Method computeLatencies

benchmark/stats/stats.go:411–446

computeLatencies computes percentile latencies based on durations stored in the stats object and updates the corresponding fields in the result object.

(result *BenchResults)

// computeLatencies computes percentile latencies based on durations stored in
// the stats object and updates the corresponding fields in the result object.
func (s *Stats) computeLatencies(result *BenchResults) {
	if len(s.hw.durations) == 0 {
		return
	}
	sort.Sort(s.hw.durations)
	minDuration := int64(s.hw.durations[0])
	maxDuration := int64(s.hw.durations[len(s.hw.durations)-1])

	// Use the largest unit that can represent the minimum time duration.
	s.hw.unit = time.Nanosecond
	for _, u := range []time.Duration{time.Microsecond, time.Millisecond, time.Second} {
		if minDuration <= int64(u) {
			break
		}
		s.hw.unit = u
	}

	numBuckets := s.numBuckets
	if n := int(maxDuration - minDuration + 1); n < numBuckets {
		numBuckets = n
	}
	s.hw.histogram = NewHistogram(HistogramOptions{
		NumBuckets: numBuckets,
		// max-min(lower bound of last bucket) = (1 + growthFactor)^(numBuckets-2) * baseBucketSize.
		GrowthFactor:   math.Pow(float64(maxDuration-minDuration), 1/float64(numBuckets-2)) - 1,
		BaseBucketSize: 1.0,
		MinValue:       minDuration,
	})
	for _, d := range s.hw.durations {
		s.hw.histogram.Add(int64(d))
	}
	result.Data.Fiftieth = s.hw.durations[max(s.hw.histogram.Count*int64(50)/100-1, 0)]
	result.Data.Ninetieth = s.hw.durations[max(s.hw.histogram.Count*int64(90)/100-1, 0)]
	result.Data.NinetyNinth = s.hw.durations[max(s.hw.histogram.Count*int64(99)/100-1, 0)]
	result.Data.Average = time.Duration(float64(s.hw.histogram.Sum) / float64(s.hw.histogram.Count))
}

// dump returns a printable version.
func (s *Stats) dump(result *BenchResults) {