/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
on failure return -1.
*/
static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf)
{
struct list_struct rec;
tdb_off_t rec_ptr;
/* find entry */
if (!(rec_ptr = tdb_find(tdb, key, hash, &rec)))
return -1;
/* 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 */
return -1;
}
if (tdb->methods->tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
dbuf.dptr, dbuf.dsize) == -1)
return -1;
if (dbuf.dsize != rec.data_len) {
/* update size */
rec.data_len = dbuf.dsize;
return tdb_rec_write(tdb, rec_ptr, &rec);
}
return 0;
}
/* As tdb_find, but if you succeed, keep the lock */
tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype,
struct list_struct *rec)
{
u32 rec_ptr;
if (tdb_lock(tdb, BUCKET(hash), locktype) == -1)
return 0;
if (!(rec_ptr = tdb_find(tdb, key, hash, rec)))
tdb_unlock(tdb, BUCKET(hash), locktype);
return rec_ptr;
}
/* delete an entry in the database given a key */
static int tdb_delete_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash)
{
tdb_off_t rec_ptr;
struct list_struct rec;
int ret;
if (tdb->max_dead_records != 0) {
/*
* Allow for some dead records per hash chain, mainly for
* tdb's with a very high create/delete rate like locking.tdb.
*/
if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
return -1;
if (tdb_count_dead(tdb, hash) >= tdb->max_dead_records) {
/*
* Don't let the per-chain freelist grow too large,
* delete all existing dead records
*/
tdb_purge_dead(tdb, hash);
}
if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) {
tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
return -1;
}
/*
* Just mark the record as dead.
*/
rec.magic = TDB_DEAD_MAGIC;
ret = tdb_rec_write(tdb, rec_ptr, &rec);
}
else {
if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK,
&rec)))
return -1;
ret = tdb_do_delete(tdb, rec_ptr, &rec);
}
if (ret == 0) {
tdb_increment_seqnum(tdb);
}
if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0)
TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_delete: WARNING tdb_unlock failed!\n"));
return ret;
}
/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
on failure return -1.
*/
static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, TDB_DATA dbuf)
{
struct tdb_record rec;
tdb_off_t rec_ptr;
/* find entry */
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_parse_record(tdb, key, tdb_update_hash_cmp, &dbuf) == 0) {
return 0;
}
/* 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 */
return -1;
}
if (tdb->methods->tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
dbuf.dptr, dbuf.dsize) == -1)
return -1;
if (dbuf.dsize != rec.data_len) {
/* update size */
rec.data_len = dbuf.dsize;
return tdb_rec_write(tdb, rec_ptr, &rec);
}
return 0;
}
