public List <IJourney <TNode> > BreadthFirstSearchRoutesWithPortRepetition(TNode start, TNode destination,
int maxNumberOfStops, Func <int, IJourney <TNode>, bool> journeyComparer)
{
IJourney <TNode> journey = new Journey <TNode>(_routeRepository).WithPort(start);
var status = new BreadthFirstSearchRoutesStatus <TNode>
{
NodeToProcessQueue = new Queue <KeyValuePair <IJourney <TNode>, IRoute <TNode> > >(),
ResultJourneys = new List <IJourney <TNode> >()
};
status.NodeToProcessQueue.Enqueue(new KeyValuePair <IJourney <TNode>, IRoute <TNode> >(journey, new Route <TNode>(default(TNode), start, 0)));
while (status.NodeToProcessQueue.Count != 0)
{
var currentNode = status.NodeToProcessQueue.Dequeue();
//could this scope be an async call !?!?
if (maxNumberOfStops == 0 && status.NodeToProcessQueue.Count == 0)
{
return(status.ResultJourneys);
}
var currentjourney = currentNode.Key;
if (journeyComparer(maxNumberOfStops, currentjourney))
{
break;
}
//this can be an async call.
status = ProcessAdjacentRoutes(destination, currentNode, status);
}
return(status.ResultJourneys);
}
private BreadthFirstSearchRoutesStatus <TNode> ProcessAdjacentRoutes(TNode destination, KeyValuePair <IJourney <TNode>, IRoute <TNode> > currentNode,
BreadthFirstSearchRoutesStatus <TNode> status)
{
var adjacentRoutes = GetAdjacentRoutes(currentNode.Value.Destination);
foreach (var route in adjacentRoutes)
{
var nextjourney = GetNextJourney(currentNode, route);
status = ProcessRoute(destination, route, nextjourney, status);
}
return(status);
}
private async Task <BreadthFirstSearchRoutesStatus <TNode> > ProcessAdjacentRoutesAsync(TNode destination, KeyValuePair <IJourney <TNode>, IRoute <TNode> > currentNode,
BreadthFirstSearchRoutesStatus <TNode> status)
{
var adjacentRoutes = GetAdjacentRoutes(currentNode.Value.Destination);
Parallel.ForEach(adjacentRoutes, route =>
{
var nextjourney = GetNextJourney(currentNode, route);
status = ProcessRoute(destination, route, nextjourney, status);
});
return(status);
}
private BreadthFirstSearchRoutesStatus <TNode> ProcessRoute(TNode destination, IRoute <TNode> route, IJourney <TNode> nextjourney, BreadthFirstSearchRoutesStatus <TNode> status)
{
//for testing purposes.
//to prove that async is faster only if the proccess is slower.
//Task.Delay(500);
if (route.Destination.Equals(destination))
{
status.ResultJourneys.Add(nextjourney);
}
else
{
status.NodeToProcessQueue.Enqueue(new KeyValuePair <IJourney <TNode>, IRoute <TNode> >(nextjourney, route));
}
return(status);
}