Add stopwatch profiler

pkg/log/log.go

@@ -38,3 +38,63 @@ func ProfileWithThreshold(start time.Time, threshold time.Duration, name string)
 		Profilef("%s: %s", elapsed, name)
 	}
 }
+
+type Profiler struct {
+	profiles map[string]time.Duration
+	starts   map[string]time.Time
+}
+
+func NewProfiler() *Profiler {
+	return &Profiler{
+		profiles: map[string]time.Duration{},
+		starts:   map[string]time.Time{},
+	}
+}
+
+func (p *Profiler) Start(name string) {
+	if p == nil {
+		return
+	}
+	p.starts[name] = time.Now()
+}
+
+func (p *Profiler) Stop(name string) time.Duration {
+	if p == nil {
+		return 0
+	}
+	if start, ok := p.starts[name]; ok {
+		elapsed := time.Since(start)
+		p.profiles[name] += elapsed
+		return elapsed
+	}
+	return 0
+}
+
+func (p *Profiler) Log(name string) {
+	if p == nil {
+		return
+	}
+	Profilef("%s: %s", p.profiles[name], name)
+}
+
+func (p *Profiler) LogAll() {
+	if p == nil {
+		return
+	}
+
+	// Print profiles, largest to smallest. (Inefficienct, but shouldn't matter.)
+	print := map[string]time.Duration{}
+	for name, value := range p.profiles {
+		print[name] = value
+	}
+	for len(print) > 0 {
+		largest := ""
+		for name := range print {
+			if print[name] > print[largest] {
+				largest = name
+			}
+		}
+		Profilef("%s: %s", print[largest], largest)
+		delete(print, largest)
+	}
+}