refactor reader implementation for standard input support

window/manager.go

@@ -159,48 +159,48 @@ func expandBacktick(filename string) (string, error) {
 }
 
 func (m *Manager) read(r io.Reader) error {
+	bs, err := func() ([]byte, error) {
+		r, stop := newReader(r)
+		defer stop()
+		return io.ReadAll(r)
+	}()
+	window, err := newWindow(bytes.NewReader(bs), "", "", m.eventCh, m.redrawCh)
+	if err != nil {
+		return err
+	}
+	return m.init(window)
+}
+
+type reader struct {
+	io.Reader
+	abort chan os.Signal
+}
+
+func newReader(r io.Reader) (*reader, func()) {
 	done := make(chan struct{})
-	defer close(done)
 	abort := make(chan os.Signal, 1)
 	signal.Notify(abort, os.Interrupt)
-	defer signal.Stop(abort)
 	go func() {
 		select {
 		case <-time.After(time.Second):
 			fmt.Fprint(os.Stderr, "Reading stdin took more than 1 second, press <C-c> to abort...")
 		case <-done:
 		}
 	}()
-	bs, err := func() ([]byte, error) {
-		// ref: io.ReadAll
-		bs := make([]byte, 0, 1024)
-		for {
-			n, err := r.Read(bs[len(bs):cap(bs)])
-			bs = bs[:len(bs)+n]
-			if err != nil {
-				if err == io.EOF {
-					err = nil
-				}
-				return bs, err
-			}
-			select {
-			case <-time.After(10 * time.Millisecond):
-			case <-abort:
-				return bs, nil
-			}
-			if len(bs) == cap(bs) {
-				bs = append(bs, 0)[:len(bs)]
-			}
-		}
-	}()
-	if err != nil {
-		return err
+	return &reader{r, abort}, func() {
+		signal.Stop(abort)
+		close(abort)
+		close(done)
 	}
-	window, err := newWindow(bytes.NewReader(bs), "", "", m.eventCh, m.redrawCh)
-	if err != nil {
-		return err
+}
+
+func (r *reader) Read(p []byte) (int, error) {
+	select {
+	case <-r.abort:
+		return 0, io.EOF
+	default:
 	}
-	return m.init(window)
+	return r.Reader.Read(p)
 }
 
 // SetSize sets the size of the screen.