As per TDB1, except that the sequence number is 63 bit.
return (char *)tdb->file->map_ptr + off;
}
+void tdb_inc_seqnum(struct tdb_context *tdb)
+{
+ tdb_off_t seq;
+
+ if (likely(!(tdb->flags & TDB_CONVERT))) {
+ int64_t *direct;
+
+ direct = tdb->methods->direct(tdb,
+ offsetof(struct tdb_header,
+ seqnum),
+ sizeof(*direct), true);
+ if (likely(direct)) {
+ /* Don't let it go negative, even briefly */
+ if (unlikely((*direct) + 1) < 0)
+ *direct = 0;
+ (*direct)++;
+ return;
+ }
+ }
+
+ seq = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+ if (!TDB_OFF_IS_ERR(seq)) {
+ seq++;
+ if (unlikely((int64_t)seq < 0))
+ seq = 0;
+ tdb_write_off(tdb, offsetof(struct tdb_header, seqnum), seq);
+ }
+}
+
void add_stat_(struct tdb_context *tdb, uint64_t *s, size_t val)
{
if ((uintptr_t)s < (uintptr_t)tdb->stats + tdb->stats->size)
tdb->hash_priv);
newdb.hdr.recovery = 0;
newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
+ newdb.hdr.seqnum = 0;
memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
/* Initial hashes are empty. */
memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
}
if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT
- | TDB_NOSYNC)) {
+ | TDB_NOSYNC | TDB_SEQNUM)) {
ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
"tdb_open: unknown flags %u", tdb_flags);
goto fail;
uint64_t features_used; /* Features all writers understand */
uint64_t features_offered; /* Features offered */
- tdb_off_t reserved[24];
+ uint64_t seqnum; /* Sequence number for TDB_SEQNUM */
+
+ tdb_off_t reserved[23];
/* Top level hash table. */
tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];
enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
void *rec, size_t len);
+/* Bump the seqnum (caller checks for tdb->flags & TDB_SEQNUM) */
+void tdb_inc_seqnum(struct tdb_context *tdb);
+
/* Adds a stat, if it's in range. */
void add_stat_(struct tdb_context *tdb, uint64_t *stat, size_t val);
#define add_stat(tdb, statname, val) \
return ecode;
}
- /* FIXME: tdb_increment_seqnum(tdb); */
+ if (tdb->flags & TDB_SEQNUM)
+ tdb_inc_seqnum(tdb);
+
return TDB_SUCCESS;
}
/* Put a zero in; future versions may append other data. */
ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
}
+ if (tdb->flags & TDB_SEQNUM)
+ tdb_inc_seqnum(tdb);
+
return ecode;
}
+ rec_data_length(&rec)
+ rec_extra_padding(&rec));
+ if (tdb->flags & TDB_SEQNUM)
+ tdb_inc_seqnum(tdb);
+
unlock:
tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
return ecode;
case TDB_NOSYNC:
tdb->flags |= TDB_NOSYNC;
break;
+ case TDB_SEQNUM:
+ tdb->flags |= TDB_SEQNUM;
+ break;
default:
tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
"tdb_add_flag: Unknown flag %u", flag);
case TDB_NOSYNC:
tdb->flags &= ~TDB_NOSYNC;
break;
+ case TDB_SEQNUM:
+ tdb->flags &= ~TDB_SEQNUM;
+ break;
default:
tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
"tdb_remove_flag: Unknown flag %u", flag);
return tdb->name;
}
+int64_t tdb_get_seqnum(struct tdb_context *tdb)
+{
+ return tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+}
+
+
int tdb_fd(const struct tdb_context *tdb)
{
return tdb->file->fd;
#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.
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()
#include <stdbool.h>
/* FIXME: Check these! */
-#define INITIAL_TDB_MALLOC "open.c", 198, FAILTEST_MALLOC
+#define INITIAL_TDB_MALLOC "open.c", 199, FAILTEST_MALLOC
#define URANDOM_OPEN "open.c", 44, FAILTEST_OPEN
#define URANDOM_READ "open.c", 24, FAILTEST_READ
--- /dev/null
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/open.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/hash.c>
+#include <ccan/tdb2/transaction.c>
+#include <ccan/tdb2/traverse.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tap/tap.h>
+#include "logging.h"
+
+int main(int argc, char *argv[])
+{
+ unsigned int i;
+ struct tdb_context *tdb;
+ struct tdb_data d = { NULL, 0 }; /* Bogus GCC warning */
+ struct tdb_data key = { (unsigned char *)"key", 3 };
+ struct tdb_data data = { (unsigned char *)"data", 4 };
+ int flags[] = { TDB_INTERNAL, TDB_DEFAULT, TDB_NOMMAP,
+ TDB_INTERNAL|TDB_CONVERT, TDB_CONVERT,
+ TDB_NOMMAP|TDB_CONVERT };
+
+ plan_tests(sizeof(flags) / sizeof(flags[0]) * 15 + 4 * 13);
+ for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+ tdb = tdb_open("run-new_database.tdb", flags[i]|TDB_SEQNUM,
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &tap_log_attr);
+ if (!ok1(tdb))
+ continue;
+
+ ok1(tdb_get_seqnum(tdb) == 0);
+ ok1(tdb_store(tdb, key, data, TDB_INSERT) == 0);
+ ok1(tdb_get_seqnum(tdb) == 1);
+ /* Fetch doesn't change seqnum */
+ if (ok1(tdb_fetch(tdb, key, &d) == TDB_SUCCESS))
+ free(d.dptr);
+ ok1(tdb_get_seqnum(tdb) == 1);
+ ok1(tdb_append(tdb, key, data) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 2);
+
+ ok1(tdb_delete(tdb, key) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 3);
+ /* Empty append works */
+ ok1(tdb_append(tdb, key, data) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 4);
+
+ ok1(tdb_wipe_all(tdb) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 5);
+
+ if (!(flags[i] & TDB_INTERNAL)) {
+ ok1(tdb_transaction_start(tdb) == TDB_SUCCESS);
+ ok1(tdb_store(tdb, key, data, TDB_INSERT) == 0);
+ ok1(tdb_get_seqnum(tdb) == 6);
+ ok1(tdb_append(tdb, key, data) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 7);
+ ok1(tdb_delete(tdb, key) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 8);
+ ok1(tdb_transaction_commit(tdb) == TDB_SUCCESS);
+ ok1(tdb_get_seqnum(tdb) == 8);
+
+ ok1(tdb_transaction_start(tdb) == TDB_SUCCESS);
+ ok1(tdb_store(tdb, key, data, TDB_INSERT) == 0);
+ ok1(tdb_get_seqnum(tdb) == 9);
+ tdb_transaction_cancel(tdb);
+ ok1(tdb_get_seqnum(tdb) == 8);
+ }
+ tdb_close(tdb);
+ ok1(tap_log_messages == 0);
+ }
+ return exit_status();
+}