func buildExemplarAttachments()

in pkg/export/transform.go [526:573]
48 lines of code
13 McCabe index (conditional complexity)

func buildExemplarAttachments(lset labels.Labels) []*anypb.Any {
	var projectID, spanID, traceID string
	var attachments []*anypb.Any
	droppedLabels := make(map[string]string)
	lset.Range(func(label labels.Label) {
		switch label.Name {
		case projectIDLabel:
			projectID = label.Value
		case spanIDLabel:
			spanID = label.Value
		case traceIDLabel:
			traceID = label.Value
		default:
			droppedLabels[label.Name] = label.Value
		}
	})
	if projectID != "" && spanID != "" && traceID != "" {
		spanCtx, err := anypb.New(&monitoring_pb.SpanContext{
			SpanName: fmt.Sprintf(spanContextFormat, projectID, traceID, spanID),
		})
		if err != nil {
			prometheusExemplarsDiscarded.WithLabelValues("error-creating-span-context").Inc()
		} else {
			attachments = append(attachments, spanCtx)
		}
	} else {
		if projectID != "" {
			droppedLabels[projectIDLabel] = projectID
		}
		if spanID != "" {
			droppedLabels[spanIDLabel] = spanID
		}
		if traceID != "" {
			droppedLabels[traceIDLabel] = traceID
		}
	}
	if len(droppedLabels) > 0 {
		droppedLabels, err := anypb.New(&monitoring_pb.DroppedLabels{
			Label: droppedLabels,
		})
		if err != nil {
			prometheusExemplarsDiscarded.WithLabelValues("error-creating-dropped-labels").Inc()
		} else {
			attachments = append(attachments, droppedLabels)
		}
	}
	return attachments
}