performance optimization for render rate

console/console.go

@@ -8,15 +8,16 @@ import (
 )
 
 const (
-	RenderRate = 100 * time.Millisecond
+	MaxRenderInterval = 1000 * time.Millisecond
-	Title      = "sampler"
+	MinRenderInterval = 100 * time.Millisecond
+	AppTitle          = "sampler"
 )
 
 type Console struct{}
 
 func (self *Console) Init() {
 
-	fmt.Printf("\033]0;%s\007", Title)
+	fmt.Printf("\033]0;%s\007", AppTitle)
 
 	if err := ui.Init(); err != nil {
 		log.Fatalf("failed to initialize termui: %v", err)

console/palette.go

@@ -33,9 +33,9 @@ type Palette struct {
 func GetPalette(theme Theme) Palette {
 	switch theme {
 	case ThemeDark:
-		return Palette{Colors: []ui.Color{ColorOlive, ColorDeepSkyBlue, ColorDeepPink, ColorWhite, ColorPurple, ColorCian, ColorOrange, ColorGreen}}
+		return Palette{Colors: []ui.Color{ColorOlive, ColorDeepSkyBlue, ColorDeepPink, ColorWhite, ColorGreen, ColorOrange, ColorCian, ColorPurple}}
 	case ThemeLight:
-		return Palette{Colors: []ui.Color{ColorOlive, ColorDeepSkyBlue, ColorDeepPink, ColorWhite, ColorPurple, ColorCian, ColorOrange, ColorGreen}}
+		return Palette{Colors: []ui.Color{ColorOlive, ColorDeepSkyBlue, ColorDeepPink, ColorWhite, ColorGreen, ColorOrange, ColorCian, ColorPurple}}
 	default:
 		panic(fmt.Sprintf("Following theme is not supported: %v", theme))
 	}

data/sampler.go

@@ -24,8 +24,8 @@ func NewSampler(consumer Consumer, item Item, rateMs int) Sampler {
 	return sampler
 }
 
-func (self *Sampler) sample() {
+func (s *Sampler) sample() {
-	value, err := self.item.nextValue()
+	value, err := s.item.nextValue()
-	sample := Sample{Value: value, Error: err, Label: *self.item.Label}
+	sample := Sample{Value: value, Error: err, Label: *s.item.Label}
-	self.consumer.ConsumeSample(sample)
+	s.consumer.ConsumeSample(sample)
 }

event/handler.go

@@ -8,44 +8,97 @@ import (
 	"time"
 )
 
+const (
+	refreshRateToRenderRateRatio = 0.8
+)
+
 type Handler struct {
-	Layout        *widgets.Layout
+	layout        *widgets.Layout
-	RenderEvents  <-chan time.Time
+	renderTicker  *time.Ticker
-	ConsoleEvents <-chan ui.Event
+	consoleEvents <-chan ui.Event
+	renderRate    time.Duration
+}
+
+func NewHandler(layout *widgets.Layout) Handler {
+	renderRate := calcMinRenderRate(layout)
+	return Handler{
+		layout:        layout,
+		consoleEvents: ui.PollEvents(),
+		renderTicker:  time.NewTicker(renderRate),
+		renderRate:    renderRate,
+	}
 }
 
 func (h *Handler) HandleEvents() {
 
+	// initial render
+	ui.Render(h.layout)
 	pause := false
 
 	for {
 		select {
-		case <-h.RenderEvents:
+		case mode := <-h.layout.ChangeModeEvents:
-			if !pause {
+			h.handleModeChange(mode)
-				ui.Render(h.Layout)
+		case <-h.renderTicker.C:
-			}
+			ui.Render(h.layout)
-		case e := <-h.ConsoleEvents:
+		case e := <-h.consoleEvents:
 			switch e.ID {
 			case console.KeyQuit, console.KeyExit:
 				h.handleExit()
 				return
 			case console.KeyPause:
-				pause = !pause
+				pause = !pause // TODO move to layout, since it will show PAUSE sign in status line, pause/unpause can be sent via channel
 			case console.SignalResize:
 				payload := e.Payload.(ui.Resize)
-				h.Layout.ChangeDimensions(payload.Width, payload.Height)
+				h.layout.ChangeDimensions(payload.Width, payload.Height)
 			default:
-				h.Layout.HandleConsoleEvent(e.ID)
+				h.layout.HandleConsoleEvent(e.ID)
 			}
 		}
 	}
 }
 
+func (h *Handler) handleModeChange(m widgets.Mode) {
+
+	// render mode change before switching the tickers
+	ui.Render(h.layout)
+	h.renderTicker.Stop()
+
+	if m == widgets.ModeDefault {
+		h.renderTicker = time.NewTicker(h.renderRate)
+	} else {
+		h.renderTicker = time.NewTicker(console.MinRenderInterval)
+	}
+}
+
 func (h *Handler) handleExit() {
 	var settings []config.ComponentSettings
-	for _, c := range h.Layout.Components {
+	for _, c := range h.layout.Components {
 		settings = append(settings,
 			config.ComponentSettings{Type: c.Type, Title: c.Title, Size: c.Size, Position: c.Position})
 	}
 	config.Update(settings)
 }
+
+func calcMinRenderRate(layout *widgets.Layout) time.Duration {
+
+	minRefreshRateMs := layout.Components[0].RefreshRateMs
+	for _, c := range layout.Components {
+		if c.RefreshRateMs < minRefreshRateMs {
+			minRefreshRateMs = c.RefreshRateMs
+		}
+	}
+
+	renderRate := time.Duration(
+		int(float64(minRefreshRateMs)*refreshRateToRenderRateRatio)) * time.Millisecond
+
+	if renderRate < console.MinRenderInterval {
+		return console.MinRenderInterval
+	}
+
+	if renderRate > console.MaxRenderInterval {
+		return console.MaxRenderInterval
+	}
+
+	return renderRate
+}

main.go

@@ -10,7 +10,6 @@ import (
 	"github.com/sqshq/sampler/widgets/barchart"
 	"github.com/sqshq/sampler/widgets/runchart"
 	ui "github.com/sqshq/termui"
-	"time"
 )
 
 func main() {
@@ -27,7 +26,7 @@ func main() {
 
 		legend := runchart.Legend{Enabled: c.Legend.Enabled, Details: c.Legend.Details}
 		chart := runchart.NewRunChart(c.Title, *c.Scale, *c.RefreshRateMs, legend)
-		layout.AddComponent(chart, c.Title, c.Position, c.Size, config.TypeRunChart)
+		layout.AddComponent(config.TypeRunChart, chart, c.Title, c.Position, c.Size, *c.RefreshRateMs)
 
 		for _, item := range c.Items {
 			chart.AddLine(*item.Label, *item.Color)
@@ -37,14 +36,14 @@ func main() {
 
 	for _, a := range cfg.AsciiBoxes {
 		box := asciibox.NewAsciiBox(a.Title, *a.Font, *a.Item.Color)
-		layout.AddComponent(box, a.Title, a.Position, a.Size, config.TypeAsciiBox)
+		layout.AddComponent(config.TypeAsciiBox, box, a.Title, a.Position, a.Size, *a.RefreshRateMs)
 		data.NewSampler(box, a.Item, *a.RefreshRateMs)
 	}
 
 	for _, c := range cfg.BarCharts {
 
 		chart := barchart.NewBarChart(c.Title, *c.Scale)
-		layout.AddComponent(chart, c.Title, c.Position, c.Size, config.TypeBarChart)
+		layout.AddComponent(config.TypeBarChart, chart, c.Title, c.Position, c.Size, *c.RefreshRateMs)
 
 		for _, item := range c.Items {
 			chart.AddBar(*item.Label, *item.Color)
@@ -52,11 +51,6 @@ func main() {
 		}
 	}
 
-	handler := event.Handler{
+	handler := event.NewHandler(layout)
-		Layout:        layout,
-		RenderEvents:  time.NewTicker(console.RenderRate).C,
-		ConsoleEvents: ui.PollEvents(),
-	}
-
 	handler.HandleEvents()
 }

widgets/component.go

@@ -6,11 +6,12 @@ import (
 )
 
 type Component struct {
+	Type          config.ComponentType
 	Drawable      ui.Drawable
 	Title         string
 	Position      config.Position
 	Size          config.Size
-	Type     config.ComponentType
+	RefreshRateMs int
 }
 
 func (c *Component) Move(x, y int) {

widgets/layout.go

@@ -10,8 +10,9 @@ import (
 type Layout struct {
 	ui.Block
 	Components       []Component
-	menu       *Menu
+	ChangeModeEvents chan Mode
 	mode             Mode
+	menu             *Menu
 	selection        int
 }
 
@@ -42,11 +43,12 @@ func NewLayout(width, height int, menu *Menu) *Layout {
 		menu:             menu,
 		mode:             ModeDefault,
 		selection:        0,
+		ChangeModeEvents: make(chan Mode, 10),
 	}
 }
 
-func (l *Layout) AddComponent(drawable ui.Drawable, title string, position config.Position, size config.Size, Type config.ComponentType) {
+func (l *Layout) AddComponent(Type config.ComponentType, drawable ui.Drawable, title string, position config.Position, size config.Size, refreshRateMs int) {
-	l.Components = append(l.Components, Component{drawable, title, position, size, Type})
+	l.Components = append(l.Components, Component{Type, drawable, title, position, size, refreshRateMs})
 }
 
 func (l *Layout) GetComponents(Type config.ComponentType) []ui.Drawable {
@@ -62,36 +64,41 @@ func (l *Layout) GetComponents(Type config.ComponentType) []ui.Drawable {
 	return components
 }
 
+func (l *Layout) changeMode(m Mode) {
+	l.mode = m
+	l.ChangeModeEvents <- m
+}
+
 func (l *Layout) HandleConsoleEvent(e string) {
 	switch e {
 	case console.KeyEnter:
 		switch l.mode {
 		case ModeComponentSelect:
 			l.menu.choose()
-			l.mode = ModeMenuOptionSelect
+			l.changeMode(ModeMenuOptionSelect)
 		case ModeMenuOptionSelect:
 			option := l.menu.getSelectedOption()
 			switch option {
 			case MenuOptionMove:
-				l.mode = ModeComponentMove
+				l.changeMode(ModeComponentMove)
 				l.menu.moveOrResize()
 			case MenuOptionResize:
-				l.mode = ModeComponentResize
+				l.changeMode(ModeComponentResize)
 				l.menu.moveOrResize()
 			case MenuOptionPinpoint:
-				l.mode = ModeChartPinpoint
+				l.changeMode(ModeChartPinpoint)
 				l.menu.idle()
 				chart := l.getSelectedComponent().Drawable.(*runchart.RunChart)
 				chart.MoveSelection(0)
 			case MenuOptionResume:
-				l.mode = ModeDefault
+				l.changeMode(ModeDefault)
 				l.menu.idle()
 			}
 		case ModeComponentMove:
 			fallthrough
 		case ModeComponentResize:
 			l.menu.idle()
-			l.mode = ModeDefault
+			l.changeMode(ModeDefault)
 		}
 	case console.KeyEsc:
 		switch l.mode {
@@ -103,12 +110,12 @@ func (l *Layout) HandleConsoleEvent(e string) {
 			fallthrough
 		case ModeMenuOptionSelect:
 			l.menu.idle()
-			l.mode = ModeDefault
+			l.changeMode(ModeDefault)
 		}
 	case console.KeyLeft:
 		switch l.mode {
 		case ModeDefault:
-			l.mode = ModeComponentSelect
+			l.changeMode(ModeComponentSelect)
 			l.selection = 0
 			l.menu.highlight(l.getComponent(l.selection))
 		case ModeChartPinpoint:
@@ -127,7 +134,7 @@ func (l *Layout) HandleConsoleEvent(e string) {
 	case console.KeyRight:
 		switch l.mode {
 		case ModeDefault:
-			l.mode = ModeComponentSelect
+			l.changeMode(ModeComponentSelect)
 			l.selection = 0
 			l.menu.highlight(l.getComponent(l.selection))
 		case ModeChartPinpoint:
@@ -146,7 +153,7 @@ func (l *Layout) HandleConsoleEvent(e string) {
 	case console.KeyUp:
 		switch l.mode {
 		case ModeDefault:
-			l.mode = ModeComponentSelect
+			l.changeMode(ModeComponentSelect)
 			l.selection = 0
 			l.menu.highlight(l.getComponent(l.selection))
 		case ModeComponentSelect:
@@ -164,7 +171,7 @@ func (l *Layout) HandleConsoleEvent(e string) {
 	case console.KeyDown:
 		switch l.mode {
 		case ModeDefault:
-			l.mode = ModeComponentSelect
+			l.changeMode(ModeComponentSelect)
 			l.selection = 0
 			l.menu.highlight(l.getComponent(l.selection))
 		case ModeComponentSelect: