src/include/commands/trigger.h

/*-------------------------------------------------------------------------
 *
 * trigger.h
 *	  Declarations for trigger handling.
 *
 * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL: pgsql/src/include/commands/trigger.h,v 1.59 2006/09/04 21:15:56 tgl Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef TRIGGER_H
#define TRIGGER_H

#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
#include "utils/rel.h"
#include "storage/buf.h"
#include "executor/instrument.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 */

#define TRIGGER_EVENT_INSERT			0x00000000
#define TRIGGER_EVENT_DELETE			0x00000001
#define TRIGGER_EVENT_UPDATE			0x00000002
#define TRIGGER_EVENT_OPMASK			0x00000003
#define TRIGGER_EVENT_ROW				0x00000004
#define TRIGGER_EVENT_BEFORE			0x00000008

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

#define AFTER_TRIGGER_DONE				0x00000010
#define AFTER_TRIGGER_IN_PROGRESS		0x00000020
#define AFTER_TRIGGER_DEFERRABLE		0x00000040
#define AFTER_TRIGGER_INITDEFERRED		0x00000080

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

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

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

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

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

#define TRIGGER_FIRED_BEFORE(event)				\
		((TriggerEvent) (event) & TRIGGER_EVENT_BEFORE)

#define TRIGGER_FIRED_AFTER(event)				\
		(!TRIGGER_FIRED_BEFORE (event))

/*
 * RI trigger function arguments are stored in pg_trigger.tgargs bytea
 *
 *	 constrname\0fkrel\0pkrel\0matchtype\0fkatt\0pkatt\0fkatt\0pkatt\0...
 *
 * There are one or more pairs of fkatt/pkatt names.
 *
 * The relation names are no longer of much use since they are not
 * guaranteed unique; they are present only for backwards compatibility.
 * Use the tgrelid and tgconstrrelid fields to identify the referenced
 * relations, instead.	(But note that which is which will depend on which
 * trigger you are looking at!)
 */
#define RI_CONSTRAINT_NAME_ARGNO		0
#define RI_FK_RELNAME_ARGNO				1
#define RI_PK_RELNAME_ARGNO				2
#define RI_MATCH_TYPE_ARGNO				3
#define RI_FIRST_ATTNAME_ARGNO			4		/* first attname pair starts
												 * here */

#define RI_KEYPAIR_FK_IDX				0
#define RI_KEYPAIR_PK_IDX				1

#define RI_MAX_NUMKEYS					INDEX_MAX_KEYS
#define RI_MAX_ARGUMENTS		(RI_FIRST_ATTNAME_ARGNO + (RI_MAX_NUMKEYS * 2))


extern Oid CreateTrigger(CreateTrigStmt *stmt, Oid relOid, Oid refRelOid,
						 bool forConstraint);

extern void DropTrigger(Oid relid, const char *trigname,
			DropBehavior behavior, bool missing_ok);
extern void RemoveTriggerById(Oid trigOid);

extern void renametrig(Oid relid, const char *oldname, const char *newname);

extern void EnableDisableTrigger(Relation rel, const char *tgname,
					 bool enable, 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 HeapTuple ExecBRInsertTriggers(EState *estate,
					 ResultRelInfo *relinfo,
					 HeapTuple trigtuple);
extern void ExecARInsertTriggers(EState *estate,
					 ResultRelInfo *relinfo,
					 HeapTuple trigtuple);
extern void ExecBSDeleteTriggers(EState *estate,
					 ResultRelInfo *relinfo);
extern void ExecASDeleteTriggers(EState *estate,
					 ResultRelInfo *relinfo);
extern bool ExecBRDeleteTriggers(EState *estate,
					 ResultRelInfo *relinfo,
					 ItemPointer tupleid,
					 CommandId cid);
extern void ExecARDeleteTriggers(EState *estate,
					 ResultRelInfo *relinfo,
					 ItemPointer tupleid);
extern void ExecBSUpdateTriggers(EState *estate,
					 ResultRelInfo *relinfo);
extern void ExecASUpdateTriggers(EState *estate,
					 ResultRelInfo *relinfo);
extern HeapTuple ExecBRUpdateTriggers(EState *estate,
					 ResultRelInfo *relinfo,
					 ItemPointer tupleid,
					 HeapTuple newtuple,
					 CommandId cid);
extern void ExecARUpdateTriggers(EState *estate,
					 ResultRelInfo *relinfo,
					 ItemPointer tupleid,
					 HeapTuple newtuple);

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_keyequal_upd_pk(Trigger *trigger, Relation pk_rel,
						HeapTuple old_row, HeapTuple new_row);
extern bool RI_FKey_keyequal_upd_fk(Trigger *trigger, Relation fk_rel,
						HeapTuple old_row, HeapTuple new_row);
extern bool RI_Initial_Check(FkConstraint *fkconstraint,
				 Relation rel,
				 Relation pkrel);

#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 HeapTuple ExecCallTriggerFunc(TriggerData *trigdata,
 					int tgindx,
 					FmgrInfo *finfo,
 					Instrumentation *instr,
 					MemoryContext per_tuple_context);
 


#endif   /* TRIGGER_H */