func DataSize(data []byte) (uint64, error) { pbdata := new(pb.Data) err := proto.Unmarshal(data, pbdata) if err != nil { return 0, err } switch pbdata.GetType() { case pb.Data_Directory: return 0, errors.New("Cant get data size of directory!") case pb.Data_File: return pbdata.GetFilesize(), nil case pb.Data_Raw: return uint64(len(pbdata.GetData())), nil default: return 0, errors.New("Unrecognized node data type!") } }