/// <summary>
/// Executes one step in the search.
/// </summary>
public bool Step()
{
if (_pointerHeap.Count == 0)
{
return(false);
}
var cPointer = _pointerHeap.Pop();
uint cVertex, cPrevious;
T cWeight;
_weightHandler.GetPathTree(_pathTree, cPointer, out cVertex, out cWeight, out cPrevious);
if (_visited.Contains(cVertex))
{
return(true);
}
_visited.Add(cVertex);
if (this.WasFound != null)
{
if (this.WasFound(cPointer, cVertex, cWeight))
{ // when true is returned, the listener signals it knows what it wants to know.
return(false);
}
}
_edgeEnumerator.MoveTo(cVertex);
while (_edgeEnumerator.MoveNext())
{
var nWeight = _weightHandler.GetEdgeWeight(_edgeEnumerator);
if ((!_backward && nWeight.Direction.F) ||
(_backward && nWeight.Direction.B))
{ // the edge is forward, and is to higher or was not contracted at all.
var nVertex = _edgeEnumerator.Neighbour;
var totalWeight = _weightHandler.Add(nWeight.Weight, cWeight);
if (!_weightHandler.IsSmallerThan(totalWeight, _max))
{
continue;
}
var nPointer = _weightHandler.AddPathTree(_pathTree, nVertex, totalWeight, cPointer);
_pointerHeap.Push(nPointer, _weightHandler.GetMetric(totalWeight));
}
}
return(true);
}
/// <summary>
/// Executes one step in the search.
/// </summary>
public bool Step()
{
// while the visit list is not empty.
var cPointer = uint.MaxValue;
while (cPointer == uint.MaxValue)
{ // choose the next edge.
if (_pointerHeap.Count == 0)
{
return(false);
}
cPointer = _pointerHeap.Pop();
}
// get details.
uint cEdge, cPreviousPointer;
T cWeight;
_weightHandler.GetPathTree(_pathTree, cPointer, out cEdge, out cWeight, out cPreviousPointer);
if (_visits.Contains(cEdge))
{
return(true);
}
_visits.Add(cEdge);
var cDirectedEdge = new DirectedEdgeId()
{
Raw = cEdge
};
// signal was found.
if (this.WasFound != null)
{
this.WasFound(cPointer, cDirectedEdge, cWeight);
}
// move to the current edge's target vertex.
_edgeEnumerator.MoveToEdge(cDirectedEdge.EdgeId);
var cOriginalEdge = new OriginalEdge(_edgeEnumerator.From, _edgeEnumerator.To);
if (!cDirectedEdge.Forward)
{
cOriginalEdge = cOriginalEdge.Reverse();
}
var cEdgeWeightAndDirection = _weightHandler.GetEdgeWeight(_edgeEnumerator);
// calculate total weight.
var totalWeight = _weightHandler.Add(cEdgeWeightAndDirection.Weight, cWeight);
if (!_weightHandler.IsSmallerThan(totalWeight, _sourceMax))
{ // weight is too big.
this.MaxReached = true;
return(true);
}
// loop over all neighbours.
_edgeEnumerator.MoveTo(cOriginalEdge.Vertex2);
var turn = new Turn(cOriginalEdge, Constants.NO_VERTEX);
_restrictions.Update(turn.Vertex2);
while (_edgeEnumerator.MoveNext())
{
turn.Vertex3 = _edgeEnumerator.To;
if (turn.IsUTurn ||
turn.IsRestrictedBy(_restrictions))
{ // turn is restricted.
continue;
}
var nDirectedEdgeId = _edgeEnumerator.DirectedEdgeId();
if (_visits.Contains(nDirectedEdgeId.Raw))
{ // has already been choosen.
continue;
}
// get the speed from cache or calculate.
var nWeightAndDirection = _weightHandler.GetEdgeWeight(_edgeEnumerator);
var nWeightMetric = _weightHandler.GetMetric(nWeightAndDirection.Weight);
if (nWeightMetric <= 0)
{ // edge is not valid for profile.
continue;
}
if (!_backward && !nWeightAndDirection.Direction.F)
{ // cannot do forward search on edge.
continue;
}
if (_backward && !nWeightAndDirection.Direction.B)
{ // cannot do backward on edge.
continue;
}
// update the visit list.
_pointerHeap.Push(_weightHandler.AddPathTree(_pathTree, nDirectedEdgeId.Raw, totalWeight, cPointer), _weightHandler.GetMetric(totalWeight));
}
return(true);
}
/// <summary>
/// Executes the actual run.
/// </summary>
protected override void DoRun(CancellationToken cancellationToken)
{
// keep settled vertices.
_pathTree = new PathTree();
// initialize the queues.
var forwardQueue = new BinaryHeap <uint>();
var backwardQueue = new BinaryHeap <uint>();
// queue sources.
if (_source.Vertex1 != Constants.NO_VERTEX)
{
forwardQueue.Push(_weightHandler.AddPathTree(_pathTree, _source.Vertex1, _source.Weight1, uint.MaxValue), 0);
}
if (_source.Vertex2 != Constants.NO_VERTEX)
{
forwardQueue.Push(_weightHandler.AddPathTree(_pathTree, _source.Vertex2, _source.Weight2, uint.MaxValue), 0);
}
// queue targets.
if (_target.Vertex1 != Constants.NO_VERTEX)
{
backwardQueue.Push(_weightHandler.AddPathTree(_pathTree, _target.Vertex1, _target.Weight1, uint.MaxValue), 0);
}
if (_target.Vertex2 != Constants.NO_VERTEX)
{
backwardQueue.Push(_weightHandler.AddPathTree(_pathTree, _target.Vertex2, _target.Weight2, uint.MaxValue), 0);
}
// update best with current visits.
_best = new Tuple <uint, uint, T>(uint.MaxValue, uint.MaxValue, _weightHandler.Infinite);
// calculate stopping conditions.
var queueBackwardWeight = backwardQueue.PeekWeight();
var queueForwardWeight = forwardQueue.PeekWeight();
while (true)
{ // keep looping until stopping conditions.
if (backwardQueue.Count == 0 && forwardQueue.Count == 0)
{ // stop the search; both queues are empty.
break;
}
var bestItem2 = _weightHandler.GetMetric(_best.Item3);
if (bestItem2 < queueForwardWeight && bestItem2 < queueBackwardWeight)
{ // stop the search: it now became impossible to find a shorter route by further searching.
break;
}
// do a forward search.
if (forwardQueue.Count > 0)
{ // first check for better path.
// get the current queued with the smallest weight that hasn't been visited yet.
var cPointer = forwardQueue.Pop();
uint cVertex, cPreviousPointer;
T cWeight;
_weightHandler.GetPathTree(_pathTree, cPointer, out cVertex, out cWeight, out cPreviousPointer);
while (_forwardVisits.ContainsKey(cVertex))
{ // keep trying.
if (forwardQueue.Count == 0)
{
cPointer = uint.MaxValue;
}
else
{
cPointer = forwardQueue.Pop();
_weightHandler.GetPathTree(_pathTree, cPointer, out cVertex, out cWeight, out cPreviousPointer);
}
}
if (cPointer != uint.MaxValue)
{
uint bPointer;
if (_backwardVisits.TryGetValue(cVertex, out bPointer))
{ // check for a new best.
uint bVertex, bPreviousPointer;
T bWeight;
_weightHandler.GetPathTree(_pathTree, bPointer, out bVertex, out bWeight, out bPreviousPointer);
var total = _weightHandler.Add(cWeight, bWeight);
if (_weightHandler.IsSmallerThan(total, _best.Item2))
{ // a better path was found.
_best = new Tuple <uint, uint, T>(cPointer, bPointer, total);
this.HasSucceeded = true;
}
}
this.SearchForward(forwardQueue, cPointer, cVertex, cWeight);
}
}
// do a backward search.
if (backwardQueue.Count > 0)
{// first check for better path.
// get the current queued with the smallest weight that hasn't been visited yet.
var cPointer = backwardQueue.Pop();
uint cVertex, cPreviousPointer;
T cWeight;
_weightHandler.GetPathTree(_pathTree, cPointer, out cVertex, out cWeight, out cPreviousPointer);
while (_backwardVisits.ContainsKey(cVertex))
{ // keep trying.
if (backwardQueue.Count == 0)
{
cPointer = uint.MaxValue;
}
else
{
cPointer = backwardQueue.Pop();
_weightHandler.GetPathTree(_pathTree, cPointer, out cVertex, out cWeight, out cPreviousPointer);
}
}
if (cPointer != uint.MaxValue)
{
uint bPointer; // best pointer.
if (_forwardVisits.TryGetValue(cVertex, out bPointer))
{ // check for a new best.
uint bVertex, bPreviousPointer;
T bWeight;
_weightHandler.GetPathTree(_pathTree, bPointer, out bVertex, out bWeight, out bPreviousPointer);
var total = _weightHandler.Add(cWeight, bWeight);
if (_weightHandler.IsSmallerThan(total, _best.Item2))
{ // a better path was found.
_best = new Tuple <uint, uint, T>(bPointer, cPointer, total);
this.HasSucceeded = true;
}
}
this.SearchBackward(backwardQueue, cPointer, cVertex, cWeight);
}
}
// calculate stopping conditions.
if (forwardQueue.Count > 0)
{
queueForwardWeight = forwardQueue.PeekWeight();
}
if (backwardQueue.Count > 0)
{
queueBackwardWeight = backwardQueue.PeekWeight();
}
}
}
