postgresql/src/include/access/xact.h

/*-------------------------------------------------------------------------
 *
 * xact.h
 *	  postgres transaction system header
 *
 *
 * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $Id: xact.h,v 1.26 2000/06/08 22:37:38 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef XACT_H
#define XACT_H

#include "access/transam.h"
#include "utils/nabstime.h"

/* ----------------
 *		transaction state structure
 * ----------------
 */
typedef struct TransactionStateData
{
	TransactionId transactionIdData;
	CommandId	commandId;
	CommandId	scanCommandId;
	AbsoluteTime startTime;
	int			state;
	int			blockState;
} TransactionStateData;

/*
 * Xact isolation levels
 */
#define XACT_DIRTY_READ			0		/* not implemented */
#define XACT_READ_COMMITTED		1
#define XACT_REPEATABLE_READ	2		/* not implemented */
#define XACT_SERIALIZABLE		3

extern int	DefaultXactIsoLevel;
extern int	XactIsoLevel;

/* ----------------
 *		transaction states
 * ----------------
 */
#define TRANS_DEFAULT			0
#define TRANS_START				1
#define TRANS_INPROGRESS		2
#define TRANS_COMMIT			3
#define TRANS_ABORT				4
#define TRANS_DISABLED			5

/* ----------------
 *		transaction block states
 * ----------------
 */
#define TBLOCK_DEFAULT			0
#define TBLOCK_BEGIN			1
#define TBLOCK_INPROGRESS		2
#define TBLOCK_END				3
#define TBLOCK_ABORT			4
#define TBLOCK_ENDABORT			5

typedef TransactionStateData *TransactionState;

#define TransactionIdIsValid(xid)		((bool) (xid != NullTransactionId))
#define TransactionIdStore(xid, dest)	\
	(*((TransactionId*)dest) = (TransactionId)xid)
#define StoreInvalidTransactionId(dest) \
	(*((TransactionId*)dest) = NullTransactionId)


/* ----------------------------------------------------------------
 *		TransactionIdEquals
 * ----------------------------------------------------------------
 */
#define TransactionIdEquals(id1, id2) \
( \
	((bool) ((id1) == (id2))) \
)


/* ----------------
 *		extern definitions
 * ----------------
 */
extern int	TransactionFlushEnabled(void);
extern void SetTransactionFlushEnabled(bool state);

extern bool IsAbortedTransactionBlockState(void);
extern void OverrideTransactionSystem(bool flag);
extern TransactionId GetCurrentTransactionId(void);
extern CommandId GetCurrentCommandId(void);
extern CommandId GetScanCommandId(void);
extern void SetScanCommandId(CommandId);
extern AbsoluteTime GetCurrentTransactionStartTime(void);
extern bool TransactionIdIsCurrentTransactionId(TransactionId xid);
extern bool CommandIdIsCurrentCommandId(CommandId cid);
extern bool CommandIdGEScanCommandId(CommandId cid);
extern void CommandCounterIncrement(void);
extern void InitializeTransactionSystem(void);
extern void StartTransactionCommand(void);
extern void CommitTransactionCommand(void);
extern void AbortCurrentTransaction(void);
extern void BeginTransactionBlock(void);
extern void EndTransactionBlock(void);
extern bool IsTransactionBlock(void);
extern void UserAbortTransactionBlock(void);
extern void AbortOutOfAnyTransaction(void);

extern TransactionId DisabledTransactionId;

/* defined in xid.c */
extern Datum xidin(PG_FUNCTION_ARGS);
extern Datum xidout(PG_FUNCTION_ARGS);
extern Datum xideq(PG_FUNCTION_ARGS);
extern void TransactionIdAdd(TransactionId *xid, int value);

#endif	 /* XACT_H */