#include <signal.h>
/* For uint64_t */
#include <stdint.h>
+/* For bool */
+#include <stdbool.h>
+/* For memcmp */
+#include <string.h>
#endif
#include <ccan/compiler/compiler.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
+#include <ccan/cast/cast.h>
union tdb_attribute;
struct tdb_context;
#define TDB_NOMMAP 8 /* don't use mmap */
#define TDB_CONVERT 16 /* convert endian */
#define TDB_NOSYNC 64 /* don't use synchronous transactions */
+#define TDB_SEQNUM 128 /* maintain a sequence number */
/**
* tdb_close - close and free a tdb.
*/
enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key);
+/**
+ * tdb_exists - does a key exist in the database?
+ * @tdb: the tdb context returned from tdb_open()
+ * @key: the key to search for.
+ *
+ * Returns true if it exists, or false if it doesn't or any other error.
+ */
+bool tdb_exists(struct tdb_context *tdb, TDB_DATA key);
+
+/**
+ * tdb_deq - are struct tdb_data equal?
+ * @a: one struct tdb_data
+ * @b: another struct tdb_data
+ */
+static inline bool tdb_deq(struct tdb_data a, struct tdb_data b)
+{
+ return a.dsize == b.dsize && memcmp(a.dptr, b.dptr, a.dsize) == 0;
+}
+
+/**
+ * tdb_mkdata - make a struct tdb_data from const data
+ * @p: the constant pointer
+ * @len: the length
+ *
+ * As the dptr member of struct tdb_data is not constant, you need to
+ * cast it. This function keeps thost casts in one place, as well as
+ * suppressing the warning some compilers give when casting away a
+ * qualifier (eg. gcc with -Wcast-qual)
+ */
+static inline struct tdb_data tdb_mkdata(const void *p, size_t len)
+{
+ struct tdb_data d;
+ d.dptr = cast_const(void *, p);
+ d.dsize = len;
+ return d;
+}
+
/**
* tdb_transaction_start - start a transaction
* @tdb: the tdb context returned from tdb_open()
int (*fn)(struct tdb_context *,
TDB_DATA, TDB_DATA, void *), void *p);
+/**
+ * tdb_parse_record - operate directly on data in the database.
+ * @tdb: the tdb context returned from tdb_open()
+ * @key: the key whose record we should hand to @parse
+ * @parse: the function to call for the data
+ * @p: the private pointer to hand to @parse (types must match).
+ *
+ * This avoids a copy for many cases, by handing you a pointer into
+ * the memory-mapped database. It also locks the record to prevent
+ * other accesses at the same time.
+ *
+ * Do not alter the data handed to parse()!
+ */
+#define tdb_parse_record(tdb, key, parse, p) \
+ tdb_parse_record_((tdb), (key), \
+ typesafe_cb_preargs(enum TDB_ERROR, (parse), (p), \
+ TDB_DATA, TDB_DATA), (p))
+
+enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
+ TDB_DATA key,
+ enum TDB_ERROR (*parse)(TDB_DATA key,
+ TDB_DATA data,
+ void *p),
+ void *p);
+
+/**
+ * tdb_get_seqnum - get a database sequence number
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This returns a sequence number: any change to the database from a
+ * tdb context opened with the TDB_SEQNUM flag will cause that number
+ * to increment. Note that the incrementing is unreliable (it is done
+ * without locking), so this is only useful as an optimization.
+ *
+ * For example, you may have a regular database backup routine which
+ * does not operate if the sequence number is unchanged. In the
+ * unlikely event of a failed increment, it will be backed up next
+ * time any way.
+ *
+ * Returns an enum TDB_ERROR (ie. negative) on error.
+ */
+int64_t tdb_get_seqnum(struct tdb_context *tdb);
+
/**
* tdb_firstkey - get the "first" key in a TDB
* @tdb: the tdb context returned from tdb_open()
* tdb_chainunlock - unlock a record in the TDB
* @tdb: the tdb context returned from tdb_open()
* @key: the key to unlock.
+ *
+ * The key must have previously been locked by tdb_chainlock().
*/
-enum TDB_ERROR tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key);
+void tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key);
+
+/**
+ * tdb_lockall - lock the entire TDB
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * You cannot hold a tdb_chainlock while calling this. It nests, so you
+ * must call tdb_unlockall as many times as you call tdb_lockall.
+ */
+enum TDB_ERROR tdb_lockall(struct tdb_context *tdb);
+
+/**
+ * tdb_unlockall - unlock the entire TDB
+ * @tdb: the tdb context returned from tdb_open()
+ */
+void tdb_unlockall(struct tdb_context *tdb);
+
+/**
+ * tdb_lockall_read - lock the entire TDB for reading
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This prevents others writing to the database, eg. tdb_delete, tdb_store,
+ * tdb_append, but not tdb_fetch.
+ *
+ * You cannot hold a tdb_chainlock while calling this. It nests, so you
+ * must call tdb_unlockall_read as many times as you call tdb_lockall_read.
+ */
+enum TDB_ERROR tdb_lockall_read(struct tdb_context *tdb);
+
+/**
+ * tdb_unlockall_read - unlock the entire TDB for reading
+ * @tdb: the tdb context returned from tdb_open()
+ */
+void tdb_unlockall_read(struct tdb_context *tdb);
+
+/**
+ * tdb_wipe_all - wipe the database clean
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * Completely erase the database. This is faster than iterating through
+ * each key and doing tdb_delete.
+ */
+enum TDB_ERROR tdb_wipe_all(struct tdb_context *tdb);
/**
* tdb_check - check a TDB for consistency
* @tdb: the tdb context returned from tdb_open()
* @check: function to check each key/data pair (or NULL)
- * @private: argument for @check, must match type.
+ * @private_data: argument for @check, must match type.
*
* This performs a consistency check of the open database, optionally calling
* a check() function on each record so you can do your own data consistency
*
* Returns TDB_SUCCESS or an error.
*/
-#define tdb_check(tdb, check, private) \
+#define tdb_check(tdb, check, private_data) \
tdb_check_((tdb), typesafe_cb_preargs(enum TDB_ERROR, \
- (check), (private), \
+ (check), (private_data), \
struct tdb_data, \
struct tdb_data), \
- (private))
+ (private_data))
enum TDB_ERROR tdb_check_(struct tdb_context *tdb,
enum TDB_ERROR (*check)(struct tdb_data key,
struct tdb_data data,
- void *private),
- void *private);
+ void *private_data),
+ void *private_data);
+
+/**
+ * tdb_error - get the last error (not threadsafe)
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * Returns the last error returned by a TDB function.
+ *
+ * This makes porting from TDB1 easier, but note that the last error is not
+ * reliable in threaded programs.
+ */
+enum TDB_ERROR tdb_error(struct tdb_context *tdb);
/**
* enum tdb_summary_flags - flags for tdb_summary.
*/
void tdb_remove_flag(struct tdb_context *tdb, unsigned flag);
+/**
+ * tdb_name - get the name of a tdb
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This returns a copy of the name string, made at tdb_open() time. If that
+ * argument was NULL (possible for a TDB_INTERNAL db) this will return NULL.
+ *
+ * This is mostly useful for logging.
+ */
+const char *tdb_name(const struct tdb_context *tdb);
+
+/**
+ * tdb_fd - get the file descriptor of a tdb
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This returns the file descriptor for the underlying database file, or -1
+ * for TDB_INTERNAL.
+ */
+int tdb_fd(const struct tdb_context *tdb);
+
/**
* enum tdb_attribute_type - descriminator for union tdb_attribute.
*/
struct tdb_attribute_stats stats;
};
-/**
- * tdb_null - a convenient value for errors.
- */
-extern struct tdb_data tdb_null;
-
#ifdef __cplusplus
}
#endif
projects / ccan / blobdiff