diff options
Diffstat (limited to 'libdb/db_ndbm.c')
| -rw-r--r-- | libdb/db_ndbm.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/libdb/db_ndbm.c b/libdb/db_ndbm.c new file mode 100644 index 0000000..64000c1 --- /dev/null +++ b/libdb/db_ndbm.c @@ -0,0 +1,163 @@ +/* + * 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 <stdlib.h> +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> + +#include <sys/file.h> /* for flock() */ +#include <sys/types.h> /* for open() */ +#include <sys/stat.h> + +#include "stat-time.h" +#include "timespec.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) +{ + flock (dbm_dirfno (wrap->file), LOCK_UN); + dbm_close (wrap->file); +} + +void man_ndbm_close (man_ndbm_wrapper wrap) +{ + man_xdbm_close (wrap, raw_close); +} + +/* open a ndbm type database, with file locking. */ +man_ndbm_wrapper man_ndbm_open (const char *name, int flags, int mode) +{ + man_ndbm_wrapper wrap; + char *name_copy; + DBM *file; + 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; + } + + /* At least GDBM's version of dbm_open declares the file name + * parameter as non-const. This is probably incorrect, but take a + * copy just in case. + */ + name_copy = xstrdup (name); + + if (flags & O_TRUNC) { + /* opening the db is destructive, need to lock first */ + char *dir_fname; + int dir_fd; + + file = NULL; + lock_failed = 1; + dir_fname = xasprintf ("%s.dir", 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))) + file = dbm_open (name_copy, flags, mode); + close (dir_fd); + } + } else { + file = dbm_open (name_copy, flags, mode); + if (file) + lock_failed = flock (dbm_dirfno (file), lock_op); + } + + free (name_copy); + + if (!file) + return NULL; + + if (lock_failed) { + gripe_lock (name); + dbm_close (file); + return NULL; + } + + wrap = xmalloc (sizeof *wrap); + wrap->name = xstrdup (name); + wrap->file = file; + + return wrap; +} + +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 _GL_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 (fstat (dbm_dirfno (wrap->file), &st) < 0) { + struct timespec t; + t.tv_sec = -1; + t.tv_nsec = -1; + return t; + } + return get_stat_mtime (&st); +} + +void man_ndbm_set_time (man_ndbm_wrapper wrap, const struct timespec time) +{ + struct timespec times[2]; + + times[0] = time; + times[1] = time; + futimens (dbm_dirfno (wrap->file), times); +} + +#endif /* NDBM */ |