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pg_probackup/xlog.c

125 lines
3.0 KiB
C

/*-------------------------------------------------------------------------
*
* xlog.c: Parse WAL files.
*
* Copyright (c) 2009, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
*
*-------------------------------------------------------------------------
*/
#include "pg_rman.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#if PG_VERSION_NUM >= 80400
typedef unsigned long Datum;
typedef struct MemoryContextData *MemoryContext;
#endif
#include "access/xlog_internal.h"
#define XLOG_PAGE_MAGIC_v80 0xD05C /* 8.0 */
#define XLOG_PAGE_MAGIC_v81 0xD05D /* 8.1 */
#define XLOG_PAGE_MAGIC_v82 0xD05E /* 8.2 */
#define XLOG_PAGE_MAGIC_v83 0xD062 /* 8.3 */
#define XLOG_PAGE_MAGIC_v84 0xD063 /* 8.4 */
#define XLOG_PAGE_MAGIC_v85 0xD166 /* 8.5 */
/*
* XLogLongPageHeaderData is modified in 8.3, but the layout is compatible
* except xlp_xlog_blcksz.
*/
typedef union XLogPage
{
XLogPageHeaderData header;
XLogLongPageHeaderData lheader;
char data[XLOG_BLCKSZ];
} XLogPage;
/*
* Return whether the file is a WAL segment or not.
* based on ValidXLOGHeader() in src/backend/access/transam/xlog.c.
*/
bool
xlog_is_complete_wal(const pgFile *file, int server_version)
{
FILE *fp;
XLogPage page;
uint16 xlog_page_magic;
fp = fopen(file->path, "r");
if (!fp)
return false;
if (fread(&page, 1, sizeof(page), fp) != XLOG_BLCKSZ)
{
fclose(fp);
return false;
}
fclose(fp);
/* xlog_page_magic from server version */
if (server_version < 80000)
return false; /* never happen */
else if (server_version < 80100)
xlog_page_magic = XLOG_PAGE_MAGIC_v80;
else if (server_version < 80200)
xlog_page_magic = XLOG_PAGE_MAGIC_v81;
else if (server_version < 80300)
xlog_page_magic = XLOG_PAGE_MAGIC_v82;
else if (server_version < 80400)
xlog_page_magic = XLOG_PAGE_MAGIC_v83;
else if (server_version < 80500)
xlog_page_magic = XLOG_PAGE_MAGIC_v84;
else if (server_version < 80600)
xlog_page_magic = XLOG_PAGE_MAGIC_v85;
else
return false; /* not supported */
/* check header */
if (page.header.xlp_magic != xlog_page_magic)
return false;
if ((page.header.xlp_info & ~XLP_ALL_FLAGS) != 0)
return false;
if ((page.header.xlp_info & XLP_LONG_HEADER) == 0)
return false;
if (page.lheader.xlp_seg_size != XLogSegSize)
return false;
if (server_version >= 80300 && page.lheader.xlp_xlog_blcksz != XLOG_BLCKSZ)
return false;
/*
* check size (actual file size, not backup file size)
* TODO: Support pre-compressed xlog. They might have different file sizes.
*/
if (file->size != XLogSegSize)
return false;
return true;
}
bool
xlog_logfname2lsn(const char *logfname, XLogRecPtr *lsn)
{
uint32 tli;
if (sscanf(logfname, "%08X%08X%08X",
&tli, &lsn->xlogid, &lsn->xrecoff) != 3)
return false;
lsn->xrecoff *= XLogSegSize;
return true;
}
/*
* based on XLogFileName() in xlog_internal.h
*/
void
xlog_fname(char *fname, size_t len, TimeLineID tli, XLogRecPtr *lsn)
{
snprintf(fname, len, "%08X%08X%08X", tli,
lsn->xlogid, lsn->xrecoff / XLogSegSize);
}