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man-db/libdb/db_ndbm.c
Daniel Baumann 1fa764a8d3
Adding upstream version 2.13.1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-21 08:13:55 +02:00

160 lines
3.7 KiB
C

/*
* db_ndbm.c: low level ndbm interface routines for man.
*
* Copyright (C) 1994, 1995 Graeme W. Wilford. (Wilf.)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Mon Aug 8 20:35:30 BST 1994 Wilf. (G.Wilford@ee.surrey.ac.uk)
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif /* HAVE_CONFIG_H */
#ifdef NDBM
# include <fcntl.h>
# include <stdbool.h>
# include <stdio.h>
# include <stdlib.h>
# include <unistd.h>
# include <sys/file.h> /* for flock() */
# include <sys/stat.h>
# include <sys/types.h> /* for open() */
# include "attribute.h"
# include "stat-time.h"
# include "timespec.h"
# include "xalloc.h"
# include "xvasprintf.h"
# include "manconfig.h"
# include "db_storage.h"
# include "db_xdbm.h"
# include "mydbm.h"
/* release the lock and close the database */
static void raw_close (man_ndbm_wrapper wrap)
{
if (wrap->file) {
flock (dbm_dirfno (wrap->file), LOCK_UN);
dbm_close (wrap->file);
}
}
void man_ndbm_free (man_ndbm_wrapper wrap)
{
man_xdbm_free (wrap, raw_close);
}
man_ndbm_wrapper man_ndbm_new (const char *name)
{
man_ndbm_wrapper wrap;
wrap = xmalloc (sizeof *wrap);
wrap->name = xstrdup (name);
wrap->file = NULL;
wrap->mtime = NULL;
return wrap;
}
/* open a ndbm type database, with file locking. */
bool man_ndbm_open (man_ndbm_wrapper wrap, int flags, int mode)
{
int lock_op;
int lock_failed;
if (flags & ~O_RDONLY) {
/* flags includes O_RDWR or O_WRONLY, need an exclusive lock */
lock_op = LOCK_EX | LOCK_NB;
} else {
lock_op = LOCK_SH | LOCK_NB;
}
if (flags & O_TRUNC) {
/* opening the db is destructive, need to lock first */
char *dir_fname;
int dir_fd;
wrap->file = NULL;
lock_failed = 1;
dir_fname = xasprintf ("%s.dir", wrap->name);
dir_fd = open (dir_fname, flags & ~O_TRUNC, mode);
free (dir_fname);
if (dir_fd != -1) {
if (!(lock_failed = flock (dir_fd, lock_op)))
wrap->file =
dbm_open (wrap->name, flags, mode);
close (dir_fd);
}
} else {
wrap->file = dbm_open (wrap->name, flags, mode);
if (wrap->file)
lock_failed = flock (dbm_dirfno (wrap->file), lock_op);
}
if (!wrap->file)
return false;
if (lock_failed) {
gripe_lock (wrap->name);
dbm_close (wrap->file);
return false;
}
return true;
}
static datum unsorted_firstkey (man_ndbm_wrapper wrap)
{
return copy_datum (dbm_firstkey (wrap->file));
}
static datum unsorted_nextkey (man_ndbm_wrapper wrap, datum key MAYBE_UNUSED)
{
return copy_datum (dbm_nextkey (wrap->file));
}
datum man_ndbm_firstkey (man_ndbm_wrapper wrap)
{
return man_xdbm_firstkey (wrap, unsorted_firstkey, unsorted_nextkey);
}
datum man_ndbm_nextkey (man_ndbm_wrapper wrap, datum key)
{
return man_xdbm_nextkey (wrap, key);
}
struct timespec man_ndbm_get_time (man_ndbm_wrapper wrap)
{
struct stat st;
if (!wrap->mtime) {
wrap->mtime = XMALLOC (struct timespec);
if (fstat (dbm_dirfno (wrap->file), &st) < 0) {
wrap->mtime->tv_sec = -1;
wrap->mtime->tv_nsec = -1;
} else
*wrap->mtime = get_stat_mtime (&st);
}
return *wrap->mtime;
}
#endif /* NDBM */