Request repository and tag list in parallel

When using S3 or others as the registry storage, the request for repository and tag list may be very slow. This commit fixes this by parallel requesting the resources.

src/ui/api/repository.go

@@ -154,12 +154,27 @@ func getRepositories(query *models.RepositoryQuery) ([]*repoResp, error) {
 		return nil, err
 	}
 
-	return assembleRepos(repositories)
+	return assembleReposInParallel(repositories), nil
 }
 
-func assembleRepos(repositories []*models.RepoRecord) ([]*repoResp, error) {
-	result := []*repoResp{}
+func assembleReposInParallel(repositories []*models.RepoRecord) []*repoResp {
+	c := make(chan *repoResp)
 	for _, repository := range repositories {
+		go assembleRepo(c, repository)
+	}
+	result := []*repoResp{}
+	var item *repoResp
+	for i := 0; i < len(repositories); i++ {
+		item = <-c
+		if item == nil {
+			continue
+		}
+		result = append(result, item)
+	}
+	return result
+}
+
+func assembleRepo(c chan *repoResp, repository *models.RepoRecord) {
 	repo := &repoResp{
 		ID:           repository.RepositoryID,
 		Name:         repository.Name,
@@ -173,9 +188,10 @@ func assembleRepos(repositories []*models.RepoRecord) ([]*repoResp, error) {
 
 	tags, err := getTags(repository.Name)
 	if err != nil {
-			return nil, err
-		}
+		log.Errorf("failed to list tags of %s: %v", repository.Name, err)
+	} else {
 		repo.TagsCount = int64(len(tags))
+	}
 
 	labels, err := dao.GetLabelsOfResource(common.ResourceTypeRepository, repository.RepositoryID)
 	if err != nil {
@@ -184,9 +200,7 @@ func assembleRepos(repositories []*models.RepoRecord) ([]*repoResp, error) {
 		repo.Labels = labels
 	}
 
-		result = append(result, repo)
-	}
-	return result, nil
+	c <- repo
 }
 
 // Delete ...
@@ -381,7 +395,7 @@ func (ra *RepositoryAPI) GetTag() {
 		return
 	}
 
-	result := assembleTags(client, repository, []string{tag},
+	result := assembleTagsInParallel(client, repository, []string{tag},
 		ra.SecurityCtx.GetUsername())
 	ra.Data["json"] = result[0]
 	ra.ServeJSON()
@@ -453,16 +467,15 @@ func (ra *RepositoryAPI) GetTags() {
 		tags = ts
 	}
 
-	ra.Data["json"] = assembleTags(client, repoName, tags,
+	ra.Data["json"] = assembleTagsInParallel(client, repoName, tags,
 		ra.SecurityCtx.GetUsername())
 	ra.ServeJSON()
 }
 
 // get config, signature and scan overview and assemble them into one
 // struct for each tag in tags
-func assembleTags(client *registry.Repository, repository string,
+func assembleTagsInParallel(client *registry.Repository, repository string,
 	tags []string, username string) []*tagResp {
-
 	var err error
 	signatures := map[string][]notary.Target{}
 	if config.WithNotary() {
@@ -473,12 +486,29 @@ func assembleTags(client *registry.Repository, repository string,
 		}
 	}
 
+	c := make(chan *tagResp)
+	for _, tag := range tags {
+		go assembleTag(c, client, repository, tag, config.WithClair(),
+			config.WithNotary(), signatures)
+	}
 	result := []*tagResp{}
-	for _, t := range tags {
-		item := &tagResp{}
+	var item *tagResp
+	for i := 0; i < len(tags); i++ {
+		item = <-c
+		if item == nil {
+			continue
+		}
+		result = append(result, item)
+	}
+	return result
+}
 
+func assembleTag(c chan *tagResp, client *registry.Repository,
+	repository, tag string, clairEnabled, notaryEnabled bool,
+	signatures map[string][]notary.Target) {
+	item := &tagResp{}
 	// labels
-		image := fmt.Sprintf("%s:%s", repository, t)
+	image := fmt.Sprintf("%s:%s", repository, tag)
 	labels, err := dao.GetLabelsOfResource(common.ResourceTypeImage, image)
 	if err != nil {
 		log.Errorf("failed to get labels of image %s: %v", image, err)
@@ -487,21 +517,21 @@ func assembleTags(client *registry.Repository, repository string,
 	}
 
 	// the detail information of tag
-		tagDetail, err := getTagDetail(client, t)
+	tagDetail, err := getTagDetail(client, tag)
 	if err != nil {
-			log.Errorf("failed to get v2 manifest of %s:%s: %v", repository, t, err)
+		log.Errorf("failed to get v2 manifest of %s:%s: %v", repository, tag, err)
 	}
 	if tagDetail != nil {
 		item.tagDetail = *tagDetail
 	}
 
 	// scan overview
-		if config.WithClair() {
+	if clairEnabled {
 		item.ScanOverview = getScanOverview(item.Digest, item.Name)
 	}
 
 	// signature, compare both digest and tag
-		if config.WithNotary() {
+	if notaryEnabled && signatures != nil {
 		if sigs, ok := signatures[item.Digest]; ok {
 			for _, sig := range sigs {
 				if item.Name == sig.Tag {
@@ -510,11 +540,7 @@ func assembleTags(client *registry.Repository, repository string,
 			}
 		}
 	}
-
-		result = append(result, item)
-	}
-
-	return result
+	c <- item
 }
 
 // getTagDetail returns the detail information for v2 manifest image
@@ -709,13 +735,7 @@ func (ra *RepositoryAPI) GetTopRepos() {
 		ra.CustomAbort(http.StatusInternalServerError, "internal server error")
 	}
 
-	result, err := assembleRepos(repos)
-	if err != nil {
-		log.Errorf("failed to popultate tags count to repositories: %v", err)
-		ra.CustomAbort(http.StatusInternalServerError, "internal server error")
-	}
-
-	ra.Data["json"] = result
+	ra.Data["json"] = assembleReposInParallel(repos)
 	ra.ServeJSON()
 }