raw dag: make raw nodes work in cat and get, add tests

License: MIT
Signed-off-by: Jeromy <why@ipfs.io>

io/dagreader.go

@@ -129,13 +129,10 @@ func (dr *DagReader) precalcNextBuf(ctx context.Context) error {
 	}
 	dr.linkPosition++
 
-	nxtpb, ok := nxt.(*mdag.ProtoNode)
-	if !ok {
-		return mdag.ErrNotProtobuf
-	}
-
+	switch nxt := nxt.(type) {
+	case *mdag.ProtoNode:
 		pb := new(ftpb.Data)
-	err = proto.Unmarshal(nxtpb.Data(), pb)
+		err = proto.Unmarshal(nxt.Data(), pb)
 		if err != nil {
 			return fmt.Errorf("incorrectly formatted protobuf: %s", err)
 		}
@@ -145,7 +142,7 @@ func (dr *DagReader) precalcNextBuf(ctx context.Context) error {
 			// A directory should not exist within a file
 			return ft.ErrInvalidDirLocation
 		case ftpb.Data_File:
-		dr.buf = NewDataFileReader(dr.ctx, nxtpb, pb, dr.serv)
+			dr.buf = NewDataFileReader(dr.ctx, nxt, pb, dr.serv)
 			return nil
 		case ftpb.Data_Raw:
 			dr.buf = NewRSNCFromBytes(pb.GetData())
@@ -157,6 +154,12 @@ func (dr *DagReader) precalcNextBuf(ctx context.Context) error {
 		default:
 			return ft.ErrUnrecognizedType
 		}
+	case *mdag.RawNode:
+		dr.buf = NewRSNCFromBytes(nxt.RawData())
+		return nil
+	default:
+		return errors.New("unrecognized node type in DagReader")
+	}
 }
 
 // Size return the total length of the data from the DAG structured file.