resolved some comments

Signed-off-by: Xiaoxuan Wang <[email protected]>

content/oci/oci.go

@@ -409,14 +409,18 @@ func (s *Store) GC(ctx context.Context) error {
 	s.sync.RLock()
 	defer s.sync.RUnlock()
 
-	rootpath := filepath.Join(s.root, "blobs", "sha256")
+	rootpath := filepath.Join(s.root, "blobs")
 	return filepath.Walk(rootpath, func(path string, info fs.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
-		// skip the working directory
+		// skip the directories
 		if !info.IsDir() {
-			blobDigest := digest.NewDigestFromEncoded("sha256", info.Name())
+			alg := filepath.Base(filepath.Dir(path))
+			blobDigest, err := digest.Parse(fmt.Sprintf("%s:%s", alg, info.Name()))
+			if err != nil {
+				return err
+			}
 			exists, desc := s.graph.ExistsInStore(blobDigest)
 			if !exists {
 				// remove the blob from storage if it does not exist in Store