private Tuple <CachedServer, double> GetBestTimeForRequest(RequestsDescription requestsDescription)
{
double time;
var server = _input.CachedServers.ArgMin(s => CalculateServerTimeForRequest(s, requestsDescription), out time);
return(new Tuple <CachedServer, double>(server, time));
}
private double CalculateRequestValue(RequestsDescription requestsDescription)
{
double currentTime = _currentTime.GetOrCreate(requestsDescription, CalculateCurrentTime);
var bestTuple = _bestTime.GetOrCreate(requestsDescription, GetBestTimeForRequest);
_serverToRequests.GetOrCreate(bestTuple.Item1, _ => new HashSet <RequestsDescription>()).Add(requestsDescription);
double bestTime = bestTuple.Item2;
return(requestsDescription.NumOfRequests * (currentTime - bestTime) / (requestsDescription.Video.Size));
}
private double CalculateCurrentTime(RequestsDescription requestsDescription)
{
var serversWithVideo =
_output.ServerAssignments.Where(kvp => kvp.Value.Contains(requestsDescription.Video)).ToList();
if (!serversWithVideo.Any())
{
return(requestsDescription.Endpoint.DataCenterLatency);
}
return(serversWithVideo.Min(kvp => CalculateServerTimeForRequest(kvp.Key, requestsDescription)));
}
private void AssignVideoToServer(CachedServer selectedServer, RequestsDescription request)
{
assigned++;
if (assigned % 200 == 0)
{
Console.WriteLine("Assigned " + assigned);
}
_input.RequestsDescriptions.Remove(request);
if (CalculateServerTimeForRequest(selectedServer, request) >= request.Endpoint.DataCenterLatency)
{
return;
}
if (_output.ServerAssignments.GetOrDefault(selectedServer, new List <Video>()).Contains(request.Video))
{
return;
}
selectedServer.Capacity -= request.Video.Size;
_output.ServerAssignments.GetOrCreate(selectedServer, _ => new List <Video>()).Add(request.Video);
foreach (var rr in _videoToDescription[request.Video])
{
if (rr.Endpoint.ServersLatency.ContainsKey(selectedServer))
{
_currentTime.Remove(rr);
}
}
foreach (
var rr in
_serverToRequests.GetOrDefault(selectedServer, new HashSet <RequestsDescription>())
.Where(rrr => selectedServer.Capacity < rrr.Video.Size)
.ToList())
{
_bestTime.Remove(rr);
_serverToRequests[selectedServer].Remove(rr);
}
}
private double CalculateServerTimeForRequest(CachedServer cachedServer, RequestsDescription request)
{
return(request.Endpoint.ServersLatency.GetOrDefault(cachedServer, request.Endpoint.DataCenterLatency));
}
private bool HasAvailableServer(RequestsDescription requestsDescription)
{
return(_input.CachedServers.Any(s => IsServerAvailableForVideo(s, requestsDescription.Video)));
}
