// 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 ( "errors" "io" "testing" v1 "github.com/google/go-containerregistry/pkg/v1" "github.com/google/go-containerregistry/pkg/v1/mutate" "github.com/google/go-containerregistry/pkg/v1/random" "github.com/google/go-containerregistry/pkg/v1/validate" ) func TestImage(t *testing.T) { img, err := random.Image(1024, 5) if err != nil { t.Fatalf("random.Image: %v", err) } m := &memcache{map[v1.Hash]v1.Layer{}} img = Image(img, m) // Validate twice to hit the cache. if err := validate.Image(img); err != nil { t.Errorf("Validate: %v", err) } if err := validate.Image(img); err != nil { t.Errorf("Validate: %v", err) } } func TestImageIndex(t *testing.T) { // ImageIndex with child Image and ImageIndex manifests. ii, err := random.Index(1024, 5, 2) if err != nil { t.Fatalf("random.Index: %v", err) } iiChild, err := random.Index(1024, 5, 2) if err != nil { t.Fatalf("random.Index: %v", err) } ii = mutate.AppendManifests(ii, mutate.IndexAddendum{Add: iiChild}) m := &memcache{map[v1.Hash]v1.Layer{}} ii = ImageIndex(ii, m) // Validate twice to hit the cache. if err := validate.Index(ii); err != nil { t.Errorf("Validate: %v", err) } if err := validate.Index(ii); err != nil { t.Errorf("Validate: %v", err) } } func TestLayersLazy(t *testing.T) { img, err := random.Image(1024, 5) if err != nil { t.Fatalf("random.Image: %v", err) } m := &memcache{map[v1.Hash]v1.Layer{}} img = Image(img, m) layers, err := img.Layers() if err != nil { t.Fatalf("img.Layers: %v", err) } // After calling Layers, nothing is cached. if got, want := len(m.m), 0; got != want { t.Errorf("Cache has %d entries, want %d", got, want) } rc, err := layers[0].Uncompressed() if err != nil { t.Fatalf("layer.Uncompressed: %v", err) } io.Copy(io.Discard, rc) if got, expected := len(m.m), 1; got != expected { t.Errorf("expected %v layers in cache after reading, got %v", expected, got) } } // TestCacheShortCircuit tests that if a layer is found in the cache, // LayerByDigest is not called in the underlying Image implementation. func TestCacheShortCircuit(t *testing.T) { l := &fakeLayer{} m := &memcache{map[v1.Hash]v1.Layer{ fakeHash: l, }} img := Image(&fakeImage{}, m) for i := 0; i < 10; i++ { if _, err := img.LayerByDigest(fakeHash); err != nil { t.Errorf("LayerByDigest[%d]: %v", i, err) } } } var fakeHash = v1.Hash{Algorithm: "fake", Hex: "data"} type fakeLayer struct{ v1.Layer } type fakeImage struct{ v1.Image } func (f *fakeImage) LayerByDigest(v1.Hash) (v1.Layer, error) { return nil, errors.New("LayerByDigest was called") } // memcache is an in-memory Cache implementation. // // It doesn't intend to actually write layer data, it just keeps a reference // to the original Layer. // // It only assumes/considers compressed layers, and so only writes layers by // digest. type memcache struct { m map[v1.Hash]v1.Layer } func (m *memcache) Put(l v1.Layer) (v1.Layer, error) { digest, err := l.Digest() if err != nil { return nil, err } m.m[digest] = l return l, nil } func (m *memcache) Get(h v1.Hash) (v1.Layer, error) { l, found := m.m[h] if !found { return nil, ErrNotFound } return l, nil } func (m *memcache) Delete(h v1.Hash) error { delete(m.m, h) return nil }