TUN-528: Move cloudflared into a separate repo

metrics/timer.go

@@ -0,0 +1,47 @@
+package metrics
+
+import (
+  "time"
+  "github.com/prometheus/client_golang/prometheus"
+)
+
+// Timer assumes the metrics is partitioned by one label
+type Timer struct {
+  startTime   map[string]time.Time
+  metrics     *prometheus.HistogramVec
+  measureUnit time.Duration
+  labelKey    string
+}
+
+func NewTimer(metrics *prometheus.HistogramVec, unit time.Duration, labelKey string) *Timer {
+  return &Timer{
+    startTime:   make(map[string]time.Time),
+    measureUnit: unit,
+    metrics:     metrics,
+    labelKey:    labelKey,
+  }
+}
+
+func (i *Timer) Start(labelVal string) {
+  i.startTime[labelVal] = time.Now()
+}
+
+func (i *Timer) End(labelVal string) time.Duration {
+  if start, ok := i.startTime[labelVal]; ok {
+    return Latency(start, time.Now())
+  }
+  return 0
+}
+
+func (i *Timer) Observe(measurement time.Duration, labelVal string) {
+  metricsLabels := prometheus.Labels{i.labelKey: labelVal}
+  i.metrics.With(metricsLabels).Observe(float64(measurement / i.measureUnit))
+}
+
+func (i *Timer) EndAndObserve(labelVal string) {
+  i.Observe(i.End(labelVal), labelVal)
+}
+
+func Latency(startTime, endTime time.Time) time.Duration {
+  return endTime.Sub(startTime)
+}