Fix Progress gauge to reach 100%

Signed-off-by: shubham <shubham.bajpai@mayadata.io>

gui/drawer.go

@@ -45,13 +45,14 @@ type values struct {
 
 // appendChartValues appends entities as soon as a result arrives.
 // Given maxSize, then it can be pre-allocated.
-func (d *drawer) appendChartValues(ctx context.Context, maxSize int) {
+func (d *drawer) appendChartValues(ctx context.Context, rate int, duration time.Duration) {
 	// TODO: Change how to stop `redrawGauge`.
 	// We currently use this way to ensure to stop `redrawGauge` after the increase process is complete.
 	// But, it's preferable to stop goroutine where it's generated.
+	maxSize := rate * int(duration/time.Second)
 	child, cancel := context.WithCancel(ctx)
 	defer cancel()
-	go d.redrawGauge(child, maxSize)
+	go d.redrawGauge(child, duration)
 
 	d.chartValues.latencies = make([]float64, 0, maxSize)
 	d.chartValues.p50 = make([]float64, 0, maxSize)
@@ -125,17 +126,22 @@ L:
 	d.chartDrawing.Store(false)
 }
 
-func (d *drawer) redrawGauge(ctx context.Context, maxSize int) {
-	var count float64
-	size := float64(maxSize)
+func (d *drawer) redrawGauge(ctx context.Context, duration time.Duration) {
+	totalTime := float64(duration)
 	d.widgets.progressGauge.Percent(0)
-	for {
+	for start := time.Now(); ; {
 		select {
 		case <-ctx.Done():
 			return
 		case <-d.gaugeCh:
-			count++
-			d.widgets.progressGauge.Percent(int(count / size * 100))
+			passed := float64(time.Since(start))
+			percent := int(passed / totalTime * 100)
+			// as time.Duration is the unit of nanoseconds
+			// small duration can exceed 100 on slow machines
+			if percent > 100 {
+				percent = 100
+			}
+			d.widgets.progressGauge.Percent(percent)
 		}
 	}
 }

gui/drawer_test.go

@@ -21,6 +21,7 @@ func TestAppendChartValues(t *testing.T) {
 	tests := []struct {
 		name          string
 		results       []*attacker.Result
+		duration      time.Duration
 		progressGauge Gauge
 	}{
 		{
@@ -34,6 +35,7 @@ func TestAppendChartValues(t *testing.T) {
 					P99:     990000,
 				},
 			},
+			duration: 1,
 			progressGauge: func() Gauge {
 				g := NewMockGauge(ctrl)
 				g.EXPECT().Percent(gomock.Any()).AnyTimes()
@@ -58,6 +60,7 @@ func TestAppendChartValues(t *testing.T) {
 					P99:     1980000,
 				},
 			},
+			duration: 2,
 			progressGauge: func() Gauge {
 				g := NewMockGauge(ctrl)
 				g.EXPECT().Percent(gomock.Any()).AnyTimes()
@@ -75,7 +78,7 @@ func TestAppendChartValues(t *testing.T) {
 				doneCh:       make(chan struct{}),
 				chartDrawing: atomic.NewBool(false),
 			}
-			go d.appendChartValues(ctx, len(tt.results))
+			go d.appendChartValues(ctx, len(tt.results), tt.duration)
 			for _, res := range tt.results {
 				d.chartCh <- res
 			}
@@ -155,7 +158,7 @@ func TestRedrawGauge(t *testing.T) {
 
 	tests := []struct {
 		name  string
-		size  int
+		size  time.Duration
 		count int
 		gauge Gauge
 	}{
@@ -178,7 +181,7 @@ func TestRedrawGauge(t *testing.T) {
 				gaugeCh: make(chan struct{}),
 			}
 			go d.redrawGauge(ctx, tt.size)
-			for i := 0; i < tt.size; i++ {
+			for i := 0; i < int(tt.size); i++ {
 				d.gaugeCh <- struct{}{}
 			}
 		})

gui/keybinds.go

@@ -2,7 +2,6 @@ package gui
 
 import (
 	"context"
-	"time"
 
 	"github.com/mum4k/termdash/container"
 	"github.com/mum4k/termdash/keyboard"
@@ -50,11 +49,10 @@ func attack(ctx context.Context, d *drawer, target string, opts attacker.Options
 	if d.chartDrawing.Load() {
 		return
 	}
-	requestNum := opts.Rate * int(opts.Duration/time.Second)
 	d.doneCh = make(chan struct{})
 
 	// To initialize, run redrawChart on a per-attack basis.
-	go d.appendChartValues(ctx, requestNum)
+	go d.appendChartValues(ctx, opts.Rate, opts.Duration)
 	go d.redrawCharts(ctx)
 	go func(ctx context.Context, d *drawer, t string, o attacker.Options) {
 		attacker.Attack(ctx, t, d.chartCh, d.metricsCh, o) // this blocks until attack finishes