private int GetId(ushort idKey)
        {
            int recordsPerBlock = MetadataBufferSize / 4;
            int block = idKey / recordsPerBlock;
            int offset = idKey % recordsPerBlock;

            MetablockReader reader = _context.UidGidTableReaders[block];
            reader.SetPosition(0, offset * 4);
            return reader.ReadInt();
        }