/// <summary>
/// Does dykstra calculation(s) with several options.
/// </summary>
/// <param name="graph"></param>
/// <param name="interpreter"></param>
/// <param name="vehicle"></param>
/// <param name="sourceList"></param>
/// <param name="targetList"></param>
/// <param name="weight"></param>
/// <param name="stopAtFirst"></param>
/// <param name="returnAtWeight"></param>
/// <param name="forward"></param>
/// <param name="parameters"></param>
/// <returns></returns>
private PathSegment <long>[] DoCalculation(IBasicRouterDataSource <LiveEdge> graph, IRoutingInterpreter interpreter, Vehicle vehicle,
PathSegmentVisitList sourceList, PathSegmentVisitList[] targetList, double weight,
bool stopAtFirst, bool returnAtWeight, bool forward, Dictionary <string, object> parameters)
{
// intialize dykstra data structures.
var heap = new BinaryHeap <DykstraVisit>(100);
var visits = new Dictionary <long, DykstraVisit>();
// initialize a dictionary of speeds per profile.
var speeds = new Dictionary <uint, Speed>();
// make copies of the target and source visitlist.
var source = sourceList.Clone() as PathSegmentVisitList;
var targets = new PathSegmentVisitList[targetList.Length];
var targetsCount = new int[targetList.Length];
for (int targetIdx = 0; targetIdx < targetList.Length; targetIdx++)
{
targets[targetIdx] = targetList[targetIdx].Clone() as PathSegmentVisitList;
targetsCount[targetIdx] = targetList[targetIdx].Count;
}
// initialize the result data structures.
var segmentsAtWeight = new List <PathSegment <long> >();
var segmentsToTarget = new PathSegment <long> [targets.Length]; // the resulting target segments.
var labels = new Dictionary <long, IList <RoutingLabel> >();
foreach (long vertex in source.GetVertices())
{
labels[vertex] = new List <RoutingLabel>();
var path = source.GetPathTo(vertex);
heap.Push(new DykstraVisit(path), (float)path.Weight);
}
// set the from node as the current node and put it in the correct data structures.
// initialize the source's neighbors.
var current = heap.Pop();
while (current != null && visits.ContainsKey(current.Vertex))
{ // keep dequeuing.
current = heap.Pop();
}
if (current == null)
{
return(null);
}
// test each target for the source.
// test each source for any of the targets.
var pathsFromSource = new Dictionary <long, PathSegment <long> >();
foreach (long sourceVertex in source.GetVertices())
{ // get the path to the vertex.
// get the source path.
var sourcePath = source.GetPathTo(sourceVertex);
sourcePath = sourcePath.From;
while (sourcePath != null)
{ // add the path to the paths from source.
// add to visits.
var visit = new DykstraVisit(sourcePath);
visits[visit.Vertex] = visit;
pathsFromSource[sourcePath.VertexId] = sourcePath;
sourcePath = sourcePath.From;
}
}
// loop over all targets, check for source.
for (int idx = 0; idx < targets.Length; idx++)
{ // loop over each vertex in the targets.
foreach (long targetVertex in new List <long>(targets[idx].GetVertices()))
{
// get the target path.
var targetPath = targets[idx].GetPathTo(targetVertex);
targetPath = targetPath.From;
while (targetPath != null)
{ // add the path to the paths from source.
PathSegment <long> pathFromSource;
if (pathsFromSource.TryGetValue(targetPath.VertexId, out pathFromSource))
{ // a path is found.
// get the existing path if any.
var existing = segmentsToTarget[idx];
if (existing == null)
{ // a path did not exist yet!
segmentsToTarget[idx] = targetPath.Reverse().ConcatenateAfter(pathFromSource);
targets[idx].Remove(targetVertex);
}
else if (existing.Weight > targetPath.Weight + pathFromSource.Weight)
{ // a new path is found with a lower weight.
segmentsToTarget[idx] = targetPath.Reverse().ConcatenateAfter(pathFromSource);
}
}
targetPath = targetPath.From;
}
}
}
if (targets.Length > 0 && targets.All(x => x.Count == 0))
{ // routing is finished!
return(segmentsToTarget.ToArray());
}
if (stopAtFirst)
{ // only one entry is needed.
var oneFound = false;
for (int idx = 0; idx < targets.Length; idx++)
{
if (targets[idx].Count < targetsCount[idx])
{
oneFound = true;
break;
}
}
if (oneFound)
{ // targets found, return the shortest!
PathSegment <long> shortest = null;
foreach (PathSegment <long> foundTarget in segmentsToTarget)
{
if (shortest == null)
{
shortest = foundTarget;
}
else if (foundTarget != null &&
shortest.Weight > foundTarget.Weight)
{
shortest = foundTarget;
}
}
segmentsToTarget = new PathSegment <long> [1];
segmentsToTarget[0] = shortest;
return(segmentsToTarget);
}
else
{ // not targets found yet!
segmentsToTarget = new PathSegment <long> [1];
}
}
// test for identical start/end point.
for (int idx = 0; idx < targets.Length; idx++)
{
var target = targets[idx];
if (returnAtWeight)
{ // add all the reached vertices larger than weight to the results.
if (current.Weight > weight)
{
var toPath = target.GetPathTo(current.Vertex);
toPath.Reverse();
toPath = toPath.ConcatenateAfter(current.ToPath(visits));
segmentsAtWeight.Add(toPath);
}
}
else if (target.Contains(current.Vertex))
{ // the current is a target!
var toPath = target.GetPathTo(current.Vertex);
toPath = toPath.Reverse();
toPath = toPath.ConcatenateAfter(current.ToPath(visits));
if (stopAtFirst)
{ // stop at the first occurrence.
segmentsToTarget[0] = toPath;
return(segmentsToTarget);
}
else
{ // normal one-to-many; add to the result.
// check if routing is finished.
if (segmentsToTarget[idx] == null)
{ // make sure only the first route is set.
segmentsToTarget[idx] = toPath;
if (targets.All(x => x.Count == 0))
{ // routing is finished!
return(segmentsToTarget.ToArray());
}
}
else if (segmentsToTarget[idx].Weight > toPath.Weight)
{ // check if the second, third or later is shorter.
segmentsToTarget[idx] = toPath;
}
}
}
}
// start OsmSharp.Routing.
var edges = graph.GetEdges(Convert.ToUInt32(current.Vertex));
visits[current.Vertex] = current;
// loop until target is found and the route is the shortest!
var noSpeed = new Speed()
{
Direction = null, MeterPerSecond = 0
};
while (true)
{
// get the current labels list (if needed).
IList <RoutingLabel> currentLabels = null;
if (interpreter.Constraints != null)
{ // there are constraints, get the labels.
currentLabels = labels[current.Vertex];
labels.Remove(current.Vertex);
}
// check turn-restrictions.
//List<uint[]> restrictions = null;
bool isRestricted = false;
//if (current.From != null &&
// current.From.Vertex > 0 &&
// graph.TryGetRestrictionAsStart(vehicle, (uint)current.From.Vertex, out restrictions))
//{ // there are restrictions!
// // search for a restriction that ends in the currently selected vertex.
// for(int idx = 0; idx < restrictions.Count; idx++)
// {
// var restriction = restrictions[idx];
// if(restriction[restriction.Length - 1] == current.VertexId)
// { // oeps, do not consider the neighbours of this vertex.
// isRestricted = true;
// break;
// }
// for(int restrictedIdx = 0; restrictedIdx < restriction.Length; restrictedIdx++)
// { // make sure the restricted vertices can be choosen multiple times.
// // restrictedVertices.Add(restriction[restrictedIdx]);
// visitList.SetRestricted(restriction[restrictedIdx]);
// }
// }
//}
if (!isRestricted)
{
// update the visited nodes.
while (edges.MoveNext())
{
var edge = edges;
var neighbour = edge.Neighbour;
if (current.From == neighbour)
{ // don't go back!
continue;
}
if (visits.ContainsKey(neighbour))
{ // has already been choosen.
continue;
}
//// prevent u-turns.
//if(current.From != null)
//{ // a possible u-turn.
// if(current.From.VertexId == neighbour.Neighbour)
// { // a u-turn, don't do this please!
// continue;
// }
//}
// get the speed from cache or calculate.
var edgeData = edge.EdgeData;
var speed = noSpeed;
if (!speeds.TryGetValue(edgeData.Tags, out speed))
{ // speed not there, calculate speed.
var tags = graph.TagsIndex.Get(edgeData.Tags);
speed = noSpeed;
if (vehicle.CanTraverse(tags))
{ // can traverse, speed not null!
speed = new Speed()
{
MeterPerSecond = ((OsmSharp.Units.Speed.MeterPerSecond)vehicle.ProbableSpeed(tags)).Value,
Direction = vehicle.IsOneWay(tags)
};
}
speeds.Add(edgeData.Tags, speed);
}
// check the tags against the interpreter.
if (speed.MeterPerSecond > 0 && (!speed.Direction.HasValue || speed.Direction.Value == edgeData.Forward))
{ // it's ok; the edge can be traversed by the given vehicle.
if ((current.From == 0 || interpreter.CanBeTraversed(current.From, current.Vertex, neighbour)))
{ // the neighbour is forward and is not settled yet!
bool restrictionsOk = true;
//if (restrictions != null)
//{ // search for a restriction that ends in the currently selected neighbour and check if it's via-vertex matches.
// for (int idx = 0; idx < restrictions.Count; idx++)
// {
// var restriction = restrictions[idx];
// if (restriction[restriction.Length - 1] == neighbour.Neighbour)
// { // oeps, do not consider the neighbours of this vertex.
// if (restriction[restriction.Length - 2] == current.VertexId)
// { // damn this route-part is restricted!
// restrictionsOk = false;
// break;
// }
// }
// }
//}
// check the labels (if needed).
bool constraintsOk = true;
if (restrictionsOk && interpreter.Constraints != null)
{ // check if the label is ok.
var neighbourLabel = interpreter.Constraints.GetLabelFor(
graph.TagsIndex.Get(edgeData.Tags));
// only test labels if there is a change.
if (currentLabels.Count == 0 || !neighbourLabel.Equals(currentLabels[currentLabels.Count - 1]))
{ // labels are different, test them!
constraintsOk = interpreter.Constraints.ForwardSequenceAllowed(currentLabels,
neighbourLabel);
if (constraintsOk)
{ // update the labels.
var neighbourLabels = new List <RoutingLabel>(currentLabels);
neighbourLabels.Add(neighbourLabel);
labels[neighbour] = neighbourLabels;
}
}
else
{ // set the same label(s).
labels[neighbour] = currentLabels;
}
}
if (constraintsOk && restrictionsOk)
{ // all constraints are validated or there are none.
// calculate neighbors weight.
double totalWeight = current.Weight + (edgeData.Distance / speed.MeterPerSecond);
//double totalWeight = current.Weight + edgeData.Distance;
// update the visit list.
var neighbourVisit = new DykstraVisit(neighbour, current.Vertex, (float)totalWeight);// new PathSegment<long>(neighbour, totalWeight, current);
heap.Push(neighbourVisit, neighbourVisit.Weight);
}
}
}
}
}
// while the visit list is not empty.
current = null;
if (heap.Count > 0)
{ // choose the next vertex.
current = heap.Pop();
while (current != null && visits.ContainsKey(current.Vertex))
{ // keep dequeuing.
current = heap.Pop();
}
}
while (current != null && current.Weight > weight)
{
if (returnAtWeight)
{ // add all the reached vertices larger than weight to the results.
segmentsAtWeight.Add(current.ToPath(visits));
}
// choose the next vertex.
current = heap.Pop();
while (current != null && visits.ContainsKey(current.Vertex))
{ // keep dequeuing.
current = heap.Pop();
}
}
if (current != null)
{ // we visit this one, set visit.
visits[current.Vertex] = current;
}
else
{ // route is not found, there are no vertices left
// or the search went outside of the max bounds.
break;
}
// check target.
for (int idx = 0; idx < targets.Length; idx++)
{
PathSegmentVisitList target = targets[idx];
if (target.Contains(current.Vertex))
{ // the current is a target!
var toPath = target.GetPathTo(current.Vertex);
toPath = toPath.Reverse();
toPath = toPath.ConcatenateAfter(current.ToPath(visits));
if (stopAtFirst)
{ // stop at the first occurrence.
segmentsToTarget[0] = toPath;
return(segmentsToTarget);
}
else
{ // normal one-to-many; add to the result.
// check if routing is finished.
if (segmentsToTarget[idx] == null)
{ // make sure only the first route is set.
segmentsToTarget[idx] = toPath;
}
else if (segmentsToTarget[idx].Weight > toPath.Weight)
{ // check if the second, third or later is shorter.
segmentsToTarget[idx] = toPath;
}
// remove this vertex from this target's paths.
target.Remove(current.Vertex);
// if this target is empty it's optimal route has been found.
if (target.Count == 0)
{ // now the shortest route has been found for sure!
if (targets.All(x => x.Count == 0))
{ // routing is finished!
// OsmSharp.Logging.Log.TraceEvent("Dykstra", TraceEventType.Information, string.Format("Finished with {0} visits.", visits.Count));
return(segmentsToTarget.ToArray());
}
}
}
}
}
// get the neighbors of the current node.
edges = graph.GetEdges(Convert.ToUInt32(current.Vertex));
}
// return the result.
if (!returnAtWeight)
{
// OsmSharp.Logging.Log.TraceEvent("Dykstra", TraceEventType.Information, string.Format("Finished with {0} visits.", visits.Count));
return(segmentsToTarget.ToArray());
}
// OsmSharp.Logging.Log.TraceEvent("Dykstra", TraceEventType.Information, string.Format("Finished with {0} visits.", visits.Count));
return(segmentsAtWeight.ToArray());
}
/// <summary>
/// Returns true if the given object equals this one.
/// </summary>
/// <param name="other"></param>
/// <returns></returns>
protected bool Equals(PathSegment <TIdType> other)
{
return(EqualityComparer <TIdType> .Default.Equals(VertexId, other.VertexId) && Weight.Equals(other.Weight) && Equals(From, other.From));
}
/// <summary>
/// Creates a new linked vertex.
/// </summary>
/// <param name="vertexId"></param>
/// <param name="weight"></param>
/// <param name="from"></param>
public PathSegment(TIdType vertexId, double weight, PathSegment <TIdType> from)
{
this.VertexId = vertexId;
this.Weight = weight;
this.From = from;
}
/// <summary>
/// Concatenates this path after the given path.
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
public PathSegment <TIdType> ConcatenateAfter(PathSegment <TIdType> path)
{
return(this.ConcatenateAfter(path, null));
}
