public static Queue<Request> SSTF(Queue<Request> requestQueue, Drive.Stats driveStatistics)
{
if (requestQueue.Count <= 1)
return new Queue<Request>(requestQueue);
return
new Queue<Request>(
requestQueue.OrderBy(request => Utilities.RequestDistance(request, driveStatistics)));
}
public static Queue<Request> LOOK(Queue<Request> requestQueue, Drive.Stats driveStatistics)
{
if (requestQueue.Count <= 1)
return new Queue<Request>(requestQueue);
Func<int, int, bool> comparisonFunc = driveStatistics.HeadDirectionFlag ? (Func<int, int, bool>)((a,b) => a > b) : ((a, b) => a < b);
var requestsInDirectPath =
requestQueue.Where(request => comparisonFunc(request.Track, driveStatistics.TrackPosition));
var requestsInOppositePath = requestQueue.Except(requestsInDirectPath);
requestsInDirectPath=
requestsInDirectPath.OrderBy(
request => Utilities.RequestDistance(request, driveStatistics));
requestsInOppositePath= requestsInOppositePath.OrderBy(request => Utilities.RequestDistance(request,(requestsInDirectPath.Count() == 0) ? new Request(0,(driveStatistics.HeadDirectionFlag) ? driveStatistics.TracksPerFace : 0, 0) : requestsInDirectPath.Last(), driveStatistics));
return new Queue<Request>(requestsInDirectPath.Concat(requestsInOppositePath));
}
public static Queue<Request> CLOOK(Queue<Request> requestQueue, Drive.Stats driveStatistics)
{
if (requestQueue.Count <= 1)
return new Queue<Request>(requestQueue);
var requestsAbove =
requestQueue.Where(
request =>
request.Track > driveStatistics.TrackPosition && request.Sector > driveStatistics.SectorPosition);
var requestsBelow = requestQueue.Except(requestsAbove);
return
new Queue<Request>(requestsAbove.OrderBy(request => Utilities.RequestDistance(request, driveStatistics))
.Concat(
requestsBelow.OrderBy(
request => Utilities.RequestDistance(request.Track, 0, request.Sector, 0, driveStatistics))));
}
static double[] simulateDrive(Drive drive)
{
var outputMetricList = new List<double>();
drive.AlgorithmEnumerator.Reset();
for (double time = 0, requestsRemaining = requestCollection.Length;
requestsRemaining > 0 || drive.ActiveRequest != null || drive.RequestsQueued > 0;)
{
if (drive.ActiveRequest != null)
{
var completionData = drive.CompleteJob();
time = completionData.Item1;
outputMetricList.Add(time - completionData.Item2);
if (requestsRemaining == 0) break;
}
requestCollection.Where(
request =>
(requestCollection.ElementAt(requestCollection.Count() - Convert.ToInt32(requestsRemaining))
.ArrivalTime <= request.ArrivalTime) && request.ArrivalTime <= time).ForEach(
request =>
{
requestsRemaining--;
drive.AddRequest(request);
});
if (drive.IsQueueEmpty())
{
time++;
continue;
}
if (drive.AlgorithmEnumerator.Current != null || drive.AlgorithmEnumerator.MoveNext())
{
Func<Queue<Request>, Drive.Stats, Queue<Request>> seekAlgorithm = null;
switch (drive.AlgorithmEnumerator.Current)
{
case "FCFS":
seekAlgorithm = RequestAlgorithms.FCFS;
break;
case "SSTF":
seekAlgorithm = RequestAlgorithms.SSTF;
break;
case "LOOK":
seekAlgorithm = RequestAlgorithms.LOOK;
break;
case "CLOOK":
seekAlgorithm = RequestAlgorithms.CLOOK;
break;
}
drive.ActivateNewJob(seekAlgorithm, time);
}
}
return outputMetricList.ToArray();
}
public static Queue<Request> FCFS(Queue<Request> requestQueue, Drive.Stats driveStatistics)
{
if (requestQueue.Count <= 1)
return new Queue<Request>(requestQueue);
return new Queue<Request>(requestQueue.OrderBy(request => request.ArrivalTime));
}
