jimwei · January 13, 2016 00:55 · Jan 13, 2016
diff --git a/stopwatch.go b/stopwatch.go
@@ -0,0 +1,133 @@
+package main
+
+import (
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+const (
+	TickPerMillisecond int64 = 0x2710
+	TicksPerSecond     int64 = 0x989680
+)
+
+var (
+	modkernel32                   = syscall.NewLazyDLL("kernel32.dll")
+	procQueryPerformanceFrequency = modkernel32.NewProc("QueryPerformanceFrequency")
+	procQueryPerformanceCounter   = modkernel32.NewProc("QueryPerformanceCounter")
+	procSleep                     = modkernel32.NewProc("Sleep")
+)
+
+type stopWatch struct {
+	elapsed          int64
+	startTimeStamp   int64
+	isRunning        bool
+	start            time.Time
+	IsHighResolution bool
+	Frequery         int64
+	tickFrequery     float64
+}
+
+func NewStopWatch() *stopWatch {
+	sw := new(stopWatch)
+	if err := queryPerformanceFrequency(&sw.Frequery); err != nil {
+		sw.IsHighResolution = false
+		sw.Frequery = 0x989680
+		sw.tickFrequery = 1.0
+	} else {
+		sw.IsHighResolution = true
+		sw.tickFrequery = 10000000.0
+		sw.tickFrequery /= float64(sw.Frequery)
+	}
+	return sw
+
+}
+func StartNew() *stopWatch {
+	sw := new(stopWatch)
+	sw.Start()
+	return sw
+}
+func (this *stopWatch) Reset() {
+	this.elapsed = 0
+	this.startTimeStamp = 0
+	this.isRunning = false
+}
+func (this *stopWatch) Start() {
+	if !this.isRunning {
+		this.startTimeStamp = this.getTimestamp()
+		this.isRunning = true
+	}
+}
+func (this *stopWatch) Stop() {
+	if this.isRunning {
+		num2 := this.getTimestamp() - this.startTimeStamp
+		this.elapsed += num2
+		this.isRunning = false
+	}
+}
+func (this *stopWatch) Elapsed() int64 {
+	return this.getElapsedDateTimeTicks()
+}
+func (this *stopWatch) ElapsedMilliseconds() int64 {
+	return this.getElapsedDateTimeTicks() / 0x2710
+}
+func (this *stopWatch) ElapsedTicks() int64 {
+	return this.getRawElapsedTicks()
+}
+func (this *stopWatch) IsRunning() bool {
+	return this.isRunning
+}
+func (this *stopWatch) getElapsedDateTimeTicks() int64 {
+	rawElapsedTicks := this.getRawElapsedTicks()
+	if this.IsHighResolution {
+		num2 := float64(rawElapsedTicks)
+		num2 *= this.tickFrequery
+		return int64(num2)
+	}
+	return rawElapsedTicks
+}
+func (this *stopWatch) getRawElapsedTicks() int64 {
+	elapsed := this.elapsed
+	if this.isRunning {
+		num3 := this.getTimestamp() - this.startTimeStamp
+		elapsed += num3
+	}
+	return elapsed
+}
+func (this *stopWatch) getTimestamp() int64 {
+	if this.IsHighResolution {
+		var num int64
+		queryPerformanceCounter(&num)
+		return num
+	}
+	return time.Now().UTC().Unix()
+}
+
+func queryPerformanceFrequency(frequency *int64) (err error) {
+	r1, _, e1 := syscall.Syscall(procQueryPerformanceFrequency.Addr(), 1, uintptr(unsafe.Pointer(frequency)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func queryPerformanceCounter(counter *int64) (err error) {
+	r1, _, e1 := syscall.Syscall(procQueryPerformanceCounter.Addr(), 1, uintptr(unsafe.Pointer(counter)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func sleep(milliseconds uint32) {
+	syscall.Syscall(procSleep.Addr(), 1, uintptr(milliseconds), 0, 0)
+	return
+}