func UnwrapData(data []byte) ([]byte, error) {
pbdata := new(pb.Data)
err := proto.Unmarshal(data, pbdata)
if err != nil {
return nil, err
}
return pbdata.GetData(), nil
}
func NewDataFileReader(ctx context.Context, n *mdag.Node, pb *ftpb.Data, serv mdag.DAGService) *DagReader {
fctx, cancel := context.WithCancel(ctx)
promises := serv.GetDAG(fctx, n)
return &DagReader{
node: n,
serv: serv,
buf: NewRSNCFromBytes(pb.GetData()),
promises: promises,
ctx: fctx,
cancel: cancel,
pbdata: pb,
}
}
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!")
}
}
// precalcNextBuf follows the next link in line and loads it from the DAGService,
// setting the next buffer to read from
func (dr *DagReader) precalcNextBuf(ctx context.Context) error {
dr.buf.Close() // Just to make sure
if dr.linkPosition >= len(dr.promises) {
return io.EOF
}
nxt, err := dr.promises[dr.linkPosition].Get(ctx)
if err != nil {
return err
}
dr.linkPosition++
pb := new(ftpb.Data)
err = proto.Unmarshal(nxt.Data, pb)
if err != nil {
return fmt.Errorf("incorrectly formatted protobuf: %s", err)
}
switch pb.GetType() {
case ftpb.Data_Directory:
// A directory should not exist within a file
return ft.ErrInvalidDirLocation
case ftpb.Data_File:
dr.buf = NewDataFileReader(dr.ctx, nxt, pb, dr.serv)
return nil
case ftpb.Data_Raw:
dr.buf = NewRSNCFromBytes(pb.GetData())
return nil
case ftpb.Data_Metadata:
return errors.New("Shouldnt have had metadata object inside file")
case ftpb.Data_Symlink:
return errors.New("shouldnt have had symlink inside file")
default:
return ft.ErrUnrecognizedType
}
}