package backend import ( "bytes" "context" "io" "io/ioutil" "testing" "github.com/restic/restic/internal/errors" "github.com/restic/restic/internal/mock" "github.com/restic/restic/internal/restic" "github.com/restic/restic/internal/test" ) func TestBackendSaveRetry(t *testing.T) { buf := bytes.NewBuffer(nil) errcount := 0 be := &mock.Backend{ SaveFn: func(ctx context.Context, h restic.Handle, rd restic.RewindReader) error { if errcount == 0 { errcount++ _, err := io.CopyN(ioutil.Discard, rd, 120) if err != nil { return err } return errors.New("injected error") } _, err := io.Copy(buf, rd) return err }, } retryBackend := NewRetryBackend(be, 10, nil) data := test.Random(23, 5*1024*1024+11241) err := retryBackend.Save(context.TODO(), restic.Handle{}, restic.NewByteReader(data)) if err != nil { t.Fatal(err) } if len(data) != buf.Len() { t.Errorf("wrong number of bytes written: want %d, got %d", len(data), buf.Len()) } if !bytes.Equal(data, buf.Bytes()) { t.Errorf("wrong data written to backend") } } func TestBackendListRetry(t *testing.T) { const ( ID1 = "id1" ID2 = "id2" ) retry := 0 be := &mock.Backend{ ListFn: func(ctx context.Context, t restic.FileType, fn func(restic.FileInfo) error) error { // fail during first retry, succeed during second retry++ if retry == 1 { fn(restic.FileInfo{Name: ID1}) return errors.New("test list error") } fn(restic.FileInfo{Name: ID1}) fn(restic.FileInfo{Name: ID2}) return nil }, } retryBackend := NewRetryBackend(be, 10, nil) var listed []string err := retryBackend.List(context.TODO(), restic.PackFile, func(fi restic.FileInfo) error { listed = append(listed, fi.Name) return nil }) test.OK(t, err) // assert overall success test.Equals(t, 2, retry) // assert retried once test.Equals(t, []string{ID1, ID2}, listed) // assert no duplicate files } func TestBackendListRetryErrorFn(t *testing.T) { var names = []string{"id1", "id2", "foo", "bar"} be := &mock.Backend{ ListFn: func(ctx context.Context, tpe restic.FileType, fn func(restic.FileInfo) error) error { t.Logf("List called for %v", tpe) for _, name := range names { err := fn(restic.FileInfo{Name: name}) if err != nil { return err } } return nil }, } retryBackend := NewRetryBackend(be, 10, nil) var ErrTest = errors.New("test error") var listed []string run := 0 err := retryBackend.List(context.TODO(), restic.PackFile, func(fi restic.FileInfo) error { t.Logf("fn called for %v", fi.Name) run++ // return an error for the third item in the list if run == 3 { t.Log("returning an error") return ErrTest } listed = append(listed, fi.Name) return nil }) if err != ErrTest { t.Fatalf("wrong error returned, want %v, got %v", ErrTest, err) } // processing should stop after the error was returned, so run should be 3 if run != 3 { t.Fatalf("function was called %d times, wanted %v", run, 3) } test.Equals(t, []string{"id1", "id2"}, listed) } func TestBackendListRetryErrorBackend(t *testing.T) { var names = []string{"id1", "id2", "foo", "bar"} var ErrBackendTest = errors.New("test error") retries := 0 be := &mock.Backend{ ListFn: func(ctx context.Context, tpe restic.FileType, fn func(restic.FileInfo) error) error { t.Logf("List called for %v, retries %v", tpe, retries) retries++ for i, name := range names { if i == 2 { return ErrBackendTest } err := fn(restic.FileInfo{Name: name}) if err != nil { return err } } return nil }, } const maxRetries = 2 retryBackend := NewRetryBackend(be, maxRetries, nil) var listed []string err := retryBackend.List(context.TODO(), restic.PackFile, func(fi restic.FileInfo) error { t.Logf("fn called for %v", fi.Name) listed = append(listed, fi.Name) return nil }) if err != ErrBackendTest { t.Fatalf("wrong error returned, want %v, got %v", ErrBackendTest, err) } if retries != maxRetries+1 { t.Fatalf("List was called %d times, wanted %v", retries, maxRetries+1) } test.Equals(t, names[:2], listed) } // failingReader returns an error after reading limit number of bytes type failingReader struct { data []byte pos int limit int } func (r failingReader) Read(p []byte) (n int, err error) { i := 0 for ; i < len(p) && i+r.pos < r.limit; i++ { p[i] = r.data[r.pos+i] } r.pos += i if r.pos >= r.limit { return i, errors.Errorf("reader reached limit of %d", r.limit) } return i, nil } func (r failingReader) Close() error { return nil } // closingReader adapts io.Reader to io.ReadCloser interface type closingReader struct { rd io.Reader } func (r closingReader) Read(p []byte) (n int, err error) { return r.rd.Read(p) } func (r closingReader) Close() error { return nil } func TestBackendLoadRetry(t *testing.T) { data := test.Random(23, 1024) limit := 100 attempt := 0 be := mock.NewBackend() be.OpenReaderFn = func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) { // returns failing reader on first invocation, good reader on subsequent invocations attempt++ if attempt > 1 { return closingReader{rd: bytes.NewReader(data)}, nil } return failingReader{data: data, limit: limit}, nil } retryBackend := NewRetryBackend(be, 10, nil) var buf []byte err := retryBackend.Load(context.TODO(), restic.Handle{}, 0, 0, func(rd io.Reader) (err error) { buf, err = ioutil.ReadAll(rd) return err }) test.OK(t, err) test.Equals(t, data, buf) test.Equals(t, 2, attempt) } func assertIsCanceled(t *testing.T, err error) { test.Assert(t, err == context.Canceled, "got unexpected err %v", err) } func TestBackendCanceledContext(t *testing.T) { // unimplemented mock backend functions return an error by default // check that we received the expected context canceled error instead retryBackend := NewRetryBackend(mock.NewBackend(), 2, nil) h := restic.Handle{Type: restic.PackFile, Name: restic.NewRandomID().String()} // create an already canceled context ctx, cancel := context.WithCancel(context.Background()) cancel() _, err := retryBackend.Test(ctx, h) assertIsCanceled(t, err) _, err = retryBackend.Stat(ctx, h) assertIsCanceled(t, err) err = retryBackend.Save(ctx, h, restic.NewByteReader([]byte{})) assertIsCanceled(t, err) err = retryBackend.Remove(ctx, h) assertIsCanceled(t, err) err = retryBackend.Load(ctx, restic.Handle{}, 0, 0, func(rd io.Reader) (err error) { return nil }) assertIsCanceled(t, err) err = retryBackend.List(ctx, restic.PackFile, func(restic.FileInfo) error { return nil }) assertIsCanceled(t, err) // don't test "Delete" as it is not used by normal code }