Example #1
0
// updateChart inserts a dataset into a line chart, scaling appropriately as to
// not display weird labels, also updating the chart label accordingly.
func updateChart(metric string, data []float64, base *int, chart *termui.LineChart, err error) (realign bool) {
	dataUnits := []string{"", "K", "M", "G", "T", "E"}
	timeUnits := []string{"ns", "µs", "ms", "s", "ks", "ms"}
	colors := []termui.Attribute{termui.ColorBlue, termui.ColorCyan, termui.ColorGreen, termui.ColorYellow, termui.ColorRed, termui.ColorRed}

	// Extract only part of the data that's actually visible
	if chart.Width*2 < len(data) {
		data = data[:chart.Width*2]
	}
	// Find the maximum value and scale under 1K
	high := 0.0
	if len(data) > 0 {
		high = data[0]
		for _, value := range data[1:] {
			high = math.Max(high, value)
		}
	}
	unit, scale := 0, 1.0
	for high >= 1000 && unit+1 < len(dataUnits) {
		high, unit, scale = high/1000, unit+1, scale*1000
	}
	// If the unit changes, re-create the chart (hack to set max height...)
	if unit != *base {
		realign, *base, *chart = true, unit, *createChart(chart.Height)
	}
	// Update the chart's data points with the scaled values
	if cap(chart.Data) < len(data) {
		chart.Data = make([]float64, len(data))
	}
	chart.Data = chart.Data[:len(data)]
	for i, value := range data {
		chart.Data[i] = value / scale
	}
	// Update the chart's label with the scale units
	units := dataUnits
	if strings.Contains(metric, "/Percentiles/") || strings.Contains(metric, "/pauses/") || strings.Contains(metric, "/time/") {
		units = timeUnits
	}
	chart.Border.Label = metric
	if len(units[unit]) > 0 {
		chart.Border.Label += " [" + units[unit] + "]"
	}
	chart.LineColor = colors[unit] | termui.AttrBold
	if err != nil {
		chart.LineColor = termui.ColorRed | termui.AttrBold
	}
	return
}
Example #2
0
func UpdateGenericChart(l *ui.LineChart, updateFunc func() float64) {
	data := make([]float64, 150)
	for {
		for i := len(data) - 1; i > 0; i-- {
			data[i] = data[i-1]
		}
		data[0] = updateFunc()
		l.Data = data
		time.Sleep(500 * time.Millisecond)
	}
}