private void AddToQueue(DateTime timestamp, double period)
{
// check if we're out of space and resize the queue if necessary
if (runTimeQueueCount == runTimeQueue.Length)
{
ResizeQueue();
}
// add to the tail location
runTimeQueue[runTimeQueueTail] = new RunTimeEntry(period, timestamp);
// increment the tail location
runTimeQueueTail = (runTimeQueueTail + 1) % runTimeQueue.Length;
// increment the size
runTimeQueueCount++;
// update the tracker variables
sumPeriod += period;
sumPeriodSq += period * period;
if (period > maxPeriod)
{
maxPeriod = period;
}
// check if we just added the first element
if (runTimeQueueCount == 1)
{
// update the oldest queue time
oldestQueueTime = timestamp;
}
}
private void ResizeQueue()
{
int averageRunRate = 0;
if (sumPeriod > 0)
{
// calculate average mark rate, round up to next integer
averageRunRate = (int)Math.Ceiling(runTimeQueueCount / sumPeriod);
}
// check if the run rate is below the default
if (averageRunRate < DefaultRate)
{
averageRunRate = DefaultRate;
}
// calculate the new target size
int newQueueSize = averageRunRate * windowSize;
// if we're resizing, we might as well do a big resize
// we'll enforce the rule that we at least make the queue 1.5x as big
int minQueueSize = 3 * runTimeQueue.Length / 2;
if (newQueueSize < minQueueSize)
{
newQueueSize = minQueueSize;
}
// create the new queue
RunTimeEntry[] newRunTimeQueue = new RunTimeEntry[newQueueSize];
// copy the old values into the new queue
if (runTimeQueueCount > 0)
{
if (runTimeQueueHead < runTimeQueueTail)
{
// we can copy directly, no wrap around at the moment
Array.Copy(runTimeQueue, runTimeQueueHead, newRunTimeQueue, 0, runTimeQueueCount);
}
else
{
// we need to copy in two parts
// 1) head to end of array
Array.Copy(runTimeQueue, runTimeQueueHead, newRunTimeQueue, 0, runTimeQueue.Length - runTimeQueueHead);
// 2) start of array to tail
Array.Copy(runTimeQueue, 0, newRunTimeQueue, runTimeQueue.Length - runTimeQueueHead, runTimeQueueTail);
}
}
// set the new queue as the current queue
runTimeQueue = newRunTimeQueue;
// adjust the head/tail indicies
runTimeQueueHead = 0;
runTimeQueueTail = runTimeQueueCount;
}
