func()

in internal/telemetrygen/metrics/worker.go [37:111]
67 lines of code
10 McCabe index (conditional complexity)

func (w worker) simulateMetrics(res *resource.Resource, exporterFunc func() (sdkmetric.Exporter, error), signalAttrs []attribute.KeyValue) {
	limiter := rate.NewLimiter(w.limitPerSecond, 1)

	exporter, err := exporterFunc()
	if err != nil {
		w.logger.Error("failed to create the exporter", zap.Error(err))
		return
	}

	defer func() {
		w.logger.Info("stopping the exporter")
		if tempError := exporter.Shutdown(context.Background()); tempError != nil {
			w.logger.Error("failed to stop the exporter", zap.Error(tempError))
		}
	}()

	var i int64
	for w.running.Load() {
		var metrics []metricdata.Metrics

		switch w.metricType {
		case metricTypeGauge:
			metrics = append(metrics, metricdata.Metrics{
				Name: "gen",
				Data: metricdata.Gauge[int64]{
					DataPoints: []metricdata.DataPoint[int64]{
						{
							Time:       time.Now(),
							Value:      i,
							Attributes: attribute.NewSet(signalAttrs...),
						},
					},
				},
			})
		case metricTypeSum:
			metrics = append(metrics, metricdata.Metrics{
				Name: "gen",
				Data: metricdata.Sum[int64]{
					IsMonotonic: true,
					Temporality: metricdata.CumulativeTemporality,
					DataPoints: []metricdata.DataPoint[int64]{
						{
							StartTime:  time.Now().Add(-1 * time.Second),
							Time:       time.Now(),
							Value:      i,
							Attributes: attribute.NewSet(signalAttrs...),
						},
					},
				},
			})
		default:
			w.logger.Fatal("unknown metric type")
		}

		rm := metricdata.ResourceMetrics{
			Resource:     res,
			ScopeMetrics: []metricdata.ScopeMetrics{{Metrics: metrics}},
		}

		if err := exporter.Export(context.Background(), &rm); err != nil {
			w.logger.Fatal("exporter failed", zap.Error(err))
		}
		if err := limiter.Wait(context.Background()); err != nil {
			w.logger.Fatal("limiter wait failed, retry", zap.Error(err))
		}

		i++
		if w.numMetrics != 0 && i >= int64(w.numMetrics) {
			break
		}
	}

	w.logger.Info("metrics generated", zap.Int64("metrics", i))
	w.wg.Done()
}