def timeToNextArrival()

in src/main/scala/com/twitter/iago/util/InfiniteSteppedPoissonProcess.scala [89:121]

27 lines of code
6 McCabe index (conditional complexity)


  def timeToNextArrival(): Duration = {
    if (!finishedWarmup) {
      totalArrivals += 1
      if (totalArrivals >= nextStepPoint.toInt) {
        // Compute when to next update rate (numerically integrate number of arrivals over the next ms).
        // Loops handles the case where step points increase more quickly than arrivals.
        while (totalArrivals >= nextStepPoint.toInt) {
          nextStepPoint += increaseStepPoint
          currentArrivalsPerSecond += stepPerMilli
        }

        // clamp rate to final arrival rate and only update distribution if it has changed (by 1+ RPS)
        val mean = 1000000000.0 / currentRate
        if (dist.getMean != mean) {
          dist = new ExponentialDistributionImpl(mean)
        }
      }

      val nanosToNextArrival = dist.inverseCumulativeProbability(rand.nextDouble())
      Duration(nanosToNextArrival.toLong, TimeUnit.NANOSECONDS)
    } else {
      val nanosToNextArrival = 1000000000.0 / currentArrivalsPerSecond
      val nextArrival = Duration(nanosToNextArrival.toLong, TimeUnit.NANOSECONDS)
      if (accumulatedDuration < stepDuration) {
        accumulatedDuration += nextArrival
      } else {
        // Time to step up the rate again
        accumulatedDuration = Duration.Zero
        currentArrivalsPerSecond += stepRate
      }
      return nextArrival
    }
  }