public CompletableResultCode export()

in exporters/metrics/src/main/java/com/google/cloud/opentelemetry/metric/InternalMetricExporter.java [179:254]
55 lines of code
14 McCabe index (conditional complexity)

  public CompletableResultCode export(Collection<MetricData> metrics) {
    // General Algorithm for export:
    // 1. Iterate over all points in the set of metrics to export
    // 2. Attempt to register MetricDescriptors (using configured strategy)
    // 3. Fire the set of time series off.
    MetricTimeSeriesBuilder builder =
        new AggregateByLabelMetricTimeSeriesBuilder(
            projectId,
            prefix,
            resourceAttributesFilter,
            monitoredResourceDescription,
            instrumentationLibraryLabelsEnabled);
    for (final MetricData metricData : metrics) {
      // Extract all the underlying points.
      switch (metricData.getType()) {
        case LONG_GAUGE:
          for (LongPointData point : metricData.getLongGaugeData().getPoints()) {
            builder.recordPoint(metricData, point);
          }
          break;
        case LONG_SUM:
          for (LongPointData point : metricData.getLongSumData().getPoints()) {
            builder.recordPoint(metricData, point);
          }
          break;
        case DOUBLE_GAUGE:
          for (DoublePointData point : metricData.getDoubleGaugeData().getPoints()) {
            builder.recordPoint(metricData, point);
          }
          break;
        case DOUBLE_SUM:
          for (DoublePointData point : metricData.getDoubleSumData().getPoints()) {
            builder.recordPoint(metricData, point);
          }
          break;
        case HISTOGRAM:
          for (HistogramPointData point : metricData.getHistogramData().getPoints()) {
            builder.recordPoint(metricData, point);
          }
          break;
        default:
          logger.error("OpenTelemetry Metric type {} not supported.", metricData.getType());
      }
      // TODO: Filter metrics by last updated time....
      // MetricWithLabels updateKey =
      // new MetricWithLabels(descriptor.getType(), metricPoint.getLabels());

      // // Cloud Monitoring API allows, for any combination of labels and
      // // metric name, one update per WRITE_INTERVAL seconds
      // long pointCollectionTime = metricPoint.getEpochNanos();
      // if (lastUpdatedTime.containsKey(updateKey)
      // && pointCollectionTime
      // <= lastUpdatedTime.get(updateKey) / NANO_PER_SECOND + WRITE_INTERVAL_SECOND)
      // {
      // continue;
      // }
    }
    // Update metric descriptors based on configured strategy.
    exportDescriptors(builder);

    List<TimeSeries> series = builder.getTimeSeries();
    Consumer<List<TimeSeries>> timeSeriesGenerator =
        timeSeries -> {
          if (useCreateServiceTimeSeries) {
            metricServiceClient.createServiceTimeSeries(ProjectName.of(projectId), timeSeries);
          } else {
            metricServiceClient.createTimeSeries(ProjectName.of(projectId), timeSeries);
          }
        };
    createTimeSeriesBatch(series, timeSeriesGenerator);
    // TODO: better error reporting.
    if (series.size() < metrics.size()) {
      return CompletableResultCode.ofFailure();
    }
    return CompletableResultCode.ofSuccess();
  }