1 // Copyright 2021 Google LLC All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package cache 16 17 import v1 "github.com/google/go-containerregistry/pkg/v1" 18 19 // ReadOnly returns a read-only implementation of the given Cache. 20 // 21 // Put and Delete operations are a no-op. 22 func ReadOnly(c Cache) Cache { return &ro{Cache: c} } 23 24 type ro struct{ Cache } 25 26 func (ro) Put(l v1.Layer) (v1.Layer, error) { return l, nil } 27 func (ro) Delete(v1.Hash) error { return nil } 28