trigger.h

Go to the documentation of this file.

/*-------------------------------------------------------------------------
 *
 * trigger.h
 *    Declarations for trigger handling.
 *
 * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/commands/trigger.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef TRIGGER_H
#define TRIGGER_H

#include "catalog/objectaddress.h"
#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"

/*
 * TriggerData is the node type that is passed as fmgr "context" info
 * when a function is called by the trigger manager.
 */

#define CALLED_AS_TRIGGER(fcinfo) \
    ((fcinfo)->context != NULL && IsA((fcinfo)->context, TriggerData))

typedef uint32 TriggerEvent;

typedef struct TriggerData
{
    NodeTag     type;
    TriggerEvent tg_event;
    Relation    tg_relation;
    HeapTuple   tg_trigtuple;
    HeapTuple   tg_newtuple;
    Trigger    *tg_trigger;
    Buffer      tg_trigtuplebuf;
    Buffer      tg_newtuplebuf;
} TriggerData;

/*
 * TriggerEvent bit flags
 *
 * Note that we assume different event types (INSERT/DELETE/UPDATE/TRUNCATE)
 * can't be OR'd together in a single TriggerEvent.  This is unlike the
 * situation for pg_trigger rows, so pg_trigger.tgtype uses a different
 * representation!
 */
#define TRIGGER_EVENT_INSERT            0x00000000
#define TRIGGER_EVENT_DELETE            0x00000001
#define TRIGGER_EVENT_UPDATE            0x00000002
#define TRIGGER_EVENT_TRUNCATE          0x00000003
#define TRIGGER_EVENT_OPMASK            0x00000003

#define TRIGGER_EVENT_ROW               0x00000004

#define TRIGGER_EVENT_BEFORE            0x00000008
#define TRIGGER_EVENT_AFTER             0x00000000
#define TRIGGER_EVENT_INSTEAD           0x00000010
#define TRIGGER_EVENT_TIMINGMASK        0x00000018

/* More TriggerEvent flags, used only within trigger.c */

#define AFTER_TRIGGER_DEFERRABLE        0x00000020
#define AFTER_TRIGGER_INITDEFERRED      0x00000040

#define TRIGGER_FIRED_BY_INSERT(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_INSERT)

#define TRIGGER_FIRED_BY_DELETE(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_DELETE)

#define TRIGGER_FIRED_BY_UPDATE(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_UPDATE)

#define TRIGGER_FIRED_BY_TRUNCATE(event) \
    (((event) & TRIGGER_EVENT_OPMASK) == TRIGGER_EVENT_TRUNCATE)

#define TRIGGER_FIRED_FOR_ROW(event) \
    ((event) & TRIGGER_EVENT_ROW)

#define TRIGGER_FIRED_FOR_STATEMENT(event) \
    (!TRIGGER_FIRED_FOR_ROW(event))

#define TRIGGER_FIRED_BEFORE(event) \
    (((event) & TRIGGER_EVENT_TIMINGMASK) == TRIGGER_EVENT_BEFORE)

#define TRIGGER_FIRED_AFTER(event) \
    (((event) & TRIGGER_EVENT_TIMINGMASK) == TRIGGER_EVENT_AFTER)

#define TRIGGER_FIRED_INSTEAD(event) \
    (((event) & TRIGGER_EVENT_TIMINGMASK) == TRIGGER_EVENT_INSTEAD)

/*
 * Definitions for replication role based firing.
 */
#define SESSION_REPLICATION_ROLE_ORIGIN     0
#define SESSION_REPLICATION_ROLE_REPLICA    1
#define SESSION_REPLICATION_ROLE_LOCAL      2
extern PGDLLIMPORT int SessionReplicationRole;

/*
 * States at which a trigger can be fired. These are the
 * possible values for pg_trigger.tgenabled.
 */
#define TRIGGER_FIRES_ON_ORIGIN             'O'
#define TRIGGER_FIRES_ALWAYS                'A'
#define TRIGGER_FIRES_ON_REPLICA            'R'
#define TRIGGER_DISABLED                    'D'

extern ObjectAddress CreateTrigger(CreateTrigStmt *stmt, const char *queryString,
              Oid relOid, Oid refRelOid, Oid constraintOid, Oid indexOid,
              bool isInternal);

extern void RemoveTriggerById(Oid trigOid);
extern Oid  get_trigger_oid(Oid relid, const char *name, bool missing_ok);

extern ObjectAddress renametrig(RenameStmt *stmt);

extern void EnableDisableTrigger(Relation rel, const char *tgname,
                     char fires_when, bool skip_system);

extern void RelationBuildTriggers(Relation relation);

extern TriggerDesc *CopyTriggerDesc(TriggerDesc *trigdesc);

extern void FreeTriggerDesc(TriggerDesc *trigdesc);

extern void ExecBSInsertTriggers(EState *estate,
                     ResultRelInfo *relinfo);
extern void ExecASInsertTriggers(EState *estate,
                     ResultRelInfo *relinfo);
extern TupleTableSlot *ExecBRInsertTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     TupleTableSlot *slot);
extern void ExecARInsertTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     HeapTuple trigtuple,
                     List *recheckIndexes);
extern TupleTableSlot *ExecIRInsertTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     TupleTableSlot *slot);
extern void ExecBSDeleteTriggers(EState *estate,
                     ResultRelInfo *relinfo);
extern void ExecASDeleteTriggers(EState *estate,
                     ResultRelInfo *relinfo);
extern bool ExecBRDeleteTriggers(EState *estate,
                     EPQState *epqstate,
                     ResultRelInfo *relinfo,
                     ItemPointer tupleid,
                     HeapTuple fdw_trigtuple);
extern void ExecARDeleteTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     ItemPointer tupleid,
                     HeapTuple fdw_trigtuple);
extern bool ExecIRDeleteTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     HeapTuple trigtuple);
extern void ExecBSUpdateTriggers(EState *estate,
                     ResultRelInfo *relinfo);
extern void ExecASUpdateTriggers(EState *estate,
                     ResultRelInfo *relinfo);
extern TupleTableSlot *ExecBRUpdateTriggers(EState *estate,
                     EPQState *epqstate,
                     ResultRelInfo *relinfo,
                     ItemPointer tupleid,
                     HeapTuple fdw_trigtuple,
                     TupleTableSlot *slot);
extern void ExecARUpdateTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     ItemPointer tupleid,
                     HeapTuple fdw_trigtuple,
                     HeapTuple newtuple,
                     List *recheckIndexes);
extern TupleTableSlot *ExecIRUpdateTriggers(EState *estate,
                     ResultRelInfo *relinfo,
                     HeapTuple trigtuple,
                     TupleTableSlot *slot);
extern void ExecBSTruncateTriggers(EState *estate,
                       ResultRelInfo *relinfo);
extern void ExecASTruncateTriggers(EState *estate,
                       ResultRelInfo *relinfo);

extern void AfterTriggerBeginXact(void);
extern void AfterTriggerBeginQuery(void);
extern void AfterTriggerEndQuery(EState *estate);
extern void AfterTriggerFireDeferred(void);
extern void AfterTriggerEndXact(bool isCommit);
extern void AfterTriggerBeginSubXact(void);
extern void AfterTriggerEndSubXact(bool isCommit);
extern void AfterTriggerSetState(ConstraintsSetStmt *stmt);
extern bool AfterTriggerPendingOnRel(Oid relid);


/*
 * in utils/adt/ri_triggers.c
 */
extern bool RI_FKey_pk_upd_check_required(Trigger *trigger, Relation pk_rel,
                              HeapTuple old_row, HeapTuple new_row);
extern bool RI_FKey_fk_upd_check_required(Trigger *trigger, Relation fk_rel,
                              HeapTuple old_row, HeapTuple new_row);
extern bool RI_Initial_Check(Trigger *trigger,
                 Relation fk_rel, Relation pk_rel);

/* result values for RI_FKey_trigger_type: */
#define RI_TRIGGER_PK   1       /* is a trigger on the PK relation */
#define RI_TRIGGER_FK   2       /* is a trigger on the FK relation */
#define RI_TRIGGER_NONE 0       /* is not an RI trigger function */

extern int  RI_FKey_trigger_type(Oid tgfoid);

extern Datum pg_trigger_depth(PG_FUNCTION_ARGS);

#endif   /* TRIGGER_H */