func (w *sleepWriter) Write(p []byte) (n int, err error) {
	time.Sleep(w.timeout)
	return len(p), nil
}

func (w *sleepWriter) Close() error {
	return nil
}

func TestDeadlineWriter(t *testing.T) {
	w := NewDeadlineWriter(&sleepWriter{timeout: 500 * time.Millisecond}, 450*time.Millisecond)
	_, err := w.Write([]byte("1"))
	if err != context.DeadlineExceeded {

		return r.err
	case <-t.C:
		return context.DeadlineExceeded
	}
}

// NewDeadlineWriter wraps a writer to make it respect given deadline
// value per Write(). If there is a blocking write, the returned Writer
// will return whenever the timer hits (the return values are n=0
// and err=context.DeadlineExceeded.)
func NewDeadlineWriter(w io.WriteCloser, timeout time.Duration) io.WriteCloser {

	r, w := io.Pipe()
	h := algo.New()

	bw := &streamingBitrotWriter{
		iow:          ioutil.NewDeadlineWriter(w, globalDriveConfig.GetMaxTimeout()),
		closeWithErr: w.CloseWithError,
		h:            h,
		shardSize:    shardSize,
		canClose:     &sync.WaitGroup{},
	}
	bw.canClose.Add(1)
	go func() {