better name and updated tests

- use ManifestDigests name instead of Indexes
- update tests to validate against multiple tags

Signed-off-by: Manish Tomar <manish.tomar@docker.com>

registry/storage/tagstore.go

@@ -197,7 +197,7 @@ func (ts *tagStore) Lookup(ctx context.Context, desc distribution.Descriptor) ([
 	return tags, nil
 }
 
-func (ts *tagStore) Indexes(ctx context.Context, tag string) ([]digest.Digest, error) {
+func (ts *tagStore) ManifestDigests(ctx context.Context, tag string) ([]digest.Digest, error) {
 	var tagLinkPath = func(name string, dgst digest.Digest) (string, error) {
 		return pathFor(manifestTagIndexEntryLinkPathSpec{
 			name:     name,

registry/storage/tagstore_test.go

@@ -226,9 +226,9 @@ func TestTagIndexes(t *testing.T) {
 	tagStore := env.ts
 	ctx := env.ctx
 
-	indexes, ok := tagStore.(distribution.TagIndexes)
+	md, ok := tagStore.(distribution.TagManifestsProvider)
 	if !ok {
-		t.Fatal("tagStore does not implement TagIndexes interface")
+		t.Fatal("tagStore does not implement TagManifestDigests interface")
 	}
 
 	conf, err := env.bs.Put(ctx, "application/octet-stream", []byte{0})
@@ -236,8 +236,9 @@ func TestTagIndexes(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	dgstsSet := make(map[digest.Digest]bool)
-	for i := 0; i < 3; i++ {
+	t1Dgsts := make(map[digest.Digest]struct{})
+	t2Dgsts := make(map[digest.Digest]struct{})
+	for i := 0; i < 5; i++ {
 		layer, err := env.bs.Put(ctx, "application/octet-stream", []byte{byte(i + 1)})
 		if err != nil {
 			t.Fatal(err)
@@ -272,22 +273,44 @@ func TestTagIndexes(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		err = tagStore.Tag(ctx, "t", desc)
+		if i < 3 {
+			// tag first 3 manifests as "t1"
+			err = tagStore.Tag(ctx, "t1", desc)
 			if err != nil {
 				t.Fatal(err)
 			}
-		dgstsSet[dgst] = true
+			t1Dgsts[dgst] = struct{}{}
+		} else {
+			// the last two under "t2"
+			err = tagStore.Tag(ctx, "t2", desc)
+			if err != nil {
+				t.Fatal(err)
+			}
+			t2Dgsts[dgst] = struct{}{}
+		}
 	}
 
-	gotDgsts, err := indexes.Indexes(ctx, "t")
+	gotT1Dgsts, err := md.ManifestDigests(ctx, "t1")
 	if err != nil {
 		t.Fatal(err)
 	}
-	gotDgstsSet := make(map[digest.Digest]bool)
-	for _, dgst := range gotDgsts {
-		gotDgstsSet[dgst] = true
+	if !reflect.DeepEqual(t1Dgsts, digestMap(gotT1Dgsts)) {
+		t.Fatalf("Expected digests: %v but got digests: %v", t1Dgsts, digestMap(gotT1Dgsts))
 	}
-	if !reflect.DeepEqual(dgstsSet, gotDgstsSet) {
-		t.Fatalf("Expected digests: %v but got digests: %v", dgstsSet, gotDgstsSet)
+
+	gotT2Dgsts, err := md.ManifestDigests(ctx, "t2")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(t2Dgsts, digestMap(gotT2Dgsts)) {
+		t.Fatalf("Expected digests: %v but got digests: %v", t2Dgsts, digestMap(gotT2Dgsts))
 	}
 }
+
+func digestMap(dgsts []digest.Digest) map[digest.Digest]struct{} {
+	set := make(map[digest.Digest]struct{})
+	for _, dgst := range dgsts {
+		set[dgst] = struct{}{}
+	}
+	return set
+}

tags.go

@@ -28,9 +28,10 @@ type TagService interface {
 	Lookup(ctx context.Context, digest Descriptor) ([]string, error)
 }
 
-// TagIndexes proves method to retreive all the digests that a tag historically pointed to
-type TagIndexes interface {
-	// Indexes returns set of digests that this tag historically pointed to. This also includes
-	// currently linked digest. There is no ordering guaranteed
-	Indexes(ctx context.Context, tag string) ([]digest.Digest, error)
+// TagManifestsProvider provides method to retreive the digests of manifests that a tag historically
+// pointed to
+type TagManifestsProvider interface {
+	// ManifestDigests returns set of digests that this tag historically pointed to. This also
+	// includes currently linked digest. There is no ordering guaranteed
+	ManifestDigests(ctx context.Context, tag string) ([]digest.Digest, error)
 }