tdb: detect tdb store of identical records and skip
This can help with ldb where we rewrite the index records
(cherry picked from samba commit
d4c0e8fdf063f88032c32de7ece60d502b322089)
Signed-off-by: Stefan Metzmacher <metze@samba.org>
+static TDB_DATA _tdb_fetch(struct tdb_context *tdb, TDB_DATA key);
/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
return -1;
if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
return -1;
+ /* it could be an exact duplicate of what is there - this is
+ * surprisingly common (eg. with a ldb re-index). */
+ if (rec.key_len == key.dsize &&
+ rec.data_len == dbuf.dsize &&
+ rec.full_hash == hash) {
+ TDB_DATA data = _tdb_fetch(tdb, key);
+ if (data.dsize == dbuf.dsize &&
+ memcmp(data.dptr, dbuf.dptr, data.dsize) == 0) {
+ if (data.dptr) {
+ free(data.dptr);
+ }
+ return 0;
+ }
+ if (data.dptr) {
+ free(data.dptr);
+ }
+ }
+
+
/* must be long enough key, data and tailer */
if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) {
tdb->ecode = TDB_SUCCESS; /* Not really an error */
/* must be long enough key, data and tailer */
if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) {
tdb->ecode = TDB_SUCCESS; /* Not really an error */