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/*
* xlog.h
*
* PostgreSQL transaction log manager
*
* $Header: /cvsroot/pgsql/src/include/access/xlog.h,v 1.16 2001/01/12 21:54:01 tgl Exp $
*/
#ifndef XLOG_H
#define XLOG_H
#include "access/rmgr.h"
#include "access/transam.h"
#include "access/xlogdefs.h"
#include "access/xlogutils.h"
typedef struct crc64
{
uint32 crc1;
uint32 crc2;
} crc64;
typedef struct XLogRecord
{
crc64 xl_crc;
XLogRecPtr xl_prev; /* ptr to previous record in log */
XLogRecPtr xl_xact_prev; /* ptr to previous record of this xact */
TransactionId xl_xid; /* xact id */
uint16 xl_len; /* total len of record *data* */
uint8 xl_info;
RmgrId xl_rmid; /* resource manager inserted this record */
/* ACTUAL LOG DATA FOLLOWS AT END OF STRUCT */
} XLogRecord;
#define SizeOfXLogRecord DOUBLEALIGN(sizeof(XLogRecord))
#define MAXLOGRECSZ (2 * BLCKSZ)
#define XLogRecGetData(record) \
((char*)record + SizeOfXLogRecord)
/*
* When there is no space on current page we continue
* on the next page with subrecord.
*/
typedef struct XLogSubRecord
{
uint16 xl_len; /* len of data left */
/* ACTUAL LOG DATA FOLLOWS AT END OF STRUCT */
} XLogSubRecord;
#define SizeOfXLogSubRecord DOUBLEALIGN(sizeof(XLogSubRecord))
/*
* XLOG uses only low 4 bits of xl_info.
* High 4 bits may be used by rmgr...
*
* We support backup of 2 blocks per record only.
* If we backed up some of these blocks then we use
* flags below to signal rmgr about this on recovery.
*/
#define XLR_SET_BKP_BLOCK(iblk) (0x08 >> iblk)
#define XLR_BKP_BLOCK_1 XLR_SET_BKP_BLOCK(0) /* 0x08 */
#define XLR_BKP_BLOCK_2 XLR_SET_BKP_BLOCK(1) /* 0x04 */
#define XLR_INFO_MASK 0x0F
/*
* Sometimes we log records which are out of transaction control.
* Rmgr may use flag below for this purpose.
*/
#define XLOG_NO_TRAN XLR_INFO_MASK
#define XLOG_PAGE_MAGIC 0x17345168
typedef struct XLogPageHeaderData
{
uint32 xlp_magic;
uint16 xlp_info;
} XLogPageHeaderData;
#define SizeOfXLogPHD DOUBLEALIGN(sizeof(XLogPageHeaderData))
typedef XLogPageHeaderData *XLogPageHeader;
/* When record crosses page boundary */
#define XLP_FIRST_IS_SUBRECORD 0x0001
#define XLByteLT(left, right) \
(right.xlogid > left.xlogid || \
(right.xlogid == left.xlogid && right.xrecoff > left.xrecoff))
#define XLByteLE(left, right) \
(right.xlogid > left.xlogid || \
(right.xlogid == left.xlogid && right.xrecoff >= left.xrecoff))
#define XLByteEQ(left, right) \
(right.xlogid == left.xlogid && right.xrecoff == left.xrecoff)
extern StartUpID ThisStartUpID; /* current SUI */
extern bool InRecovery;
extern XLogRecPtr MyLastRecPtr;
extern volatile uint32 CritSectionCount;
typedef struct RmgrData
{
char *rm_name;
void (*rm_redo)(XLogRecPtr lsn, XLogRecord *rptr);
void (*rm_undo)(XLogRecPtr lsn, XLogRecord *rptr);
void (*rm_desc)(char *buf, uint8 xl_info, char *rec);
} RmgrData;
extern RmgrData RmgrTable[];
/*
* List of these structs is used to pass data to XLOG.
* If buffer is valid then XLOG will check if buffer must
* be backup-ed. For backup-ed buffer data will not be
* inserted into record (and XLOG sets
* XLR_BKP_BLOCK_X bit in xl_info).
*/
typedef struct XLogRecData
{
Buffer buffer; /* buffer associated with this data */
char *data;
uint32 len;
struct XLogRecData *next;
} XLogRecData;
extern XLogRecPtr XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata);
extern void XLogFlush(XLogRecPtr RecPtr);
extern void CreateCheckPoint(bool shutdown);
extern void xlog_redo(XLogRecPtr lsn, XLogRecord *record);
extern void xlog_undo(XLogRecPtr lsn, XLogRecord *record);
extern void xlog_desc(char *buf, uint8 xl_info, char* rec);
extern void UpdateControlFile(void);
extern int XLOGShmemSize(void);
extern void XLOGShmemInit(void);
extern void XLOGPathInit(void);
extern void BootStrapXLOG(void);
extern void StartupXLOG(void);
extern void ShutdownXLOG(void);
extern void CreateCheckPoint(bool shutdown);
extern void SetThisStartUpID(void);
#endif /* XLOG_H */
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