Merge pull request #2616 from greatroar/no-cache-interface

Remove practically unused cache interface

internal/cache/backend.go

@@ -40,7 +40,7 @@ func (b *Backend) Remove(ctx context.Context, h restic.Handle) error {
 		return err
 	}
 
-	return b.Cache.Remove(h)
+	return b.Cache.remove(h)
 }
 
 var autoCacheTypes = map[restic.FileType]struct{}{
@@ -77,7 +77,7 @@ func (b *Backend) Save(ctx context.Context, h restic.Handle, rd restic.RewindRea
 	err = b.Cache.Save(h, rd)
 	if err != nil {
 		debug.Log("unable to save %v to cache: %v", h, err)
-		_ = b.Cache.Remove(h)
+		_ = b.Cache.remove(h)
 		return nil
 	}
 
@@ -116,7 +116,7 @@ func (b *Backend) cacheFile(ctx context.Context, h restic.Handle) error {
 		})
 		if err != nil {
 			// try to remove from the cache, ignore errors
-			_ = b.Cache.Remove(h)
+			_ = b.Cache.remove(h)
 		}
 	}
 
@@ -134,7 +134,7 @@ func (b *Backend) cacheFile(ctx context.Context, h restic.Handle) error {
 // loadFromCacheOrDelegate will try to load the file from the cache, and fall
 // back to the backend if that fails.
 func (b *Backend) loadFromCacheOrDelegate(ctx context.Context, h restic.Handle, length int, offset int64, consumer func(rd io.Reader) error) error {
-	rd, err := b.Cache.Load(h, length, offset)
+	rd, err := b.Cache.load(h, length, offset)
 	if err != nil {
 		debug.Log("error caching %v: %v, falling back to backend", h, err)
 		return b.Backend.Load(ctx, h, length, offset, consumer)
@@ -162,7 +162,7 @@ func (b *Backend) Load(ctx context.Context, h restic.Handle, length int, offset
 
 	if b.Cache.Has(h) {
 		debug.Log("Load(%v, %v, %v) from cache", h, length, offset)
-		rd, err := b.Cache.Load(h, length, offset)
+		rd, err := b.Cache.load(h, length, offset)
 		if err == nil {
 			err = consumer(rd)
 			if err != nil {
@@ -216,7 +216,7 @@ func (b *Backend) Stat(ctx context.Context, h restic.Handle) (restic.FileInfo, e
 	if err != nil {
 		if b.Backend.IsNotExist(err) {
 			// try to remove from the cache, ignore errors
-			_ = b.Cache.Remove(h)
+			_ = b.Cache.remove(h)
 		}
 
 		return fi, err

internal/cache/cache.go

@@ -17,7 +17,7 @@ import (
 
 // Cache manages a local cache.
 type Cache struct {
-	Path             string
+	path             string
 	Base             string
 	Created          bool
 	PerformReadahead func(restic.Handle) bool
@@ -46,9 +46,6 @@ func readVersion(dir string) (v uint, err error) {
 
 const cacheVersion = 1
 
-// ensure Cache implements restic.Cache
-var _ restic.Cache = &Cache{}
-
 var cacheLayoutPaths = map[restic.FileType]string{
 	restic.PackFile:     "data",
 	restic.SnapshotFile: "snapshots",
@@ -151,7 +148,7 @@ func New(id string, basedir string) (c *Cache, err error) {
 	}
 
 	c = &Cache{
-		Path:    cachedir,
+		path:    cachedir,
 		Base:    basedir,
 		Created: created,
 		PerformReadahead: func(restic.Handle) bool {
@@ -253,22 +250,6 @@ func IsOld(t time.Time, maxAge time.Duration) bool {
 	return t.Before(oldest)
 }
 
-// errNoSuchFile is returned when a file is not cached.
-type errNoSuchFile struct {
-	Type string
-	Name string
-}
-
-func (e errNoSuchFile) Error() string {
-	return fmt.Sprintf("file %v (%v) is not cached", e.Name, e.Type)
-}
-
-// IsNotExist returns true if the error was caused by a non-existing file.
-func (c *Cache) IsNotExist(err error) bool {
-	_, ok := errors.Cause(err).(errNoSuchFile)
-	return ok
-}
-
 // Wrap returns a backend with a cache.
 func (c *Cache) Wrap(be restic.Backend) restic.Backend {
 	return newBackend(be, c)

internal/cache/file.go

@@ -17,7 +17,7 @@ func (c *Cache) filename(h restic.Handle) string {
 		panic("Name is empty or too short")
 	}
 	subdir := h.Name[:2]
-	return filepath.Join(c.Path, cacheLayoutPaths[h.Type], subdir, h.Name)
+	return filepath.Join(c.path, cacheLayoutPaths[h.Type], subdir, h.Name)
 }
 
 func (c *Cache) canBeCached(t restic.FileType) bool {
@@ -40,7 +40,7 @@ type readCloser struct {
 // Load returns a reader that yields the contents of the file with the
 // given handle. rd must be closed after use. If an error is returned, the
 // ReadCloser is nil.
-func (c *Cache) Load(h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
+func (c *Cache) load(h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
 	debug.Log("Load from cache: %v", h)
 	if !c.canBeCached(h.Type) {
 		return nil, errors.New("cannot be cached")
@@ -59,13 +59,13 @@ func (c *Cache) Load(h restic.Handle, length int, offset int64) (io.ReadCloser,
 
 	if fi.Size() <= crypto.Extension {
 		_ = f.Close()
-		_ = c.Remove(h)
+		_ = c.remove(h)
 		return nil, errors.Errorf("cached file %v is truncated, removing", h)
 	}
 
 	if fi.Size() < offset+int64(length) {
 		_ = f.Close()
-		_ = c.Remove(h)
+		_ = c.remove(h)
 		return nil, errors.Errorf("cached file %v is too small, removing", h)
 	}
 
@@ -85,7 +85,7 @@ func (c *Cache) Load(h restic.Handle, length int, offset int64) (io.ReadCloser,
 }
 
 // SaveWriter returns a writer for the cache object h. It must be closed after writing is finished.
-func (c *Cache) SaveWriter(h restic.Handle) (io.WriteCloser, error) {
+func (c *Cache) saveWriter(h restic.Handle) (io.WriteCloser, error) {
 	debug.Log("Save to cache: %v", h)
 	if !c.canBeCached(h.Type) {
 		return nil, errors.New("cannot be cached")
@@ -112,7 +112,7 @@ func (c *Cache) Save(h restic.Handle, rd io.Reader) error {
 		return errors.New("Save() called with nil reader")
 	}
 
-	f, err := c.SaveWriter(h)
+	f, err := c.saveWriter(h)
 	if err != nil {
 		return err
 	}
@@ -120,19 +120,19 @@ func (c *Cache) Save(h restic.Handle, rd io.Reader) error {
 	n, err := io.Copy(f, rd)
 	if err != nil {
 		_ = f.Close()
-		_ = c.Remove(h)
+		_ = c.remove(h)
 		return errors.Wrap(err, "Copy")
 	}
 
 	if n <= crypto.Extension {
 		_ = f.Close()
-		_ = c.Remove(h)
+		_ = c.remove(h)
 		debug.Log("trying to cache truncated file %v, removing", h)
 		return nil
 	}
 
 	if err = f.Close(); err != nil {
-		_ = c.Remove(h)
+		_ = c.remove(h)
 		return errors.Wrap(err, "Close")
 	}
 
@@ -140,7 +140,7 @@ func (c *Cache) Save(h restic.Handle, rd io.Reader) error {
 }
 
 // Remove deletes a file. When the file is not cache, no error is returned.
-func (c *Cache) Remove(h restic.Handle) error {
+func (c *Cache) remove(h restic.Handle) error {
 	if !c.Has(h) {
 		return nil
 	}
@@ -185,7 +185,7 @@ func (c *Cache) list(t restic.FileType) (restic.IDSet, error) {
 	}
 
 	list := restic.NewIDSet()
-	dir := filepath.Join(c.Path, cacheLayoutPaths[t])
+	dir := filepath.Join(c.path, cacheLayoutPaths[t])
 	err := filepath.Walk(dir, func(name string, fi os.FileInfo, err error) error {
 		if err != nil {
 			return errors.Wrap(err, "Walk")

internal/cache/file_test.go

@@ -42,13 +42,13 @@ func randomID(s restic.IDSet) restic.ID {
 }
 
 func load(t testing.TB, c *Cache, h restic.Handle) []byte {
-	rd, err := c.Load(h, 0, 0)
+	rd, err := c.load(h, 0, 0)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	if rd == nil {
-		t.Fatalf("Load() returned nil reader")
+		t.Fatalf("load() returned nil reader")
 	}
 
 	buf, err := ioutil.ReadAll(rd)
@@ -148,7 +148,7 @@ func TestFileSaveWriter(t *testing.T) {
 		Name: id.String(),
 	}
 
-	wr, err := c.SaveWriter(h)
+	wr, err := c.saveWriter(h)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -166,7 +166,7 @@ func TestFileSaveWriter(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	rd, err := c.Load(h, 0, 0)
+	rd, err := c.load(h, 0, 0)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -223,7 +223,7 @@ func TestFileLoad(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(fmt.Sprintf("%v/%v", test.length, test.offset), func(t *testing.T) {
-			rd, err := c.Load(h, test.length, test.offset)
+			rd, err := c.load(h, test.length, test.offset)
 			if err != nil {
 				t.Fatal(err)
 			}

internal/repository/repository.go

@@ -28,7 +28,8 @@ type Repository struct {
 	key     *crypto.Key
 	keyName string
 	idx     *MasterIndex
-	restic.Cache
+	Cache   *cache.Cache
+
 	noAutoIndexUpdate bool
 
 	treePM *packerManager
@@ -59,7 +60,7 @@ func (r *Repository) Config() restic.Config {
 }
 
 // UseCache replaces the backend with the wrapped cache.
-func (r *Repository) UseCache(c restic.Cache) {
+func (r *Repository) UseCache(c *cache.Cache) {
 	if c == nil {
 		return
 	}
@@ -552,7 +553,7 @@ func (r *Repository) PrepareCache(indexIDs restic.IDSet) error {
 
 	// use readahead
 	debug.Log("using readahead")
-	cache := r.Cache.(*cache.Cache)
+	cache := r.Cache
 	cache.PerformReadahead = func(h restic.Handle) bool {
 		if h.Type != restic.PackFile {
 			debug.Log("no readahead for %v, is not a pack file", h)

internal/restic/cache.go

@@ -1,37 +0,0 @@
-package restic
-
-import "io"
-
-// Cache manages a local cache.
-type Cache interface {
-	// BaseDir returns the base directory of the cache.
-	BaseDir() string
-
-	// Wrap returns a backend with a cache.
-	Wrap(Backend) Backend
-
-	// IsNotExist returns true if the error was caused by a non-existing file.
-	IsNotExist(err error) bool
-
-	// Load returns a reader that yields the contents of the file with the
-	// given id if it is cached. rd must be closed after use. If an error is
-	// returned, the ReadCloser is nil. The files are still encrypted
-	Load(h Handle, length int, offset int64) (io.ReadCloser, error)
-
-	// SaveIndex saves an index in the cache.
-	Save(Handle, io.Reader) error
-
-	// SaveWriter returns a writer for the to be cached object h. It must be
-	// closed after writing is finished.
-	SaveWriter(Handle) (io.WriteCloser, error)
-
-	// Remove deletes a single file from the cache. If it isn't cached, this
-	// functions must return no error.
-	Remove(Handle) error
-
-	// Clear removes all files of type t from the cache that are not contained in the set.
-	Clear(FileType, IDSet) error
-
-	// Has returns true if the file is cached.
-	Has(Handle) bool
-}