postgresql/contrib/pg_archivecleanup/pg_archivecleanup.c
Tom Lane 449c73f466 Clean up pg_archivecleanup's error and logging output: put newlines in
sane places, make messages follow project's message style guidelines.

Also, avoid closedir(NULL).

Fujii Masao and Tom Lane
2010-06-17 17:31:27 +00:00

317 lines
8.5 KiB
C

/*
* $PostgreSQL: pgsql/contrib/pg_archivecleanup/pg_archivecleanup.c,v 1.2 2010/06/17 17:31:27 tgl Exp $
*
* pg_archivecleanup.c
*
* Production-ready example of an archive_cleanup_command
* used to clean an archive when using standby_mode = on in 9.0
* or for standalone use for any version of PostgreSQL 8.0+.
*
* Original author: Simon Riggs simon@2ndquadrant.com
* Current maintainer: Simon Riggs
*/
#include "postgres_fe.h"
#include <ctype.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#ifdef WIN32
int getopt(int argc, char *const argv[], const char *optstring);
#else
#include <sys/time.h>
#include <unistd.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#endif /* ! WIN32 */
extern char *optarg;
extern int optind;
const char *progname;
/* Options and defaults */
bool debug = false; /* are we debugging? */
char *archiveLocation; /* where to find the archive? */
char *restartWALFileName; /* the file from which we can restart restore */
char WALFilePath[MAXPGPATH]; /* the file path including archive */
char exclusiveCleanupFileName[MAXPGPATH]; /* the oldest file we want to
* remain in archive */
/* =====================================================================
*
* Customizable section
*
* =====================================================================
*
* Currently, this section assumes that the Archive is a locally
* accessible directory. If you want to make other assumptions,
* such as using a vendor-specific archive and access API, these
* routines are the ones you'll need to change. You're
* enouraged to submit any changes to pgsql-hackers@postgresql.org
* or personally to the current maintainer. Those changes may be
* folded in to later versions of this program.
*/
#define XLOG_DATA_FNAME_LEN 24
/* Reworked from access/xlog_internal.h */
#define XLogFileName(fname, tli, log, seg) \
snprintf(fname, XLOG_DATA_FNAME_LEN + 1, "%08X%08X%08X", tli, log, seg)
#define XLOG_BACKUP_FNAME_LEN 40
/*
* Initialize allows customized commands into the archive cleanup program.
*
* You may wish to add code to check for tape libraries, etc..
*/
static void
Initialize(void)
{
/*
* This code assumes that archiveLocation is a directory, so we use
* stat to test if it's accessible.
*/
struct stat stat_buf;
if (stat(archiveLocation, &stat_buf) != 0 ||
!S_ISDIR(stat_buf.st_mode))
{
fprintf(stderr, "%s: archiveLocation \"%s\" does not exist\n",
progname, archiveLocation);
exit(2);
}
}
static void
CleanupPriorWALFiles(void)
{
int rc;
DIR *xldir;
struct dirent *xlde;
if ((xldir = opendir(archiveLocation)) != NULL)
{
while ((xlde = readdir(xldir)) != NULL)
{
/*
* We ignore the timeline part of the XLOG segment identifiers
* in deciding whether a segment is still needed. This
* ensures that we won't prematurely remove a segment from a
* parent timeline. We could probably be a little more
* proactive about removing segments of non-parent timelines,
* but that would be a whole lot more complicated.
*
* We use the alphanumeric sorting property of the filenames
* to decide which ones are earlier than the
* exclusiveCleanupFileName file. Note that this means files
* are not removed in the order they were originally written,
* in case this worries you.
*/
if (strlen(xlde->d_name) == XLOG_DATA_FNAME_LEN &&
strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN &&
strcmp(xlde->d_name + 8, exclusiveCleanupFileName + 8) < 0)
{
#ifdef WIN32
snprintf(WALFilePath, MAXPGPATH, "%s\\%s", archiveLocation, xlde->d_name);
#else
snprintf(WALFilePath, MAXPGPATH, "%s/%s", archiveLocation, xlde->d_name);
#endif
if (debug)
fprintf(stderr, "%s: removing file \"%s\"\n",
progname, WALFilePath);
rc = unlink(WALFilePath);
if (rc != 0)
{
fprintf(stderr, "%s: ERROR: could not remove file \"%s\": %s\n",
progname, WALFilePath, strerror(errno));
break;
}
}
}
closedir(xldir);
}
else
fprintf(stderr, "%s: could not open archiveLocation \"%s\": %s\n",
progname, archiveLocation, strerror(errno));
}
/*
* SetWALFileNameForCleanup()
*
* Set the earliest WAL filename that we want to keep on the archive
* and decide whether we need_cleanup
*/
static void
SetWALFileNameForCleanup(void)
{
bool fnameOK = false;
/*
* If restartWALFileName is a WAL file name then just use it directly.
* If restartWALFileName is a .backup filename, make sure we use
* the prefix of the filename, otherwise we will remove wrong files
* since 000000010000000000000010.00000020.backup is after
* 000000010000000000000010.
*/
if (strlen(restartWALFileName) == XLOG_DATA_FNAME_LEN &&
strspn(restartWALFileName, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN)
{
strcpy(exclusiveCleanupFileName, restartWALFileName);
fnameOK = true;
}
else if (strlen(restartWALFileName) == XLOG_BACKUP_FNAME_LEN)
{
int args;
uint32 tli = 1,
log = 0,
seg = 0,
offset = 0;
args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
if (args == 4)
{
fnameOK = true;
/*
* Use just the prefix of the filename, ignore everything after first period
*/
XLogFileName(exclusiveCleanupFileName, tli, log, seg);
}
}
if (!fnameOK)
{
fprintf(stderr, "%s: invalid filename input\n", progname);
fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
exit(2);
}
}
/* =====================================================================
* End of Customizable section
* =====================================================================
*/
static void
usage(void)
{
printf("%s removes older WAL files from PostgreSQL archives.\n\n", progname);
printf("Usage:\n");
printf(" %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n", progname);
printf("\n"
"for use as an archive_cleanup_command in the recovery.conf when standby_mode = on:\n"
" archive_cleanup_command = 'pg_archivecleanup [OPTION]... ARCHIVELOCATION %%r'\n"
"e.g.\n"
" archive_cleanup_command = 'pg_archivecleanup /mnt/server/archiverdir %%r'\n");
printf("\n"
"or for use as a standalone archive cleaner:\n"
"e.g.\n"
" pg_archivecleanup /mnt/server/archiverdir 000000010000000000000010.00000020.backup\n");
printf("\nOptions:\n");
printf(" -d generates debug output (verbose mode)\n");
printf(" --help show this help, then exit\n");
printf(" --version output version information, then exit\n");
printf("\nReport bugs to <pgsql-bugs@postgresql.org>.\n");
}
/*------------ MAIN ----------------------------------------*/
int
main(int argc, char **argv)
{
int c;
progname = get_progname(argv[0]);
if (argc > 1)
{
if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
{
usage();
exit(0);
}
if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
{
puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
exit(0);
}
}
while ((c = getopt(argc, argv, "d")) != -1)
{
switch (c)
{
case 'd': /* Debug mode */
debug = true;
break;
default:
fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
exit(2);
break;
}
}
/*
* We will go to the archiveLocation to check restartWALFileName.
* restartWALFileName may not exist anymore, which would not be an error, so
* we separate the archiveLocation and restartWALFileName so we can check
* separately whether archiveLocation exists, if not that is an error
*/
if (optind < argc)
{
archiveLocation = argv[optind];
optind++;
}
else
{
fprintf(stderr, "%s: must specify archive location\n", progname);
fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
exit(2);
}
if (optind < argc)
{
restartWALFileName = argv[optind];
optind++;
}
else
{
fprintf(stderr, "%s: must specify restartfilename\n", progname);
fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
exit(2);
}
if (optind < argc)
{
fprintf(stderr, "%s: too many parameters\n", progname);
fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
exit(2);
}
/*
* Check archive exists and other initialization if required.
*/
Initialize();
/*
* Check filename is a valid name, then process to find cut-off
*/
SetWALFileNameForCleanup();
if (debug)
fprintf(stderr, "%s: keep WAL file \"%s\" and later\n",
progname, exclusiveCleanupFileName);
/*
* Remove WAL files older than cut-off
*/
CleanupPriorWALFiles();
exit(0);
}