Bugfix: Incorrect AllSequentialIncreasesLessThan (nee IncreasesLessThan) Calculation

In AllSequentialIncreasesLessThan (nee IncreasesLessThan), an earlier
version of this function did not properly take into account the order
in which values were added to the moving average when calculating
the percent change. This patch fixes that error and adds an additional
criteria for the function to return `true`: there must be *at least*
`intervals` collected samples.

2 files changed, 12 insertions, 4 deletions

diff --git a/ma/ma.go b/ma/ma.go
index b591d19..8d06a67 100644
--- a/ma/ma.go
+++ b/ma/ma.go
@@ -32,10 +32,18 @@ func (ma *MovingAverage) CalculateAverage() float64 {
 	return float64(total) / float64(ma.divisor.Value())
 }
 
-func (ma *MovingAverage) IncreasesLessThan(limit float64) bool {
-	previous := ma.instants[0]
+func (ma *MovingAverage) AllSequentialIncreasesLessThan(limit float64) bool {
+
+	// If we have not yet accumulated a complete set of intervals,
+	// this is false.
+	if ma.divisor.Value() != ma.intervals {
+		return false
+	}
+
+	previous := ma.instants[ma.index]
 	for i := 1; i < ma.intervals; i++ {
-		current := ma.instants[i]
+		currentIndex := (ma.index + i) % ma.intervals
+		current := ma.instants[currentIndex]
 		percentChange := utilities.SignedPercentDifference(current, previous)
 		previous = current
 		if percentChange > limit {
diff --git a/networkQuality.go b/networkQuality.go
index 54c4260..e052e1f 100644
--- a/networkQuality.go
+++ b/networkQuality.go
@@ -242,7 +242,7 @@ func saturate(saturationCtx context.Context, operatingCtx context.Context, lbcGe
 					fmt.Printf("%v: Network reached saturation with current flow count.\n", debug)
 				}
 				// If new flows added and for 4 seconds the moving average throughput did not change: network reached stable saturation
-				if (currentIteration-previousFlowIncreaseIteration) < 4 && movingAverageAverage.IncreasesLessThan(float64(5)) {
+				if (currentIteration-previousFlowIncreaseIteration) < 4 && movingAverageAverage.AllSequentialIncreasesLessThan(float64(5)) {
 					if debug != nil {
 						fmt.Printf("%v: New flows added within the last four seconds and the moving-average average is consistent!\n", debug)
 					}