDesc structures for logical equality. */ #ifdef NOT_USED bool equalTriggerDescs(TriggerDesc *trigdesc1, TriggerDesc *trigdesc2) { int i, j; /* * We need not examine the hint flags, just the trigger array itself; if * we have the same triggers with the same types, the flags should match. * * As of 7.3 we assume trigger set ordering is significant in the * comparison; so we just compare corresponding slots of the two sets. * * Note: comparing the stringToNode forms of the WHEN clauses means that * parse column locations will affect the result. This is okay as long as * this function is only used for detecting exact equality, as for example * in checking for staleness of a cache entry. */ if (trigdesc1 != NULL) { if (trigdesc2 == NULL) return false; if (trigdesc1->numtriggers != trigdesc2->numtriggers) return false; for (i = 0; i < trigdesc1->numtriggers; i++) { Trigger *trig1 = trigdesc1->triggers + i; Trigger *trig2 = trigdesc2->triggers + i; if (trig1->tgoid != trig2->tgoid) return false; if (strcmp(trig1->tgname, trig2->tgname) != 0) return false; if (trig1->tgfoid != trig2->tgfoid) return false; if (trig1->tgtype != trig2->tgtype) return false; if (trig1->tgenabled != trig2->tgenabled) return false; if (trig1->tgisinternal != trig2->tgisinternal) return false; if (trig1->tgisclone != trig2->tgisclone) return false; if (trig1->tgconstrrelid != trig2->tgconstrrelid) return false; if (trig1->tgconstrindid != trig2->tgconstrindid) return false; if (trig1->tgconstraint != trig2->tgconstraint) return false; if (trig1->tgdeferrable != trig2->tgdeferrable) return false; if (trig1->tginitdeferred != trig2->tginitdeferred) return false; if (trig1->tgnargs != trig2->tgnargs) return false; if (trig1->tgnattr != trig2->tgnattr) return false; if (trig1->tgnattr > 0 && memcmp(trig1->tgattr, trig2->tgattr, trig1->tgnattr * sizeof(int16)) != 0) return false; for (j = 0; j < trig1->tgnargs; j++) if (strcmp(trig1->tgargs[j], trig2->tgargs[j]) != 0) return false; if (trig1->tgqual == NULL && trig2->tgqual == NULL) /* ok */ ; else if (trig1->tgqual == NULL || trig2->tgqual == NULL) return false; else if (strcmp(trig1->tgqual, trig2->tgqual) != 0) return false; if (trig1->tgoldtable == NULL && trig2->tgoldtable == NULL) /* ok */ ; else if (trig1->tgoldtable == NULL || trig2->tgoldtable == NULL) return false; else if (strcmp(trig1->tgoldtable, trig2->tgoldtable) != 0) return false; if (trig1->tgnewtable == NULL && trig2->tgnewtable == NULL) /* ok */ ; else if (trig1->tgnewtable == NULL || trig2->tgnewtable == NULL) return false; else if (strcmp(trig1->tgnewtable, trig2->tgnewtable) != 0) return false; } } else if (trigdesc2 != NULL) return false; return true; } #endif /* NOT_USED */ /* * Check if there is a row-level trigger with transition tables that prevents * a table from becoming an inheritance child or partition. Return the name * of the first such incompatible trigger, or NULL if there is none. */ const char * FindTriggerIncompatibleWithInheritance(TriggerDesc *trigdesc) { if (trigdesc != NULL) { int i; for (i = 0; i < trigdesc->numtriggers; ++i) { Trigger *trigger = &trigdesc->triggers[i]; if (trigger->tgoldtable != NULL || trigger->tgnewtable != NULL) return trigger->tgname; } } return NULL; } /* * Call a trigger function. * * trigdata: trigger descriptor. * tgindx: trigger's index in finfo and instr arrays. * finfo: array of cached trigger function call information. * instr: optional array of EXPLAIN ANALYZE instrumentation state. * per_tuple_context: memory context to execute the function in. * * Returns the tuple (or NULL) as returned by the function. */ static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata, int tgindx, FmgrInfo *finfo, Instrumentation *instr, MemoryContext per_tuple_context) { LOCAL_FCINFO(fcinfo, 0); PgStat_FunctionCallUsage fcusage; Datum result; MemoryContext oldContext; /* * Protect against code paths that may fail to initialize transition table * info. */ Assert(((TRIGGER_FIRED_BY_INSERT(trigdata->tg_event) || TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event) || TRIGGER_FIRED_BY_DELETE(trigdata->tg_event)) && TRIGGER_FIRED_AFTER(trigdata->tg_event) && !(trigdata->tg_event & AFTER_TRIGGER_DEFERRABLE) && !(trigdata->tg_event & AFTER_TRIGGER_INITDEFERRED)) || (trigdata->tg_oldtable == NULL && trigdata->tg_newtable == NULL)); finfo += tgindx; /* * We cache fmgr lookup info, to avoid making the lookup again on each * call. */ if (finfo->fn_oid == InvalidOid) fmgr_info(trigdata->tg_trigger->tgfoid, finfo); Assert(finfo->fn_oid == trigdata->tg_trigger->tgfoid); /* * If doing EXPLAIN ANALYZE, start charging time to this trigger. */ if (instr) InstrStartNode(instr + tgindx); /* * Do the function evaluation in the per-tuple memory context, so that * leaked memory will be reclaimed once per tuple. Note in particular that * any new tuple created by the trigger function will live till the end of * the tuple cycle. */ oldContext = MemoryContextSwitchTo(per_tuple_context); /* * Call the function, passing no arguments but setting a context. */ InitFunctionCallInfoData(*fcinfo, finfo, 0, InvalidOid, (Node *) trigdata, NULL); pgstat_init_function_usage(fcinfo, &fcusage); MyTriggerDepth++; PG_TRY(); { result = FunctionCallInvoke(fcinfo); } PG_FINALLY(); { MyTriggerDepth--; } PG_END_TRY(); pgstat_end_function_usage(&fcusage, true); MemoryContextSwitchTo(oldContext); /* * Trigger protocol allows function to return a null pointer, but NOT to * set the isnull result flag. */ if (fcinfo->isnull) ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), errmsg("trigger function %u returned null value", fcinfo->flinfo->fn_oid))); /* * If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count * one "tuple returned" (really the number of firings). */ if (instr) InstrStopNode(instr + tgindx, 1); return (HeapTuple) DatumGetPointer(result); } void ExecBSInsertTriggers(EState *estate, ResultRelInfo *relinfo) { TriggerDesc *trigdesc; int i; TriggerData LocTriggerData = {0}; trigdesc = relinfo->ri_TrigDesc; if (trigdesc == NULL) return; if (!trigdesc->trig_insert_before_statement) return; /* no-op if we already fired BS triggers in this context */ if (before_stmt_triggers_fired(RelationGetRelid(relinfo->ri_RelationDesc), CMD_INSERT)) return; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple newtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_INSERT)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, NULL, NULL)) continue; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple) ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), errmsg("BEFORE STATEMENT trigger cannot return a value"))); } } void ExecASInsertTriggers(EState *estate, ResultRelInfo *relinfo, TransitionCaptureState *transition_capture) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if (trigdesc && trigdesc->trig_insert_after_statement) AfterTriggerSaveEvent(estate, relinfo, NULL, NULL, TRIGGER_EVENT_INSERT, false, NULL, NULL, NIL, NULL, transition_capture, false); } bool ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo, TupleTableSlot *slot) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; HeapTuple newtuple = NULL; bool should_free; TriggerData LocTriggerData = {0}; int i; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple oldtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_INSERT)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, NULL, slot)) continue; if (!newtuple) newtuple = ExecFetchSlotHeapTuple(slot, true, &should_free); LocTriggerData.tg_trigslot = slot; LocTriggerData.tg_trigtuple = oldtuple = newtuple; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple == NULL) { if (should_free) heap_freetuple(oldtuple); return false; /* "do nothing" */ } else if (newtuple != oldtuple) { ExecForceStoreHeapTuple(newtuple, slot, false); /* * After a tuple in a partition goes through a trigger, the user * could have changed the partition key enough that the tuple no * longer fits the partition. Verify that. */ if (trigger->tgisclone && !ExecPartitionCheck(relinfo, slot, estate, false)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("moving row to another partition during a BEFORE FOR EACH ROW trigger is not supported"), errdetail("Before executing trigger \"%s\", the row was to be in partition \"%s.%s\".", trigger->tgname, get_namespace_name(RelationGetNamespace(relinfo->ri_RelationDesc)), RelationGetRelationName(relinfo->ri_RelationDesc)))); if (should_free) heap_freetuple(oldtuple); /* signal tuple should be re-fetched if used */ newtuple = NULL; } } return true; } void ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo, TupleTableSlot *slot, List *recheckIndexes, TransitionCaptureState *transition_capture) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if ((trigdesc && trigdesc->trig_insert_after_row) || (transition_capture && transition_capture->tcs_insert_new_table)) AfterTriggerSaveEvent(estate, relinfo, NULL, NULL, TRIGGER_EVENT_INSERT, true, NULL, slot, recheckIndexes, NULL, transition_capture, false); } bool ExecIRInsertTriggers(EState *estate, ResultRelInfo *relinfo, TupleTableSlot *slot) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; HeapTuple newtuple = NULL; bool should_free; TriggerData LocTriggerData = {0}; int i; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW | TRIGGER_EVENT_INSTEAD; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple oldtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_INSERT)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, NULL, slot)) continue; if (!newtuple) newtuple = ExecFetchSlotHeapTuple(slot, true, &should_free); LocTriggerData.tg_trigslot = slot; LocTriggerData.tg_trigtuple = oldtuple = newtuple; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple == NULL) { if (should_free) heap_freetuple(oldtuple); return false; /* "do nothing" */ } else if (newtuple != oldtuple) { ExecForceStoreHeapTuple(newtuple, slot, false); if (should_free) heap_freetuple(oldtuple); /* signal tuple should be re-fetched if used */ newtuple = NULL; } } return true; } void ExecBSDeleteTriggers(EState *estate, ResultRelInfo *relinfo) { TriggerDesc *trigdesc; int i; TriggerData LocTriggerData = {0}; trigdesc = relinfo->ri_TrigDesc; if (trigdesc == NULL) return; if (!trigdesc->trig_delete_before_statement) return; /* no-op if we already fired BS triggers in this context */ if (before_stmt_triggers_fired(RelationGetRelid(relinfo->ri_RelationDesc), CMD_DELETE)) return; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_DELETE | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple newtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_DELETE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, NULL, NULL)) continue; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple) ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), errmsg("BEFORE STATEMENT trigger cannot return a value"))); } } void ExecASDeleteTriggers(EState *estate, ResultRelInfo *relinfo, TransitionCaptureState *transition_capture) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if (trigdesc && trigdesc->trig_delete_after_statement) AfterTriggerSaveEvent(estate, relinfo, NULL, NULL, TRIGGER_EVENT_DELETE, false, NULL, NULL, NIL, NULL, transition_capture, false); } /* * Execute BEFORE ROW DELETE triggers. * * True indicates caller can proceed with the delete. False indicates caller * need to suppress the delete and additionally if requested, we need to pass * back the concurrently updated tuple if any. */ bool ExecBRDeleteTriggers(EState *estate, EPQState *epqstate, ResultRelInfo *relinfo, ItemPointer tupleid, HeapTuple fdw_trigtuple, TupleTableSlot **epqslot, TM_Result *tmresult, TM_FailureData *tmfd) { TupleTableSlot *slot = ExecGetTriggerOldSlot(estate, relinfo); TriggerDesc *trigdesc = relinfo->ri_TrigDesc; bool result = true; TriggerData LocTriggerData = {0}; HeapTuple trigtuple; bool should_free = false; int i; Assert(HeapTupleIsValid(fdw_trigtuple) ^ ItemPointerIsValid(tupleid)); if (fdw_trigtuple == NULL) { TupleTableSlot *epqslot_candidate = NULL; if (!GetTupleForTrigger(estate, epqstate, relinfo, tupleid, LockTupleExclusive, slot, &epqslot_candidate, tmresult, tmfd)) return false; /* * If the tuple was concurrently updated and the caller of this * function requested for the updated tuple, skip the trigger * execution. */ if (epqslot_candidate != NULL && epqslot != NULL) { *epqslot = epqslot_candidate; return false; } trigtuple = ExecFetchSlotHeapTuple(slot, true, &should_free); } else { trigtuple = fdw_trigtuple; ExecForceStoreHeapTuple(trigtuple, slot, false); } LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_DELETE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; for (i = 0; i < trigdesc->numtriggers; i++) { HeapTuple newtuple; Trigger *trigger = &trigdesc->triggers[i]; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_DELETE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, slot, NULL)) continue; LocTriggerData.tg_trigslot = slot; LocTriggerData.tg_trigtuple = trigtuple; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple == NULL) { result = false; /* tell caller to suppress delete */ break; } if (newtuple != trigtuple) heap_freetuple(newtuple); } if (should_free) heap_freetuple(trigtuple); return result; } /* * Note: is_crosspart_update must be true if the DELETE is being performed * as part of a cross-partition update. */ void ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo, ItemPointer tupleid, HeapTuple fdw_trigtuple, TransitionCaptureState *transition_capture, bool is_crosspart_update) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if ((trigdesc && trigdesc->trig_delete_after_row) || (transition_capture && transition_capture->tcs_delete_old_table)) { TupleTableSlot *slot = ExecGetTriggerOldSlot(estate, relinfo); Assert(HeapTupleIsValid(fdw_trigtuple) ^ ItemPointerIsValid(tupleid)); if (fdw_trigtuple == NULL) GetTupleForTrigger(estate, NULL, relinfo, tupleid, LockTupleExclusive, slot, NULL, NULL, NULL); else ExecForceStoreHeapTuple(fdw_trigtuple, slot, false); AfterTriggerSaveEvent(estate, relinfo, NULL, NULL, TRIGGER_EVENT_DELETE, true, slot, NULL, NIL, NULL, transition_capture, is_crosspart_update); } } bool ExecIRDeleteTriggers(EState *estate, ResultRelInfo *relinfo, HeapTuple trigtuple) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; TupleTableSlot *slot = ExecGetTriggerOldSlot(estate, relinfo); TriggerData LocTriggerData = {0}; int i; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_DELETE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_INSTEAD; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; ExecForceStoreHeapTuple(trigtuple, slot, false); for (i = 0; i < trigdesc->numtriggers; i++) { HeapTuple rettuple; Trigger *trigger = &trigdesc->triggers[i]; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_DELETE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, slot, NULL)) continue; LocTriggerData.tg_trigslot = slot; LocTriggerData.tg_trigtuple = trigtuple; LocTriggerData.tg_trigger = trigger; rettuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (rettuple == NULL) return false; /* Delete was suppressed */ if (rettuple != trigtuple) heap_freetuple(rettuple); } return true; } void ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo) { TriggerDesc *trigdesc; int i; TriggerData LocTriggerData = {0}; Bitmapset *updatedCols; trigdesc = relinfo->ri_TrigDesc; if (trigdesc == NULL) return; if (!trigdesc->trig_update_before_statement) return; /* no-op if we already fired BS triggers in this context */ if (before_stmt_triggers_fired(RelationGetRelid(relinfo->ri_RelationDesc), CMD_UPDATE)) return; /* statement-level triggers operate on the parent table */ Assert(relinfo->ri_RootResultRelInfo == NULL); updatedCols = ExecGetAllUpdatedCols(relinfo, estate); LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; LocTriggerData.tg_updatedcols = updatedCols; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple newtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_UPDATE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, updatedCols, NULL, NULL)) continue; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple) ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), errmsg("BEFORE STATEMENT trigger cannot return a value"))); } } void ExecASUpdateTriggers(EState *estate, ResultRelInfo *relinfo, TransitionCaptureState *transition_capture) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; /* statement-level triggers operate on the parent table */ Assert(relinfo->ri_RootResultRelInfo == NULL); if (trigdesc && trigdesc->trig_update_after_statement) AfterTriggerSaveEvent(estate, relinfo, NULL, NULL, TRIGGER_EVENT_UPDATE, false, NULL, NULL, NIL, ExecGetAllUpdatedCols(relinfo, estate), transition_capture, false); } bool ExecBRUpdateTriggers(EState *estate, EPQState *epqstate, ResultRelInfo *relinfo, ItemPointer tupleid, HeapTuple fdw_trigtuple, TupleTableSlot *newslot, TM_Result *tmresult, TM_FailureData *tmfd) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; TupleTableSlot *oldslot = ExecGetTriggerOldSlot(estate, relinfo); HeapTuple newtuple = NULL; HeapTuple trigtuple; bool should_free_trig = false; bool should_free_new = false; TriggerData LocTriggerData = {0}; int i; Bitmapset *updatedCols; LockTupleMode lockmode; /* Determine lock mode to use */ lockmode = ExecUpdateLockMode(estate, relinfo); Assert(HeapTupleIsValid(fdw_trigtuple) ^ ItemPointerIsValid(tupleid)); if (fdw_trigtuple == NULL) { TupleTableSlot *epqslot_candidate = NULL; /* get a copy of the on-disk tuple we are planning to update */ if (!GetTupleForTrigger(estate, epqstate, relinfo, tupleid, lockmode, oldslot, &epqslot_candidate, tmresult, tmfd)) return false; /* cancel the update action */ /* * In READ COMMITTED isolation level it's possible that target tuple * was changed due to concurrent update. In that case we have a raw * subplan output tuple in epqslot_candidate, and need to form a new * insertable tuple using ExecGetUpdateNewTuple to replace the one we * received in newslot. Neither we nor our callers have any further * interest in the passed-in tuple, so it's okay to overwrite newslot * with the newer data. */ if (epqslot_candidate != NULL) { TupleTableSlot *epqslot_clean; epqslot_clean = ExecGetUpdateNewTuple(relinfo, epqslot_candidate, oldslot); /* * Typically, the caller's newslot was also generated by * ExecGetUpdateNewTuple, so that epqslot_clean will be the same * slot and copying is not needed. But do the right thing if it * isn't. */ if (unlikely(newslot != epqslot_clean)) ExecCopySlot(newslot, epqslot_clean); /* * At this point newslot contains a virtual tuple that may * reference some fields of oldslot's tuple in some disk buffer. * If that tuple is in a different page than the original target * tuple, then our only pin on that buffer is oldslot's, and we're * about to release it. Hence we'd better materialize newslot to * ensure it doesn't contain references into an unpinned buffer. * (We'd materialize it below anyway, but too late for safety.) */ ExecMaterializeSlot(newslot); } /* * Here we convert oldslot to a materialized slot holding trigtuple. * Neither slot passed to the triggers will hold any buffer pin. */ trigtuple = ExecFetchSlotHeapTuple(oldslot, true, &should_free_trig); } else { /* Put the FDW-supplied tuple into oldslot to unify the cases */ ExecForceStoreHeapTuple(fdw_trigtuple, oldslot, false); trigtuple = fdw_trigtuple; } LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; updatedCols = ExecGetAllUpdatedCols(relinfo, estate); LocTriggerData.tg_updatedcols = updatedCols; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple oldtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_UPDATE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, updatedCols, oldslot, newslot)) continue; if (!newtuple) newtuple = ExecFetchSlotHeapTuple(newslot, true, &should_free_new); LocTriggerData.tg_trigslot = oldslot; LocTriggerData.tg_trigtuple = trigtuple; LocTriggerData.tg_newtuple = oldtuple = newtuple; LocTriggerData.tg_newslot = newslot; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple == NULL) { if (should_free_trig) heap_freetuple(trigtuple); if (should_free_new) heap_freetuple(oldtuple); return false; /* "do nothing" */ } else if (newtuple != oldtuple) { ExecForceStoreHeapTuple(newtuple, newslot, false); /* * If the tuple returned by the trigger / being stored, is the old * row version, and the heap tuple passed to the trigger was * allocated locally, materialize the slot. Otherwise we might * free it while still referenced by the slot. */ if (should_free_trig && newtuple == trigtuple) ExecMaterializeSlot(newslot); if (should_free_new) heap_freetuple(oldtuple); /* signal tuple should be re-fetched if used */ newtuple = NULL; } } if (should_free_trig) heap_freetuple(trigtuple); return true; } /* * Note: 'src_partinfo' and 'dst_partinfo', when non-NULL, refer to the source * and destination partitions, respectively, of a cross-partition update of * the root partitioned table mentioned in the query, given by 'relinfo'. * 'tupleid' in that case refers to the ctid of the "old" tuple in the source * partition, and 'newslot' contains the "new" tuple in the destination * partition. This interface allows to support the requirements of * ExecCrossPartitionUpdateForeignKey(); is_crosspart_update must be true in * that case. */ void ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo, ResultRelInfo *src_partinfo, ResultRelInfo *dst_partinfo, ItemPointer tupleid, HeapTuple fdw_trigtuple, TupleTableSlot *newslot, List *recheckIndexes, TransitionCaptureState *transition_capture, bool is_crosspart_update) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if ((trigdesc && trigdesc->trig_update_after_row) || (transition_capture && (transition_capture->tcs_update_old_table || transition_capture->tcs_update_new_table))) { /* * Note: if the UPDATE is converted into a DELETE+INSERT as part of * update-partition-key operation, then this function is also called * separately for DELETE and INSERT to capture transition table rows. * In such case, either old tuple or new tuple can be NULL. */ TupleTableSlot *oldslot; ResultRelInfo *tupsrc; Assert((src_partinfo != NULL && dst_partinfo != NULL) || !is_crosspart_update); tupsrc = src_partinfo ? src_partinfo : relinfo; oldslot = ExecGetTriggerOldSlot(estate, tupsrc); if (fdw_trigtuple == NULL && ItemPointerIsValid(tupleid)) GetTupleForTrigger(estate, NULL, tupsrc, tupleid, LockTupleExclusive, oldslot, NULL, NULL, NULL); else if (fdw_trigtuple != NULL) ExecForceStoreHeapTuple(fdw_trigtuple, oldslot, false); else ExecClearTuple(oldslot); AfterTriggerSaveEvent(estate, relinfo, src_partinfo, dst_partinfo, TRIGGER_EVENT_UPDATE, true, oldslot, newslot, recheckIndexes, ExecGetAllUpdatedCols(relinfo, estate), transition_capture, is_crosspart_update); } } bool ExecIRUpdateTriggers(EState *estate, ResultRelInfo *relinfo, HeapTuple trigtuple, TupleTableSlot *newslot) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; TupleTableSlot *oldslot = ExecGetTriggerOldSlot(estate, relinfo); HeapTuple newtuple = NULL; bool should_free; TriggerData LocTriggerData = {0}; int i; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE | TRIGGER_EVENT_ROW | TRIGGER_EVENT_INSTEAD; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; ExecForceStoreHeapTuple(trigtuple, oldslot, false); for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple oldtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_ROW, TRIGGER_TYPE_INSTEAD, TRIGGER_TYPE_UPDATE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, oldslot, newslot)) continue; if (!newtuple) newtuple = ExecFetchSlotHeapTuple(newslot, true, &should_free); LocTriggerData.tg_trigslot = oldslot; LocTriggerData.tg_trigtuple = trigtuple; LocTriggerData.tg_newslot = newslot; LocTriggerData.tg_newtuple = oldtuple = newtuple; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple == NULL) { return false; /* "do nothing" */ } else if (newtuple != oldtuple) { ExecForceStoreHeapTuple(newtuple, newslot, false); if (should_free) heap_freetuple(oldtuple); /* signal tuple should be re-fetched if used */ newtuple = NULL; } } return true; } void ExecBSTruncateTriggers(EState *estate, ResultRelInfo *relinfo) { TriggerDesc *trigdesc; int i; TriggerData LocTriggerData = {0}; trigdesc = relinfo->ri_TrigDesc; if (trigdesc == NULL) return; if (!trigdesc->trig_truncate_before_statement) return; LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = TRIGGER_EVENT_TRUNCATE | TRIGGER_EVENT_BEFORE; LocTriggerData.tg_relation = relinfo->ri_RelationDesc; for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; HeapTuple newtuple; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, TRIGGER_TYPE_STATEMENT, TRIGGER_TYPE_BEFORE, TRIGGER_TYPE_TRUNCATE)) continue; if (!TriggerEnabled(estate, relinfo, trigger, LocTriggerData.tg_event, NULL, NULL, NULL)) continue; LocTriggerData.tg_trigger = trigger; newtuple = ExecCallTriggerFunc(&LocTriggerData, i, relinfo->ri_TrigFunctions, relinfo->ri_TrigInstrument, GetPerTupleMemoryContext(estate)); if (newtuple) ereport(ERROR, (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), errmsg("BEFORE STATEMENT trigger cannot return a value"))); } } void ExecASTruncateTriggers(EState *estate, ResultRelInfo *relinfo) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if (trigdesc && trigdesc->trig_truncate_after_statement) AfterTriggerSaveEvent(estate, relinfo, NULL, NULL, TRIGGER_EVENT_TRUNCATE, false, NULL, NULL, NIL, NULL, NULL, false); } /* * Fetch tuple into "oldslot", dealing with locking and EPQ if necessary */ static bool GetTupleForTrigger(EState *estate, EPQState *epqstate, ResultRelInfo *relinfo, ItemPointer tid, LockTupleMode lockmode, TupleTableSlot *oldslot, TupleTableSlot **epqslot, TM_Result *tmresultp, TM_FailureData *tmfdp) { Relation relation = relinfo->ri_RelationDesc; if (epqslot != NULL) { TM_Result test; TM_FailureData tmfd; int lockflags = 0; *epqslot = NULL; /* caller must pass an epqstate if EvalPlanQual is possible */ Assert(epqstate != NULL); /* * lock tuple for update */ if (!IsolationUsesXactSnapshot()) lockflags |= TUPLE_LOCK_FLAG_FIND_LAST_VERSION; test = table_tuple_lock(relation, tid, estate->es_snapshot, oldslot, estate->es_output_cid, lockmode, LockWaitBlock, lockflags, &tmfd); /* Let the caller know about the status of this operation */ if (tmresultp) *tmresultp = test; if (tmfdp) *tmfdp = tmfd; switch (test) { case TM_SelfModified: /* * The target tuple was already updated or deleted by the * current command, or by a later command in the current * transaction. We ignore the tuple in the former case, and * throw error in the latter case, for the same reasons * enumerated in ExecUpdate and ExecDelete in * nodeModifyTable.c. */ if (tmfd.cmax != estate->es_output_cid) ereport(ERROR, (errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION), errmsg("tuple to be updated was already modified by an operation triggered by the current command"), errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows."))); /* treat it as deleted; do not process */ return false; case TM_Ok: if (tmfd.traversed) { /* * Recheck the tuple using EPQ. For MERGE, we leave this * to the caller (it must do additional rechecking, and * might end up executing a different action entirely). */ if (estate->es_plannedstmt->commandType == CMD_MERGE) { if (tmresultp) *tmresultp = TM_Updated; return false; } *epqslot = EvalPlanQual(epqstate, relation, relinfo->ri_RangeTableIndex, oldslot); /* * If PlanQual failed for updated tuple - we must not * process this tuple! */ if (TupIsNull(*epqslot)) { *epqslot = NULL; return false; } } break; case TM_Updated: if (IsolationUsesXactSnapshot()) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("could not serialize access due to concurrent update"))); elog(ERROR, "unexpected table_tuple_lock status: %u", test); break; case TM_Deleted: if (IsolationUsesXactSnapshot()) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("could not serialize access due to concurrent delete"))); /* tuple was deleted */ return false; case TM_Invisible: elog(ERROR, "attempted to lock invisible tuple"); break; default: elog(ERROR, "unrecognized table_tuple_lock status: %u", test); return false; /* keep compiler quiet */ } } else { /* * We expect the tuple to be present, thus very simple error handling * suffices. */ if (!table_tuple_fetch_row_version(relation, tid, SnapshotAny, oldslot)) elog(ERROR, "failed to fetch tuple for trigger"); } return true; } /* * Is trigger enabled to fire? */ static bool TriggerEnabled(EState *estate, ResultRelInfo *relinfo, Trigger *trigger, TriggerEvent event, Bitmapset *modifiedCols, TupleTableSlot *oldslot, TupleTableSlot *newslot) { /* Check replication-role-dependent enable state */ if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA) { if (trigger->tgenabled == TRIGGER_FIRES_ON_ORIGIN || trigger->tgenabled == TRIGGER_DISABLED) return false; } else /* ORIGIN or LOCAL role */ { if (trigger->tgenabled == TRIGGER_FIRES_ON_REPLICA || trigger->tgenabled == TRIGGER_DISABLED) return false; } /* * Check for column-specific trigger (only possible for UPDATE, and in * fact we *must* ignore tgattr for other event types) */ if (trigger->tgnattr > 0 && TRIGGER_FIRED_BY_UPDATE(event)) { int i; bool modified; modified = false; for (i = 0; i < trigger->tgnattr; i++) { if (bms_is_member(trigger->tgattr[i] - FirstLowInvalidHeapAttributeNumber, modifiedCols)) { modified = true; break; } } if (!modified) return false; } /* Check for WHEN clause */ if (trigger->tgqual) { ExprState **predicate; ExprContext *econtext; MemoryContext oldContext; int i; Assert(estate != NULL); /* * trigger is an element of relinfo->ri_TrigDesc->triggers[]; find the * matching element of relinfo->ri_TrigWhenExprs[] */ i = trigger - relinfo->ri_TrigDesc->triggers; predicate = &relinfo->ri_TrigWhenExprs[i]; /* * If first time through for this WHEN expression, build expression * nodetrees for it. Keep them in the per-query memory context so * they'll survive throughout the query. */ if (*predicate == NULL) { Node *tgqual; oldContext = MemoryContextSwitchTo(estate->es_query_cxt); tgqual = stringToNode(trigger->tgqual); /* Change references to OLD and NEW to INNER_VAR and OUTER_VAR */ ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER_VAR, 0); ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER_VAR, 0); /* ExecPrepareQual wants implicit-AND form */ tgqual = (Node *) make_ands_implicit((Expr *) tgqual); *predicate = ExecPrepareQual((List *) tgqual, estate); MemoryContextSwitchTo(oldContext); } /* * We will use the EState's per-tuple context for evaluating WHEN * expressions (creating it if it's not already there). */ econtext = GetPerTupleExprContext(estate); /* * Finally evaluate the expression, making the old and/or new tuples * available as INNER_VAR/OUTER_VAR respectively. */ econtext->ecxt_innertuple = oldslot; econtext->ecxt_outertuple = newslot; if (!ExecQual(*predicate, econtext)) return false; } return true; } /* ---------- * After-trigger stuff * * The AfterTriggersData struct holds data about pending AFTER trigger events * during the current transaction tree. (BEFORE triggers are fired * immediately so we don't need any persistent state about them.) The struct * and most of its subsidiary data are kept in TopTransactionContext; however * some data that can be discarded sooner appears in the CurTransactionContext * of the relevant subtransaction. Also, the individual event records are * kept in a separate sub-context of TopTransactionContext. This is done * mainly so that it's easy to tell from a memory context dump how much space * is being eaten by trigger events. * * Because the list of pending events can grow large, we go to some * considerable effort to minimize per-event memory consumption. The event * records are grouped into chunks and common data for similar events in the * same chunk is only stored once. * * XXX We need to be able to save the per-event data in a file if it grows too * large. * ---------- */ /* Per-trigger SET CONSTRAINT status */ typedef struct SetConstraintTriggerData { Oid sct_tgoid; bool sct_tgisdeferred; } SetConstraintTriggerData; typedef struct SetConstraintTriggerData *SetConstraintTrigger; /* * SET CONSTRAINT intra-transaction status. * * We make this a single palloc'd object so it can be copied and freed easily. * * all_isset and all_isdeferred are used to keep track * of SET CONSTRAINTS ALL {DEFERRED, IMMEDIATE}. * * trigstates[] stores per-trigger tgisdeferred settings. */ typedef struct SetConstraintStateData { bool all_isset; bool all_isdeferred; int numstates; /* number of trigstates[] entries in use */ int numalloc; /* allocated size of trigstates[] */ SetConstraintTriggerData trigstates[FLEXIBLE_ARRAY_MEMBER]; } SetConstraintStateData; typedef SetConstraintStateData *SetConstraintState; /* * Per-trigger-event data * * The actual per-event data, AfterTriggerEventData, includes DONE/IN_PROGRESS * status bits, up to two tuple CTIDs, and optionally two OIDs of partitions. * Each event record also has an associated AfterTriggerSharedData that is * shared across all instances of similar events within a "chunk". * * For row-level triggers, we arrange not to waste storage on unneeded ctid * fields. Updates of regular tables use two; inserts and deletes of regular * tables use one; foreign tables always use zero and save the tuple(s) to a * tuplestore. AFTER_TRIGGER_FDW_FETCH directs AfterTriggerExecute() to * retrieve a fresh tuple or pair of tuples from that tuplestore, while * AFTER_TRIGGER_FDW_REUSE directs it to use the most-recently-retrieved * tuple(s). This permits storing tuples once regardless of the number of * row-level triggers on a foreign table. * * When updates on partitioned tables cause rows to move between partitions, * the OIDs of both partitions are stored too, so that the tuples can be * fetched; such entries are marked AFTER_TRIGGER_CP_UPDATE (for "cross- * partition update"). * * Note that we need triggers on foreign tables to be fired in exactly the * order they were queued, so that the tuples come out of the tuplestore in * the right order. To ensure that, we forbid deferrable (constraint) * triggers on foreign tables. This also ensures that such triggers do not * get deferred into outer trigger query levels, meaning that it's okay to * destroy the tuplestore at the end of the query level. * * Statement-level triggers always bear AFTER_TRIGGER_1CTID, though they * require no ctid field. We lack the flag bit space to neatly represent that * distinct case, and it seems unlikely to be worth much trouble. * * Note: ats_firing_id is initially zero and is set to something else when * AFTER_TRIGGER_IN_PROGRESS is set. It indicates which trigger firing * cycle the trigger will be fired in (or was fired in, if DONE is set). * Although this is mutable state, we can keep it in AfterTriggerSharedData * because all instances of the same type of event in a given event list will * be fired at the same time, if they were queued between the same firing * cycles. So we need only ensure that ats_firing_id is zero when attaching * a new event to an existing AfterTriggerSharedData record. */ typedef uint32 TriggerFlags; #define AFTER_TRIGGER_OFFSET 0x07FFFFFF /* must be low-order bits */ #define AFTER_TRIGGER_DONE 0x80000000 #define AFTER_TRIGGER_IN_PROGRESS 0x40000000 /* bits describing the size and tuple sources of this event */ #define AFTER_TRIGGER_FDW_REUSE 0x00000000 #define AFTER_TRIGGER_FDW_FETCH 0x20000000 #define AFTER_TRIGGER_1CTID 0x10000000 #define AFTER_TRIGGER_2CTID 0x30000000 #define AFTER_TRIGGER_CP_UPDATE 0x08000000 #define AFTER_TRIGGER_TUP_BITS 0x38000000 typedef struct AfterTriggerSharedData *AfterTriggerShared; typedef struct AfterTriggerSharedData { TriggerEvent ats_event; /* event type indicator, see trigger.h */ Oid ats_tgoid; /* the trigger's ID */ Oid ats_relid; /* the relation it's on */ CommandId ats_firing_id; /* ID for firing cycle */ struct AfterTriggersTableData *ats_table; /* transition table access */ Bitmapset *ats_modifiedcols; /* modified columns */ } AfterTriggerSharedData; typedef struct AfterTriggerEventData *AfterTriggerEvent; typedef struct AfterTriggerEventData { TriggerFlags ate_flags; /* status bits and offset to shared data */ ItemPointerData ate_ctid1; /* inserted, deleted, or old updated tuple */ ItemPointerData ate_ctid2; /* new updated tuple */ /* * During a cross-partition update of a partitioned table, we also store * the OIDs of source and destination partitions that are needed to fetch * the old (ctid1) and the new tuple (ctid2) from, respectively. */ Oid ate_src_part; Oid ate_dst_part; } AfterTriggerEventData; /* AfterTriggerEventData, minus ate_src_part, ate_dst_part */ typedef struct AfterTriggerEventDataNoOids { TriggerFlags ate_flags; ItemPointerData ate_ctid1; ItemPointerData ate_ctid2; } AfterTriggerEventDataNoOids; /* AfterTriggerEventData, minus ate_*_part and ate_ctid2 */ typedef struct AfterTriggerEventDataOneCtid { TriggerFlags ate_flags; /* status bits and offset to shared data */ ItemPointerData ate_ctid1; /* inserted, deleted, or old updated tuple */ } AfterTriggerEventDataOneCtid; /* AfterTriggerEventData, minus ate_*_part, ate_ctid1 and ate_ctid2 */ typedef struct AfterTriggerEventDataZeroCtids { TriggerFlags ate_flags; /* status bits and offset to shared data */ } AfterTriggerEventDataZeroCtids; #define SizeofTriggerEvent(evt) \ (((evt)->ate_flags & AFTER_TRIGGER_TUP_BITS) == AFTER_TRIGGER_CP_UPDATE ? \ sizeof(AfterTriggerEventData) : \ (((evt)->ate_flags & AFTER_TRIGGER_TUP_BITS) == AFTER_TRIGGER_2CTID ? \ sizeof(AfterTriggerEventDataNoOids) : \ (((evt)->ate_flags & AFTER_TRIGGER_TUP_BITS) == AFTER_TRIGGER_1CTID ? \ sizeof(AfterTriggerEventDataOneCtid) : \ sizeof(AfterTriggerEventDataZeroCtids)))) #define GetTriggerSharedData(evt) \ ((AfterTriggerShared) ((char *) (evt) + ((evt)->ate_flags & AFTER_TRIGGER_OFFSET))) /* * To avoid palloc overhead, we keep trigger events in arrays in successively- * larger chunks (a slightly more sophisticated version of an expansible * array). The space between CHUNK_DATA_START and freeptr is occupied by * AfterTriggerEventData records; the space between endfree and endptr is * occupied by AfterTriggerSharedData records. */ typedef struct AfterTriggerEventChunk { struct AfterTriggerEventChunk *next; /* list link */ char *freeptr; /* start of free space in chunk */ char *endfree; /* end of free space in chunk */ char *endptr; /* end of chunk */ /* event data follows here */ } AfterTriggerEventChunk; #define CHUNK_DATA_START(cptr) ((char *) (cptr) + MAXALIGN(sizeof(AfterTriggerEventChunk))) /* A list of events */ typedef struct AfterTriggerEventList { AfterTriggerEventChunk *head; AfterTriggerEventChunk *tail; char *tailfree; /* freeptr of tail chunk */ } AfterTriggerEventList; /* Macros to help in iterating over a list of events */ #define for_each_chunk(cptr, evtlist) \ for (cptr = (evtlist).head; cptr != NULL; cptr = cptr->next) #define for_each_event(eptr, cptr) \ for (eptr = (AfterTriggerEvent) CHUNK_DATA_START(cptr); \ (char *) eptr < (cptr)->freeptr; \ eptr = (AfterTriggerEvent) (((char *) eptr) + SizeofTriggerEvent(eptr))) /* Use this if no special per-chunk processing is needed */ #define for_each_event_chunk(eptr, cptr, evtlist) \ for_each_chunk(cptr, evtlist) for_each_event(eptr, cptr) /* Macros for iterating from a start point that might not be list start */ #define for_each_chunk_from(cptr) \ for (; cptr != NULL; cptr = cptr->next) #define for_each_event_from(eptr, cptr) \ for (; \ (char *) eptr < (cptr)->freeptr; \ eptr = (AfterTriggerEvent) (((char *) eptr) + SizeofTriggerEvent(eptr))) /* * All per-transaction data for the AFTER TRIGGERS module. * * AfterTriggersData has the following fields: * * firing_counter is incremented for each call of afterTriggerInvokeEvents. * We mark firable events with the current firing cycle's ID so that we can * tell which ones to work on. This ensures sane behavior if a trigger * function chooses to do SET CONSTRAINTS: the inner SET CONSTRAINTS will * only fire those events that weren't already scheduled for firing. * * state keeps track of the transaction-local effects of SET CONSTRAINTS. * This is saved and restored across failed subtransactions. * * events is the current list of deferred events. This is global across * all subtransactions of the current transaction. In a subtransaction * abort, we know that the events added by the subtransaction are at the * end of the list, so it is relatively easy to discard them. The event * list chunks themselves are stored in event_cxt. * * query_depth is the current depth of nested AfterTriggerBeginQuery calls * (-1 when the stack is empty). * * query_stack[query_depth] is the per-query-level data, including these fields: * * events is a list of AFTER trigger events queued by the current query. * None of these are valid until the matching AfterTriggerEndQuery call * occurs. At that point we fire immediate-mode triggers, and append any * deferred events to the main events list. * * fdw_tuplestore is a tuplestore containing the foreign-table tuples * needed by events queued by the current query. (Note: we use just one * tuplestore even though more than one foreign table might be involved. * This is okay because tuplestores don't really care what's in the tuples * they store; but it's possible that someday it'd break.) * * tables is a List of AfterTriggersTableData structs for target tables * of the current query (see below). * * maxquerydepth is just the allocated length of query_stack. * * trans_stack holds per-subtransaction data, including these fields: * * state is NULL or a pointer to a saved copy of the SET CONSTRAINTS * state data. Each subtransaction level that modifies that state first * saves a copy, which we use to restore the state if we abort. * * events is a copy of the events head/tail pointers, * which we use to restore those values during subtransaction abort. * * query_depth is the subtransaction-start-time value of query_depth, * which we similarly use to clean up at subtransaction abort. * * firing_counter is the subtransaction-start-time value of firing_counter. * We use this to recognize which deferred triggers were fired (or marked * for firing) within an aborted subtransaction. * * We use GetCurrentTransactionNestLevel() to determine the correct array * index in trans_stack. maxtransdepth is the number of allocated entries in * trans_stack. (By not keeping our own stack pointer, we can avoid trouble * in cases where errors during subxact abort cause multiple invocations * of AfterTriggerEndSubXact() at the same nesting depth.) * * We create an AfterTriggersTableData struct for each target table of the * current query, and each operation mode (INSERT/UPDATE/DELETE), that has * either transition tables or statement-level triggers. This is used to * hold the relevant transition tables, as well as info tracking whether * we already queued the statement triggers. (We use that info to prevent * firing the same statement triggers more than once per statement, or really * once per transition table set.) These structs, along with the transition * table tuplestores, live in the (sub)transaction's CurTransactionContext. * That's sufficient lifespan because we don't allow transition tables to be * used by deferrable triggers, so they only need to survive until * AfterTriggerEndQuery. */ typedef struct AfterTriggersQueryData AfterTriggersQueryData; typedef struct AfterTriggersTransData AfterTriggersTransData; typedef struct AfterTriggersTableData AfterTriggersTableData; typedef struct AfterTriggersData { CommandId firing_counter; /* next firing ID to assign */ SetConstraintState state; /* the active S C state */ AfterTriggerEventList events; /* deferred-event list */ MemoryContext event_cxt; /* memory context for events, if any */ /* per-query-level data: */ AfterTriggersQueryData *query_stack; /* array of structs shown below */ int query_depth; /* current index in above array */ int maxquerydepth; /* allocated len of above array */ /* per-subtransaction-level data: */ AfterTriggersTransData *trans_stack; /* array of structs shown below */ int maxtransdepth; /* allocated len of above array */ } AfterTriggersData; struct AfterTriggersQueryData { AfterTriggerEventList events; /* events pending from this query */ Tuplestorestate *fdw_tuplestore; /* foreign tuples for said events */ List *tables; /* list of AfterTriggersTableData, see below */ }; struct AfterTriggersTransData { /* these fields are just for resetting at subtrans abort: */ SetConstraintState state; /* saved S C state, or NULL if not yet saved */ AfterTriggerEventList events; /* saved list pointer */ int query_depth; /* saved query_depth */ CommandId firing_counter; /* saved firing_counter */ }; struct AfterTriggersTableData { /* relid + cmdType form the lookup key for these structs: */ Oid relid; /* target table's OID */ CmdType cmdType; /* event type, CMD_INSERT/UPDATE/DELETE */ bool closed; /* true when no longer OK to add tuples */ bool before_trig_done; /* did we already queue BS triggers? */ bool after_trig_done; /* did we already queue AS triggers? */ AfterTriggerEventList after_trig_events; /* if so, saved list pointer */ /* * We maintain separate transition tables for UPDATE/INSERT/DELETE since * MERGE can run all three actions in a single statement. Note that UPDATE * needs both old and new transition tables whereas INSERT needs only new, * and DELETE needs only old. */ /* "old" transition table for UPDATE, if any */ Tuplestorestate *old_upd_tuplestore; /* "new" transition table for UPDATE, if any */ Tuplestorestate *new_upd_tuplestore; /* "old" transition table for DELETE, if any */ Tuplestorestate *old_del_tuplestore; /* "new" transition table for INSERT, if any */ Tuplestorestate *new_ins_tuplestore; TupleTableSlot *storeslot; /* for converting to tuplestore's format */ }; static AfterTriggersData afterTriggers; static void AfterTriggerExecute(EState *estate, AfterTriggerEvent event, ResultRelInfo *relInfo, ResultRelInfo *src_relInfo, ResultRelInfo *dst_relInfo, TriggerDesc *trigdesc, FmgrInfo *finfo, Instrumentation *instr, MemoryContext per_tuple_context, TupleTableSlot *trig_tuple_slot1, TupleTableSlot *trig_tuple_slot2); static AfterTriggersTableData *GetAfterTriggersTableData(Oid relid, CmdType cmdType); static TupleTableSlot *GetAfterTriggersStoreSlot(AfterTriggersTableData *table, TupleDesc tupdesc); static Tuplestorestate *GetAfterTriggersTransitionTable(int event, TupleTableSlot *oldslot, TupleTableSlot *newslot, TransitionCaptureState *transition_capture); static void TransitionTableAddTuple(EState *estate, TransitionCaptureState *transition_capture, ResultRelInfo *relinfo, TupleTableSlot *slot, TupleTableSlot *original_insert_tuple, Tuplestorestate *tuplestore); static void AfterTriggerFreeQuery(AfterTriggersQueryData *qs); static SetConstraintState SetConstraintStateCreate(int numalloc); static SetConstraintState SetConstraintStateCopy(SetConstraintState origstate); static SetConstraintState SetConstraintStateAddItem(SetConstraintState state, Oid tgoid, bool tgisdeferred); static void cancel_prior_stmt_triggers(Oid relid, CmdType cmdType, int tgevent); /* * Get the FDW tuplestore for the current trigger query level, creating it * if necessary. */ static Tuplestorestate * GetCurrentFDWTuplestore(void) { Tuplestorestate *ret; ret = afterTriggers.query_stack[afterTriggers.query_depth].fdw_tuplestore; if (ret == NULL) { MemoryContext oldcxt; ResourceOwner saveResourceOwner; /* * Make the tuplestore valid until end of subtransaction. We really * only need it until AfterTriggerEndQuery(). */ oldcxt = MemoryContextSwitchTo(CurTransactionContext); saveResourceOwner = CurrentResourceOwner; CurrentResourceOwner = CurTransactionResourceOwner; ret = tuplestore_begin_heap(false, false, work_mem); CurrentResourceOwner = saveResourceOwner; MemoryContextSwitchTo(oldcxt); afterTriggers.query_stack[afterTriggers.query_depth].fdw_tuplestore = ret; } return ret; } /* ---------- * afterTriggerCheckState() * * Returns true if the trigger event is actually in state DEFERRED. * ---------- */ static bool afterTriggerCheckState(AfterTriggerShared evtshared) { Oid tgoid = evtshared->ats_tgoid; SetConstraintState state = afterTriggers.state; int i; /* * For not-deferrable triggers (i.e. normal AFTER ROW triggers and * constraints declared NOT DEFERRABLE), the state is always false. */ if ((evtshared->ats_event & AFTER_TRIGGER_DEFERRABLE) == 0) return false; /* * If constraint state exists, SET CONSTRAINTS might have been executed * either for this trigger or for all triggers. */ if (state != NULL) { /* Check for SET CONSTRAINTS for this specific trigger. */ for (i = 0; i < state->numstates; i++) { if (state->trigstates[i].sct_tgoid == tgoid) return state->trigstates[i].sct_tgisdeferred; } /* Check for SET CONSTRAINTS ALL. */ if (state->all_isset) return state->all_isdeferred; } /* * Otherwise return the default state for the trigger. */ return ((evtshared->ats_event & AFTER_TRIGGER_INITDEFERRED) != 0); } /* ---------- * afterTriggerCopyBitmap() * * Copy bitmap into AfterTriggerEvents memory context, which is where the after * trigger events are kept. * ---------- */ static Bitmapset * afterTriggerCopyBitmap(Bitmapset *src) { Bitmapset *dst; MemoryContext oldcxt; if (src == NULL) return NULL; /* Create event context if we didn't already */ if (afterTriggers.event_cxt == NULL) afterTriggers.event_cxt = AllocSetContextCreate(TopTransactionContext, "AfterTriggerEvents", ALLOCSET_DEFAULT_SIZES); oldcxt = MemoryContextSwitchTo(afterTriggers.event_cxt); dst = bms_copy(src); MemoryContextSwitchTo(oldcxt); return dst; } /* ---------- * afterTriggerAddEvent() * * Add a new trigger event to the specified queue. * The passed-in event data is copied. * ---------- */ static void afterTriggerAddEvent(AfterTriggerEventList *events, AfterTriggerEvent event, AfterTriggerShared evtshared) { Size eventsize = SizeofTriggerEvent(event); Size needed = eventsize + sizeof(AfterTriggerSharedData); AfterTriggerEventChunk *chunk; AfterTriggerShared newshared; AfterTriggerEvent newevent; /* * If empty list or not enough room in the tail chunk, make a new chunk. * We assume here that a new shared record will always be needed. */ chunk = events->tail; if (chunk == NULL || chunk->endfree - chunk->freeptr < needed) { Size chunksize; /* Create event context if we didn't already */ if (afterTriggers.event_cxt == NULL) afterTriggers.event_cxt = AllocSetContextCreate(TopTransactionContext, "AfterTriggerEvents", ALLOCSET_DEFAULT_SIZES); /* * Chunk size starts at 1KB and is allowed to increase up to 1MB. * These numbers are fairly arbitrary, though there is a hard limit at * AFTER_TRIGGER_OFFSET; else we couldn't link event records to their * shared records using the available space in ate_flags. Another * constraint is that if the chunk size gets too huge, the search loop * below would get slow given a (not too common) usage pattern with * many distinct event types in a chunk. Therefore, we double the * preceding chunk size only if there weren't too many shared records * in the preceding chunk; otherwise we halve it. This gives us some * ability to adapt to the actual usage pattern of the current query * while still having large chunk sizes in typical usage. All chunk * sizes used should be MAXALIGN multiples, to ensure that the shared * records will be aligned safely. */ #define MIN_CHUNK_SIZE 1024 #define MAX_CHUNK_SIZE (1024*1024) #if MAX_CHUNK_SIZE > (AFTER_TRIGGER_OFFSET+1) #error MAX_CHUNK_SIZE must not exceed AFTER_TRIGGER_OFFSET #endif if (chunk == NULL) chunksize = MIN_CHUNK_SIZE; else { /* preceding chunk size... */ chunksize = chunk->endptr - (char *) chunk; /* check number of shared records in preceding chunk */ if ((chunk->endptr - chunk->endfree) <= (100 * sizeof(AfterTriggerSharedData))) chunksize *= 2; /* okay, double it */ else chunksize /= 2; /* too many shared records */ chunksize = Min(chunksize, MAX_CHUNK_SIZE); } chunk = MemoryContextAlloc(afterTriggers.event_cxt, chunksize); chunk->next = NULL; chunk->freeptr = CHUNK_DATA_START(chunk); chunk->endptr = chunk->endfree = (char *) chunk + chunksize; Assert(chunk->endfree - chunk->freeptr >= needed); if (events->head == NULL) events->head = chunk; else events->tail->next = chunk; events->tail = chunk; /* events->tailfree is now out of sync, but we'll fix it below */ } /* * Try to locate a matching shared-data record already in the chunk. If * none, make a new one. */ for (newshared = ((AfterTriggerShared) chunk->endptr) - 1; (char *) newshared >= chunk->endfree; newshared--) { if (newshared->ats_tgoid == evtshared->ats_tgoid && newshared->ats_relid == evtshared->ats_relid && newshared->ats_event == evtshared->ats_event && newshared->ats_table == evtshared->ats_table && newshared->ats_firing_id == 0) break; } if ((char *) newshared < chunk->endfree) { *newshared = *evtshared; newshared->ats_firing_id = 0; /* just to be sure */ chunk->endfree = (char *) newshared; } /* Insert the data */ newevent = (AfterTriggerEvent) chunk->freeptr; memcpy(newevent, event, eventsize); /* ... and link the new event to its shared record */ newevent->ate_flags &= ~AFTER_TRIGGER_OFFSET; newevent->ate_flags |= (char *) newshared - (char *) newevent; chunk->freeptr += eventsize; events->tailfree = chunk->freeptr; } /* ---------- * afterTriggerFreeEventList() * * Free all the event storage in the given list. * ---------- */ static void afterTriggerFreeEventList(AfterTriggerEventList *events) { AfterTriggerEventChunk *chunk; while ((chunk = events->head) != NULL) { events->head = chunk->next; pfree(chunk); } events->tail = NULL; events->tailfree = NULL; } /* ---------- * afterTriggerRestoreEventList() * * Restore an event list to its prior length, removing all the events * added since it had the value old_events. * ---------- */ static void afterTriggerRestoreEventList(AfterTriggerEventList *events, const AfterTriggerEventList *old_events) { AfterTriggerEventChunk *chunk; AfterTriggerEventChunk *next_chunk; if (old_events->tail == NULL) { /* restoring to a completely empty state, so free everything */ afterTriggerFreeEventList(events); } else { *events = *old_events; /* free any chunks after the last one we want to keep */ for (chunk = events->tail->next; chunk != NULL; chunk = next_chunk) { next_chunk = chunk->next; pfree(chunk); } /* and clean up the tail chunk to be the right length */ events->tail->next = NULL; events->tail->freeptr = events->tailfree; /* * We don't make any effort to remove now-unused shared data records. * They might still be useful, anyway. */ } } /* ---------- * afterTriggerDeleteHeadEventChunk() * * Remove the first chunk of events from the query level's event list. * Keep any event list pointers elsewhere in the query level's data * structures in sync. * ---------- */ static void afterTriggerDeleteHeadEventChunk(AfterTriggersQueryData *qs) { AfterTriggerEventChunk *target = qs->events.head; ListCell *lc; Assert(target && target->next); /* * First, update any pointers in the per-table data, so that they won't be * dangling. Resetting obsoleted pointers to NULL will make * cancel_prior_stmt_triggers start from the list head, which is fine. */ foreach(lc, qs->tables) { AfterTriggersTableData *table = (AfterTriggersTableData *) lfirst(lc); if (table->after_trig_done && table->after_trig_events.tail == target) { table->after_trig_events.head = NULL; table->after_trig_events.tail = NULL; table->after_trig_events.tailfree = NULL; } } /* Now we can flush the head chunk */ qs->events.head = target->next; pfree(target); } /* ---------- * AfterTriggerExecute() * * Fetch the required tuples back from the heap and fire one * single trigger function. * * Frequently, this will be fired many times in a row for triggers of * a single relation. Therefore, we cache the open relation and provide * fmgr lookup cache space at the caller level. (For triggers fired at * the end of a query, we can even piggyback on the executor's state.) * * When fired for a cross-partition update of a partitioned table, the old * tuple is fetched using 'src_relInfo' (the source leaf partition) and * the new tuple using 'dst_relInfo' (the destination leaf partition), though * both are converted into the root partitioned table's format before passing * to the trigger function. * * event: event currently being fired. * relInfo: result relation for event. * src_relInfo: source partition of a cross-partition update * dst_relInfo: its destination partition * trigdesc: working copy of rel's trigger info. * finfo: array of fmgr lookup cache entries (one per trigger in trigdesc). * instr: array of EXPLAIN ANALYZE instrumentation nodes (one per trigger), * or NULL if no instrumentation is wanted. * per_tuple_context: memory context to call trigger function in. * trig_tuple_slot1: scratch slot for tg_trigtuple (foreign tables only) * trig_tuple_slot2: scratch slot for tg_newtuple (foreign tables only) * ---------- */ static void AfterTriggerExecute(EState *estate, AfterTriggerEvent event, ResultRelInfo *relInfo, ResultRelInfo *src_relInfo, ResultRelInfo *dst_relInfo, TriggerDesc *trigdesc, FmgrInfo *finfo, Instrumentation *instr, MemoryContext per_tuple_context, TupleTableSlot *trig_tuple_slot1, TupleTableSlot *trig_tuple_slot2) { Relation rel = relInfo->ri_RelationDesc; Relation src_rel = src_relInfo->ri_RelationDesc; Relation dst_rel = dst_relInfo->ri_RelationDesc; AfterTriggerShared evtshared = GetTriggerSharedData(event); Oid tgoid = evtshared->ats_tgoid; TriggerData LocTriggerData = {0}; HeapTuple rettuple; int tgindx; bool should_free_trig = false; bool should_free_new = false; /* * Locate trigger in trigdesc. */ for (tgindx = 0; tgindx < trigdesc->numtriggers; tgindx++) { if (trigdesc->triggers[tgindx].tgoid == tgoid) { LocTriggerData.tg_trigger = &(trigdesc->triggers[tgindx]); break; } } if (LocTriggerData.tg_trigger == NULL) elog(ERROR, "could not find trigger %u", tgoid); /* * If doing EXPLAIN ANALYZE, start charging time to this trigger. We want * to include time spent re-fetching tuples in the trigger cost. */ if (instr) InstrStartNode(instr + tgindx); /* * Fetch the required tuple(s). */ switch (event->ate_flags & AFTER_TRIGGER_TUP_BITS) { case AFTER_TRIGGER_FDW_FETCH: { Tuplestorestate *fdw_tuplestore = GetCurrentFDWTuplestore(); if (!tuplestore_gettupleslot(fdw_tuplestore, true, false, trig_tuple_slot1)) elog(ERROR, "failed to fetch tuple1 for AFTER trigger"); if ((evtshared->ats_event & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_UPDATE && !tuplestore_gettupleslot(fdw_tuplestore, true, false, trig_tuple_slot2)) elog(ERROR, "failed to fetch tuple2 for AFTER trigger"); } /* fall through */ case AFTER_TRIGGER_FDW_REUSE: /* * Store tuple in the slot so that tg_trigtuple does not reference * tuplestore memory. (It is formally possible for the trigger * function to queue trigger events that add to the same * tuplestore, which can push other tuples out of memory.) The * distinction is academic, because we start with a minimal tuple * that is stored as a heap tuple, constructed in different memory * context, in the slot anyway. */ LocTriggerData.tg_trigslot = trig_tuple_slot1; LocTriggerData.tg_trigtuple = ExecFetchSlotHeapTuple(trig_tuple_slot1, true, &should_free_trig); if ((evtshared->ats_event & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_UPDATE) { LocTriggerData.tg_newslot = trig_tuple_slot2; LocTriggerData.tg_newtuple = ExecFetchSlotHeapTuple(trig_tuple_slot2, true, &should_free_new); } else { LocTriggerData.tg_newtuple = NULL; } break; default: if (ItemPointerIsValid(&(event->ate_ctid1))) { TupleTableSlot *src_slot = ExecGetTriggerOldSlot(estate, src_relInfo); if (!table_tuple_fetch_row_version(src_rel, &(event->ate_ctid1), SnapshotAny, src_slot)) elog(ERROR, "failed to fetch tuple1 for AFTER trigger"); /* * Store the tuple fetched from the source partition into the * target (root partitioned) table slot, converting if needed. */ if (src_relInfo != relInfo) { TupleConversionMap *map = ExecGetChildToRootMap(src_relInfo); LocTriggerData.tg_trigslot = ExecGetTriggerOldSlot(estate, relInfo); if (map) { execute_attr_map_slot(map->attrMap, src_slot, LocTriggerData.tg_trigslot); } else ExecCopySlot(LocTriggerData.tg_trigslot, src_slot); } else LocTriggerData.tg_trigslot = src_slot; LocTriggerData.tg_trigtuple = ExecFetchSlotHeapTuple(LocTriggerData.tg_trigslot, false, &should_free_trig); } else { LocTriggerData.tg_trigtuple = NULL; } /* don't touch ctid2 if not there */ if (((event->ate_flags & AFTER_TRIGGER_TUP_BITS) == AFTER_TRIGGER_2CTID || (event->ate_flags & AFTER_TRIGGER_CP_UPDATE)) && ItemPointerIsValid(&(event->ate_ctid2))) { TupleTableSlot *dst_slot = ExecGetTriggerNewSlot(estate, dst_relInfo); if (!table_tuple_fetch_row_version(dst_rel, &(event->ate_ctid2), SnapshotAny, dst_slot)) elog(ERROR, "failed to fetch tuple2 for AFTER trigger"); /* * Store the tuple fetched from the destination partition into * the target (root partitioned) table slot, converting if * needed. */ if (dst_relInfo != relInfo) { TupleConversionMap *map = ExecGetChildToRootMap(dst_relInfo); LocTriggerData.tg_newslot = ExecGetTriggerNewSlot(estate, relInfo); if (map) { execute_attr_map_slot(map->attrMap, dst_slot, LocTriggerData.tg_newslot); } else ExecCopySlot(LocTriggerData.tg_newslot, dst_slot); } else LocTriggerData.tg_newslot = dst_slot; LocTriggerData.tg_newtuple = ExecFetchSlotHeapTuple(LocTriggerData.tg_newslot, false, &should_free_new); } else { LocTriggerData.tg_newtuple = NULL; } } /* * Set up the tuplestore information to let the trigger have access to * transition tables. When we first make a transition table available to * a trigger, mark it "closed" so that it cannot change anymore. If any * additional events of the same type get queued in the current trigger * query level, they'll go into new transition tables. */ LocTriggerData.tg_oldtable = LocTriggerData.tg_newtable = NULL; if (evtshared->ats_table) { if (LocTriggerData.tg_trigger->tgoldtable) { if (TRIGGER_FIRED_BY_UPDATE(evtshared->ats_event)) LocTriggerData.tg_oldtable = evtshared->ats_table->old_upd_tuplestore; else LocTriggerData.tg_oldtable = evtshared->ats_table->old_del_tuplestore; evtshared->ats_table->closed = true; } if (LocTriggerData.tg_trigger->tgnewtable) { if (TRIGGER_FIRED_BY_INSERT(evtshared->ats_event)) LocTriggerData.tg_newtable = evtshared->ats_table->new_ins_tuplestore; else LocTriggerData.tg_newtable = evtshared->ats_table->new_upd_tuplestore; evtshared->ats_table->closed = true; } } /* * Setup the remaining trigger information */ LocTriggerData.type = T_TriggerData; LocTriggerData.tg_event = evtshared->ats_event & (TRIGGER_EVENT_OPMASK | TRIGGER_EVENT_ROW); LocTriggerData.tg_relation = rel; if (TRIGGER_FOR_UPDATE(LocTriggerData.tg_trigger->tgtype)) LocTriggerData.tg_updatedcols = evtshared->ats_modifiedcols; MemoryContextReset(per_tuple_context); /* * Call the trigger and throw away any possibly returned updated tuple. * (Don't let ExecCallTriggerFunc measure EXPLAIN time.) */ rettuple = ExecCallTriggerFunc(&LocTriggerData, tgindx, finfo, NULL, per_tuple_context); if (rettuple != NULL && rettuple != LocTriggerData.tg_trigtuple && rettuple != LocTriggerData.tg_newtuple) heap_freetuple(rettuple); /* * Release resources */ if (should_free_trig) heap_freetuple(LocTriggerData.tg_trigtuple); if (should_free_new) heap_freetuple(LocTriggerData.tg_newtuple); /* don't clear slots' contents if foreign table */ if (trig_tuple_slot1 == NULL) { if (LocTriggerData.tg_trigslot) ExecClearTuple(LocTriggerData.tg_trigslot); if (LocTriggerData.tg_newslot) ExecClearTuple(LocTriggerData.tg_newslot); } /* * If doing EXPLAIN ANALYZE, stop charging time to this trigger, and count * one "tuple returned" (really the number of firings). */ if (instr) InstrStopNode(instr + tgindx, 1); } /* * afterTriggerMarkEvents() * * Scan the given event list for not yet invoked events. Mark the ones * that can be invoked now with the current firing ID. * * If move_list isn't NULL, events that are not to be invoked now are * transferred to move_list. * * When immediate_only is true, do not invoke currently-deferred triggers. * (This will be false only at main transaction exit.) * * Returns true if any invokable events were found. */ static bool afterTriggerMarkEvents(AfterTriggerEventList *events, AfterTriggerEventList *move_list, bool immediate_only) { bool found = false; bool deferred_found = false; AfterTriggerEvent event; AfterTriggerEventChunk *chunk; for_each_event_chunk(event, chunk, *events) { AfterTriggerShared evtshared = GetTriggerSharedData(event); bool defer_it = false; if (!(event->ate_flags & (AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS))) { /* * This trigger hasn't been called or scheduled yet. Check if we * should call it now. */ if (immediate_only && afterTriggerCheckState(evtshared)) { defer_it = true; } else { /* * Mark it as to be fired in this firing cycle. */ evtshared->ats_firing_id = afterTriggers.firing_counter; event->ate_flags |= AFTER_TRIGGER_IN_PROGRESS; found = true; } } /* * If it's deferred, move it to move_list, if requested. */ if (defer_it && move_list != NULL) { deferred_found = true; /* add it to move_list */ afterTriggerAddEvent(move_list, event, evtshared); /* mark original copy "done" so we don't do it again */ event->ate_flags |= AFTER_TRIGGER_DONE; } } /* * We could allow deferred triggers if, before the end of the * security-restricted operation, we were to verify that a SET CONSTRAINTS * ... IMMEDIATE has fired all such triggers. For now, don't bother. */ if (deferred_found && InSecurityRestrictedOperation()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("cannot fire deferred trigger within security-restricted operation"))); return found; } /* * afterTriggerInvokeEvents() * * Scan the given event list for events that are marked as to be fired * in the current firing cycle, and fire them. * * If estate isn't NULL, we use its result relation info to avoid repeated * openings and closing of trigger target relations. If it is NULL, we * make one locally to cache the info in case there are multiple trigger * events per rel. * * When delete_ok is true, it's safe to delete fully-processed events. * (We are not very tense about that: we simply reset a chunk to be empty * if all its events got fired. The objective here is just to avoid useless * rescanning of events when a trigger queues new events during transaction * end, so it's not necessary to worry much about the case where only * some events are fired.) * * Returns true if no unfired events remain in the list (this allows us * to avoid repeating afterTriggerMarkEvents). */ static bool afterTriggerInvokeEvents(AfterTriggerEventList *events, CommandId firing_id, EState *estate, bool delete_ok) { bool all_fired = true; AfterTriggerEventChunk *chunk; MemoryContext per_tuple_context; bool local_estate = false; ResultRelInfo *rInfo = NULL; Relation rel = NULL; TriggerDesc *trigdesc = NULL; FmgrInfo *finfo = NULL; Instrumentation *instr = NULL; TupleTableSlot *slot1 = NULL, *slot2 = NULL; /* Make a local EState if need be */ if (estate == NULL) { estate = CreateExecutorState(); local_estate = true; } /* Make a per-tuple memory context for trigger function calls */ per_tuple_context = AllocSetContextCreate(CurrentMemoryContext, "AfterTriggerTupleContext", ALLOCSET_DEFAULT_SIZES); for_each_chunk(chunk, *events) { AfterTriggerEvent event; bool all_fired_in_chunk = true; for_each_event(event, chunk) { AfterTriggerShared evtshared = GetTriggerSharedData(event); /* * Is it one for me to fire? */ if ((event->ate_flags & AFTER_TRIGGER_IN_PROGRESS) && evtshared->ats_firing_id == firing_id) { ResultRelInfo *src_rInfo, *dst_rInfo; /* * So let's fire it... but first, find the correct relation if * this is not the same relation as before. */ if (rel == NULL || RelationGetRelid(rel) != evtshared->ats_relid) { rInfo = ExecGetTriggerResultRel(estate, evtshared->ats_relid, NULL); rel = rInfo->ri_RelationDesc; /* Catch calls with insufficient relcache refcounting */ Assert(!RelationHasReferenceCountZero(rel)); trigdesc = rInfo->ri_TrigDesc; finfo = rInfo->ri_TrigFunctions; instr = rInfo->ri_TrigInstrument; if (slot1 != NULL) { ExecDropSingleTupleTableSlot(slot1); ExecDropSingleTupleTableSlot(slot2); slot1 = slot2 = NULL; } if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { slot1 = MakeSingleTupleTableSlot(rel->rd_att, &TTSOpsMinimalTuple); slot2 = MakeSingleTupleTableSlot(rel->rd_att, &TTSOpsMinimalTuple); } if (trigdesc == NULL) /* should not happen */ elog(ERROR, "relation %u has no triggers", evtshared->ats_relid); } /* * Look up source and destination partition result rels of a * cross-partition update event. */ if ((event->ate_flags & AFTER_TRIGGER_TUP_BITS) == AFTER_TRIGGER_CP_UPDATE) { Assert(OidIsValid(event->ate_src_part) && OidIsValid(event->ate_dst_part)); src_rInfo = ExecGetTriggerResultRel(estate, event->ate_src_part, rInfo); dst_rInfo = ExecGetTriggerResultRel(estate, event->ate_dst_part, rInfo); } else src_rInfo = dst_rInfo = rInfo; /* * Fire it. Note that the AFTER_TRIGGER_IN_PROGRESS flag is * still set, so recursive examinations of the event list * won't try to re-fire it. */ AfterTriggerExecute(estate, event, rInfo, src_rInfo, dst_rInfo, trigdesc, finfo, instr, per_tuple_context, slot1, slot2); /* * Mark the event as done. */ event->ate_flags &= ~AFTER_TRIGGER_IN_PROGRESS; event->ate_flags |= AFTER_TRIGGER_DONE; } else if (!(event->ate_flags & AFTER_TRIGGER_DONE)) { /* something remains to be done */ all_fired = all_fired_in_chunk = false; } } /* Clear the chunk if delete_ok and nothing left of interest */ if (delete_ok && all_fired_in_chunk) { chunk->freeptr = CHUNK_DATA_START(chunk); chunk->endfree = chunk->endptr; /* * If it's last chunk, must sync event list's tailfree too. Note * that delete_ok must NOT be passed as true if there could be * additional AfterTriggerEventList values pointing at this event * list, since we'd fail to fix their copies of tailfree. */ if (chunk == events->tail) events->tailfree = chunk->freeptr; } } if (slot1 != NULL) { ExecDropSingleTupleTableSlot(slot1); ExecDropSingleTupleTableSlot(slot2); } /* Release working resources */ MemoryContextDelete(per_tuple_context); if (local_estate) { ExecCloseResultRelations(estate); ExecResetTupleTable(estate->es_tupleTable, false); FreeExecutorState(estate); } return all_fired; } /* * GetAfterTriggersTableData * * Find or create an AfterTriggersTableData struct for the specified * trigger event (relation + operation type). Ignore existing structs * marked "closed"; we don't want to put any additional tuples into them, * nor change their stmt-triggers-fired state. * * Note: the AfterTriggersTableData list is allocated in the current * (sub)transaction's CurTransactionContext. This is OK because * we don't need it to live past AfterTriggerEndQuery. */ static AfterTriggersTableData * GetAfterTriggersTableData(Oid relid, CmdType cmdType) { AfterTriggersTableData *table; AfterTriggersQueryData *qs; MemoryContext oldcxt; ListCell *lc; /* Caller should have ensured query_depth is OK. */ Assert(afterTriggers.query_depth >= 0 && afterTriggers.query_depth < afterTriggers.maxquerydepth); qs = &afterTriggers.query_stack[afterTriggers.query_depth]; foreach(lc, qs->tables) { table = (AfterTriggersTableData *) lfirst(lc); if (table->relid == relid && table->cmdType == cmdType && !table->closed) return table; } oldcxt = MemoryContextSwitchTo(CurTransactionContext); table = (AfterTriggersTableData *) palloc0(sizeof(AfterTriggersTableData)); table->relid = relid; table->cmdType = cmdType; qs->tables = lappend(qs->tables, table); MemoryContextSwitchTo(oldcxt); return table; } /* * Returns a TupleTableSlot suitable for holding the tuples to be put * into AfterTriggersTableData's transition table tuplestores. */ static TupleTableSlot * GetAfterTriggersStoreSlot(AfterTriggersTableData *table, TupleDesc tupdesc) { /* Create it if not already done. */ if (!table->storeslot) { MemoryContext oldcxt; /* * We need this slot only until AfterTriggerEndQuery, but making it * last till end-of-subxact is good enough. It'll be freed by * AfterTriggerFreeQuery(). However, the passed-in tupdesc might have * a different lifespan, so we'd better make a copy of that. */ oldcxt = MemoryContextSwitchTo(CurTransactionContext); tupdesc = CreateTupleDescCopy(tupdesc); table->storeslot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual); MemoryContextSwitchTo(oldcxt); } return table->storeslot; } /* * MakeTransitionCaptureState * * Make a TransitionCaptureState object for the given TriggerDesc, target * relation, and operation type. The TCS object holds all the state needed * to decide whether to capture tuples in transition tables. * * If there are no triggers in 'trigdesc' that request relevant transition * tables, then return NULL. * * The resulting object can be passed to the ExecAR* functions. When * dealing with child tables, the caller can set tcs_original_insert_tuple * to avoid having to reconstruct the original tuple in the root table's * format. * * Note that we copy the flags from a parent table into this struct (rather * than subsequently using the relation's TriggerDesc directly) so that we can * use it to control collection of transition tuples from child tables. * * Per SQL spec, all operations of the same kind (INSERT/UPDATE/DELETE) * on the same table during one query should share one transition table. * Therefore, the Tuplestores are owned by an AfterTriggersTableData struct * looked up using the table OID + CmdType, and are merely referenced by * the TransitionCaptureState objects we hand out to callers. */ TransitionCaptureState * MakeTransitionCaptureState(TriggerDesc *trigdesc, Oid relid, CmdType cmdType) { TransitionCaptureState *state; bool need_old_upd, need_new_upd, need_old_del, need_new_ins; AfterTriggersTableData *table; MemoryContext oldcxt; ResourceOwner saveResourceOwner; if (trigdesc == NULL) return NULL; /* Detect which table(s) we need. */ switch (cmdType) { case CMD_INSERT: need_old_upd = need_old_del = need_new_upd = false; need_new_ins = trigdesc->trig_insert_new_table; break; case CMD_UPDATE: need_old_upd = trigdesc->trig_update_old_table; need_new_upd = trigdesc->trig_update_new_table; need_old_del = need_new_ins = false; break; case CMD_DELETE: need_old_del = trigdesc->trig_delete_old_table; need_old_upd = need_new_upd = need_new_ins = false; break; case CMD_MERGE: need_old_upd = trigdesc->trig_update_old_table; need_new_upd = trigdesc->trig_update_new_table; need_old_del = trigdesc->trig_delete_old_table; need_new_ins = trigdesc->trig_insert_new_table; break; default: elog(ERROR, "unexpected CmdType: %d", (int) cmdType); /* keep compiler quiet */ need_old_upd = need_new_upd = need_old_del = need_new_ins = false; break; } if (!need_old_upd && !need_new_upd && !need_new_ins && !need_old_del) return NULL; /* Check state, like AfterTriggerSaveEvent. */ if (afterTriggers.query_depth < 0) elog(ERROR, "MakeTransitionCaptureState() called outside of query"); /* Be sure we have enough space to record events at this query depth. */ if (afterTriggers.query_depth >= afterTriggers.maxquerydepth) AfterTriggerEnlargeQueryState(); /* * Find or create an AfterTriggersTableData struct to hold the * tuplestore(s). If there's a matching struct but it's marked closed, * ignore it; we need a newer one. * * Note: the AfterTriggersTableData list, as well as the tuplestores, are * allocated in the current (sub)transaction's CurTransactionContext, and * the tuplestores are managed by the (sub)transaction's resource owner. * This is sufficient lifespan because we do not allow triggers using * transition tables to be deferrable; they will be fired during * AfterTriggerEndQuery, after which it's okay to delete the data. */ table = GetAfterTriggersTableData(relid, cmdType); /* Now create required tuplestore(s), if we don't have them already. */ oldcxt = MemoryContextSwitchTo(CurTransactionContext); saveResourceOwner = CurrentResourceOwner; CurrentResourceOwner = CurTransactionResourceOwner; if (need_old_upd && table->old_upd_tuplestore == NULL) table->old_upd_tuplestore = tuplestore_begin_heap(false, false, work_mem); if (need_new_upd && table->new_upd_tuplestore == NULL) table->new_upd_tuplestore = tuplestore_begin_heap(false, false, work_mem); if (need_old_del && table->old_del_tuplestore == NULL) table->old_del_tuplestore = tuplestore_begin_heap(false, false, work_mem); if (need_new_ins && table->new_ins_tuplestore == NULL) table->new_ins_tuplestore = tuplestore_begin_heap(false, false, work_mem); CurrentResourceOwner = saveResourceOwner; MemoryContextSwitchTo(oldcxt); /* Now build the TransitionCaptureState struct, in caller's context */ state = (TransitionCaptureState *) palloc0(sizeof(TransitionCaptureState)); state->tcs_delete_old_table = trigdesc->trig_delete_old_table; state->tcs_update_old_table = trigdesc->trig_update_old_table; state->tcs_update_new_table = trigdesc->trig_update_new_table; state->tcs_insert_new_table = trigdesc->trig_insert_new_table; state->tcs_private = table; return state; } /* ---------- * AfterTriggerBeginXact() * * Called at transaction start (either BEGIN or implicit for single * statement outside of transaction block). * ---------- */ void AfterTriggerBeginXact(void) { /* * Initialize after-trigger state structure to empty */ afterTriggers.firing_counter = (CommandId) 1; /* mustn't be 0 */ afterTriggers.query_depth = -1; /* * Verify that there is no leftover state remaining. If these assertions * trip, it means that AfterTriggerEndXact wasn't called or didn't clean * up properly. */ Assert(afterTriggers.state == NULL); Assert(afterTriggers.query_stack == NULL); Assert(afterTriggers.maxquerydepth == 0); Assert(afterTriggers.event_cxt == NULL); Assert(afterTriggers.events.head == NULL); Assert(afterTriggers.trans_stack == NULL); Assert(afterTriggers.maxtransdepth == 0); } /* ---------- * AfterTriggerBeginQuery() * * Called just before we start processing a single query within a * transaction (or subtransaction). Most of the real work gets deferred * until somebody actually tries to queue a trigger event. * ---------- */ void AfterTriggerBeginQuery(void) { /* Increase the query stack depth */ afterTriggers.query_depth++; } /* ---------- * AfterTriggerEndQuery() * * Called after one query has been completely processed. At this time * we invoke all AFTER IMMEDIATE trigger events queued by the query, and * transfer deferred trigger events to the global deferred-trigger list. * * Note that this must be called BEFORE closing down the executor * with ExecutorEnd, because we make use of the EState's info about * target relations. Normally it is called from ExecutorFinish. * ---------- */ void AfterTriggerEndQuery(EState *estate) { AfterTriggersQueryData *qs; /* Must be inside a query, too */ Assert(afterTriggers.query_depth >= 0); /* * If we never even got as far as initializing the event stack, there * certainly won't be any events, so exit quickly. */ if (afterTriggers.query_depth >= afterTriggers.maxquerydepth) { afterTriggers.query_depth--; return; } /* * Process all immediate-mode triggers queued by the query, and move the * deferred ones to the main list of deferred events. * * Notice that we decide which ones will be fired, and put the deferred * ones on the main list, before anything is actually fired. This ensures * reasonably sane behavior if a trigger function does SET CONSTRAINTS ... * IMMEDIATE: all events we have decided to defer will be available for it * to fire. * * We loop in case a trigger queues more events at the same query level. * Ordinary trigger functions, including all PL/pgSQL trigger functions, * will instead fire any triggers in a dedicated query level. Foreign key * enforcement triggers do add to the current query level, thanks to their * passing fire_triggers = false to SPI_execute_snapshot(). Other * C-language triggers might do likewise. * * If we find no firable events, we don't have to increment * firing_counter. */ qs = &afterTriggers.query_stack[afterTriggers.query_depth]; for (;;) { if (afterTriggerMarkEvents(&qs->events, &afterTriggers.events, true)) { CommandId firing_id = afterTriggers.firing_counter++; AfterTriggerEventChunk *oldtail = qs->events.tail; if (afterTriggerInvokeEvents(&qs->events, firing_id, estate, false)) break; /* all fired */ /* * Firing a trigger could result in query_stack being repalloc'd, * so we must recalculate qs after each afterTriggerInvokeEvents * call. Furthermore, it's unsafe to pass delete_ok = true here, * because that could cause afterTriggerInvokeEvents to try to * access qs->events after the stack has been repalloc'd. */ qs = &afterTriggers.query_stack[afterTriggers.query_depth]; /* * We'll need to scan the events list again. To reduce the cost * of doing so, get rid of completely-fired chunks. We know that * all events were marked IN_PROGRESS or DONE at the conclusion of * afterTriggerMarkEvents, so any still-interesting events must * have been added after that, and so must be in the chunk that * was then the tail chunk, or in later chunks. So, zap all * chunks before oldtail. This is approximately the same set of * events we would have gotten rid of by passing delete_ok = true. */ Assert(oldtail != NULL); while (qs->events.head != oldtail) afterTriggerDeleteHeadEventChunk(qs); } else break; } /* Release query-level-local storage, including tuplestores if any */ AfterTriggerFreeQuery(&afterTriggers.query_stack[afterTriggers.query_depth]); afterTriggers.query_depth--; } /* * AfterTriggerFreeQuery * Release subsidiary storage for a trigger query level. * This includes closing down tuplestores. * Note: it's important for this to be safe if interrupted by an error * and then called again for the same query level. */ static void AfterTriggerFreeQuery(AfterTriggersQueryData *qs) { Tuplestorestate *ts; List *tables; ListCell *lc; /* Drop the trigger events */ afterTriggerFreeEventList(&qs->events); /* Drop FDW tuplestore if any */ ts = qs->fdw_tuplestore; qs->fdw_tuplestore = NULL; if (ts) tuplestore_end(ts); /* Release per-table subsidiary storage */ tables = qs->tables; foreach(lc, tables) { AfterTriggersTableData *table = (AfterTriggersTableData *) lfirst(lc); ts = table->old_upd_tuplestore; table->old_upd_tuplestore = NULL; if (ts) tuplestore_end(ts); ts = table->new_upd_tuplestore; table->new_upd_tuplestore = NULL; if (ts) tuplestore_end(ts); ts = table->old_del_tuplestore; table->old_del_tuplestore = NULL; if (ts) tuplestore_end(ts); ts = table->new_ins_tuplestore; table->new_ins_tuplestore = NULL; if (ts) tuplestore_end(ts); if (table->storeslot) { TupleTableSlot *slot = table->storeslot; table->storeslot = NULL; ExecDropSingleTupleTableSlot(slot); } } /* * Now free the AfterTriggersTableData structs and list cells. Reset list * pointer first; if list_free_deep somehow gets an error, better to leak * that storage than have an infinite loop. */ qs->tables = NIL; list_free_deep(tables); } /* ---------- * AfterTriggerFireDeferred() * * Called just before the current transaction is committed. At this * time we invoke all pending DEFERRED triggers. * * It is possible for other modules to queue additional deferred triggers * during pre-commit processing; therefore xact.c may have to call this * multiple times. * ---------- */ void AfterTriggerFireDeferred(void) { AfterTriggerEventList *events; bool snap_pushed = false; /* Must not be inside a query */ Assert(afterTriggers.query_depth == -1); /* * If there are any triggers to fire, make sure we have set a snapshot for * them to use. (Since PortalRunUtility doesn't set a snap for COMMIT, we * can't assume ActiveSnapshot is valid on entry.) */ events = &afterTriggers.events; if (events->head != NULL) { PushActiveSnapshot(GetTransactionSnapshot()); snap_pushed = true; } /* * Run all the remaining triggers. Loop until they are all gone, in case * some trigger queues more for us to do. */ while (afterTriggerMarkEvents(events, NULL, false)) { CommandId firing_id = afterTriggers.firing_counter++; if (afterTriggerInvokeEvents(events, firing_id, NULL, true)) break; /* all fired */ } /* * We don't bother freeing the event list, since it will go away anyway * (and more efficiently than via pfree) in AfterTriggerEndXact. */ if (snap_pushed) PopActiveSnapshot(); } /* ---------- * AfterTriggerEndXact() * * The current transaction is finishing. * * Any unfired triggers are canceled so we simply throw * away anything we know. * * Note: it is possible for this to be called repeatedly in case of * error during transaction abort; therefore, do not complain if * already closed down. * ---------- */ void AfterTriggerEndXact(bool isCommit) { /* * Forget the pending-events list. * * Since all the info is in TopTransactionContext or children thereof, we * don't really need to do anything to reclaim memory. However, the * pending-events list could be large, and so it's useful to discard it as * soon as possible --- especially if we are aborting because we ran out * of memory for the list! */ if (afterTriggers.event_cxt) { MemoryContextDelete(afterTriggers.event_cxt); afterTriggers.event_cxt = NULL; afterTriggers.events.head = NULL; afterTriggers.events.tail = NULL; afterTriggers.events.tailfree = NULL; } /* * Forget any subtransaction state as well. Since this can't be very * large, we let the eventual reset of TopTransactionContext free the * memory instead of doing it here. */ afterTriggers.trans_stack = NULL; afterTriggers.maxtransdepth = 0; /* * Forget the query stack and constraint-related state information. As * with the subtransaction state information, we don't bother freeing the * memory here. */ afterTriggers.query_stack = NULL; afterTriggers.maxquerydepth = 0; afterTriggers.state = NULL; /* No more afterTriggers manipulation until next transaction starts. */ afterTriggers.query_depth = -1; } /* * AfterTriggerBeginSubXact() * * Start a subtransaction. */ void AfterTriggerBeginSubXact(void) { int my_level = GetCurrentTransactionNestLevel(); /* * Allocate more space in the trans_stack if needed. (Note: because the * minimum nest level of a subtransaction is 2, we waste the first couple * entries of the array; not worth the notational effort to avoid it.) */ while (my_level >= afterTriggers.maxtransdepth) { if (afterTriggers.maxtransdepth == 0) { /* Arbitrarily initialize for max of 8 subtransaction levels */ afterTriggers.trans_stack = (AfterTriggersTransData *) MemoryContextAlloc(TopTransactionContext, 8 * sizeof(AfterTriggersTransData)); afterTriggers.maxtransdepth = 8; } else { /* repalloc will keep the stack in the same context */ int new_alloc = afterTriggers.maxtransdepth * 2; afterTriggers.trans_stack = (AfterTriggersTransData *) repalloc(afterTriggers.trans_stack, new_alloc * sizeof(AfterTriggersTransData)); afterTriggers.maxtransdepth = new_alloc; } } /* * Push the current information into the stack. The SET CONSTRAINTS state * is not saved until/unless changed. Likewise, we don't make a * per-subtransaction event context until needed. */ afterTriggers.trans_stack[my_level].state = NULL; afterTriggers.trans_stack[my_level].events = afterTriggers.events; afterTriggers.trans_stack[my_level].query_depth = afterTriggers.query_depth; afterTriggers.trans_stack[my_level].firing_counter = afterTriggers.firing_counter; } /* * AfterTriggerEndSubXact() * * The current subtransaction is ending. */ void AfterTriggerEndSubXact(bool isCommit) { int my_level = GetCurrentTransactionNestLevel(); SetConstraintState state; AfterTriggerEvent event; AfterTriggerEventChunk *chunk; CommandId subxact_firing_id; /* * Pop the prior state if needed. */ if (isCommit) { Assert(my_level < afterTriggers.maxtransdepth); /* If we saved a prior state, we don't need it anymore */ state = afterTriggers.trans_stack[my_level].state; if (state != NULL) pfree(state); /* this avoids double pfree if error later: */ afterTriggers.trans_stack[my_level].state = NULL; Assert(afterTriggers.query_depth == afterTriggers.trans_stack[my_level].query_depth); } else { /* * Aborting. It is possible subxact start failed before calling * AfterTriggerBeginSubXact, in which case we mustn't risk touching * trans_stack levels that aren't there. */ if (my_level >= afterTriggers.maxtransdepth) return; /* * Release query-level storage for queries being aborted, and restore * query_depth to its pre-subxact value. This assumes that a * subtransaction will not add events to query levels started in a * earlier transaction state. */ while (afterTriggers.query_depth > afterTriggers.trans_stack[my_level].query_depth) { if (afterTriggers.query_depth < afterTriggers.maxquerydepth) AfterTriggerFreeQuery(&afterTriggers.query_stack[afterTriggers.query_depth]); afterTriggers.query_depth--; } Assert(afterTriggers.query_depth == afterTriggers.trans_stack[my_level].query_depth); /* * Restore the global deferred-event list to its former length, * discarding any events queued by the subxact. */ afterTriggerRestoreEventList(&afterTriggers.events, &afterTriggers.trans_stack[my_level].events); /* * Restore the trigger state. If the saved state is NULL, then this * subxact didn't save it, so it doesn't need restoring. */ state = afterTriggers.trans_stack[my_level].state; if (state != NULL) { pfree(afterTriggers.state); afterTriggers.state = state; } /* this avoids double pfree if error later: */ afterTriggers.trans_stack[my_level].state = NULL; /* * Scan for any remaining deferred events that were marked DONE or IN * PROGRESS by this subxact or a child, and un-mark them. We can * recognize such events because they have a firing ID greater than or * equal to the firing_counter value we saved at subtransaction start. * (This essentially assumes that the current subxact includes all * subxacts started after it.) */ subxact_firing_id = afterTriggers.trans_stack[my_level].firing_counter; for_each_event_chunk(event, chunk, afterTriggers.events) { AfterTriggerShared evtshared = GetTriggerSharedData(event); if (event->ate_flags & (AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS)) { if (evtshared->ats_firing_id >= subxact_firing_id) event->ate_flags &= ~(AFTER_TRIGGER_DONE | AFTER_TRIGGER_IN_PROGRESS); } } } } /* * Get the transition table for the given event and depending on whether we are * processing the old or the new tuple. */ static Tuplestorestate * GetAfterTriggersTransitionTable(int event, TupleTableSlot *oldslot, TupleTableSlot *newslot, TransitionCaptureState *transition_capture) { Tuplestorestate *tuplestore = NULL; bool delete_old_table = transition_capture->tcs_delete_old_table; bool update_old_table = transition_capture->tcs_update_old_table; bool update_new_table = transition_capture->tcs_update_new_table; bool insert_new_table = transition_capture->tcs_insert_new_table; /* * For INSERT events NEW should be non-NULL, for DELETE events OLD should * be non-NULL, whereas for UPDATE events normally both OLD and NEW are * non-NULL. But for UPDATE events fired for capturing transition tuples * during UPDATE partition-key row movement, OLD is NULL when the event is * for a row being inserted, whereas NEW is NULL when the event is for a * row being deleted. */ Assert(!(event == TRIGGER_EVENT_DELETE && delete_old_table && TupIsNull(oldslot))); Assert(!(event == TRIGGER_EVENT_INSERT && insert_new_table && TupIsNull(newslot))); if (!TupIsNull(oldslot)) { Assert(TupIsNull(newslot)); if (event == TRIGGER_EVENT_DELETE && delete_old_table) tuplestore = transition_capture->tcs_private->old_del_tuplestore; else if (event == TRIGGER_EVENT_UPDATE && update_old_table) tuplestore = transition_capture->tcs_private->old_upd_tuplestore; } else if (!TupIsNull(newslot)) { Assert(TupIsNull(oldslot)); if (event == TRIGGER_EVENT_INSERT && insert_new_table) tuplestore = transition_capture->tcs_private->new_ins_tuplestore; else if (event == TRIGGER_EVENT_UPDATE && update_new_table) tuplestore = transition_capture->tcs_private->new_upd_tuplestore; } return tuplestore; } /* * Add the given heap tuple to the given tuplestore, applying the conversion * map if necessary. * * If original_insert_tuple is given, we can add that tuple without conversion. */ static void TransitionTableAddTuple(EState *estate, TransitionCaptureState *transition_capture, ResultRelInfo *relinfo, TupleTableSlot *slot, TupleTableSlot *original_insert_tuple, Tuplestorestate *tuplestore) { TupleConversionMap *map; /* * Nothing needs to be done if we don't have a tuplestore. */ if (tuplestore == NULL) return; if (original_insert_tuple) tuplestore_puttupleslot(tuplestore, original_insert_tuple); else if ((map = ExecGetChildToRootMap(relinfo)) != NULL) { AfterTriggersTableData *table = transition_capture->tcs_private; TupleTableSlot *storeslot; storeslot = GetAfterTriggersStoreSlot(table, map->outdesc); execute_attr_map_slot(map->attrMap, slot, storeslot); tuplestore_puttupleslot(tuplestore, storeslot); } else tuplestore_puttupleslot(tuplestore, slot); } /* ---------- * AfterTriggerEnlargeQueryState() * * Prepare the necessary state so that we can record AFTER trigger events * queued by a query. It is allowed to have nested queries within a * (sub)transaction, so we need to have separate state for each query * nesting level. * ---------- */ static void AfterTriggerEnlargeQueryState(void) { int init_depth = afterTriggers.maxquerydepth; Assert(afterTriggers.query_depth >= afterTriggers.maxquerydepth); if (afterTriggers.maxquerydepth == 0) { int new_alloc = Max(afterTriggers.query_depth + 1, 8); afterTriggers.query_stack = (AfterTriggersQueryData *) MemoryContextAlloc(TopTransactionContext, new_alloc * sizeof(AfterTriggersQueryData)); afterTriggers.maxquerydepth = new_alloc; } else { /* repalloc will keep the stack in the same context */ int old_alloc = afterTriggers.maxquerydepth; int new_alloc = Max(afterTriggers.query_depth + 1, old_alloc * 2); afterTriggers.query_stack = (AfterTriggersQueryData *) repalloc(afterTriggers.query_stack, new_alloc * sizeof(AfterTriggersQueryData)); afterTriggers.maxquerydepth = new_alloc; } /* Initialize new array entries to empty */ while (init_depth < afterTriggers.maxquerydepth) { AfterTriggersQueryData *qs = &afterTriggers.query_stack[init_depth]; qs->events.head = NULL; qs->events.tail = NULL; qs->events.tailfree = NULL; qs->fdw_tuplestore = NULL; qs->tables = NIL; ++init_depth; } } /* * Create an empty SetConstraintState with room for numalloc trigstates */ static SetConstraintState SetConstraintStateCreate(int numalloc) { SetConstraintState state; /* Behave sanely with numalloc == 0 */ if (numalloc <= 0) numalloc = 1; /* * We assume that zeroing will correctly initialize the state values. */ state = (SetConstraintState) MemoryContextAllocZero(TopTransactionContext, offsetof(SetConstraintStateData, trigstates) + numalloc * sizeof(SetConstraintTriggerData)); state->numalloc = numalloc; return state; } /* * Copy a SetConstraintState */ static SetConstraintState SetConstraintStateCopy(SetConstraintState origstate) { SetConstraintState state; state = SetConstraintStateCreate(origstate->numstates); state->all_isset = origstate->all_isset; state->all_isdeferred = origstate->all_isdeferred; state->numstates = origstate->numstates; memcpy(state->trigstates, origstate->trigstates, origstate->numstates * sizeof(SetConstraintTriggerData)); return state; } /* * Add a per-trigger item to a SetConstraintState. Returns possibly-changed * pointer to the state object (it will change if we have to repalloc). */ static SetConstraintState SetConstraintStateAddItem(SetConstraintState state, Oid tgoid, bool tgisdeferred) { if (state->numstates >= state->numalloc) { int newalloc = state->numalloc * 2; newalloc = Max(newalloc, 8); /* in case original has size 0 */ state = (SetConstraintState) repalloc(state, offsetof(SetConstraintStateData, trigstates) + newalloc * sizeof(SetConstraintTriggerData)); state->numalloc = newalloc; Assert(state->numstates < state->numalloc); } state->trigstates[state->numstates].sct_tgoid = tgoid; state->trigstates[state->numstates].sct_tgisdeferred = tgisdeferred; state->numstates++; return state; } /* ---------- * AfterTriggerSetState() * * Execute the SET CONSTRAINTS ... utility command. * ---------- */ void AfterTriggerSetState(ConstraintsSetStmt *stmt) { int my_level = GetCurrentTransactionNestLevel(); /* If we haven't already done so, initialize our state. */ if (afterTriggers.state == NULL) afterTriggers.state = SetConstraintStateCreate(8); /* * If in a subtransaction, and we didn't save the current state already, * save it so it can be restored if the subtransaction aborts. */ if (my_level > 1 && afterTriggers.trans_stack[my_level].state == NULL) { afterTriggers.trans_stack[my_level].state = SetConstraintStateCopy(afterTriggers.state); } /* * Handle SET CONSTRAINTS ALL ... */ if (stmt->constraints == NIL) { /* * Forget any previous SET CONSTRAINTS commands in this transaction. */ afterTriggers.state->numstates = 0; /* * Set the per-transaction ALL state to known. */ afterTriggers.state->all_isset = true; afterTriggers.state->all_isdeferred = stmt->deferred; } else { Relation conrel; Relation tgrel; List *conoidlist = NIL; List *tgoidlist = NIL; ListCell *lc; /* * Handle SET CONSTRAINTS constraint-name [, ...] * * First, identify all the named constraints and make a list of their * OIDs. Since, unlike the SQL spec, we allow multiple constraints of * the same name within a schema, the specifications are not * necessarily unique. Our strategy is to target all matching * constraints within the first search-path schema that has any * matches, but disregard matches in schemas beyond the first match. * (This is a bit odd but it's the historical behavior.) * * A constraint in a partitioned table may have corresponding * constraints in the partitions. Grab those too. */ conrel = table_open(ConstraintRelationId, AccessShareLock); foreach(lc, stmt->constraints) { RangeVar *constraint = lfirst(lc); bool found; List *namespacelist; ListCell *nslc; if (constraint->catalogname) { if (strcmp(constraint->catalogname, get_database_name(MyDatabaseId)) != 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cross-database references are not implemented: \"%s.%s.%s\"", constraint->catalogname, constraint->schemaname, constraint->relname))); } /* * If we're given the schema name with the constraint, look only * in that schema. If given a bare constraint name, use the * search path to find the first matching constraint. */ if (constraint->schemaname) { Oid namespaceId = LookupExplicitNamespace(constraint->schemaname, false); namespacelist = list_make1_oid(namespaceId); } else { namespacelist = fetch_search_path(true); } found = false; foreach(nslc, namespacelist) { Oid namespaceId = lfirst_oid(nslc); SysScanDesc conscan; ScanKeyData skey[2]; HeapTuple tup; ScanKeyInit(&skey[0], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(constraint->relname)); ScanKeyInit(&skey[1], Anum_pg_constraint_connamespace, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(namespaceId)); conscan = systable_beginscan(conrel, ConstraintNameNspIndexId, true, NULL, 2, skey); while (HeapTupleIsValid(tup = systable_getnext(conscan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tup); if (con->condeferrable) conoidlist = lappend_oid(conoidlist, con->oid); else if (stmt->deferred) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("constraint \"%s\" is not deferrable", constraint->relname))); found = true; } systable_endscan(conscan); /* * Once we've found a matching constraint we do not search * later parts of the search path. */ if (found) break; } list_free(namespacelist); /* * Not found ? */ if (!found) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" does not exist", constraint->relname))); } /* * Scan for any possible descendants of the constraints. We append * whatever we find to the same list that we're scanning; this has the * effect that we create new scans for those, too, so if there are * further descendents, we'll also catch them. */ foreach(lc, conoidlist) { Oid parent = lfirst_oid(lc); ScanKeyData key; SysScanDesc scan; HeapTuple tuple; ScanKeyInit(&key, Anum_pg_constraint_conparentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(parent)); scan = systable_beginscan(conrel, ConstraintParentIndexId, true, NULL, 1, &key); while (HeapTupleIsValid(tuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tuple); conoidlist = lappend_oid(conoidlist, con->oid); } systable_endscan(scan); } table_close(conrel, AccessShareLock); /* * Now, locate the trigger(s) implementing each of these constraints, * and make a list of their OIDs. */ tgrel = table_open(TriggerRelationId, AccessShareLock); foreach(lc, conoidlist) { Oid conoid = lfirst_oid(lc); ScanKeyData skey; SysScanDesc tgscan; HeapTuple htup; ScanKeyInit(&skey, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true, NULL, 1, &skey); while (HeapTupleIsValid(htup = systable_getnext(tgscan))) { Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(htup); /* * Silently skip triggers that are marked as non-deferrable in * pg_trigger. This is not an error condition, since a * deferrable RI constraint may have some non-deferrable * actions. */ if (pg_trigger->tgdeferrable) tgoidlist = lappend_oid(tgoidlist, pg_trigger->oid); } systable_endscan(tgscan); } table_close(tgrel, AccessShareLock); /* * Now we can set the trigger states of individual triggers for this * xact. */ foreach(lc, tgoidlist) { Oid tgoid = lfirst_oid(lc); SetConstraintState state = afterTriggers.state; bool found = false; int i; for (i = 0; i < state->numstates; i++) { if (state->trigstates[i].sct_tgoid == tgoid) { state->trigstates[i].sct_tgisdeferred = stmt->deferred; found = true; break; } } if (!found) { afterTriggers.state = SetConstraintStateAddItem(state, tgoid, stmt->deferred); } } } /* * SQL99 requires that when a constraint is set to IMMEDIATE, any deferred * checks against that constraint must be made when the SET CONSTRAINTS * command is executed -- i.e. the effects of the SET CONSTRAINTS command * apply retroactively. We've updated the constraints state, so scan the * list of previously deferred events to fire any that have now become * immediate. * * Obviously, if this was SET ... DEFERRED then it can't have converted * any unfired events to immediate, so we need do nothing in that case. */ if (!stmt->deferred) { AfterTriggerEventList *events = &afterTriggers.events; bool snapshot_set = false; while (afterTriggerMarkEvents(events, NULL, true)) { CommandId firing_id = afterTriggers.firing_counter++; /* * Make sure a snapshot has been established in case trigger * functions need one. Note that we avoid setting a snapshot if * we don't find at least one trigger that has to be fired now. * This is so that BEGIN; SET CONSTRAINTS ...; SET TRANSACTION * ISOLATION LEVEL SERIALIZABLE; ... works properly. (If we are * at the start of a transaction it's not possible for any trigger * events to be queued yet.) */ if (!snapshot_set) { PushActiveSnapshot(GetTransactionSnapshot()); snapshot_set = true; } /* * We can delete fired events if we are at top transaction level, * but we'd better not if inside a subtransaction, since the * subtransaction could later get rolled back. */ if (afterTriggerInvokeEvents(events, firing_id, NULL, !IsSubTransaction())) break; /* all fired */ } if (snapshot_set) PopActiveSnapshot(); } } /* ---------- * AfterTriggerPendingOnRel() * Test to see if there are any pending after-trigger events for rel. * * This is used by TRUNCATE, CLUSTER, ALTER TABLE, etc to detect whether * it is unsafe to perform major surgery on a relation. Note that only * local pending events are examined. We assume that having exclusive lock * on a rel guarantees there are no unserviced events in other backends --- * but having a lock does not prevent there being such events in our own. * * In some scenarios it'd be reasonable to remove pending events (more * specifically, mark them DONE by the current subxact) but without a lot * of knowledge of the trigger semantics we can't do this in general. * ---------- */ bool AfterTriggerPendingOnRel(Oid relid) { AfterTriggerEvent event; AfterTriggerEventChunk *chunk; int depth; /* Scan queued events */ for_each_event_chunk(event, chunk, afterTriggers.events) { AfterTriggerShared evtshared = GetTriggerSharedData(event); /* * We can ignore completed events. (Even if a DONE flag is rolled * back by subxact abort, it's OK because the effects of the TRUNCATE * or whatever must get rolled back too.) */ if (event->ate_flags & AFTER_TRIGGER_DONE) continue; if (evtshared->ats_relid == relid) return true; } /* * Also scan events queued by incomplete queries. This could only matter * if TRUNCATE/etc is executed by a function or trigger within an updating * query on the same relation, which is pretty perverse, but let's check. */ for (depth = 0; depth <= afterTriggers.query_depth && depth < afterTriggers.maxquerydepth; depth++) { for_each_event_chunk(event, chunk, afterTriggers.query_stack[depth].events) { AfterTriggerShared evtshared = GetTriggerSharedData(event); if (event->ate_flags & AFTER_TRIGGER_DONE) continue; if (evtshared->ats_relid == relid) return true; } } return false; } /* ---------- * AfterTriggerSaveEvent() * * Called by ExecA[RS]...Triggers() to queue up the triggers that should * be fired for an event. * * NOTE: this is called whenever there are any triggers associated with * the event (even if they are disabled). This function decides which * triggers actually need to be queued. It is also called after each row, * even if there are no triggers for that event, if there are any AFTER * STATEMENT triggers for the statement which use transition tables, so that * the transition tuplestores can be built. Furthermore, if the transition * capture is happening for UPDATEd rows being moved to another partition due * to the partition-key being changed, then this function is called once when * the row is deleted (to capture OLD row), and once when the row is inserted * into another partition (to capture NEW row). This is done separately because * DELETE and INSERT happen on different tables. * * Transition tuplestores are built now, rather than when events are pulled * off of the queue because AFTER ROW triggers are allowed to select from the * transition tables for the statement. * * This contains special support to queue the update events for the case where * a partitioned table undergoing a cross-partition update may have foreign * keys pointing into it. Normally, a partitioned table's row triggers are * not fired because the leaf partition(s) which are modified as a result of * the operation on the partitioned table contain the same triggers which are * fired instead. But that general scheme can cause problematic behavior with * foreign key triggers during cross-partition updates, which are implemented * as DELETE on the source partition followed by INSERT into the destination * partition. Specifically, firing DELETE triggers would lead to the wrong * foreign key action to be enforced considering that the original command is * UPDATE; in this case, this function is called with relinfo as the * partitioned table, and src_partinfo and dst_partinfo referring to the * source and target leaf partitions, respectively. * * is_crosspart_update is true either when a DELETE event is fired on the * source partition (which is to be ignored) or an UPDATE event is fired on * the root partitioned table. * ---------- */ static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo, ResultRelInfo *src_partinfo, ResultRelInfo *dst_partinfo, int event, bool row_trigger, TupleTableSlot *oldslot, TupleTableSlot *newslot, List *recheckIndexes, Bitmapset *modifiedCols, TransitionCaptureState *transition_capture, bool is_crosspart_update) { Relation rel = relinfo->ri_RelationDesc; TriggerDesc *trigdesc = relinfo->ri_TrigDesc; AfterTriggerEventData new_event; AfterTriggerSharedData new_shared; char relkind = rel->rd_rel->relkind; int tgtype_event; int tgtype_level; int i; Tuplestorestate *fdw_tuplestore = NULL; /* * Check state. We use a normal test not Assert because it is possible to * reach here in the wrong state given misconfigured RI triggers, in * particular deferring a cascade action trigger. */ if (afterTriggers.query_depth < 0) elog(ERROR, "AfterTriggerSaveEvent() called outside of query"); /* Be sure we have enough space to record events at this query depth. */ if (afterTriggers.query_depth >= afterTriggers.maxquerydepth) AfterTriggerEnlargeQueryState(); /* * If the directly named relation has any triggers with transition tables, * then we need to capture transition tuples. */ if (row_trigger && transition_capture != NULL) { TupleTableSlot *original_insert_tuple = transition_capture->tcs_original_insert_tuple; /* * Capture the old tuple in the appropriate transition table based on * the event. */ if (!TupIsNull(oldslot)) { Tuplestorestate *old_tuplestore; old_tuplestore = GetAfterTriggersTransitionTable(event, oldslot, NULL, transition_capture); TransitionTableAddTuple(estate, transition_capture, relinfo, oldslot, NULL, old_tuplestore); } /* * Capture the new tuple in the appropriate transition table based on * the event. */ if (!TupIsNull(newslot)) { Tuplestorestate *new_tuplestore; new_tuplestore = GetAfterTriggersTransitionTable(event, NULL, newslot, transition_capture); TransitionTableAddTuple(estate, transition_capture, relinfo, newslot, original_insert_tuple, new_tuplestore); } /* * If transition tables are the only reason we're here, return. As * mentioned above, we can also be here during update tuple routing in * presence of transition tables, in which case this function is * called separately for OLD and NEW, so we expect exactly one of them * to be NULL. */ if (trigdesc == NULL || (event == TRIGGER_EVENT_DELETE && !trigdesc->trig_delete_after_row) || (event == TRIGGER_EVENT_INSERT && !trigdesc->trig_insert_after_row) || (event == TRIGGER_EVENT_UPDATE && !trigdesc->trig_update_after_row) || (event == TRIGGER_EVENT_UPDATE && (TupIsNull(oldslot) ^ TupIsNull(newslot)))) return; } /* * We normally don't see partitioned tables here for row level triggers * except in the special case of a cross-partition update. In that case, * nodeModifyTable.c:ExecCrossPartitionUpdateForeignKey() calls here to * queue an update event on the root target partitioned table, also * passing the source and destination partitions and their tuples. */ Assert(!row_trigger || rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE || (is_crosspart_update && TRIGGER_FIRED_BY_UPDATE(event) && src_partinfo != NULL && dst_partinfo != NULL)); /* * Validate the event code and collect the associated tuple CTIDs. * * The event code will be used both as a bitmask and an array offset, so * validation is important to make sure we don't walk off the edge of our * arrays. * * Also, if we're considering statement-level triggers, check whether we * already queued a set of them for this event, and cancel the prior set * if so. This preserves the behavior that statement-level triggers fire * just once per statement and fire after row-level triggers. */ switch (event) { case TRIGGER_EVENT_INSERT: tgtype_event = TRIGGER_TYPE_INSERT; if (row_trigger) { Assert(oldslot == NULL); Assert(newslot != NULL); ItemPointerCopy(&(newslot->tts_tid), &(new_event.ate_ctid1)); ItemPointerSetInvalid(&(new_event.ate_ctid2)); } else { Assert(oldslot == NULL); Assert(newslot == NULL); ItemPointerSetInvalid(&(new_event.ate_ctid1)); ItemPointerSetInvalid(&(new_event.ate_ctid2)); cancel_prior_stmt_triggers(RelationGetRelid(rel), CMD_INSERT, event); } break; case TRIGGER_EVENT_DELETE: tgtype_event = TRIGGER_TYPE_DELETE; if (row_trigger) { Assert(oldslot != NULL); Assert(newslot == NULL); ItemPointerCopy(&(oldslot->tts_tid), &(new_event.ate_ctid1)); ItemPointerSetInvalid(&(new_event.ate_ctid2)); } else { Assert(oldslot == NULL); Assert(newslot == NULL); ItemPointerSetInvalid(&(new_event.ate_ctid1)); ItemPointerSetInvalid(&(new_event.ate_ctid2)); cancel_prior_stmt_triggers(RelationGetRelid(rel), CMD_DELETE, event); } break; case TRIGGER_EVENT_UPDATE: tgtype_event = TRIGGER_TYPE_UPDATE; if (row_trigger) { Assert(oldslot != NULL); Assert(newslot != NULL); ItemPointerCopy(&(oldslot->tts_tid), &(new_event.ate_ctid1)); ItemPointerCopy(&(newslot->tts_tid), &(new_event.ate_ctid2)); /* * Also remember the OIDs of partitions to fetch these tuples * out of later in AfterTriggerExecute(). */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { Assert(src_partinfo != NULL && dst_partinfo != NULL); new_event.ate_src_part = RelationGetRelid(src_partinfo->ri_RelationDesc); new_event.ate_dst_part = RelationGetRelid(dst_partinfo->ri_RelationDesc); } } else { Assert(oldslot == NULL); Assert(newslot == NULL); ItemPointerSetInvalid(&(new_event.ate_ctid1)); ItemPointerSetInvalid(&(new_event.ate_ctid2)); cancel_prior_stmt_triggers(RelationGetRelid(rel), CMD_UPDATE, event); } break; case TRIGGER_EVENT_TRUNCATE: tgtype_event = TRIGGER_TYPE_TRUNCATE; Assert(oldslot == NULL); Assert(newslot == NULL); ItemPointerSetInvalid(&(new_event.ate_ctid1)); ItemPointerSetInvalid(&(new_event.ate_ctid2)); break; default: elog(ERROR, "invalid after-trigger event code: %d", event); tgtype_event = 0; /* keep compiler quiet */ break; } /* Determine flags */ if (!(relkind == RELKIND_FOREIGN_TABLE && row_trigger)) { if (row_trigger && event == TRIGGER_EVENT_UPDATE) { if (relkind == RELKIND_PARTITIONED_TABLE) new_event.ate_flags = AFTER_TRIGGER_CP_UPDATE; else new_event.ate_flags = AFTER_TRIGGER_2CTID; } else new_event.ate_flags = AFTER_TRIGGER_1CTID; } /* else, we'll initialize ate_flags for each trigger */ tgtype_level = (row_trigger ? TRIGGER_TYPE_ROW : TRIGGER_TYPE_STATEMENT); /* * Must convert/copy the source and destination partition tuples into the * root partitioned table's format/slot, because the processing in the * loop below expects both oldslot and newslot tuples to be in that form. */ if (row_trigger && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { TupleTableSlot *rootslot; TupleConversionMap *map; rootslot = ExecGetTriggerOldSlot(estate, relinfo); map = ExecGetChildToRootMap(src_partinfo); if (map) oldslot = execute_attr_map_slot(map->attrMap, oldslot, rootslot); else oldslot = ExecCopySlot(rootslot, oldslot); rootslot = ExecGetTriggerNewSlot(estate, relinfo); map = ExecGetChildToRootMap(dst_partinfo); if (map) newslot = execute_attr_map_slot(map->attrMap, newslot, rootslot); else newslot = ExecCopySlot(rootslot, newslot); } for (i = 0; i < trigdesc->numtriggers; i++) { Trigger *trigger = &trigdesc->triggers[i]; if (!TRIGGER_TYPE_MATCHES(trigger->tgtype, tgtype_level, TRIGGER_TYPE_AFTER, tgtype_event)) continue; if (!TriggerEnabled(estate, relinfo, trigger, event, modifiedCols, oldslot, newslot)) continue; if (relkind == RELKIND_FOREIGN_TABLE && row_trigger) { if (fdw_tuplestore == NULL) { fdw_tuplestore = GetCurrentFDWTuplestore(); new_event.ate_flags = AFTER_TRIGGER_FDW_FETCH; } else /* subsequent event for the same tuple */ new_event.ate_flags = AFTER_TRIGGER_FDW_REUSE; } /* * If the trigger is a foreign key enforcement trigger, there are * certain cases where we can skip queueing the event because we can * tell by inspection that the FK constraint will still pass. There * are also some cases during cross-partition updates of a partitioned * table where queuing the event can be skipped. */ if (TRIGGER_FIRED_BY_UPDATE(event) || TRIGGER_FIRED_BY_DELETE(event)) { switch (RI_FKey_trigger_type(trigger->tgfoid)) { case RI_TRIGGER_PK: /* * For cross-partitioned updates of partitioned PK table, * skip the event fired by the component delete on the * source leaf partition unless the constraint originates * in the partition itself (!tgisclone), because the * update event that will be fired on the root * (partitioned) target table will be used to perform the * necessary foreign key enforcement action. */ if (is_crosspart_update && TRIGGER_FIRED_BY_DELETE(event) && trigger->tgisclone) continue; /* Update or delete on trigger's PK table */ if (!RI_FKey_pk_upd_check_required(trigger, rel, oldslot, newslot)) { /* skip queuing this event */ continue; } break; case RI_TRIGGER_FK: /* * Update on trigger's FK table. We can skip the update * event fired on a partitioned table during a * cross-partition of that table, because the insert event * that is fired on the destination leaf partition would * suffice to perform the necessary foreign key check. * Moreover, RI_FKey_fk_upd_check_required() expects to be * passed a tuple that contains system attributes, most of * which are not present in the virtual slot belonging to * a partitioned table. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE || !RI_FKey_fk_upd_check_required(trigger, rel, oldslot, newslot)) { /* skip queuing this event */ continue; } break; case RI_TRIGGER_NONE: /* * Not an FK trigger. No need to queue the update event * fired during a cross-partitioned update of a * partitioned table, because the same row trigger must be * present in the leaf partition(s) that are affected as * part of this update and the events fired on them are * queued instead. */ if (row_trigger && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) continue; break; } } /* * If the trigger is a deferred unique constraint check trigger, only * queue it if the unique constraint was potentially violated, which * we know from index insertion time. */ if (trigger->tgfoid == F_UNIQUE_KEY_RECHECK) { if (!list_member_oid(recheckIndexes, trigger->tgconstrindid)) continue; /* Uniqueness definitely not violated */ } /* * Fill in event structure and add it to the current query's queue. * Note we set ats_table to NULL whenever this trigger doesn't use * transition tables, to improve sharability of the shared event data. */ new_shared.ats_event = (event & TRIGGER_EVENT_OPMASK) | (row_trigger ? TRIGGER_EVENT_ROW : 0) | (trigger->tgdeferrable ? AFTER_TRIGGER_DEFERRABLE : 0) | (trigger->tginitdeferred ? AFTER_TRIGGER_INITDEFERRED : 0); new_shared.ats_tgoid = trigger->tgoid; new_shared.ats_relid = RelationGetRelid(rel); new_shared.ats_firing_id = 0; if ((trigger->tgoldtable || trigger->tgnewtable) && transition_capture != NULL) new_shared.ats_table = transition_capture->tcs_private; else new_shared.ats_table = NULL; new_shared.ats_modifiedcols = afterTriggerCopyBitmap(modifiedCols); afterTriggerAddEvent(&afterTriggers.query_stack[afterTriggers.query_depth].events, &new_event, &new_shared); } /* * Finally, spool any foreign tuple(s). The tuplestore squashes them to * minimal tuples, so this loses any system columns. The executor lost * those columns before us, for an unrelated reason, so this is fine. */ if (fdw_tuplestore) { if (oldslot != NULL) tuplestore_puttupleslot(fdw_tuplestore, oldslot); if (newslot != NULL) tuplestore_puttupleslot(fdw_tuplestore, newslot); } } /* * Detect whether we already queued BEFORE STATEMENT triggers for the given * relation + operation, and set the flag so the next call will report "true". */ static bool before_stmt_triggers_fired(Oid relid, CmdType cmdType) { bool result; AfterTriggersTableData *table; /* Check state, like AfterTriggerSaveEvent. */ if (afterTriggers.query_depth < 0) elog(ERROR, "before_stmt_triggers_fired() called outside of query"); /* Be sure we have enough space to record events at this query depth. */ if (afterTriggers.query_depth >= afterTriggers.maxquerydepth) AfterTriggerEnlargeQueryState(); /* * We keep this state in the AfterTriggersTableData that also holds * transition tables for the relation + operation. In this way, if we are * forced to make a new set of transition tables because more tuples get * entered after we've already fired triggers, we will allow a new set of * statement triggers to get queued. */ table = GetAfterTriggersTableData(relid, cmdType); result = table->before_trig_done; table->before_trig_done = true; return result; } /* * If we previously queued a set of AFTER STATEMENT triggers for the given * relation + operation, and they've not been fired yet, cancel them. The * caller will queue a fresh set that's after any row-level triggers that may * have been queued by the current sub-statement, preserving (as much as * possible) the property that AFTER ROW triggers fire before AFTER STATEMENT * triggers, and that the latter only fire once. This deals with the * situation where several FK enforcement triggers sequentially queue triggers * for the same table into the same trigger query level. We can't fully * prevent odd behavior though: if there are AFTER ROW triggers taking * transition tables, we don't want to change the transition tables once the * first such trigger has seen them. In such a case, any additional events * will result in creating new transition tables and allowing new firings of * statement triggers. * * This also saves the current event list location so that a later invocation * of this function can cheaply find the triggers we're about to queue and * cancel them. */ static void cancel_prior_stmt_triggers(Oid relid, CmdType cmdType, int tgevent) { AfterTriggersTableData *table; AfterTriggersQueryData *qs = &afterTriggers.query_stack[afterTriggers.query_depth]; /* * We keep this state in the AfterTriggersTableData that also holds * transition tables for the relation + operation. In this way, if we are * forced to make a new set of transition tables because more tuples get * entered after we've already fired triggers, we will allow a new set of * statement triggers to get queued without canceling the old ones. */ table = GetAfterTriggersTableData(relid, cmdType); if (table->after_trig_done) { /* * We want to start scanning from the tail location that existed just * before we inserted any statement triggers. But the events list * might've been entirely empty then, in which case scan from the * current head. */ AfterTriggerEvent event; AfterTriggerEventChunk *chunk; if (table->after_trig_events.tail) { chunk = table->after_trig_events.tail; event = (AfterTriggerEvent) table->after_trig_events.tailfree; } else { chunk = qs->events.head; event = NULL; } for_each_chunk_from(chunk) { if (event == NULL) event = (AfterTriggerEvent) CHUNK_DATA_START(chunk); for_each_event_from(event, chunk) { AfterTriggerShared evtshared = GetTriggerSharedData(event); /* * Exit loop when we reach events that aren't AS triggers for * the target relation. */ if (evtshared->ats_relid != relid) goto done; if ((evtshared->ats_event & TRIGGER_EVENT_OPMASK) != tgevent) goto done; if (!TRIGGER_FIRED_FOR_STATEMENT(evtshared->ats_event)) goto done; if (!TRIGGER_FIRED_AFTER(evtshared->ats_event)) goto done; /* OK, mark it DONE */ event->ate_flags &= ~AFTER_TRIGGER_IN_PROGRESS; event->ate_flags |= AFTER_TRIGGER_DONE; } /* signal we must reinitialize event ptr for next chunk */ event = NULL; } } done: /* In any case, save current insertion point for next time */ table->after_trig_done = true; table->after_trig_events = qs->events; } /* * GUC assign_hook for session_replication_role */ void assign_session_replication_role(int newval, void *extra) { /* * Must flush the plan cache when changing replication role; but don't * flush unnecessarily. */ if (SessionReplicationRole != newval) ResetPlanCache(); } /* * SQL function pg_trigger_depth() */ Datum pg_trigger_depth(PG_FUNCTION_ARGS) { PG_RETURN_INT32(MyTriggerDepth); }