resolved comments

Signed-off-by: Xiaoxuan Wang <wangxiaoxuan119@gmail.com>

content/oci/oci.go

@@ -55,15 +55,17 @@
 	AutoSaveIndex bool
 
 	// AutoGC controls if the OCI store will automatically clean newly produced
-	// dangling nodes during Delete() operation. Dangling nodes are those without
-	// any predecessors, such as blobs whose manifests have been deleted.
+	// dangling (unreferenced) blobs during Delete() operation. For example the
+	// blobs whose manifests have been deleted. Manifests in the index will not
+	// be deleted.
 	//   - Default value: true.
 	AutoGC bool
 
-	// AutoRemoveReferrers controls if the OCI store will automatically delete its
-	// referrers when a manifest is deleted.
+	// AutoDeleteReferrers controls if the OCI store will automatically delete its
+	// referrers when a manifest is deleted. When set to true, the referrers will
+	// be deleted even if they exist in the index.
 	//   - Default value: true.
-	AutoRemoveReferrers bool
+	AutoDeleteReferrers bool
 
 	root        string
 	indexPath   string
@@ -99,7 +101,7 @@
 	store := &Store{
 		AutoSaveIndex:       true,
 		AutoGC:              true,
-		AutoRemoveReferrers: true,
+		AutoDeleteReferrers: true,
 		root:                rootAbs,
 		indexPath:           filepath.Join(rootAbs, ocispec.ImageIndexFile),
 		storage:             storage,
@@ -163,38 +165,35 @@
 // is set to true, Delete will recursively remove the referrers of the manifests
 // being deleted.
 func (s *Store) Delete(ctx context.Context, target ocispec.Descriptor) error {
-	var deleteQueue []ocispec.Descriptor
-	deleteQueue = append(deleteQueue, target)
+	deleteQueue := []ocispec.Descriptor{target}
 
 	for len(deleteQueue) > 0 {
 		head := deleteQueue[0]
 		deleteQueue = deleteQueue[1:]
 
 		// get referrers if applicable
-		var referrers []ocispec.Descriptor
-		var err error
-		if s.AutoRemoveReferrers && descriptor.IsManifest(head) {
-			referrers, err = registry.Referrers(ctx, s, head, "")
+		if s.AutoDeleteReferrers && descriptor.IsManifest(head) {
+			referrers, err := registry.Referrers(ctx, s, head, "")
 			if err != nil {
 				return err
 			}
+			deleteQueue = append(deleteQueue, referrers...)
 		}
-		deleteQueue = append(deleteQueue, referrers...)
 
 		// delete the head of queue if applicable
 		s.sync.Lock()
 
 		danglings, err := s.delete(ctx, head)
 		if err != nil {
 			s.sync.Unlock()
 			return err
 		}
 
 		if s.AutoGC {
 			for _, d := range danglings {
 				// do not delete existing manifests in tagResolver
 				_, err = s.tagResolver.Resolve(ctx, string(d.Digest))
-				if err == errdef.ErrNotFound {
+				if errors.Is(err, errdef.ErrNotFound) {
 					deleteQueue = append(deleteQueue, d)
 				}
 			}
@@ -220,12 +219,12 @@
 	if untagged && s.AutoSaveIndex {
 		err := s.saveIndex()
 		if err != nil {
 			return nil, err
 		}
 	}
 	if err := s.storage.Delete(ctx, target); err != nil {
 		return nil, err
 	}
 	return danglings, nil
 }
 

content/oci/oci_test.go

@@ -2422,7 +2422,7 @@ func TestStore_DeleteDisableAutoRemoveReferrers(t *testing.T) {
 	if err != nil {
 		t.Fatal("New() error =", err)
 	}
-	s.AutoRemoveReferrers = false
+	s.AutoDeleteReferrers = false
 	ctx := context.Background()
 
 	// generate test content
@@ -2577,7 +2577,7 @@ func TestStore_DeleteDisableAutoGCAndAutoRemoveReferrers(t *testing.T) {
 	if err != nil {
 		t.Fatal("New() error =", err)
 	}
-	s.AutoRemoveReferrers = false
+	s.AutoDeleteReferrers = false
 	s.AutoGC = false
 	ctx := context.Background()
 

internal/graph/memory.go

@@ -31,21 +31,21 @@ import (
 
 // Memory is a memory based PredecessorFinder.
 type Memory struct {
-	// properties and behaviors of Memory.nodes:
+	// nodes has the following properties and behaviors:
 	//  1. a node exists in Memory.nodes if and only if it exists in the memory
 	//  2. Memory.nodes saves the ocispec.Descriptor map keys, which are used by
 	//    the other fields.
 	nodes map[descriptor.Descriptor]ocispec.Descriptor
 
-	// properties and behaviors of Memory.predecessors:
+	// predecessors has the following properties and behaviors:
 	//  1. a node exists in Memory.predecessors if it has at least one predecessor
 	//    in the memory, regardless of whether or not the node itself exists in
 	//    the memory.
 	//  2. a node does not exist in Memory.predecessors, if it doesn't have any predecessors
 	//    in the memory.
 	predecessors map[descriptor.Descriptor]set.Set[descriptor.Descriptor]
 
-	// properties and behaviors of Memory.successors:
+	// successors has the following properties and behaviors:
 	//  1. a node exists in Memory.successors if and only if it exists in the memory.
 	//  2. a node's entry in Memory.successors is always consistent with the actual
 	//    content of the node, regardless of whether or not each successor exists