1 files changed, 27 insertions, 0 deletions
diff --git a/pkg/v1/cache/ro.go b/pkg/v1/cache/ro.go
new file mode 100644
index 0000000..028a612
--- /dev/null
+++ b/pkg/v1/cache/ro.go
@@ -0,0 +1,27 @@
+// Copyright 2021 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cache
+
+import v1 "github.com/google/go-containerregistry/pkg/v1"
+
+// ReadOnly returns a read-only implementation of the given Cache.
+//
+// Put and Delete operations are a no-op.
+func ReadOnly(c Cache) Cache { return &ro{Cache: c} }
+
+type ro struct{ Cache }
+
+func (ro) Put(l v1.Layer) (v1.Layer, error) { return l, nil }
+func (ro) Delete(v1.Hash) error             { return nil }