Support WithJobs in remote.Write (#958)

pkg/v1/remote/write.go

@@ -64,39 +64,60 @@ func Write(ref name.Reference, img v1.Image, options ...Option) error {
 		context: o.context,
 	}
 
+	// Upload individual blobs and collect any errors.
+	blobChan := make(chan v1.Layer, 2*o.jobs)
+	g, ctx := errgroup.WithContext(o.context)
+	for i := 0; i < o.jobs; i++ {
+		// Start N workers consuming blobs to upload.
+		g.Go(func() error {
+			for b := range blobChan {
+				if err := w.uploadOne(b); err != nil {
+					return err
+				}
+			}
+			return nil
+		})
+	}
+
 	// Upload individual layers in goroutines and collect any errors.
 	// If we can dedupe by the layer digest, try to do so. If we can't determine
 	// the digest for whatever reason, we can't dedupe and might re-upload.
-	var g errgroup.Group
-	uploaded := map[v1.Hash]bool{}
-	for _, l := range ls {
-		l := l
-
-		// Handle foreign layers.
-		mt, err := l.MediaType()
-		if err != nil {
-			return err
-		}
-		if !mt.IsDistributable() && !o.allowNondistributableArtifacts {
-			continue
-		}
+	g.Go(func() error {
+		defer close(blobChan)
+		uploaded := map[v1.Hash]bool{}
+		for _, l := range ls {
+			l := l
+
+			// Handle foreign layers.
+			mt, err := l.MediaType()
+			if err != nil {
+				return err
+			}
+			if !mt.IsDistributable() && !o.allowNondistributableArtifacts {
+				continue
+			}
 
-		// Streaming layers calculate their digests while uploading them. Assume
-		// an error here indicates we need to upload the layer.
-		h, err := l.Digest()
-		if err == nil {
-			// If we can determine the layer's digest ahead of
-			// time, use it to dedupe uploads.
-			if uploaded[h] {
-				continue // Already uploading.
+			// Streaming layers calculate their digests while uploading them. Assume
+			// an error here indicates we need to upload the layer.
+			h, err := l.Digest()
+			if err == nil {
+				// If we can determine the layer's digest ahead of
+				// time, use it to dedupe uploads.
+				if uploaded[h] {
+					continue // Already uploading.
+				}
+				uploaded[h] = true
+			}
+			select {
+			case blobChan <- l:
+			case <-ctx.Done():
+				return ctx.Err()
 			}
-			uploaded[h] = true
 		}
-
-		// TODO(#803): Pipe through remote.WithJobs and upload these in parallel.
-		g.Go(func() error {
-			return w.uploadOne(l)
-		})
+		return nil
+	})
+	if err := g.Wait(); err != nil {
+		return err
 	}
 
 	if l, err := partial.ConfigLayer(img); err != nil {