func labelDescriptors()

in exporter/metric/metric.go [310:355]

• 45 lines of code
• 15 McCabe index (conditional complexity)

func labelDescriptors(metrics metricdata.Metrics, extraLabels *attribute.Set) []*label.LabelDescriptor {
	labels := []*label.LabelDescriptor{}
	seenKeys := map[string]struct{}{}
	addAttributes := func(attr *attribute.Set) {
		iter := attr.Iter()
		for iter.Next() {
			kv := iter.Attribute()
			// Skip keys that have already been set
			if _, ok := seenKeys[normalizeLabelKey(string(kv.Key))]; ok {
				continue
			}
			labels = append(labels, &label.LabelDescriptor{
				Key: normalizeLabelKey(string(kv.Key)),
			})
			seenKeys[normalizeLabelKey(string(kv.Key))] = struct{}{}
		}
	}
	addAttributes(extraLabels)
	switch a := metrics.Data.(type) {
	case metricdata.Gauge[int64]:
		for _, pt := range a.DataPoints {
			addAttributes(&pt.Attributes)
		}
	case metricdata.Gauge[float64]:
		for _, pt := range a.DataPoints {
			addAttributes(&pt.Attributes)
		}
	case metricdata.Sum[int64]:
		for _, pt := range a.DataPoints {
			addAttributes(&pt.Attributes)
		}
	case metricdata.Sum[float64]:
		for _, pt := range a.DataPoints {
			addAttributes(&pt.Attributes)
		}
	case metricdata.Histogram[float64]:
		for _, pt := range a.DataPoints {
			addAttributes(&pt.Attributes)
		}
	case metricdata.Histogram[int64]:
		for _, pt := range a.DataPoints {
			addAttributes(&pt.Attributes)
		}
	}
	return labels
}