Exemplo n.º 1
0
func (a *App) zset_rank(key []byte, member []byte, reverse bool) (int64, error) {
	k := encode_zset_key(key, member)

	if v, err := a.db.Get(k); err != nil {
		return 0, err
	} else if v == nil {
		return -1, nil
	} else {
		if s, err := Int64(v, err); err != nil {
			return 0, err
		} else {
			var it *leveldb.Iterator

			sk := encode_zscore_key(key, member, s)

			if !reverse {
				minKey := encode_start_zscore_key(key, MinScore)
				it = a.db.Iterator(minKey, sk, leveldb.RangeClose, 0, -1)
			} else {
				maxKey := encode_stop_zscore_key(key, MaxScore)
				it = a.db.RevIterator(sk, maxKey, leveldb.RangeClose, 0, -1)
			}

			var lastKey []byte = nil
			var n int64 = 0

			for ; it.Valid(); it.Next() {
				n++

				lastKey = it.Key()
			}

			it.Close()

			if _, m, _, err := decode_zscore_key(lastKey); err == nil && bytes.Equal(m, member) {
				n--
				return n, nil
			}
		}
	}

	return -1, nil
}