Merge pull request #8734 from djdongjin/content-copy-dedup

Simplify `content.Copy` logic

content/helpers.go

@@ -148,32 +148,28 @@ func OpenWriter(ctx context.Context, cs Ingester, opts ...WriterOpt) (Writer, er
 //
 // Copy is buffered, so no need to wrap reader in buffered io.
 func Copy(ctx context.Context, cw Writer, or io.Reader, size int64, expected digest.Digest, opts ...Opt) error {
+	r := or
+	for i := 0; i < maxResets; i++ {
+		if i >= 1 {
+			log.G(ctx).WithField("digest", expected).Debugf("retrying copy due to reset")
+		}
+
 		ws, err := cw.Status()
 		if err != nil {
 			return fmt.Errorf("failed to get status: %w", err)
 		}
-	r := or
+		// Reset the original reader if
-	if ws.Offset > 0 {
+		// 1. there is an offset, or
+		// 2. this is a retry due to Reset error
+		if ws.Offset > 0 || i > 0 {
 			r, err = seekReader(or, ws.Offset, size)
 			if err != nil {
 				return fmt.Errorf("unable to resume write to %v: %w", ws.Ref, err)
 			}
 		}
 
-	for i := 0; i < maxResets; i++ {
-		if i >= 1 {
-			log.G(ctx).WithField("digest", expected).Debugf("retrying copy due to reset")
-		}
 		copied, err := copyWithBuffer(cw, r)
 		if errors.Is(err, ErrReset) {
-			ws, err := cw.Status()
-			if err != nil {
-				return fmt.Errorf("failed to get status: %w", err)
-			}
-			r, err = seekReader(or, ws.Offset, size)
-			if err != nil {
-				return fmt.Errorf("unable to resume write to %v: %w", ws.Ref, err)
-			}
 			continue
 		}
 		if err != nil {
@@ -185,14 +181,6 @@ func Copy(ctx context.Context, cw Writer, or io.Reader, size int64, expected dig
 		}
 		if err := cw.Commit(ctx, size, expected, opts...); err != nil {
 			if errors.Is(err, ErrReset) {
-				ws, err := cw.Status()
-				if err != nil {
-					return fmt.Errorf("failed to get status: %w", err)
-				}
-				r, err = seekReader(or, ws.Offset, size)
-				if err != nil {
-					return fmt.Errorf("unable to resume write to %v: %w", ws.Ref, err)
-				}
 				continue
 			}
 			if !errdefs.IsAlreadyExists(err) {

services/content/contentserver/contentserver.go

@@ -40,12 +40,15 @@ type service struct {
 	api.UnimplementedContentServer
 }
 
-var bufPool = sync.Pool{
+var (
+	empty   = &ptypes.Empty{}
+	bufPool = sync.Pool{
 		New: func() interface{} {
 			buffer := make([]byte, 1<<20)
 			return &buffer
 		},
 	}
+)
 
 // New returns the content GRPC server
 func New(cs content.Store) api.ContentServer {
@@ -101,12 +104,7 @@ func (s *service) List(req *api.ListContentRequest, session api.Content_ListServ
 	)
 
 	if err := s.store.Walk(session.Context(), func(info content.Info) error {
-		buffer = append(buffer, &api.Info{
+		buffer = append(buffer, infoToGRPC(info))
-			Digest:    info.Digest.String(),
-			Size:      info.Size,
-			CreatedAt: protobuf.ToTimestamp(info.CreatedAt),
-			Labels:    info.Labels,
-		})
 
 		if len(buffer) >= 100 {
 			if err := sendBlock(buffer); err != nil {
@@ -142,7 +140,7 @@ func (s *service) Delete(ctx context.Context, req *api.DeleteContentRequest) (*p
 		return nil, errdefs.ToGRPC(err)
 	}
 
-	return &ptypes.Empty{}, nil
+	return empty, nil
 }
 
 func (s *service) Read(req *api.ReadContentRequest, session api.Content_ReadServer) error {
@@ -449,7 +447,7 @@ func (s *service) Abort(ctx context.Context, req *api.AbortRequest) (*ptypes.Emp
 		return nil, errdefs.ToGRPC(err)
 	}
 
-	return &ptypes.Empty{}, nil
+	return empty, nil
 }
 
 func infoToGRPC(info content.Info) *api.Info {