func BenchmarkWindowedHistogramRecordAndRotate(b *testing.B) {
w := hdrhistogram.NewWindowed(3, 1, 10000000, 3)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
if err := w.Current.RecordValue(100); err != nil {
b.Fatal(err)
}
if i%100000 == 1 {
w.Rotate()
}
}
}
func TestWindowedHistogram(t *testing.T) {
w := hdrhistogram.NewWindowed(2, 1, 1000, 3)
for i := 0; i < 100; i++ {
w.Current.RecordValue(int64(i))
}
w.Rotate()
for i := 100; i < 200; i++ {
w.Current.RecordValue(int64(i))
}
w.Rotate()
for i := 200; i < 300; i++ {
w.Current.RecordValue(int64(i))
}
if v, want := w.Merge().ValueAtQuantile(50), int64(199); v != want {
t.Errorf("Median was %v, but expected %v", v, want)
}
}
// NewHistogram returns a windowed HDR histogram which drops data older than
// five minutes. The returned histogram is safe to use from multiple goroutines.
//
// Use a histogram to track the distribution of a stream of values (e.g., the
// latency associated with HTTP requests).
func NewHistogram(name string, minValue, maxValue int64, sigfigs int) *Histogram {
hm.Lock()
defer hm.Unlock()
if _, ok := histograms[name]; ok {
panic(name + " already exists")
}
hist := &Histogram{
name: name,
hist: hdrhistogram.NewWindowed(5, minValue, maxValue, sigfigs),
}
histograms[name] = hist
Gauge(name+".P50").SetBatchFunc(hname(name), hist.merge, hist.valueAt(50))
Gauge(name+".P75").SetBatchFunc(hname(name), hist.merge, hist.valueAt(75))
Gauge(name+".P90").SetBatchFunc(hname(name), hist.merge, hist.valueAt(90))
Gauge(name+".P95").SetBatchFunc(hname(name), hist.merge, hist.valueAt(95))
Gauge(name+".P99").SetBatchFunc(hname(name), hist.merge, hist.valueAt(99))
Gauge(name+".P999").SetBatchFunc(hname(name), hist.merge, hist.valueAt(99.9))
return hist
}