Merge pull request #1430 from dgageot/faster-spinner

Faster spinner

Author: rumpl

pkg/tui/components/spinner/spinner.go

@@ -2,6 +2,7 @@ package spinner
 
 import (
 	"math/rand/v2"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -17,32 +18,26 @@ type Mode int
 const (
 	ModeBoth Mode = iota
 	ModeSpinnerOnly
-	ModeMessageOnly
 )
 
-var lastID int64
-
-func nextID() int {
-	return int(atomic.AddInt64(&lastID, 1))
-}
+var lastID atomic.Int64
 
 type tickMsg struct {
-	Time time.Time
-	tag  int
-	ID   int
+	tag int
+	id  int
 }
 
 type Spinner struct {
-	dotsStyle      lipgloss.Style
-	messages       []string
-	mode           Mode
-	currentMessage string
-	lightPosition  int
-	frame          int
-	id             int
-	tag            int
-	direction      int // 1 for forward, -1 for backward
-	pauseFrames    int
+	dotsStyle           lipgloss.Style
+	styledSpinnerFrames []string // pre-rendered spinner frames
+	mode                Mode
+	currentMessage      string
+	lightPosition       int
+	frame               int
+	id                  int
+	tag                 int
+	direction           int // 1 for forward, -1 for backward
+	pauseFrames         int
 }
 
 // Default messages for the spinner
@@ -70,21 +65,21 @@ var defaultMessages = []string{
 }
 
 func New(mode Mode, dotsStyle lipgloss.Style) Spinner {
-	return Spinner{
-		dotsStyle:      dotsStyle,
-		messages:       defaultMessages,
-		mode:           mode,
-		currentMessage: defaultMessages[rand.IntN(len(defaultMessages))],
-		lightPosition:  -3,
-		frame:          0,
-		id:             nextID(),
-		direction:      1,
-		pauseFrames:    0,
+	// Pre-render all spinner frames for fast lookup during render
+	styledFrames := make([]string, len(spinnerChars))
+	for i, char := range spinnerChars {
+		styledFrames[i] = dotsStyle.Render(char)
 	}
-}
 
-func (s Spinner) Init() tea.Cmd {
-	return s.Tick()
+	return Spinner{
+		dotsStyle:           dotsStyle,
+		styledSpinnerFrames: styledFrames,
+		mode:                mode,
+		currentMessage:      defaultMessages[rand.IntN(len(defaultMessages))],
+		lightPosition:       -3,
+		id:                  int(lastID.Add(1)),
+		direction:           1,
+	}
 }
 
 func (s Spinner) Reset() Spinner {
@@ -93,107 +88,64 @@ func (s Spinner) Reset() Spinner {
 
 func (s Spinner) Update(message tea.Msg) (layout.Model, tea.Cmd) {
 	msg, ok := message.(tickMsg)
-	if !ok {
-		return s, nil
-	}
-
-	if msg.ID > 0 && msg.ID != s.id {
-		return s, nil
-	}
-	if msg.tag > 0 && msg.tag != s.tag {
+	if !ok || (msg.id > 0 && msg.id != s.id) || (msg.tag > 0 && msg.tag != s.tag) {
 		return s, nil
 	}
 
 	s.tag++
 	s.frame++
 
-	if s.pauseFrames > 0 {
-		s.pauseFrames--
-		if s.pauseFrames == 0 {
-			s.direction = -1
-		}
-	} else {
-		s.lightPosition += s.direction
-
-		// Use rune count for proper Unicode character handling in light animation
-		messageRuneCount := len([]rune(s.currentMessage))
-		if s.direction == 1 && s.lightPosition > messageRuneCount+2 {
-			s.pauseFrames = 6
-		}
-
-		if s.direction == -1 && s.lightPosition < -3 {
-			s.direction = 1
+	// Light animation only needed for ModeBoth
+	if s.mode == ModeBoth {
+		if s.pauseFrames > 0 {
+			s.pauseFrames--
+			if s.pauseFrames == 0 {
+				s.direction = -1
+			}
+		} else {
+			s.lightPosition += s.direction
+			if s.direction == 1 && s.lightPosition > len([]rune(s.currentMessage))+2 {
+				s.pauseFrames = 6
+			} else if s.direction == -1 && s.lightPosition < -3 {
+				s.direction = 1
+			}
 		}
 	}
 
 	return s, s.Tick()
 }
 
 func (s Spinner) View() string {
-	return s.render()
-}
-
-func (s Spinner) SetSize(_, _ int) tea.Cmd {
-	return nil
+	spinner := s.styledSpinnerFrames[s.frame%len(s.styledSpinnerFrames)]
+	if s.mode == ModeSpinnerOnly {
+		return spinner
+	}
+	return spinner + " " + s.renderMessage()
 }
 
+func (s Spinner) SetSize(_, _ int) tea.Cmd { return nil }
+func (s Spinner) Init() tea.Cmd            { return s.Tick() }
 func (s Spinner) Tick() tea.Cmd {
-	return tea.Tick(50*time.Millisecond, func(t time.Time) tea.Msg {
-		return tickMsg{
-			Time: t,
-			ID:   s.id,
-			tag:  s.tag,
-		}
+	return tea.Tick(50*time.Millisecond, func(time.Time) tea.Msg {
+		return tickMsg{id: s.id, tag: s.tag}
 	})
 }
 
-func (s Spinner) render() string {
-	message := s.currentMessage
-	output := make([]rune, 0, len(message))
-
-	for i, char := range message {
-		distance := abs(i - s.lightPosition)
-
-		var style lipgloss.Style
-		switch distance {
-		case 0:
-			style = styles.SpinnerTextBrightestStyle
-		case 1:
-			style = styles.SpinnerTextBrightStyle
-		case 2:
-			style = styles.SpinnerTextDimStyle
-		default:
-			style = styles.SpinnerTextDimmestStyle
-		}
-
-		output = append(output, []rune(style.Render(string(char)))...)
-	}
-
-	spinnerChars := []string{"⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"}
-	spinnerChar := spinnerChars[s.frame%len(spinnerChars)]
-	spinnerStyled := s.dotsStyle.Render(spinnerChar)
-
-	switch s.mode {
-	case ModeSpinnerOnly:
-		return spinnerStyled
-	case ModeMessageOnly:
-		return string(output)
-	}
-
-	return spinnerStyled + " " + string(output)
-}
-
-func (s *Spinner) Render() string {
-	return s.render()
-}
+var spinnerChars = []string{"⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"}
 
-func (s *Spinner) SetMessage(message string) {
-	s.currentMessage = message
+// lightStyles maps distance from light position to style (0=brightest, 1=bright, 2=dim, 3+=dimmest).
+var lightStyles = []lipgloss.Style{
+	styles.SpinnerTextBrightestStyle,
+	styles.SpinnerTextBrightStyle,
+	styles.SpinnerTextDimStyle,
+	styles.SpinnerTextDimmestStyle,
 }
 
-func abs(x int) int {
-	if x < 0 {
-		return -x
+func (s Spinner) renderMessage() string {
+	var out strings.Builder
+	for i, char := range s.currentMessage {
+		dist := min(max(i-s.lightPosition, s.lightPosition-i), len(lightStyles)-1)
+		out.WriteString(lightStyles[dist].Render(string(char)))
 	}
-	return x
+	return out.String()
 }

pkg/tui/components/spinner/spinner_test.go

@@ -0,0 +1,21 @@
+package spinner
+
+import (
+	"testing"
+
+	"charm.land/lipgloss/v2"
+)
+
+func BenchmarkSpinner_ModeSpinnerOnly(b *testing.B) {
+	s := New(ModeSpinnerOnly, lipgloss.NewStyle())
+	for b.Loop() {
+		_ = s.View()
+	}
+}
+
+func BenchmarkSpinner_ModeBoth(b *testing.B) {
+	s := New(ModeBoth, lipgloss.NewStyle())
+	for b.Loop() {
+		_ = s.View()
+	}
+}