1 files changed, 213 insertions, 0 deletions
diff --git a/pkg/v1/cache/fs_test.go b/pkg/v1/cache/fs_test.go
new file mode 100644
index 0000000..2e05d29
--- /dev/null
+++ b/pkg/v1/cache/fs_test.go
@@ -0,0 +1,213 @@
+// 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"
+	"os"
+	"testing"
+
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/random"
+	"github.com/google/go-containerregistry/pkg/v1/tarball"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+func TestFilesystemCache(t *testing.T) {
+	dir := t.TempDir()
+
+	numLayers := 5
+	img, err := random.Image(10, int64(numLayers))
+	if err != nil {
+		t.Fatalf("random.Image: %v", err)
+	}
+	c := NewFilesystemCache(dir)
+	img = Image(img, c)
+
+	// Read all the (compressed) layers to populate the cache.
+	ls, err := img.Layers()
+	if err != nil {
+		t.Fatalf("Layers: %v", err)
+	}
+	for i, l := range ls {
+		rc, err := l.Compressed()
+		if err != nil {
+			t.Fatalf("layer[%d].Compressed: %v", i, err)
+		}
+		if _, err := io.Copy(io.Discard, rc); err != nil {
+			t.Fatalf("Error reading contents: %v", err)
+		}
+		rc.Close()
+	}
+
+	// Check that layers exist in the fs cache.
+	dirEntries, err := os.ReadDir(dir)
+	if err != nil {
+		t.Fatalf("ReadDir: %v", err)
+	}
+	if got, want := len(dirEntries), numLayers; got != want {
+		t.Errorf("Got %d cached files, want %d", got, want)
+	}
+	for _, de := range dirEntries {
+		fi, err := de.Info()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if fi.Size() == 0 {
+			t.Errorf("Cached file %q is empty", fi.Name())
+		}
+	}
+
+	// Read all (uncompressed) layers, those populate the cache too.
+	for i, l := range ls {
+		rc, err := l.Uncompressed()
+		if err != nil {
+			t.Fatalf("layer[%d].Compressed: %v", i, err)
+		}
+		if _, err := io.Copy(io.Discard, rc); err != nil {
+			t.Fatalf("Error reading contents: %v", err)
+		}
+		rc.Close()
+	}
+
+	// Check that double the layers are present now, both compressed and
+	// uncompressed.
+	dirEntries, err = os.ReadDir(dir)
+	if err != nil {
+		t.Fatalf("ReadDir: %v", err)
+	}
+	if got, want := len(dirEntries), numLayers*2; got != want {
+		t.Errorf("Got %d cached files, want %d", got, want)
+	}
+	for _, de := range dirEntries {
+		fi, err := de.Info()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if fi.Size() == 0 {
+			t.Errorf("Cached file %q is empty", fi.Name())
+		}
+	}
+
+	// Delete a cached layer, see it disappear.
+	l := ls[0]
+	h, err := l.Digest()
+	if err != nil {
+		t.Fatalf("layer.Digest: %v", err)
+	}
+	if err := c.Delete(h); err != nil {
+		t.Errorf("cache.Delete: %v", err)
+	}
+	dirEntries, err = os.ReadDir(dir)
+	if err != nil {
+		t.Fatalf("ReadDir: %v", err)
+	}
+	if got, want := len(dirEntries), numLayers*2-1; got != want {
+		t.Errorf("Got %d cached files, want %d", got, want)
+	}
+
+	// Read the image again, see the layer reappear.
+	for i, l := range ls {
+		rc, err := l.Compressed()
+		if err != nil {
+			t.Fatalf("layer[%d].Compressed: %v", i, err)
+		}
+		if _, err := io.Copy(io.Discard, rc); err != nil {
+			t.Fatalf("Error reading contents: %v", err)
+		}
+		rc.Close()
+	}
+
+	// Check that layers exist in the fs cache.
+	dirEntries, err = os.ReadDir(dir)
+	if err != nil {
+		t.Fatalf("ReadDir: %v", err)
+	}
+	if got, want := len(dirEntries), numLayers*2; got != want {
+		t.Errorf("Got %d cached files, want %d", got, want)
+	}
+	for _, de := range dirEntries {
+		fi, err := de.Info()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if fi.Size() == 0 {
+			t.Errorf("Cached file %q is empty", fi.Name())
+		}
+	}
+}
+
+func TestErrNotFound(t *testing.T) {
+	dir := t.TempDir()
+
+	c := NewFilesystemCache(dir)
+	h := v1.Hash{Algorithm: "fake", Hex: "not-found"}
+	if _, err := c.Get(h); !errors.Is(err, ErrNotFound) {
+		t.Errorf("Get(%q): %v", h, err)
+	}
+	if err := c.Delete(h); !errors.Is(err, ErrNotFound) {
+		t.Errorf("Delete(%q): %v", h, err)
+	}
+}
+
+func TestErrUnexpectedEOF(t *testing.T) {
+	dir := t.TempDir()
+
+	// create a random layer
+	l, err := random.Layer(10, types.DockerLayer)
+	if err != nil {
+		t.Fatalf("random.Layer: %v", err)
+	}
+	rc, err := l.Compressed()
+	if err != nil {
+		t.Fatalf("layer.Compressed(): %v", err)
+	}
+
+	h, err := l.Digest()
+	if err != nil {
+		t.Fatalf("layer.Digest(): %v", err)
+	}
+	p := cachepath(dir, h)
+
+	// Write only the first segment of the compressed layer to produce an
+	// UnexpectedEOF error when reading it
+	buf := make([]byte, 10)
+	n, err := rc.Read(buf)
+	if err != nil {
+		t.Fatalf("Read(buf): %v", err)
+	}
+	if err := os.WriteFile(p, buf[:n], 0644); err != nil {
+		t.Fatalf("os.WriteFile(%s, buf[:%d]): %v", p, n, err)
+	}
+
+	c := NewFilesystemCache(dir)
+
+	// make sure LayerFromFile returns UnexpectedEOF
+	if _, err := tarball.LayerFromFile(p); !errors.Is(err, io.ErrUnexpectedEOF) {
+		t.Fatalf("tarball.LayerFromFile(%s): expected %v, got %v", p, io.ErrUnexpectedEOF, err)
+	}
+
+	// Try to Get the layer
+	if _, err := c.Get(h); !errors.Is(err, ErrNotFound) {
+		t.Errorf("Get(%q): %v", h, err)
+	}
+
+	// If we had an UnexpectedEOF and the cache deleted the broken layer no file
+	// should exist
+	if _, err := os.Stat(p); !os.IsNotExist(err) {
+		t.Errorf("os.Stat(%q): %v", p, err)
+	}
+}