private Optional stabilizeRecommendation()

in src/main/java/com/google/cloud/run/kafkascaler/ScalingStabilizer.java [382:428]
41 lines of code
11 McCabe index (conditional complexity)

  private Optional<Integer> stabilizeRecommendation(
      Behavior behavior,
      Instant time,
      int currentInstanceCount,
      int recommendedInstances,
      BoundsDebugInfo debug) {
    Instant scaleUpStabilizationCutoff = getStabilizationCutoff(time, behavior.scaleUp());
    Instant scaleDownStabilizationCutoff = getStabilizationCutoff(time, behavior.scaleDown());

    int minInUpStabilizationWindow = recommendedInstances;
    int maxInDownStabilizationWindow = recommendedInstances;

    Iterator<DataPoint> iterator = recommendations.iterator();
    while (iterator.hasNext()) {
      DataPoint recommendation = iterator.next();
      if (recommendation.timestamp().isAfter(time)) {
        // We're done searching once we reach this because the list is sorted by time.
        break;
      }
      if (recommendation.timestamp().isAfter(scaleUpStabilizationCutoff)) {
        minInUpStabilizationWindow = min(minInUpStabilizationWindow, recommendation.value());
      }
      if (recommendation.timestamp().isAfter(scaleDownStabilizationCutoff)) {
        maxInDownStabilizationWindow = max(maxInDownStabilizationWindow, recommendation.value());
      }
      if (recommendation.timestamp().isBefore(scaleUpStabilizationCutoff)
          && recommendation.timestamp().isBefore(scaleDownStabilizationCutoff)) {
        iterator.remove();
      }
    }

    int stabilizedRecommendation = currentInstanceCount;
    if (stabilizedRecommendation < minInUpStabilizationWindow) {
      stabilizedRecommendation = minInUpStabilizationWindow;
    }
    if (stabilizedRecommendation > maxInDownStabilizationWindow) {
      stabilizedRecommendation = maxInDownStabilizationWindow;
    }

    if (recommendedInstances > currentInstanceCount) {
      debug.addScaleUp(Policy.Type.STABILIZATION, minInUpStabilizationWindow);
    } else if (recommendedInstances < currentInstanceCount) {
      debug.addScaleDown(Policy.Type.STABILIZATION, maxInDownStabilizationWindow);
    }

    return Optional.of(stabilizedRecommendation);
  }