resource usage mod

resourceusage/widget.go

@@ -0,0 +1,141 @@
+package resourceusage
+
+import (
+	"code.cloudfoundry.org/bytefmt"
+	"fmt"
+	"github.com/c9s/goprocinfo/linux"
+	"github.com/rivo/tview"
+	"github.com/senorprogrammer/wtf/wtf"
+)
+
+var started = false
+var ok = true
+var prevStats []linux.CPUStat
+
+// Widget define wtf widget to register widget later
+type Widget struct {
+	wtf.BarGraph
+}
+
+// NewWidget Make new instance of widget
+func NewWidget(app *tview.Application) *Widget {
+	widget := Widget{
+		BarGraph: wtf.NewBarGraph(app,  "Resource Usage", "resourceusage", false),
+	}
+
+	widget.View.SetWrap(true)
+	widget.View.SetWordWrap(true)
+
+	return &widget
+}
+
+/* -------------------- Exported Functions -------------------- */
+
+// MakeGraph - Load the dead drop stats
+func MakeGraph(widget *Widget) {
+
+	cpuStat, err := linux.ReadStat("/proc/stat")
+	if err != nil {
+		return
+	}
+
+	var stats = make([]wtf.Bar, len(cpuStat.CPUStats)+2)
+
+	for i, stat := range cpuStat.CPUStats {
+		prevStat := stat
+		if len(prevStats) > i {
+			prevStat = prevStats[i]
+		} else {
+			prevStats = append(prevStats, stat)
+		}
+
+		// based on htop algorithm described here: https://stackoverflow.com/a/23376195/1516085
+		prevIdle := prevStat.Idle + prevStat.IOWait
+		idle := stat.Idle + stat.IOWait
+
+		prevNonIdle := prevStat.User + prevStat.Nice + prevStat.System + prevStat.IRQ + prevStat.SoftIRQ + prevStat.Steal
+		nonIdle := stat.User + stat.Nice + stat.System + stat.IRQ + stat.SoftIRQ + stat.Steal
+
+		prevTotal := prevIdle + prevNonIdle
+		total := idle + nonIdle
+
+		// differentiate: actual value minus the previous one
+		difference := total - prevTotal
+		idled := idle - prevIdle
+
+		percentage := float64(0)
+		if difference > 0 {
+			percentage = float64(difference-idled) / float64(difference)
+		}
+
+		bar := wtf.Bar{
+			Label:      fmt.Sprint(i),
+			Percent:    int(percentage * 100),
+			ValueLabel: fmt.Sprintf("%d%%", int(percentage*100)),
+		}
+
+		stats[i] = bar
+		prevStats[i] = stat
+	}
+
+	memInfo, err := linux.ReadMemInfo("/proc/meminfo")
+	if err != nil {
+		return
+	}
+
+	memIndex := len(cpuStat.CPUStats)
+	memUsed := memInfo.MemTotal - memInfo.MemAvailable
+	memPercent := float64(memUsed) / float64(memInfo.MemTotal)
+
+	usedMemLabel := bytefmt.ByteSize(memUsed * bytefmt.KILOBYTE)
+	totalMemLabel := bytefmt.ByteSize(memInfo.MemTotal * bytefmt.KILOBYTE)
+
+	if usedMemLabel[len(usedMemLabel)-1] == totalMemLabel[len(totalMemLabel)-1] {
+		usedMemLabel = usedMemLabel[:len(usedMemLabel)-1]
+	}
+
+	stats[memIndex] = wtf.Bar{
+		Label:      "Mem",
+		Percent:    int(memPercent * 100),
+		ValueLabel: fmt.Sprintf("%s/%s", usedMemLabel, totalMemLabel),
+	}
+
+	swapIndex := len(cpuStat.CPUStats) + 1
+	swapUsed := memInfo.SwapTotal - memInfo.SwapFree
+	swapPercent := float64(swapUsed) / float64(memInfo.SwapTotal)
+
+	usedSwapLabel := bytefmt.ByteSize(swapUsed * bytefmt.KILOBYTE)
+	totalSwapLabel := bytefmt.ByteSize(memInfo.SwapTotal * bytefmt.KILOBYTE)
+
+	if usedSwapLabel[len(usedSwapLabel)-1] == totalMemLabel[len(totalSwapLabel)-1] {
+		usedSwapLabel = usedSwapLabel[:len(usedSwapLabel)-1]
+	}
+
+	stats[swapIndex] = wtf.Bar{
+		Label:      "Swp",
+		Percent:    int(swapPercent * 100),
+		ValueLabel: fmt.Sprintf("%s/%s", usedSwapLabel, totalSwapLabel),
+	}
+
+	widget.BarGraph.BuildBars(stats[:])
+
+}
+
+// Refresh & update after interval time
+func (widget *Widget) Refresh() {
+
+	if widget.Disabled() {
+		return
+	}
+
+	widget.View.Clear()
+
+	display(widget)
+
+}
+
+/* -------------------- Unexported Functions -------------------- */
+
+func display(widget *Widget) {
+	MakeGraph(widget)
+}