public static Map sliceFromTimelineMetric()

in ambari-metrics-timelineservice/src/main/java/org/apache/ambari/metrics/core/timeline/aggregators/AggregatorUtils.java [73:137]
54 lines of code
14 McCabe index (conditional complexity)

  public static Map<TimelineClusterMetric, Double> sliceFromTimelineMetric(
    TimelineMetric timelineMetric, List<Long[]> timeSlices, boolean interpolationEnabled) {

    if (timelineMetric.getMetricValues().isEmpty()) {
      return null;
    }

    Map<TimelineClusterMetric, Double> timelineClusterMetricMap =
      new HashMap<>();

    Long prevTimestamp = -1l;
    TimelineClusterMetric prevMetric = null;
    int count = 0;
    double sum = 0.0;

    Map<Long,Double> timeSliceValueMap = new HashMap<>();
    for (Map.Entry<Long, Double> metric : timelineMetric.getMetricValues().entrySet()) {
      if (metric.getValue() == null) {
        continue;
      }

      Long timestamp = getSliceTimeForMetric(timeSlices, Long.parseLong(metric.getKey().toString()));
      if (timestamp != -1) {
        // Metric is within desired time range
        TimelineClusterMetric clusterMetric = new TimelineClusterMetric(
          timelineMetric.getMetricName(),
          timelineMetric.getAppId(),
          timelineMetric.getInstanceId(),
          timestamp);

        if (prevTimestamp < 0 || timestamp.equals(prevTimestamp)) {
          Double newValue = metric.getValue();
          if (newValue > 0.0) {
            sum += newValue;
            count++;
          }
        } else {
          double metricValue = (count > 0) ? (sum / count) : 0.0;
          timelineClusterMetricMap.put(prevMetric, metricValue);
          timeSliceValueMap.put(prevMetric.getTimestamp(), metricValue);
          sum = metric.getValue();
          count = sum > 0.0 ? 1 : 0;
        }

        prevTimestamp = timestamp;
        prevMetric = clusterMetric;
      }
    }

    if (prevTimestamp > 0) {
      double metricValue = (count > 0) ? (sum / count) : 0.0;
      timelineClusterMetricMap.put(prevMetric, metricValue);
      timeSliceValueMap.put(prevTimestamp, metricValue);
    }

    if (interpolationEnabled) {
      Map<Long, Double> interpolatedValues = interpolateMissingPeriods(timelineMetric.getMetricValues(), timeSlices, timeSliceValueMap, timelineMetric.getType());
      for (Map.Entry<Long, Double> entry : interpolatedValues.entrySet()) {
        TimelineClusterMetric timelineClusterMetric = new TimelineClusterMetric(timelineMetric.getMetricName(), timelineMetric.getAppId(), timelineMetric.getInstanceId(), entry.getKey());
        timelineClusterMetricMap.putIfAbsent(timelineClusterMetric, entry.getValue());
      }
    }

    return timelineClusterMetricMap;
  }