progress: option to display progress speed (#224)

cmd/demo-progress/demo.go

@@ -18,6 +18,8 @@ var (
 	flagHidePercentage     = flag.Bool("hide-percentage", false, "Hide the progress percent?")
 	flagHideTime           = flag.Bool("hide-time", false, "Hide the time taken?")
 	flagHideValue          = flag.Bool("hide-value", false, "Hide the tracker value?")
+	flagHideSpeed          = flag.Bool("hide-speed", false, "Hide the tracker speed?")
+	flagHideSpeedOverall   = flag.Bool("hide-speed-overall", false, "Hide the overall tracker speed?")
 	flagNumTrackers        = flag.Int("num-trackers", 13, "Number of Trackers")
 	flagRandomFail         = flag.Bool("rnd-fail", false, "Introduce random failures in tracking")
 	flagRandomLogs         = flag.Bool("rnd-logs", false, "Output random logs in the middle of tracking")
@@ -113,12 +115,15 @@ func main() {
 	pw.SetUpdateFrequency(time.Millisecond * 100)
 	pw.Style().Colors = progress.StyleColorsExample
 	pw.Style().Options.PercentFormat = "%4.1f%%"
+	pw.Style().Options.SpeedOverallFormatter = progress.FormatNumber
 	pw.Style().Visibility.ETA = !*flagHideETA
 	pw.Style().Visibility.ETAOverall = !*flagHideETAOverall
 	pw.Style().Visibility.Percentage = !*flagHidePercentage
 	pw.Style().Visibility.Time = !*flagHideTime
 	pw.Style().Visibility.TrackerOverall = !*flagHideOverallTracker
 	pw.Style().Visibility.Value = !*flagHideValue
+	pw.Style().Visibility.Speed = !*flagHideSpeed
+	pw.Style().Visibility.SpeedOverall = !*flagHideSpeedOverall
 
 	// call Render() in async mode; yes we don't have any trackers at the moment
 	go pw.Render()

progress/render.go

@@ -322,6 +322,9 @@ func (p *Progress) renderTrackerStats(out *strings.Builder, t *Tracker, hint ren
 	if !hint.hideValue || !hint.hideTime {
 		var outStats strings.Builder
 		outStats.WriteString(" [")
+
+		p.renderTrackerSpeed(&outStats, t, hint)
+
 		if !hint.hideValue {
 			outStats.WriteString(p.style.Colors.Value.Sprint(t.Units.Sprint(t.Value())))
 		}
@@ -372,3 +375,42 @@ func (p *Progress) renderTrackerStatsETA(out *strings.Builder, t *Tracker, hint
 		out.WriteString(p.style.Colors.Time.Sprint(eta))
 	}
 }
+
+func (p *Progress) renderTrackerSpeed(out *strings.Builder, t *Tracker, hint renderHint) {
+	if hint.isOverallTracker && !p.style.Visibility.SpeedOverall {
+		return
+	}
+	if !hint.isOverallTracker && !p.style.Visibility.Speed {
+		return
+	}
+
+	tpSpeed := p.style.Options.SpeedPrecision
+
+	write := func(speed float64, formatter func(int64) string) {
+		if formatter == nil {
+			formatter = FormatNumber
+		}
+		out.WriteString(p.style.Colors.Speed.Sprint(formatter(int64(speed))))
+		out.WriteString("/s; ")
+	}
+
+	if hint.isOverallTracker {
+		speed := float64(0)
+
+		p.trackersActiveMutex.RLock()
+		for _, tracker := range p.trackersActive {
+			speed += float64(tracker.Value()) / time.Since(tracker.timeStart).Round(tpSpeed).Seconds()
+		}
+		p.trackersActiveMutex.RUnlock()
+
+		if speed > 0 {
+			write(speed, p.style.Options.SpeedOverallFormatter)
+		}
+		return
+	}
+
+	since := time.Since(t.timeStart)
+	if eta := since.Round(tpSpeed); eta > tpSpeed {
+		write(float64(t.Value())/eta.Seconds(), t.Units.Formatter)
+	}
+}