/// <summary>
/// Calculates the priority of the given vertex.
/// </summary>
public float Calculate(BitArray32 contractedFlags, Func <uint, IEnumerable <uint[]> > getRestrictions, uint vertex)
{
var removed = 0;
var added = 0;
// get and keep edges.
var edges = new List <DynamicEdge>(_graph.GetEdgeEnumerator(vertex));
// check if this vertex has a potential restrictions.
var restrictions = getRestrictions(vertex);
var hasRestrictions = restrictions != null && restrictions.Any();
// remove 'downward' edge to vertex.
var i = 0;
while (i < edges.Count)
{
var edgeEnumerator = _graph.GetEdgeEnumerator(edges[i].Neighbour);
edgeEnumerator.Reset();
while (edgeEnumerator.MoveNext())
{
if (edgeEnumerator.Neighbour == vertex)
{
removed++;
}
}
if (contractedFlags[edges[i].Neighbour])
{ // neighbour was already contracted, remove 'downward' edge and exclude it.
edgeEnumerator.MoveTo(vertex);
edgeEnumerator.Reset();
while (edgeEnumerator.MoveNext())
{
if (edgeEnumerator.Neighbour == edges[i].Neighbour)
{
removed++;
}
}
edges.RemoveAt(i);
}
else
{ // move to next edge.
i++;
}
}
// loop over all edge-pairs once.
for (var j = 1; j < edges.Count; j++)
{
var edge1 = edges[j];
bool?edge1Direction;
var edge1Weight = _weightHandler.GetEdgeWeight(edge1, out edge1Direction);
var edge1CanMoveForward = edge1Direction == null || edge1Direction.Value;
var edge1CanMoveBackward = edge1Direction == null || !edge1Direction.Value;
// figure out what witness paths to calculate.
var forwardWitnesses = new EdgePath <T> [j];
var backwardWitnesses = new EdgePath <T> [j];
var targets = new List <uint>(j);
var targetWeights = new List <T>(j);
for (var k = 0; k < j; k++)
{
var edge2 = edges[k];
bool?edge2Direction;
var edge2Weight = _weightHandler.GetEdgeWeight(edge2, out edge2Direction);
var edge2CanMoveForward = edge2Direction == null || edge2Direction.Value;
var edge2CanMoveBackward = edge2Direction == null || !edge2Direction.Value;
if (!(edge1CanMoveBackward && edge2CanMoveForward))
{
forwardWitnesses[k] = new EdgePath <T>();
}
if (!(edge1CanMoveForward && edge2CanMoveBackward))
{
backwardWitnesses[k] = new EdgePath <T>();
}
targets.Add(edge2.Neighbour);
if (hasRestrictions)
{ // weight can potentially be bigger.
targetWeights.Add(_weightHandler.Infinite);
}
else
{ // weight can max be the sum of the two edges.
targetWeights.Add(_weightHandler.Add(edge1Weight, edge2Weight));
}
}
// calculate all witness paths.
_witnessCalculator.Calculate(_graph, getRestrictions, edge1.Neighbour, targets, targetWeights,
ref forwardWitnesses, ref backwardWitnesses, Constants.NO_VERTEX);
// add contracted edges if needed.
for (var k = 0; k < j; k++)
{
var edge2 = edges[k];
var removedLocal = 0;
var addedLocal = 0;
if (forwardWitnesses[k].HasVertex(vertex) && backwardWitnesses[k].HasVertex(vertex))
{ // add bidirectional edge.
_graph.TryAddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
_weightHandler.GetMetric(targetWeights[k]), null, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
_graph.TryAddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
_weightHandler.GetMetric(targetWeights[k]), null, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
}
else if (forwardWitnesses[k].HasVertex(vertex))
{ // add forward edge.
_graph.TryAddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
_weightHandler.GetMetric(targetWeights[k]), true, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
_graph.TryAddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
_weightHandler.GetMetric(targetWeights[k]), false, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
}
else if (backwardWitnesses[k].HasVertex(vertex))
{ // add forward edge.
_graph.TryAddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
_weightHandler.GetMetric(targetWeights[k]), false, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
_graph.TryAddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
_weightHandler.GetMetric(targetWeights[k]), true, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
}
}
}
var contracted = 0;
_contractionCount.TryGetValue(vertex, out contracted);
var depth = 0;
_depth.TryGetValue(vertex, out depth);
return(this.DifferenceFactor * (added - removed) + (this.DepthFactor * depth) +
(this.ContractedFactor * contracted));
}
/// <summary>
/// Remove all witnessed edges.
/// </summary>
private void RemoveWitnessedEdges()
{
_logger.Log(TraceEventType.Information, "Removing witnessed edges...");
var edges = new List <MetaEdge>();
var weights = new List <T>();
var metrics = new List <float>();
var targets = new List <uint>();
for (uint vertex = 0; vertex < _graph.VertexCount; vertex++)
{
edges.Clear();
weights.Clear();
metrics.Clear();
targets.Clear();
edges.AddRange(_graph.GetEdgeEnumerator(vertex));
var forwardWitnesses = new bool[edges.Count];
var backwardWitnesses = new bool[edges.Count];
for (var i = 0; i < edges.Count; i++)
{
var edge = edges[i];
bool?edgeDirection;
var edgeWeight = _weightHandler.GetEdgeWeight(edge, out edgeDirection);
var edgeCanMoveForward = edgeDirection == null || edgeDirection.Value;
var edgeCanMoveBackward = edgeDirection == null || !edgeDirection.Value;
forwardWitnesses[i] = !edgeCanMoveForward;
backwardWitnesses[i] = !edgeCanMoveBackward;
weights.Add(edgeWeight);
metrics.Add(_weightHandler.GetMetric(edgeWeight));
targets.Add(edge.Neighbour);
}
// calculate all witness paths.
_witnessCalculator.Calculate(_graph.Graph, vertex, targets, metrics,
ref forwardWitnesses, ref backwardWitnesses, uint.MaxValue);
// check witness paths.
for (var i = 0; i < edges.Count; i++)
{
if (forwardWitnesses[i] && backwardWitnesses[i])
{ // in both directions the edge does not represent the shortest path.
_graph.RemoveEdge(vertex, targets[i]);
}
else if (forwardWitnesses[i])
{ // only in forward direction is this edge useless.
_graph.RemoveEdge(vertex, targets[i]);
_weightHandler.AddEdge(_graph, vertex, targets[i], Constants.NO_VERTEX, false, weights[i]);
//_graph.AddEdge(vertex, targets[i], weights[i], false, Constants.NO_VERTEX);
}
else if (backwardWitnesses[i])
{ // only in backward direction is this edge useless.
_graph.RemoveEdge(vertex, targets[i]);
_weightHandler.AddEdge(_graph, vertex, targets[i], Constants.NO_VERTEX, true, weights[i]);
}
}
}
}
/// <summary>
/// Contracts the given vertex.
/// </summary>
private void Contract(uint vertex)
{
// get and keep edges.
var enumerator = _graph.GetEdgeEnumerator(vertex);
var edges = new List <DynamicEdge>(enumerator);
// check if this vertex has a potential restrictions.
var hasRestrictions = _restrictionFlags[vertex];
// loop over all edge-pairs once.
for (var j = 1; j < edges.Count; j++)
{
var edge1 = edges[j];
var edge1Sequence2 = edges[j].GetSequence2();
if (edge1Sequence2.Length == 0)
{
edge1Sequence2 = new uint[] { vertex };
}
bool?edge1Direction;
var edge1Weight = _weightHandler.GetEdgeWeight(edge1, out edge1Direction);
var edge1CanMoveForward = edge1Direction == null || edge1Direction.Value;
var edge1CanMoveBackward = edge1Direction == null || !edge1Direction.Value;
// figure out what witness paths to calculate.
var forwardWitnesses = new EdgePath <T> [j];
var backwardWitnesses = new EdgePath <T> [j];
var targets = new List <uint>(j);
var targetWeights = new List <T>(j);
for (var k = 0; k < j; k++)
{
var edge2 = edges[k];
bool?edge2Direction;
var edge2Weight = _weightHandler.GetEdgeWeight(edge2, out edge2Direction);
var edge2CanMoveForward = edge2Direction == null || edge2Direction.Value;
var edge2CanMoveBackward = edge2Direction == null || !edge2Direction.Value;
// use witness flags to represent impossible routes.
if (!(edge1CanMoveBackward && edge2CanMoveForward))
{
forwardWitnesses[k] = new EdgePath <T>();
}
if (!(edge1CanMoveForward && edge2CanMoveBackward))
{
backwardWitnesses[k] = new EdgePath <T>();
}
targets.Add(edge2.Neighbour);
if (hasRestrictions)
{
targetWeights.Add(_weightHandler.Infinite);
}
else
{
targetWeights.Add(_weightHandler.Add(edge1Weight, edge2Weight));
}
}
// calculate all witness paths.
_witnessCalculator.Calculate(_graph, _getRestrictions, edge1.Neighbour, targets, targetWeights, ref forwardWitnesses,
ref backwardWitnesses, Constants.NO_VERTEX);
// get all sequences where needed.
var s1forward = new uint[forwardWitnesses.Length][];
var s2forward = new uint[forwardWitnesses.Length][];
var s1backward = new uint[backwardWitnesses.Length][];
var s2backward = new uint[backwardWitnesses.Length][];
for (var k = 0; k < j; k++)
{
var edge2Sequence2 = edges[k].GetSequence2();
if (edge2Sequence2.Length == 0)
{
edge2Sequence2 = new uint[] { vertex };
}
if (forwardWitnesses[k].HasVertex(vertex))
{ // get forward sequences.
s1forward[k] = forwardWitnesses[k].GetSequence1(enumerator, 1);
s2forward[k] = forwardWitnesses[k].GetSequence2(enumerator, 1);
if (!s1forward[k].IsSequenceIdentical(edge1Sequence2) ||
!s2forward[k].IsSequenceIdentical(edge2Sequence2))
{ // start and end sequences of shortest paths need to match.
s1forward[k] = null;
s2forward[k] = null;
}
}
if (backwardWitnesses[k].HasVertex(vertex))
{ // get backward sequences.
s1backward[k] = backwardWitnesses[k].GetSequence1(enumerator, 1);
s2backward[k] = backwardWitnesses[k].GetSequence2(enumerator, 1);
if (!s1backward[k].IsSequenceIdentical(edge1Sequence2) ||
!s2backward[k].IsSequenceIdentical(edge2Sequence2))
{ // start and end sequences of shortest paths need to match.
s1backward[k] = null;
s2backward[k] = null;
}
}
}
// add contracted edges if needed.
for (var k = 0; k < j; k++)
{
var edge2 = edges[k];
if (edge1.Neighbour == edge2.Neighbour)
{ // do not try to add a shortcut between identical vertices.
continue;
}
//if (s1forward[k] != null && s1backward[k] != null &&
// System.Math.Abs(_weightHandler.GetMetric(forwardWitnesses[k].Weight) - _weightHandler.GetMetric(backwardWitnesses[k].Weight)) < E)
//{ // paths in both direction are possible and with the same weight, add just one edge in each direction.
// s1backward[k].Reverse();
// s2backward[k].Reverse();
// _weightHandler.AddOrUpdateEdge(_graph, edge1.Neighbour, edge2.Neighbour, vertex, null,
// forwardWitnesses[k].Weight, s1forward[k], s2forward[k]);
// //_graph.AddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
// // forwardWitnesses[k].Weight, null, vertex, s1forward[k], s2forward[k]);
// _weightHandler.AddOrUpdateEdge(_graph, edge2.Neighbour, edge1.Neighbour, vertex, null,
// backwardWitnesses[k].Weight, s2backward[k], s1backward[k]);
// //_graph.AddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
// // backwardWitnesses[k].Weight, null, vertex, s2backward[k], s1backward[k]);
//}
//else
//{ // add two edge per direction.
if (s1forward[k] != null)
{ // add forward edge.
_weightHandler.AddOrUpdateEdge(_graph, edge1.Neighbour, edge2.Neighbour, vertex, true,
forwardWitnesses[k].Weight, s1forward[k], s2forward[k]);
//_graph.AddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
// forwardWitnesses[k].Weight, true, vertex, s1forward[k], s2forward[k]);
s1forward[k].Reverse();
s2forward[k].Reverse();
_weightHandler.AddOrUpdateEdge(_graph, edge2.Neighbour, edge1.Neighbour, vertex, false,
forwardWitnesses[k].Weight, s2forward[k], s1forward[k]);
//_graph.AddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
// forwardWitnesses[k].Weight, false, vertex, s2forward[k], s1forward[k]);
}
if (s1backward[k] != null)
{ // add forward edge.
_weightHandler.AddOrUpdateEdge(_graph, edge1.Neighbour, edge2.Neighbour, vertex, false,
backwardWitnesses[k].Weight, s1backward[k], s2backward[k]);
//_graph.AddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
// backwardWitnesses[k].Weight, false, vertex, s2backward[k], s1backward[k]);
s1backward[k].Reverse();
s2backward[k].Reverse();
_weightHandler.AddOrUpdateEdge(_graph, edge2.Neighbour, edge1.Neighbour, vertex, true,
backwardWitnesses[k].Weight, s2backward[k], s1backward[k]);
//_graph.AddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
// backwardWitnesses[k].Weight, true, vertex, s1backward[k], s2backward[k]);
}
//}
}
}
// remove 'downward' edge to vertex.
var i = 0;
while (i < edges.Count)
{
_graph.RemoveEdge(edges[i].Neighbour, vertex);
if (_contractedFlags[edges[i].Neighbour])
{ // neighbour was already contracted, remove 'downward' edge and exclude it.
_graph.RemoveEdge(vertex, edges[i].Neighbour);
edges.RemoveAt(i);
}
else
{ // move to next edge.
i++;
}
}
_contractedFlags[vertex] = true;
_priorityCalculator.NotifyContracted(vertex);
}
/// <summary>
/// Calculates the priority of the given vertex.
/// </summary>
public float Calculate(BitArray32 contractedFlags, uint vertex)
{
var removed = 0;
var added = 0;
// get and keep edges.
var edges = new List <Edge>(_graph.Graph.GetEdgeEnumerator(vertex));
// remove 'downward' edge to vertex.
var i = 0;
while (i < edges.Count)
{
var edgeEnumerator = _graph.GetEdgeEnumerator(edges[i].Neighbour);
edgeEnumerator.Reset();
while (edgeEnumerator.MoveNext())
{
if (edgeEnumerator.Neighbour == vertex)
{
removed++;
}
}
if (contractedFlags[edges[i].Neighbour])
{ // neighbour was already contracted, remove 'downward' edge and exclude it.
edgeEnumerator.MoveTo(vertex);
edgeEnumerator.Reset();
while (edgeEnumerator.MoveNext())
{
if (edgeEnumerator.Neighbour == edges[i].Neighbour)
{
removed++;
}
}
edges.RemoveAt(i);
}
else
{ // move to next edge.
i++;
}
}
// loop over all edge-pairs once.
for (var j = 1; j < edges.Count; j++)
{
var edge1 = edges[j];
float edge1Weight;
bool? edge1Direction;
Data.Contracted.Edges.ContractedEdgeDataSerializer.Deserialize(edge1.Data[0],
out edge1Weight, out edge1Direction);
var edge1CanMoveForward = edge1Direction == null || edge1Direction.Value;
var edge1CanMoveBackward = edge1Direction == null || !edge1Direction.Value;
// figure out what witness paths to calculate.
var forwardWitnesses = new bool[j];
var backwardWitnesses = new bool[j];
var targets = new List <uint>(j);
var targetWeights = new List <float>(j);
for (var k = 0; k < j; k++)
{
var edge2 = edges[k];
float edge2Weight;
bool? edge2Direction;
Data.Contracted.Edges.ContractedEdgeDataSerializer.Deserialize(edge2.Data[0],
out edge2Weight, out edge2Direction);
var edge2CanMoveForward = edge2Direction == null || edge2Direction.Value;
var edge2CanMoveBackward = edge2Direction == null || !edge2Direction.Value;
forwardWitnesses[k] = !(edge1CanMoveBackward && edge2CanMoveForward);
backwardWitnesses[k] = !(edge1CanMoveForward && edge2CanMoveBackward);
targets.Add(edge2.Neighbour);
targetWeights.Add(edge1Weight + edge2Weight);
}
// calculate all witness paths.
_witnessCalculator.Calculate(_graph.Graph, edge1.Neighbour, targets, targetWeights,
ref forwardWitnesses, ref backwardWitnesses, vertex);
// add contracted edges if needed.
for (var k = 0; k < j; k++)
{
var edge2 = edges[k];
var removedLocal = 0;
var addedLocal = 0;
if (!forwardWitnesses[k] && !backwardWitnesses[k])
{ // add bidirectional edge.
_graph.TryAddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
targetWeights[k], null, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
_graph.TryAddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
targetWeights[k], null, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
}
else if (!forwardWitnesses[k])
{ // add forward edge.
_graph.TryAddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
targetWeights[k], true, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
_graph.TryAddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
targetWeights[k], false, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
}
else if (!backwardWitnesses[k])
{ // add forward edge.
_graph.TryAddOrUpdateEdge(edge1.Neighbour, edge2.Neighbour,
targetWeights[k], false, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
_graph.TryAddOrUpdateEdge(edge2.Neighbour, edge1.Neighbour,
targetWeights[k], true, vertex, out addedLocal, out removedLocal);
added += addedLocal;
removed += removedLocal;
}
}
}
var contracted = 0;
_contractionCount.TryGetValue(vertex, out contracted);
var depth = 0;
_depth.TryGetValue(vertex, out depth);
return(this.DifferenceFactor * (added - removed) + (this.DepthFactor * depth) +
(this.ContractedFactor * contracted));
}