func()

in exporter/collector/metrics.go [1071:1127]

• 47 lines of code
• 6 McCabe index (conditional complexity)

func (m *metricMapper) exponentialHistogramPoint(point pmetric.ExponentialHistogramDataPoint, projectID string) *monitoringpb.TypedValue {
	// First calculate underflow bucket with all negatives + zeros.
	underflow := point.ZeroCount()
	negativeBuckets := point.Negative().BucketCounts()
	for i := 0; i < negativeBuckets.Len(); i++ {
		underflow += negativeBuckets.At(i)
	}

	// Next, pull in remaining buckets.
	counts := make([]int64, point.Positive().BucketCounts().Len()+2)
	bucketOptions := &distribution.Distribution_BucketOptions{}
	counts[0] = int64(underflow)
	positiveBuckets := point.Positive().BucketCounts()
	for i := 0; i < positiveBuckets.Len(); i++ {
		counts[i+1] = int64(positiveBuckets.At(i))
	}
	// Overflow bucket is always empty
	counts[len(counts)-1] = 0

	if point.Positive().BucketCounts().Len() == 0 {
		// We cannot send exponential distributions with no positive buckets,
		// instead we send a simple overflow/underflow histogram.
		bucketOptions.Options = &distribution.Distribution_BucketOptions_ExplicitBuckets{
			ExplicitBuckets: &distribution.Distribution_BucketOptions_Explicit{
				Bounds: []float64{0},
			},
		}
	} else {
		// Exponential histogram
		growth := math.Exp2(math.Exp2(-float64(point.Scale())))
		scale := math.Pow(growth, float64(point.Positive().Offset()))
		bucketOptions.Options = &distribution.Distribution_BucketOptions_ExponentialBuckets{
			ExponentialBuckets: &distribution.Distribution_BucketOptions_Exponential{
				GrowthFactor:     growth,
				Scale:            scale,
				NumFiniteBuckets: int32(len(counts) - 2),
			},
		}
	}

	mean := float64(0)
	if !math.IsNaN(point.Sum()) && point.Count() > 0 { // Avoid divide-by-zero
		mean = float64(point.Sum() / float64(point.Count()))
	}

	return &monitoringpb.TypedValue{
		Value: &monitoringpb.TypedValue_DistributionValue{
			DistributionValue: &distribution.Distribution{
				Count:         int64(point.Count()),
				Mean:          mean,
				BucketCounts:  counts,
				BucketOptions: bucketOptions,
				Exemplars:     m.exemplars(point.Exemplars(), projectID),
			},
		},
	}
}