2 Trivial Database 2: fetch, store and misc routines.
3 Copyright (C) Rusty Russell 2010
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 3 of the License, or (at your option) any later version.
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, see <http://www.gnu.org/licenses/>.
20 #include <ccan/asprintf/asprintf.h>
24 static enum TDB_ERROR update_rec_hdr(struct tdb_context *tdb,
28 struct tdb_used_record *rec,
31 uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
34 ecode = set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
35 keylen + dataroom, h);
36 if (ecode == TDB_SUCCESS) {
37 ecode = tdb_write_convert(tdb, off, rec, sizeof(*rec));
42 static enum TDB_ERROR replace_data(struct tdb_context *tdb,
44 struct tdb_data key, struct tdb_data dbuf,
45 tdb_off_t old_off, tdb_len_t old_room,
51 /* Allocate a new record. */
52 new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
54 if (TDB_OFF_IS_ERR(new_off)) {
58 /* We didn't like the existing one: remove it. */
61 ecode = add_free_record(tdb, old_off,
62 sizeof(struct tdb_used_record)
63 + key.dsize + old_room,
65 if (ecode == TDB_SUCCESS)
66 ecode = replace_in_hash(tdb, h, new_off);
68 ecode = add_to_hash(tdb, h, new_off);
70 if (ecode != TDB_SUCCESS) {
74 new_off += sizeof(struct tdb_used_record);
75 ecode = tdb->tdb2.io->twrite(tdb, new_off, key.dptr, key.dsize);
76 if (ecode != TDB_SUCCESS) {
81 ecode = tdb->tdb2.io->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
82 if (ecode != TDB_SUCCESS) {
86 if (tdb->flags & TDB_SEQNUM)
92 static enum TDB_ERROR update_data(struct tdb_context *tdb,
99 ecode = tdb->tdb2.io->twrite(tdb, off, dbuf.dptr, dbuf.dsize);
100 if (ecode == TDB_SUCCESS && extra) {
101 /* Put a zero in; future versions may append other data. */
102 ecode = tdb->tdb2.io->twrite(tdb, off + dbuf.dsize, "", 1);
104 if (tdb->flags & TDB_SEQNUM)
110 enum TDB_ERROR tdb_store(struct tdb_context *tdb,
111 struct tdb_data key, struct tdb_data dbuf, int flag)
115 tdb_len_t old_room = 0;
116 struct tdb_used_record rec;
117 enum TDB_ERROR ecode;
119 if (tdb->flags & TDB_VERSION1) {
120 if (tdb1_store(tdb, key, dbuf, flag) == -1)
121 return tdb->last_error;
125 off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
126 if (TDB_OFF_IS_ERR(off)) {
127 return tdb->last_error = off;
130 /* Now we have lock on this hash bucket. */
131 if (flag == TDB_INSERT) {
133 ecode = TDB_ERR_EXISTS;
138 old_room = rec_data_length(&rec)
139 + rec_extra_padding(&rec);
140 if (old_room >= dbuf.dsize) {
141 /* Can modify in-place. Easy! */
142 ecode = update_rec_hdr(tdb, off,
143 key.dsize, dbuf.dsize,
145 if (ecode != TDB_SUCCESS) {
148 ecode = update_data(tdb,
151 old_room - dbuf.dsize);
152 if (ecode != TDB_SUCCESS) {
155 tdb_unlock_hashes(tdb, h.hlock_start,
156 h.hlock_range, F_WRLCK);
157 return tdb->last_error = TDB_SUCCESS;
160 if (flag == TDB_MODIFY) {
161 /* if the record doesn't exist and we
162 are in TDB_MODIFY mode then we should fail
164 ecode = TDB_ERR_NOEXIST;
170 /* If we didn't use the old record, this implies we're growing. */
171 ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
173 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
174 return tdb->last_error = ecode;
177 enum TDB_ERROR tdb_append(struct tdb_context *tdb,
178 struct tdb_data key, struct tdb_data dbuf)
182 struct tdb_used_record rec;
183 tdb_len_t old_room = 0, old_dlen;
184 unsigned char *newdata;
185 struct tdb_data new_dbuf;
186 enum TDB_ERROR ecode;
188 if (tdb->flags & TDB_VERSION1) {
189 if (tdb1_append(tdb, key, dbuf) == -1)
190 return tdb->last_error;
194 off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
195 if (TDB_OFF_IS_ERR(off)) {
196 return tdb->last_error = off;
200 old_dlen = rec_data_length(&rec);
201 old_room = old_dlen + rec_extra_padding(&rec);
203 /* Fast path: can append in place. */
204 if (rec_extra_padding(&rec) >= dbuf.dsize) {
205 ecode = update_rec_hdr(tdb, off, key.dsize,
206 old_dlen + dbuf.dsize, &rec,
208 if (ecode != TDB_SUCCESS) {
212 off += sizeof(rec) + key.dsize + old_dlen;
213 ecode = update_data(tdb, off, dbuf,
214 rec_extra_padding(&rec));
219 newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
221 ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
223 " failed to allocate %zu bytes",
224 (size_t)(key.dsize + old_dlen
228 ecode = tdb->tdb2.io->tread(tdb, off + sizeof(rec) + key.dsize,
230 if (ecode != TDB_SUCCESS) {
231 goto out_free_newdata;
233 memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
234 new_dbuf.dptr = newdata;
235 new_dbuf.dsize = old_dlen + dbuf.dsize;
241 /* If they're using tdb_append(), it implies they're growing record. */
242 ecode = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
247 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
248 return tdb->last_error = ecode;
251 enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
252 struct tdb_data *data)
255 struct tdb_used_record rec;
257 enum TDB_ERROR ecode;
259 if (tdb->flags & TDB_VERSION1)
260 return tdb1_fetch(tdb, key, data);
262 off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
263 if (TDB_OFF_IS_ERR(off)) {
264 return tdb->last_error = off;
268 ecode = TDB_ERR_NOEXIST;
270 data->dsize = rec_data_length(&rec);
271 data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
273 if (TDB_PTR_IS_ERR(data->dptr)) {
274 ecode = TDB_PTR_ERR(data->dptr);
279 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
280 return tdb->last_error = ecode;
283 bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
286 struct tdb_used_record rec;
289 if (tdb->flags & TDB_VERSION1) {
290 return tdb1_exists(tdb, key);
293 off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
294 if (TDB_OFF_IS_ERR(off)) {
295 tdb->last_error = off;
298 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
300 tdb->last_error = TDB_SUCCESS;
301 return off ? true : false;
304 enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
307 struct tdb_used_record rec;
309 enum TDB_ERROR ecode;
311 if (tdb->flags & TDB_VERSION1) {
312 if (tdb1_delete(tdb, key) == -1)
313 return tdb->last_error;
317 off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
318 if (TDB_OFF_IS_ERR(off)) {
319 return tdb->last_error = off;
323 ecode = TDB_ERR_NOEXIST;
327 ecode = delete_from_hash(tdb, &h);
328 if (ecode != TDB_SUCCESS) {
332 /* Free the deleted entry. */
334 ecode = add_free_record(tdb, off,
335 sizeof(struct tdb_used_record)
336 + rec_key_length(&rec)
337 + rec_data_length(&rec)
338 + rec_extra_padding(&rec),
339 TDB_LOCK_WAIT, true);
341 if (tdb->flags & TDB_SEQNUM)
345 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
346 return tdb->last_error = ecode;
349 unsigned int tdb_get_flags(struct tdb_context *tdb)
354 static bool inside_transaction(const struct tdb_context *tdb)
356 if (tdb->flags & TDB_VERSION1)
357 return tdb->tdb1.transaction != NULL;
359 return tdb->tdb2.transaction != NULL;
362 static bool readonly_changable(struct tdb_context *tdb, const char *caller)
364 if (inside_transaction(tdb)) {
365 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
368 " TDB_RDONLY inside transaction",
373 if (tdb->file->allrecord_lock.count != 0
374 || tdb->file->num_lockrecs != 0) {
375 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
378 " TDB_RDONLY holding locks",
385 void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
387 if (tdb->flags & TDB_INTERNAL) {
388 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
390 "tdb_add_flag: internal db");
395 tdb->flags |= TDB_NOLOCK;
398 tdb->flags |= TDB_NOMMAP;
399 tdb_munmap(tdb->file);
402 tdb->flags |= TDB_NOSYNC;
405 tdb->flags |= TDB_SEQNUM;
407 case TDB_ALLOW_NESTING:
408 tdb->flags |= TDB_ALLOW_NESTING;
411 if (readonly_changable(tdb, "tdb_add_flag"))
412 tdb->flags |= TDB_RDONLY;
415 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
417 "tdb_add_flag: Unknown flag %u",
422 void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
424 if (tdb->flags & TDB_INTERNAL) {
425 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
427 "tdb_remove_flag: internal db");
432 tdb->flags &= ~TDB_NOLOCK;
435 tdb->flags &= ~TDB_NOMMAP;
439 tdb->flags &= ~TDB_NOSYNC;
442 tdb->flags &= ~TDB_SEQNUM;
444 case TDB_ALLOW_NESTING:
445 tdb->flags &= ~TDB_ALLOW_NESTING;
448 if ((tdb->open_flags & O_ACCMODE) == O_RDONLY) {
449 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
451 "tdb_remove_flag: can't"
452 " remove TDB_RDONLY on tdb"
453 " opened with O_RDONLY");
456 if (readonly_changable(tdb, "tdb_remove_flag"))
457 tdb->flags &= ~TDB_RDONLY;
460 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
462 "tdb_remove_flag: Unknown flag %u",
467 const char *tdb_errorstr(enum TDB_ERROR ecode)
469 /* Gcc warns if you miss a case in the switch, so use that. */
471 case TDB_SUCCESS: return "Success";
472 case TDB_ERR_CORRUPT: return "Corrupt database";
473 case TDB_ERR_IO: return "IO Error";
474 case TDB_ERR_LOCK: return "Locking error";
475 case TDB_ERR_OOM: return "Out of memory";
476 case TDB_ERR_EXISTS: return "Record exists";
477 case TDB_ERR_EINVAL: return "Invalid parameter";
478 case TDB_ERR_NOEXIST: return "Record does not exist";
479 case TDB_ERR_RDONLY: return "write not permitted";
481 return "Invalid error code";
484 enum TDB_ERROR tdb_error(struct tdb_context *tdb)
486 return tdb->last_error;
489 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
490 enum TDB_ERROR ecode,
491 enum tdb_log_level level,
492 const char *fmt, ...)
497 /* tdb_open paths care about errno, so save it. */
498 int saved_errno = errno;
504 len = vasprintf(&message, fmt, ap);
508 tdb->log_fn(tdb, TDB_LOG_ERROR, TDB_ERR_OOM,
509 "out of memory formatting message:", tdb->log_data);
510 tdb->log_fn(tdb, level, ecode, fmt, tdb->log_data);
512 tdb->log_fn(tdb, level, ecode, message, tdb->log_data);
519 enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
521 enum TDB_ERROR (*parse)(TDB_DATA k,
527 struct tdb_used_record rec;
529 enum TDB_ERROR ecode;
531 if (tdb->flags & TDB_VERSION1) {
532 return tdb->last_error = tdb1_parse_record(tdb, key, parse,
536 off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
537 if (TDB_OFF_IS_ERR(off)) {
538 return tdb->last_error = off;
542 ecode = TDB_ERR_NOEXIST;
545 dptr = tdb_access_read(tdb, off + sizeof(rec) + key.dsize,
546 rec_data_length(&rec), false);
547 if (TDB_PTR_IS_ERR(dptr)) {
548 ecode = TDB_PTR_ERR(dptr);
550 TDB_DATA d = tdb_mkdata(dptr, rec_data_length(&rec));
552 ecode = parse(key, d, data);
553 tdb_access_release(tdb, dptr);
557 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
558 return tdb->last_error = ecode;
561 const char *tdb_name(const struct tdb_context *tdb)
566 int64_t tdb_get_seqnum(struct tdb_context *tdb)
570 if (tdb->flags & TDB_VERSION1) {
572 tdb->last_error = TDB_SUCCESS;
573 val = tdb1_get_seqnum(tdb);
575 if (tdb->last_error != TDB_SUCCESS)
576 return tdb->last_error;
581 off = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
582 if (TDB_OFF_IS_ERR(off))
583 tdb->last_error = off;
585 tdb->last_error = TDB_SUCCESS;
590 int tdb_fd(const struct tdb_context *tdb)
592 return tdb->file->fd;