Merge pull request #10077 from crosbymichael/parallel-image-check

Parallel image lookup

graph/push.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"sync"
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/docker/docker/engine"
@@ -61,85 +62,145 @@ func (s *TagStore) getImageList(localRepo map[string]string, requestedTag string
 	return imageList, tagsByImage, nil
 }
 
-func (s *TagStore) pushRepository(r *registry.Session, out io.Writer, repoInfo *registry.RepositoryInfo, localRepo map[string]string, tag string, sf *utils.StreamFormatter) error {
-	out = utils.NewWriteFlusher(out)
-	log.Debugf("Local repo: %s", localRepo)
-	imgList, tagsByImage, err := s.getImageList(localRepo, tag)
-	if err != nil {
-		return err
-	}
-
-	out.Write(sf.FormatStatus("", "Sending image list"))
-
-	var (
-		repoData   *registry.RepositoryData
-		imageIndex []*registry.ImgData
-	)
-
-	for _, imgId := range imgList {
-		if tags, exists := tagsByImage[imgId]; exists {
+// createImageIndex returns an index of an image's layer IDs and tags.
+func (s *TagStore) createImageIndex(images []string, tags map[string][]string) []*registry.ImgData {
+	var imageIndex []*registry.ImgData
+	for _, id := range images {
+		if tags, hasTags := tags[id]; hasTags {
 			// If an image has tags you must add an entry in the image index
 			// for each tag
 			for _, tag := range tags {
 				imageIndex = append(imageIndex, &registry.ImgData{
-					ID:  imgId,
+					ID:  id,
 					Tag: tag,
 				})
 			}
-		} else {
-			// If the image does not have a tag it still needs to be sent to the
-			// registry with an empty tag so that it is accociated with the repository
-			imageIndex = append(imageIndex, &registry.ImgData{
-				ID:  imgId,
-				Tag: "",
-			})
+			continue
+		}
+		// If the image does not have a tag it still needs to be sent to the
+		// registry with an empty tag so that it is accociated with the repository
+		imageIndex = append(imageIndex, &registry.ImgData{
+			ID:  id,
+			Tag: "",
+		})
+	}
+	return imageIndex
+}
+
+type imagePushData struct {
+	id       string
+	endpoint string
+	tokens   []string
+}
 
+// lookupImageOnEndpoint checks the specified endpoint to see if an image exists
+// and if it is absent then it sends the image id to the channel to be pushed.
+func lookupImageOnEndpoint(wg *sync.WaitGroup, r *registry.Session, out io.Writer, sf *utils.StreamFormatter,
+	images chan imagePushData, imagesToPush chan string) {
+	defer wg.Done()
+	for image := range images {
+		if err := r.LookupRemoteImage(image.id, image.endpoint, image.tokens); err != nil {
+			log.Errorf("Error in LookupRemoteImage: %s", err)
+			imagesToPush <- image.id
+			continue
 		}
+		out.Write(sf.FormatStatus("", "Image %s already pushed, skipping", utils.TruncateID(image.id)))
 	}
+}
 
+func (s *TagStore) pushImageToEndpoint(endpoint string, out io.Writer, remoteName string, imageIDs []string,
+	tags map[string][]string, repo *registry.RepositoryData, sf *utils.StreamFormatter, r *registry.Session) error {
+	workerCount := len(imageIDs)
+	// start a maximum of 5 workers to check if images exist on the specified endpoint.
+	if workerCount > 5 {
+		workerCount = 5
+	}
+	var (
+		wg           = &sync.WaitGroup{}
+		imageData    = make(chan imagePushData, workerCount*2)
+		imagesToPush = make(chan string, workerCount*2)
+		pushes       = make(chan map[string]struct{}, 1)
+	)
+	for i := 0; i < workerCount; i++ {
+		wg.Add(1)
+		go lookupImageOnEndpoint(wg, r, out, sf, imageData, imagesToPush)
+	}
+	// start a go routine that consumes the images to push
+	go func() {
+		shouldPush := make(map[string]struct{})
+		for id := range imagesToPush {
+			shouldPush[id] = struct{}{}
+		}
+		pushes <- shouldPush
+	}()
+	for _, id := range imageIDs {
+		imageData <- imagePushData{
+			id:       id,
+			endpoint: endpoint,
+			tokens:   repo.Tokens,
+		}
+	}
+	// close the channel to notify the workers that there will be no more images to check.
+	close(imageData)
+	wg.Wait()
+	close(imagesToPush)
+	// wait for all the images that require pushes to be collected into a consumable map.
+	shouldPush := <-pushes
+	// finish by pushing any images and tags to the endpoint.  The order that the images are pushed
+	// is very important that is why we are still itterating over the ordered list of imageIDs.
+	for _, id := range imageIDs {
+		if _, push := shouldPush[id]; push {
+			if _, err := s.pushImage(r, out, id, endpoint, repo.Tokens, sf); err != nil {
+				// FIXME: Continue on error?
+				return err
+			}
+		}
+		for _, tag := range tags[id] {
+			out.Write(sf.FormatStatus("", "Pushing tag for rev [%s] on {%s}", utils.TruncateID(id), endpoint+"repositories/"+remoteName+"/tags/"+tag))
+			if err := r.PushRegistryTag(remoteName, id, tag, endpoint, repo.Tokens); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// pushRepository pushes layers that do not already exist on the registry.
+func (s *TagStore) pushRepository(r *registry.Session, out io.Writer,
+	repoInfo *registry.RepositoryInfo, localRepo map[string]string,
+	tag string, sf *utils.StreamFormatter) error {
+	log.Debugf("Local repo: %s", localRepo)
+	out = utils.NewWriteFlusher(out)
+	imgList, tags, err := s.getImageList(localRepo, tag)
+	if err != nil {
+		return err
+	}
+	out.Write(sf.FormatStatus("", "Sending image list"))
+
+	imageIndex := s.createImageIndex(imgList, tags)
 	log.Debugf("Preparing to push %s with the following images and tags", localRepo)
 	for _, data := range imageIndex {
 		log.Debugf("Pushing ID: %s with Tag: %s", data.ID, data.Tag)
 	}
-
 	// Register all the images in a repository with the registry
 	// If an image is not in this list it will not be associated with the repository
-	repoData, err = r.PushImageJSONIndex(repoInfo.RemoteName, imageIndex, false, nil)
+	repoData, err := r.PushImageJSONIndex(repoInfo.RemoteName, imageIndex, false, nil)
 	if err != nil {
 		return err
 	}
-
 	nTag := 1
 	if tag == "" {
 		nTag = len(localRepo)
 	}
-	for _, ep := range repoData.Endpoints {
-		out.Write(sf.FormatStatus("", "Pushing repository %s (%d tags)", repoInfo.CanonicalName, nTag))
-		for _, imgId := range imgList {
-			if err := r.LookupRemoteImage(imgId, ep, repoData.Tokens); err != nil {
-				log.Errorf("Error in LookupRemoteImage: %s", err)
-				if _, err := s.pushImage(r, out, imgId, ep, repoData.Tokens, sf); err != nil {
-					// FIXME: Continue on error?
-					return err
-				}
-			} else {
-				out.Write(sf.FormatStatus("", "Image %s already pushed, skipping", utils.TruncateID(imgId)))
-			}
-			for _, tag := range tagsByImage[imgId] {
-				out.Write(sf.FormatStatus("", "Pushing tag for rev [%s] on {%s}", utils.TruncateID(imgId), ep+"repositories/"+repoInfo.RemoteName+"/tags/"+tag))
-
-				if err := r.PushRegistryTag(repoInfo.RemoteName, imgId, tag, ep, repoData.Tokens); err != nil {
-					return err
-				}
-			}
+	out.Write(sf.FormatStatus("", "Pushing repository %s (%d tags)", repoInfo.CanonicalName, nTag))
+	// push the repository to each of the endpoints only if it does not exist.
+	for _, endpoint := range repoData.Endpoints {
+		if err := s.pushImageToEndpoint(endpoint, out, repoInfo.RemoteName, imgList, tags, repoData, sf, r); err != nil {
+			return err
 		}
 	}
-
-	if _, err := r.PushImageJSONIndex(repoInfo.RemoteName, imageIndex, true, repoData.Endpoints); err != nil {
-		return err
-	}
-
-	return nil
+	_, err = r.PushImageJSONIndex(repoInfo.RemoteName, imageIndex, true, repoData.Endpoints)
+	return err
 }
 
 func (s *TagStore) pushImage(r *registry.Session, out io.Writer, imgID, ep string, token []string, sf *utils.StreamFormatter) (checksum string, err error) {