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mirror of https://github.com/postgrespro/pg_probackup.git synced 2024-12-01 09:51:43 +02:00
pg_probackup/fetch.c
Michael Paquier 308d00b80c Obtain timeline ID with control file and not XLOG system function
The system function used up to now was pg_xlogfile_name_offset, which
cannot be used on a node in recovery, and it was the only way present
to fetch the timeline ID of a backup, either incremental or full. So
instead scan the control file of server and fetch the timeline from
that. This also removes the restriction on which a backup could not
be taken on a standby node. The next step being to have the possibility
to take backups from streams.
2013-12-13 03:55:39 +09:00

70 lines
1.8 KiB
C

/*-------------------------------------------------------------------------
*
* fetch.c
* Functions for fetching files from PostgreSQL data directory
*
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include "catalog/catalog.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include "pg_rman.h"
/*
* Read a file into memory. The file to be read is <datadir>/<path>.
* The file contents are returned in a malloc'd buffer, and *filesize
* is set to the length of the file.
*
* The returned buffer is always zero-terminated; the size of the returned
* buffer is actually *filesize + 1. That's handy when reading a text file.
* This function can be used to read binary files as well, you can just
* ignore the zero-terminator in that case.
*
*/
char *
slurpFile(const char *datadir, const char *path, size_t *filesize)
{
int fd;
char *buffer;
struct stat statbuf;
char fullpath[MAXPGPATH];
int len;
snprintf(fullpath, sizeof(fullpath), "%s/%s", datadir, path);
if ((fd = open(fullpath, O_RDONLY | PG_BINARY, 0)) == -1)
elog(ERROR_CORRUPTED, _("could not open file \"%s\" for reading: %s\n"),
fullpath, strerror(errno));
if (fstat(fd, &statbuf) < 0)
elog(ERROR_CORRUPTED, _("could not open file \"%s\" for reading: %s\n"),
fullpath, strerror(errno));
len = statbuf.st_size;
buffer = pg_malloc(len + 1);
if (read(fd, buffer, len) != len)
elog(ERROR_CORRUPTED, _("could not read file \"%s\": %s\n"),
fullpath, strerror(errno));
close(fd);
/* Zero-terminate the buffer. */
buffer[len] = '\0';
if (filesize)
*filesize = len;
return buffer;
}