5 TDB version 2: trivial database library
7 Copyright (C) Andrew Tridgell 1999-2004
8 Copyright (C) Rusty Russell 2010-2011
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
34 #include <sys/types.h>
37 /* For sig_atomic_t. */
46 #include <ccan/compiler/compiler.h>
47 #include <ccan/typesafe_cb/typesafe_cb.h>
48 #include <ccan/cast/cast.h>
54 * tdb_open - open a database file
55 * @name: the file name (can be NULL if flags contains TDB_INTERNAL)
56 * @tdb_flags: options for this database
57 * @open_flags: flags argument for tdb's open() call.
58 * @mode: mode argument for tdb's open() call.
59 * @attributes: linked list of extra attributes for this tdb.
61 * This call opens (and potentially creates) a database file.
62 * Multiple processes can have the TDB file open at once.
64 * On failure it will return NULL, and set errno: it may also call
65 * any log attribute found in @attributes.
70 struct tdb_context *tdb_open(const char *name, int tdb_flags,
71 int open_flags, mode_t mode,
72 union tdb_attribute *attributes);
75 /* flags for tdb_open() */
76 #define TDB_DEFAULT 0 /* just a readability place holder */
77 #define TDB_INTERNAL 2 /* don't store on disk */
78 #define TDB_NOLOCK 4 /* don't do any locking */
79 #define TDB_NOMMAP 8 /* don't use mmap */
80 #define TDB_CONVERT 16 /* convert endian */
81 #define TDB_NOSYNC 64 /* don't use synchronous transactions */
82 #define TDB_SEQNUM 128 /* maintain a sequence number */
83 #define TDB_ALLOW_NESTING 256 /* fake nested transactions */
86 * tdb_close - close and free a tdb.
87 * @tdb: the tdb context returned from tdb_open()
89 * This always succeeds, in that @tdb is unusable after this call. But if
90 * some unexpected error occurred while closing, it will return non-zero
91 * (the only clue as to cause will be via the log attribute).
93 int tdb_close(struct tdb_context *tdb);
96 * struct tdb_data - representation of keys or values.
97 * @dptr: the data pointer
98 * @dsize: the size of the data pointed to by dptr.
100 * This is the "blob" representation of keys and data used by TDB.
102 typedef struct tdb_data {
108 * enum TDB_ERROR - error returns for TDB
114 TDB_SUCCESS = 0, /* No error. */
115 TDB_ERR_CORRUPT = -1, /* We read the db, and it was bogus. */
116 TDB_ERR_IO = -2, /* We couldn't read/write the db. */
117 TDB_ERR_LOCK = -3, /* Locking failed. */
118 TDB_ERR_OOM = -4, /* Out of Memory. */
119 TDB_ERR_EXISTS = -5, /* The key already exists. */
120 TDB_ERR_NOEXIST = -6, /* The key does not exist. */
121 TDB_ERR_EINVAL = -7, /* You're using it wrong. */
122 TDB_ERR_RDONLY = -8, /* The database is read-only. */
123 TDB_ERR_LAST = TDB_ERR_RDONLY
127 * tdb_store - store a key/value pair in a tdb.
128 * @tdb: the tdb context returned from tdb_open()
130 * @dbuf: the data to associate with the key.
131 * @flag: TDB_REPLACE, TDB_INSERT or TDB_MODIFY.
133 * This inserts (or overwrites) a key/value pair in the TDB. If flag
134 * is TDB_REPLACE, it doesn't matter whether the key exists or not;
135 * TDB_INSERT means it must not exist (returns TDB_ERR_EXISTS otherwise),
136 * and TDB_MODIFY means it must exist (returns TDB_ERR_NOEXIST otherwise).
138 * On success, this returns TDB_SUCCESS.
141 * tdb_fetch, tdb_transaction_start, tdb_append, tdb_delete.
143 enum TDB_ERROR tdb_store(struct tdb_context *tdb,
145 struct tdb_data dbuf,
148 /* flags to tdb_store() */
149 #define TDB_REPLACE 1 /* A readability place holder */
150 #define TDB_INSERT 2 /* Don't overwrite an existing entry */
151 #define TDB_MODIFY 3 /* Don't create an existing entry */
154 * tdb_fetch - fetch a value from a tdb.
155 * @tdb: the tdb context returned from tdb_open()
157 * @data: pointer to data.
159 * This looks up a key in the database and sets it in @data.
161 * If it returns TDB_SUCCESS, the key was found: it is your
162 * responsibility to call free() on @data->dptr.
164 * Otherwise, it returns an error (usually, TDB_ERR_NOEXIST) and @data is
167 enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
168 struct tdb_data *data);
171 * tdb_errorstr - map the tdb error onto a constant readable string
172 * @ecode: the enum TDB_ERROR to map.
174 * This is useful for displaying errors to users.
176 const char *tdb_errorstr(enum TDB_ERROR ecode);
179 * tdb_append - append a value to a key/value pair in a tdb.
180 * @tdb: the tdb context returned from tdb_open()
182 * @dbuf: the data to append.
184 * This is equivalent to fetching a record, reallocating .dptr to add the
185 * data, and writing it back, only it's much more efficient. If the key
186 * doesn't exist, it's equivalent to tdb_store (with an additional hint that
187 * you expect to expand the record in future).
190 * tdb_fetch(), tdb_store()
192 enum TDB_ERROR tdb_append(struct tdb_context *tdb,
193 struct tdb_data key, struct tdb_data dbuf);
196 * tdb_delete - delete a key from a tdb.
197 * @tdb: the tdb context returned from tdb_open()
198 * @key: the key to delete.
200 * Returns TDB_SUCCESS on success, or an error (usually TDB_ERR_NOEXIST).
203 * tdb_fetch(), tdb_store()
205 enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key);
208 * tdb_exists - does a key exist in the database?
209 * @tdb: the tdb context returned from tdb_open()
210 * @key: the key to search for.
212 * Returns true if it exists, or false if it doesn't or any other error.
214 bool tdb_exists(struct tdb_context *tdb, TDB_DATA key);
217 * tdb_deq - are struct tdb_data equal?
218 * @a: one struct tdb_data
219 * @b: another struct tdb_data
221 static inline bool tdb_deq(struct tdb_data a, struct tdb_data b)
223 return a.dsize == b.dsize && memcmp(a.dptr, b.dptr, a.dsize) == 0;
227 * tdb_mkdata - make a struct tdb_data from const data
228 * @p: the constant pointer
231 * As the dptr member of struct tdb_data is not constant, you need to
232 * cast it. This function keeps thost casts in one place, as well as
233 * suppressing the warning some compilers give when casting away a
234 * qualifier (eg. gcc with -Wcast-qual)
236 static inline struct tdb_data tdb_mkdata(const void *p, size_t len)
239 d.dptr = cast_const(void *, p);
245 * tdb_transaction_start - start a transaction
246 * @tdb: the tdb context returned from tdb_open()
248 * This begins a series of atomic operations. Other processes will be able
249 * to read the tdb, but not alter it (they will block), nor will they see
250 * any changes until tdb_transaction_commit() is called.
252 * Note that if the TDB_ALLOW_NESTING flag is set, a tdb_transaction_start()
253 * within a transaction will succeed, but it's not a real transaction:
254 * (1) An inner transaction which is committed is not actually committed until
255 * the outer transaction is; if the outer transaction is cancelled, the
256 * inner ones are discarded.
257 * (2) tdb_transaction_cancel() marks the outer transaction as having an error,
258 * so the final tdb_transaction_commit() will fail.
259 * (3) the outer transaction will see the results of the inner transaction.
262 * tdb_transaction_cancel, tdb_transaction_commit.
264 enum TDB_ERROR tdb_transaction_start(struct tdb_context *tdb);
267 * tdb_transaction_cancel - abandon a transaction
268 * @tdb: the tdb context returned from tdb_open()
270 * This aborts a transaction, discarding any changes which were made.
271 * tdb_close() does this implicitly.
273 void tdb_transaction_cancel(struct tdb_context *tdb);
276 * tdb_transaction_commit - commit a transaction
277 * @tdb: the tdb context returned from tdb_open()
279 * This completes a transaction, writing any changes which were made.
281 * fsync() is used to commit the transaction (unless TDB_NOSYNC is set),
282 * making it robust against machine crashes, but very slow compared to
283 * other TDB operations.
285 * A failure can only be caused by unexpected errors (eg. I/O or
286 * memory); this is no point looping on transaction failure.
289 * tdb_transaction_prepare_commit()
291 enum TDB_ERROR tdb_transaction_commit(struct tdb_context *tdb);
294 * tdb_transaction_prepare_commit - prepare to commit a transaction
295 * @tdb: the tdb context returned from tdb_open()
297 * This ensures we have the resources to commit a transaction (using
298 * tdb_transaction_commit): if this succeeds then a transaction will only
299 * fail if the write() or fsync() calls fail.
301 * If this fails you must still call tdb_transaction_cancel() to cancel
305 * tdb_transaction_commit()
307 enum TDB_ERROR tdb_transaction_prepare_commit(struct tdb_context *tdb);
310 * tdb_traverse - traverse a TDB
311 * @tdb: the tdb context returned from tdb_open()
312 * @fn: the function to call for every key/value pair (or NULL)
313 * @p: the pointer to hand to @f
315 * This walks the TDB until all they keys have been traversed, or @fn
316 * returns non-zero. If the traverse function or other processes are
317 * changing data or adding or deleting keys, the traverse may be
318 * unreliable: keys may be skipped or (rarely) visited twice.
320 * There is one specific exception: the special case of deleting the
321 * current key does not undermine the reliability of the traversal.
323 * On success, returns the number of keys iterated. On error returns
324 * a negative enum TDB_ERROR value.
326 #define tdb_traverse(tdb, fn, p) \
327 tdb_traverse_(tdb, typesafe_cb_preargs(int, void *, (fn), (p), \
328 struct tdb_context *, \
329 TDB_DATA, TDB_DATA), (p))
331 int64_t tdb_traverse_(struct tdb_context *tdb,
332 int (*fn)(struct tdb_context *,
333 TDB_DATA, TDB_DATA, void *), void *p);
336 * tdb_parse_record - operate directly on data in the database.
337 * @tdb: the tdb context returned from tdb_open()
338 * @key: the key whose record we should hand to @parse
339 * @parse: the function to call for the data
340 * @data: the private pointer to hand to @parse (types must match).
342 * This avoids a copy for many cases, by handing you a pointer into
343 * the memory-mapped database. It also locks the record to prevent
344 * other accesses at the same time.
346 * Do not alter the data handed to parse()!
348 #define tdb_parse_record(tdb, key, parse, data) \
349 tdb_parse_record_((tdb), (key), \
350 typesafe_cb_preargs(enum TDB_ERROR, void *, \
352 TDB_DATA, TDB_DATA), (data))
354 enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
356 enum TDB_ERROR (*parse)(TDB_DATA k,
362 * tdb_get_seqnum - get a database sequence number
363 * @tdb: the tdb context returned from tdb_open()
365 * This returns a sequence number: any change to the database from a
366 * tdb context opened with the TDB_SEQNUM flag will cause that number
367 * to increment. Note that the incrementing is unreliable (it is done
368 * without locking), so this is only useful as an optimization.
370 * For example, you may have a regular database backup routine which
371 * does not operate if the sequence number is unchanged. In the
372 * unlikely event of a failed increment, it will be backed up next
375 * Returns an enum TDB_ERROR (ie. negative) on error.
377 int64_t tdb_get_seqnum(struct tdb_context *tdb);
380 * tdb_firstkey - get the "first" key in a TDB
381 * @tdb: the tdb context returned from tdb_open()
382 * @key: pointer to key.
384 * This returns an arbitrary key in the database; with tdb_nextkey() it allows
385 * open-coded traversal of the database, though it is slightly less efficient
388 * It is your responsibility to free @key->dptr on success.
390 * Returns TDB_ERR_NOEXIST if the database is empty.
392 enum TDB_ERROR tdb_firstkey(struct tdb_context *tdb, struct tdb_data *key);
395 * tdb_nextkey - get the "next" key in a TDB
396 * @tdb: the tdb context returned from tdb_open()
397 * @key: a key returned by tdb_firstkey() or tdb_nextkey().
399 * This returns another key in the database; it will free @key.dptr for
402 * Returns TDB_ERR_NOEXIST if there are no more keys.
404 enum TDB_ERROR tdb_nextkey(struct tdb_context *tdb, struct tdb_data *key);
407 * tdb_chainlock - lock a record in the TDB
408 * @tdb: the tdb context returned from tdb_open()
409 * @key: the key to lock.
411 * This prevents any access occurring to a group of keys including @key,
412 * even if @key does not exist. This allows primitive atomic updates of
413 * records without using transactions.
415 * You cannot begin a transaction while holding a tdb_chainlock(), nor can
416 * you do any operations on any other keys in the database. This also means
417 * that you cannot hold more than one tdb_chainlock() at a time.
422 enum TDB_ERROR tdb_chainlock(struct tdb_context *tdb, TDB_DATA key);
425 * tdb_chainunlock - unlock a record in the TDB
426 * @tdb: the tdb context returned from tdb_open()
427 * @key: the key to unlock.
429 * The key must have previously been locked by tdb_chainlock().
431 void tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key);
434 * tdb_chainlock_read - lock a record in the TDB, for reading
435 * @tdb: the tdb context returned from tdb_open()
436 * @key: the key to lock.
438 * This prevents any changes from occurring to a group of keys including @key,
439 * even if @key does not exist. This allows primitive atomic updates of
440 * records without using transactions.
442 * You cannot begin a transaction while holding a tdb_chainlock_read(), nor can
443 * you do any operations on any other keys in the database. This also means
444 * that you cannot hold more than one tdb_chainlock()/read() at a time.
449 enum TDB_ERROR tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key);
452 * tdb_chainunlock_read - unlock a record in the TDB for reading
453 * @tdb: the tdb context returned from tdb_open()
454 * @key: the key to unlock.
456 * The key must have previously been locked by tdb_chainlock_read().
458 void tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key);
461 * tdb_lockall - lock the entire TDB
462 * @tdb: the tdb context returned from tdb_open()
464 * You cannot hold a tdb_chainlock while calling this. It nests, so you
465 * must call tdb_unlockall as many times as you call tdb_lockall.
467 enum TDB_ERROR tdb_lockall(struct tdb_context *tdb);
470 * tdb_unlockall - unlock the entire TDB
471 * @tdb: the tdb context returned from tdb_open()
473 void tdb_unlockall(struct tdb_context *tdb);
476 * tdb_lockall_read - lock the entire TDB for reading
477 * @tdb: the tdb context returned from tdb_open()
479 * This prevents others writing to the database, eg. tdb_delete, tdb_store,
480 * tdb_append, but not tdb_fetch.
482 * You cannot hold a tdb_chainlock while calling this. It nests, so you
483 * must call tdb_unlockall_read as many times as you call tdb_lockall_read.
485 enum TDB_ERROR tdb_lockall_read(struct tdb_context *tdb);
488 * tdb_unlockall_read - unlock the entire TDB for reading
489 * @tdb: the tdb context returned from tdb_open()
491 void tdb_unlockall_read(struct tdb_context *tdb);
494 * tdb_wipe_all - wipe the database clean
495 * @tdb: the tdb context returned from tdb_open()
497 * Completely erase the database. This is faster than iterating through
498 * each key and doing tdb_delete.
500 enum TDB_ERROR tdb_wipe_all(struct tdb_context *tdb);
503 * tdb_check - check a TDB for consistency
504 * @tdb: the tdb context returned from tdb_open()
505 * @check: function to check each key/data pair (or NULL)
506 * @data: argument for @check, must match type.
508 * This performs a consistency check of the open database, optionally calling
509 * a check() function on each record so you can do your own data consistency
510 * checks as well. If check() returns an error, that is returned from
513 * Returns TDB_SUCCESS or an error.
515 #define tdb_check(tdb, check, data) \
516 tdb_check_((tdb), typesafe_cb_preargs(enum TDB_ERROR, void *, \
522 enum TDB_ERROR tdb_check_(struct tdb_context *tdb,
523 enum TDB_ERROR (*check)(struct tdb_data k,
529 * tdb_error - get the last error (not threadsafe)
530 * @tdb: the tdb context returned from tdb_open()
532 * Returns the last error returned by a TDB function.
534 * This makes porting from TDB1 easier, but note that the last error is not
535 * reliable in threaded programs.
537 enum TDB_ERROR tdb_error(struct tdb_context *tdb);
540 * enum tdb_summary_flags - flags for tdb_summary.
542 enum tdb_summary_flags {
543 TDB_SUMMARY_HISTOGRAMS = 1 /* Draw graphs in the summary. */
547 * tdb_summary - return a string describing the TDB state
548 * @tdb: the tdb context returned from tdb_open()
549 * @flags: flags to control the summary output.
550 * @summary: pointer to string to allocate.
552 * This returns a developer-readable string describing the overall
553 * state of the tdb, such as the percentage used and sizes of records.
554 * It is designed to provide information about the tdb at a glance
555 * without displaying any keys or data in the database.
557 * On success, sets @summary to point to a malloc()'ed nul-terminated
558 * multi-line string. It is your responsibility to free() it.
560 enum TDB_ERROR tdb_summary(struct tdb_context *tdb,
561 enum tdb_summary_flags flags,
566 * tdb_get_flags - return the flags for a tdb
567 * @tdb: the tdb context returned from tdb_open()
569 * This returns the flags on the current tdb. Some of these are caused by
570 * the flags argument to tdb_open(), others (such as TDB_CONVERT) are
573 unsigned int tdb_get_flags(struct tdb_context *tdb);
576 * tdb_add_flag - set a flag for a tdb
577 * @tdb: the tdb context returned from tdb_open()
578 * @flag: one of TDB_NOLOCK, TDB_NOMMAP, TDB_NOSYNC or TDB_ALLOW_NESTING.
580 * You can use this to set a flag on the TDB. You cannot set these flags
581 * on a TDB_INTERNAL tdb.
583 void tdb_add_flag(struct tdb_context *tdb, unsigned flag);
586 * tdb_remove_flag - unset a flag for a tdb
587 * @tdb: the tdb context returned from tdb_open()
588 * @flag: one of TDB_NOLOCK, TDB_NOMMAP, TDB_NOSYNC or TDB_ALLOW_NESTING.
590 * You can use this to clear a flag on the TDB. You cannot clear flags
591 * on a TDB_INTERNAL tdb.
593 void tdb_remove_flag(struct tdb_context *tdb, unsigned flag);
596 * enum tdb_attribute_type - descriminator for union tdb_attribute.
598 enum tdb_attribute_type {
599 TDB_ATTRIBUTE_LOG = 0,
600 TDB_ATTRIBUTE_HASH = 1,
601 TDB_ATTRIBUTE_SEED = 2,
602 TDB_ATTRIBUTE_STATS = 3,
603 TDB_ATTRIBUTE_OPENHOOK = 4,
604 TDB_ATTRIBUTE_FLOCK = 5
608 * tdb_get_attribute - get an attribute for an existing tdb
609 * @tdb: the tdb context returned from tdb_open()
610 * @attr: the union tdb_attribute to set.
612 * This gets an attribute from a TDB which has previously been set (or
613 * may return the default values). Set @attr.base.attr to the
614 * attribute type you want get.
616 * Currently this does not work for TDB_ATTRIBUTE_OPENHOOK.
618 enum TDB_ERROR tdb_get_attribute(struct tdb_context *tdb,
619 union tdb_attribute *attr);
622 * tdb_set_attribute - set an attribute for an existing tdb
623 * @tdb: the tdb context returned from tdb_open()
624 * @attr: the union tdb_attribute to set.
626 * This sets an attribute on a TDB, overriding any previous attribute
627 * of the same type. It returns TDB_ERR_EINVAL if the attribute is
628 * unknown or invalid.
630 * Note that TDB_ATTRIBUTE_HASH, TDB_ATTRIBUTE_SEED and
631 * TDB_ATTRIBUTE_OPENHOOK cannot currently be set after tdb_open.
633 enum TDB_ERROR tdb_set_attribute(struct tdb_context *tdb,
634 const union tdb_attribute *attr);
637 * tdb_unset_attribute - reset an attribute for an existing tdb
638 * @tdb: the tdb context returned from tdb_open()
639 * @type: the attribute type to unset.
641 * This unsets an attribute on a TDB, returning it to the defaults
642 * (where applicable).
644 * Note that it only makes sense for TDB_ATTRIBUTE_LOG and TDB_ATTRIBUTE_FLOCK
647 void tdb_unset_attribute(struct tdb_context *tdb,
648 enum tdb_attribute_type type);
651 * tdb_name - get the name of a tdb
652 * @tdb: the tdb context returned from tdb_open()
654 * This returns a copy of the name string, made at tdb_open() time. If that
655 * argument was NULL (possible for a TDB_INTERNAL db) this will return NULL.
657 * This is mostly useful for logging.
659 const char *tdb_name(const struct tdb_context *tdb);
662 * tdb_fd - get the file descriptor of a tdb
663 * @tdb: the tdb context returned from tdb_open()
665 * This returns the file descriptor for the underlying database file, or -1
668 int tdb_fd(const struct tdb_context *tdb);
671 * struct tdb_attribute_base - common fields for all tdb attributes.
673 struct tdb_attribute_base {
674 enum tdb_attribute_type attr;
675 union tdb_attribute *next;
679 * enum tdb_log_level - log levels for tdb_attribute_log
680 * @TDB_LOG_ERROR: used to log unrecoverable errors such as I/O errors
681 * or internal consistency failures.
682 * @TDB_LOG_USE_ERROR: used to log usage errors such as invalid parameters
683 * or writing to a read-only database.
684 * @TDB_LOG_WARNING: used for informational messages on issues which
685 * are unusual but handled by TDB internally, such
686 * as a failure to mmap or failure to open /dev/urandom.
695 * struct tdb_attribute_log - log function attribute
697 * This attribute provides a hook for you to log errors.
699 struct tdb_attribute_log {
700 struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_LOG */
701 void (*fn)(struct tdb_context *tdb,
702 enum tdb_log_level level,
709 * struct tdb_attribute_hash - hash function attribute
711 * This attribute allows you to provide an alternative hash function.
712 * This hash function will be handed keys from the database; it will also
713 * be handed the 8-byte TDB_HASH_MAGIC value for checking the header (the
714 * tdb_open() will fail if the hash value doesn't match the header).
716 * Note that if your hash function gives different results on
717 * different machine endians, your tdb will no longer work across
718 * different architectures!
720 struct tdb_attribute_hash {
721 struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_HASH */
722 uint64_t (*fn)(const void *key, size_t len, uint64_t seed,
728 * struct tdb_attribute_seed - hash function seed attribute
730 * The hash function seed is normally taken from /dev/urandom (or equivalent)
731 * but can be set manually here. This is mainly for testing purposes.
733 struct tdb_attribute_seed {
734 struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_SEED */
739 * struct tdb_attribute_stats - tdb operational statistics
741 * This attribute records statistics of various low-level TDB operations.
742 * This can be used to assist performance evaluation. This is only
743 * useful for tdb_get_attribute().
745 * New fields will be added at the end, hence the "size" argument which
746 * indicates how large your structure is: it must be filled in before
747 * calling tdb_get_attribute(), which will overwrite it with the size
750 struct tdb_attribute_stats {
751 struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_STATS */
752 size_t size; /* = sizeof(struct tdb_attribute_stats) */
754 uint64_t alloc_subhash;
755 uint64_t alloc_chain;
756 uint64_t alloc_bucket_exact;
757 uint64_t alloc_bucket_max;
758 uint64_t alloc_leftover;
759 uint64_t alloc_coalesce_tried;
760 uint64_t alloc_coalesce_lockfail;
761 uint64_t alloc_coalesce_race;
762 uint64_t alloc_coalesce_succeeded;
763 uint64_t alloc_coalesce_num_merged;
765 uint64_t compare_wrong_bucket;
766 uint64_t compare_wrong_offsetbits;
767 uint64_t compare_wrong_keylen;
768 uint64_t compare_wrong_rechash;
769 uint64_t compare_wrong_keycmp;
773 uint64_t lock_lowlevel;
774 uint64_t lock_nonblock;
778 * struct tdb_attribute_openhook - tdb special effects hook for open
780 * This attribute contains a function to call once we have the OPEN_LOCK
781 * for the tdb, but before we've examined its contents. If this succeeds,
782 * the tdb will be populated if it's then zero-length.
784 * This is a hack to allow support for TDB1-style TDB_CLEAR_IF_FIRST
787 struct tdb_attribute_openhook {
788 struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_OPENHOOK */
789 enum TDB_ERROR (*fn)(int fd, void *data);
794 * struct tdb_attribute_flock - tdb special effects hook for file locking
796 * This attribute contains function to call to place locks on a file; it can
797 * be used to support non-blocking operations or lock proxying.
799 * They should return 0 on success, -1 on failure and set errno.
801 * An error will be logged on error if errno is neither EAGAIN nor EINTR
802 * (normally it would only return EAGAIN if waitflag is false, and
803 * loop internally on EINTR).
805 struct tdb_attribute_flock {
806 struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_FLOCK */
807 int (*lock)(int fd,int rw, off_t off, off_t len, bool waitflag, void *);
808 int (*unlock)(int fd, int rw, off_t off, off_t len, void *);
813 * union tdb_attribute - tdb attributes.
815 * This represents all the known attributes.
818 * struct tdb_attribute_log, struct tdb_attribute_hash,
819 * struct tdb_attribute_seed, struct tdb_attribute_stats,
820 * struct tdb_attribute_openhook, struct tdb_attribute_flock.
822 union tdb_attribute {
823 struct tdb_attribute_base base;
824 struct tdb_attribute_log log;
825 struct tdb_attribute_hash hash;
826 struct tdb_attribute_seed seed;
827 struct tdb_attribute_stats stats;
828 struct tdb_attribute_openhook openhook;
829 struct tdb_attribute_flock flock;