/// <summary>
/// Contracts the given vertex.
/// </summary>
private void Contract()
{
var vertex = _vertexInfo.Vertex;
var enumerator = _graph.GetEdgeEnumerator();
// remove 'downward' edge to vertex.
var i = 0;
while (i < _vertexInfo.Count)
{
var edge = _vertexInfo[i];
_graph.RemoveEdge(edge.Neighbour, vertex);
i++;
}
// add shortcuts.
foreach (var s in _vertexInfo.Shortcuts)
{
var shortcut = s.Value;
var edge = s.Key;
var forwardMetric = _weightHandler.GetMetric(shortcut.Forward);
var backwardMetric = _weightHandler.GetMetric(shortcut.Backward);
if (forwardMetric > 0 && forwardMetric < float.MaxValue &&
backwardMetric > 0 && backwardMetric < float.MaxValue &&
System.Math.Abs(backwardMetric - forwardMetric) < HierarchyBuilder <float> .E)
{ // forward and backward and identical weights.
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex1, edge.Vertex2,
vertex, null, shortcut.Forward);
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex2, edge.Vertex1,
vertex, null, shortcut.Backward);
}
else
{
if (forwardMetric > 0 && forwardMetric < float.MaxValue)
{
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex1, edge.Vertex2,
vertex, true, shortcut.Forward);
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex2, edge.Vertex1,
vertex, false, shortcut.Forward);
}
if (backwardMetric > 0 && backwardMetric < float.MaxValue)
{
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex1, edge.Vertex2,
vertex, false, shortcut.Backward);
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex2, edge.Vertex1,
vertex, true, shortcut.Backward);
}
}
}
_contractedFlags[vertex] = true;
this.NotifyContracted(vertex);
}
public void TestRemoveEdge()
{
var graph = new DirectedMetaGraph(1, 1, 10);
// add and remove edge.
graph.AddEdge(0, 1, 10, 100);
Assert.AreEqual(0, graph.RemoveEdge(1, 0));
Assert.AreEqual(1, graph.RemoveEdge(0, 1));
graph = new DirectedMetaGraph(1, 1, 10);
// add and remove edge.
graph.AddEdge(0, 1, 10, 100);
graph.AddEdge(0, 1, 20, 200);
Assert.AreEqual(2, graph.GetEdgeEnumerator(0).Count);
Assert.AreEqual(0, graph.RemoveEdge(1, 0));
Assert.AreEqual(2, graph.RemoveEdge(0, 1));
Assert.AreEqual(0, graph.GetEdgeEnumerator(0).Count);
graph = new DirectedMetaGraph(1, 1, 10);
// add and remove edge.
graph.AddEdge(0, 1, 10, 100);
graph.AddEdge(0, 1, 20, 200);
Assert.AreEqual(2, graph.GetEdgeEnumerator(0).Count);
Assert.AreEqual(0, graph.RemoveEdge(1, 0));
Assert.AreEqual(2, graph.RemoveEdge(0, 1));
Assert.AreEqual(0, graph.GetEdgeEnumerator(0).Count);
graph = new DirectedMetaGraph(1, 1, 10);
// add and remove edge.
graph.AddEdge(0, 1, 10, 100);
graph.AddEdge(0, 2, 20, 200);
graph.RemoveEdge(0, 1);
var edges = graph.GetEdgeEnumerator(0);
Assert.IsNotNull(edges);
Assert.AreEqual(2, edges.First().Neighbour);
}
public void TestEdgeCount()
{
var graph = new DirectedMetaGraph(1, 1, 10);
// add edge.
graph.AddEdge(0, 1, 1, 100);
Assert.AreEqual(1, graph.EdgeCount);
graph = new DirectedMetaGraph(1, 1, 10);
// add edge.
graph.AddEdge(0, 1, 1, 100);
graph.AddEdge(0, 11001, 1, 100);
Assert.AreEqual(2, graph.EdgeCount);
graph.AddEdge(0, 11001, 2, 200);
Assert.AreEqual(3, graph.EdgeCount);
graph.RemoveEdge(0, 11001);
Assert.AreEqual(1, graph.EdgeCount);
graph.RemoveEdge(0, 1);
Assert.AreEqual(0, graph.EdgeCount);
}
public void TestSerialize()
{
var graph = new DirectedMetaGraph(1, 1, 10);
// add and compress.
graph.AddEdge(0, 1, 1, 100);
graph.Compress();
var expectedSize = 1 + 1 + 8 + 8 + 4 + 4 + // the header: two longs representing vertex and edge count and one int for edge size and one for vertex size.
graph.VertexCount * 2 * 4 + // the bytes for the vertex-index: 2 uint's.
graph.EdgeCount * 2 * 4 + // the bytes for the edges: one edge 1 uint.
4 + 4 + // the header for the meta-data: 2 uint for sizes.
graph.EdgeCount * 4; // the bytes for the edges: one edge 1 uint.
using (var stream = new System.IO.MemoryStream())
{
Assert.AreEqual(expectedSize, graph.Serialize(stream));
Assert.AreEqual(expectedSize, stream.Position);
}
// verify all edges.
var edges = graph.GetEdgeEnumerator(0);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(1, edges.First().Data[0]);
Assert.AreEqual(1, edges.First().Neighbour);
graph = new DirectedMetaGraph(1, 1, 10);
// add and compress.
graph.AddEdge(0, 1, 10, 100);
graph.AddEdge(1, 2, 20, 200);
graph.AddEdge(2, 3, 30, 300);
graph.AddEdge(3, 4, 40, 400);
graph.RemoveEdge(1, 2);
graph.Compress();
expectedSize = 1 + 1 + 8 + 8 + 4 + 4 + // the header: two longs representing vertex and edge count and one int for edge size and one for vertex size.
graph.VertexCount * 2 * 4 + // the bytes for the vertex-index: 2 uint's.
graph.EdgeCount * 2 * 4 + // the bytes for the edges: one edge 1 uint.
4 + 4 + // the header for the meta-data: 2 uint for sizes.
graph.EdgeCount * 4; // the bytes for the edges: one edge 1 uint.
using (var stream = new System.IO.MemoryStream())
{
Assert.AreEqual(expectedSize, graph.Serialize(stream));
Assert.AreEqual(expectedSize, stream.Position);
}
}
public static void AddOrUpdateEdge(this DirectedMetaGraph graph, uint vertex1, uint vertex2, float weight, bool?direction, uint contractedId)
{
uint data1 = ContractedEdgeDataSerializer.Serialize(weight, direction);
bool hasExistingEdge = false;
bool hasExistingEdgeOnlySameDirection = true;
if ((int)graph.UpdateEdge(vertex1, vertex2, (Func <uint[], bool>)(data =>
{
hasExistingEdge = true;
if (ContractedEdgeDataSerializer.HasDirection(data[0], direction))
{
return((double)weight < (double)ContractedEdgeDataSerializer.DeserializeWeight(data[0]));
}
hasExistingEdgeOnlySameDirection = false;
return(false);
}), new uint[1] {
data1
}, contractedId) != -1)
{
return;
}
if (!hasExistingEdge)
{
int num1 = (int)graph.AddEdge(vertex1, vertex2, data1, contractedId);
}
else
{
if (hasExistingEdgeOnlySameDirection)
{
return;
}
bool flag1 = false;
float weight1 = float.MaxValue;
uint metaData1 = uint.MaxValue;
bool flag2 = false;
float weight2 = float.MaxValue;
uint metaData2 = uint.MaxValue;
if (!direction.HasValue || direction.Value)
{
flag1 = true;
weight1 = weight;
metaData1 = contractedId;
}
if (!direction.HasValue || !direction.Value)
{
flag2 = true;
weight2 = weight;
metaData2 = contractedId;
}
DirectedMetaGraph.EdgeEnumerator edgeEnumerator = graph.GetEdgeEnumerator(vertex1);
while (edgeEnumerator.MoveNext())
{
if ((int)edgeEnumerator.Neighbour == (int)vertex2)
{
float weight3;
bool? direction1;
uint contractedId1;
ContractedEdgeDataSerializer.Deserialize(edgeEnumerator.Data0, edgeEnumerator.MetaData0, out weight3, out direction1, out contractedId1);
if ((!direction1.HasValue || direction1.Value) && (double)weight3 < (double)weight1)
{
weight1 = weight3;
flag1 = true;
metaData1 = contractedId1;
}
if ((!direction1.HasValue || !direction1.Value) && (double)weight3 < (double)weight2)
{
weight2 = weight3;
flag2 = true;
metaData2 = contractedId1;
}
}
}
graph.RemoveEdge(vertex1, vertex2);
if (flag1 & flag2 && (double)weight1 == (double)weight2 && (int)metaData1 == (int)metaData2)
{
int num2 = (int)graph.AddEdge(vertex1, vertex2, ContractedEdgeDataSerializer.Serialize(weight1, new bool?()), metaData1);
}
else
{
if (flag1)
{
int num3 = (int)graph.AddEdge(vertex1, vertex2, ContractedEdgeDataSerializer.Serialize(weight1, new bool?(true)), metaData1);
}
if (!flag2)
{
return;
}
int num4 = (int)graph.AddEdge(vertex1, vertex2, ContractedEdgeDataSerializer.Serialize(weight2, new bool?(false)), metaData2);
}
}
}
public void TestCompress()
{
var graph = new DirectedMetaGraph(1, 1, 10);
// add and compress.
graph.AddEdge(0, 1, 1, 100);
graph.Compress();
// verify all edges.
var edges = graph.GetEdgeEnumerator(0);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(1, edges.First().Data[0]);
Assert.AreEqual(1, edges.First().Neighbour);
graph = new DirectedMetaGraph(1, 1, 10);
// add and compress.
graph.AddEdge(0, 1, 10, 100);
graph.AddEdge(1, 2, 20, 200);
graph.AddEdge(2, 3, 30, 300);
graph.AddEdge(3, 4, 40, 400);
graph.RemoveEdge(1, 2);
// verify all edges.
edges = graph.GetEdgeEnumerator(0);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(10, edges.First().Data[0]);
Assert.AreEqual(100, edges.First().MetaData[0]);
Assert.AreEqual(1, edges.First().Neighbour);
edges = graph.GetEdgeEnumerator(1);
Assert.AreEqual(0, edges.Count());
edges = graph.GetEdgeEnumerator(2);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(30, edges.First().Data[0]);
Assert.AreEqual(300, edges.First().MetaData[0]);
Assert.AreEqual(3, edges.First().Neighbour);
edges = graph.GetEdgeEnumerator(3);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(40, edges.First().Data[0]);
Assert.AreEqual(400, edges.First().MetaData[0]);
Assert.AreEqual(4, edges.First().Neighbour);
// compress.
graph.Compress();
// verify all edges.
edges = graph.GetEdgeEnumerator(0);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(10, edges.First().Data[0]);
Assert.AreEqual(100, edges.First().MetaData[0]);
Assert.AreEqual(1, edges.First().Neighbour);
edges = graph.GetEdgeEnumerator(1);
Assert.AreEqual(0, edges.Count());
edges = graph.GetEdgeEnumerator(2);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(30, edges.First().Data[0]);
Assert.AreEqual(300, edges.First().MetaData[0]);
Assert.AreEqual(3, edges.First().Neighbour);
edges = graph.GetEdgeEnumerator(3);
Assert.AreEqual(1, edges.Count());
Assert.AreEqual(40, edges.First().Data[0]);
Assert.AreEqual(400, edges.First().MetaData[0]);
Assert.AreEqual(4, edges.First().Neighbour);
}
/// <summary>
/// Add or update edge.
/// </summary>
/// <returns></returns>
public static void AddOrUpdateEdge(this DirectedMetaGraph graph, uint vertex1, uint vertex2, float weight,
bool?direction, uint contractedId, float distance, float time)
{
var current = ContractedEdgeDataSerializer.Serialize(weight, direction);
var hasExistingEdge = false;
var hasExistingEdgeOnlySameDirection = true;
if (graph.UpdateEdge(vertex1, vertex2, (data) =>
{
hasExistingEdge = true;
if (ContractedEdgeDataSerializer.HasDirection(data[0], direction))
{ // has the same direction.
if (weight < ContractedEdgeDataSerializer.DeserializeWeight(data[0]))
{ // the weight is better, just update.
return(true);
}
return(false);
}
hasExistingEdgeOnlySameDirection = false;
return(false);
}, new uint[] { current }, ContractedEdgeDataSerializer.SerializeMetaAugmented(contractedId, distance, time)) != Constants.NO_EDGE)
{ // updating the edge succeeded.
return;
}
if (!hasExistingEdge)
{ // no edge exists yet.
graph.AddEdge(vertex1, vertex2, new uint[] { current }, ContractedEdgeDataSerializer.SerializeMetaAugmented(
contractedId, distance, time));
return;
}
else if (hasExistingEdgeOnlySameDirection)
{ // there is an edge already but it has a better weight.
return;
}
else
{ // see what's there and update if needed.
var forward = false;
var forwardWeight = float.MaxValue;
var forwardContractedId = uint.MaxValue;
var forwardTime = float.MaxValue;
var forwardDistance = float.MaxValue;
var backward = false;
var backwardWeight = float.MaxValue;
var backwardContractedId = uint.MaxValue;
var backwardTime = float.MaxValue;
var backwardDistance = float.MaxValue;
if (direction == null || direction.Value)
{
forward = true;
forwardWeight = weight;
forwardContractedId = contractedId;
forwardTime = time;
forwardDistance = distance;
}
if (direction == null || !direction.Value)
{
backward = true;
backwardWeight = weight;
backwardContractedId = contractedId;
backwardTime = time;
backwardDistance = distance;
}
var edgeEnumerator = graph.GetEdgeEnumerator(vertex1);
while (edgeEnumerator.MoveNext())
{
if (edgeEnumerator.Neighbour == vertex2)
{
float localWeight;
bool? localDirection;
ContractedEdgeDataSerializer.Deserialize(edgeEnumerator.Data0,
out localWeight, out localDirection);
uint localContractedId;
float localTime;
float localDistance;
ContractedEdgeDataSerializer.DeserializeMetaAgumented(edgeEnumerator.MetaData, out localContractedId, out localDistance, out localTime);
if (localDirection == null || localDirection.Value)
{
if (localWeight < forwardWeight)
{
forwardWeight = localWeight;
forward = true;
forwardContractedId = localContractedId;
forwardTime = localTime;
forwardDistance = localDistance;
}
}
if (localDirection == null || !localDirection.Value)
{
if (localWeight < backwardWeight)
{
backwardWeight = localWeight;
backward = true;
backwardContractedId = localContractedId;
backwardDistance = localDistance;
backwardTime = localTime;
}
}
}
}
graph.RemoveEdge(vertex1, vertex2);
if (forward && backward &&
forwardWeight == backwardWeight &&
forwardContractedId == backwardContractedId)
{ // add one bidirectional edge.
graph.AddEdge(vertex1, vertex2, forwardWeight, null, forwardContractedId, forwardDistance, forwardTime);
//graph.AddEdge(vertex1, vertex2,
// ContractedEdgeDataSerializer.Serialize(forwardWeight, null), forwardContractedId);
}
else
{ // add two unidirectional edges if needed.
if (forward)
{ // there is a forward edge.
graph.AddEdge(vertex1, vertex2, forwardWeight, true, forwardContractedId, forwardDistance, forwardTime);
//graph.AddEdge(vertex1, vertex2,
// ContractedEdgeDataSerializer.Serialize(forwardWeight, true), forwardContractedId);
}
if (backward)
{ // there is a backward edge.
graph.AddEdge(vertex1, vertex2, backwardWeight, false, backwardContractedId, backwardDistance, backwardTime);
}
}
}
}
/// <summary>
/// Contracts the given vertex.
/// </summary>
protected virtual void Contract()
{
var vertex = _vertexInfo.Vertex;
// remove 'downward' edge to vertex.
var i = 0;
while (i < _vertexInfo.Count)
{
var edge = _vertexInfo[i];
_graph.RemoveEdge(edge.Neighbour, vertex);
i++;
// TOOD: what to do when stuff is only removed, is nothing ok?
//_witnessQueue.Add(edge.Neighbour);
}
// add shortcuts.
foreach (var s in _vertexInfo.Shortcuts)
{
var shortcut = s.Value;
var edge = s.Key;
if (edge.Vertex1 == edge.Vertex2)
{ // TODO: figure out how this is possible, it shouldn't!
continue;
}
var forwardMetric = _weightHandler.GetMetric(shortcut.Forward);
var backwardMetric = _weightHandler.GetMetric(shortcut.Backward);
if (forwardMetric > 0 && forwardMetric < float.MaxValue &&
backwardMetric > 0 && backwardMetric < float.MaxValue &&
System.Math.Abs(backwardMetric - forwardMetric) < FastHierarchyBuilder <float> .E)
{ // forward and backward and identical weights.
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex1, edge.Vertex2,
vertex, null, shortcut.Forward);
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex2, edge.Vertex1,
vertex, null, shortcut.Backward);
_witnessQueue.Add(edge.Vertex1);
_witnessQueue.Add(edge.Vertex2);
}
else
{
if (forwardMetric > 0 && forwardMetric < float.MaxValue)
{
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex1, edge.Vertex2,
vertex, true, shortcut.Forward);
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex2, edge.Vertex1,
vertex, false, shortcut.Forward);
_witnessQueue.Add(edge.Vertex1);
_witnessQueue.Add(edge.Vertex2);
}
if (backwardMetric > 0 && backwardMetric < float.MaxValue)
{
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex1, edge.Vertex2,
vertex, false, shortcut.Backward);
_weightHandler.AddOrUpdateEdge(_graph, edge.Vertex2, edge.Vertex1,
vertex, true, shortcut.Backward);
_witnessQueue.Add(edge.Vertex1);
_witnessQueue.Add(edge.Vertex2);
}
}
}
_contractedFlags[vertex] = true;
this.NotifyContracted(vertex);
}
/// <summary>
/// Remove all witnessed edges.
/// </summary>
private void RemoveWitnessedEdges()
{
_logger.Log(TraceEventType.Information, "Removing witnessed edges...");
var witnessEdgeEnumerator = _witnessGraph.GetEdgeEnumerator();
var edgeEnumerator = _graph.GetEdgeEnumerator();
var edges = new List <MetaEdge>();
for (uint vertex = 0; vertex < _graph.VertexCount; vertex++)
{
// collect all relevant edges.
edges.Clear();
if (witnessEdgeEnumerator.MoveTo(vertex) &&
edgeEnumerator.MoveTo(vertex))
{
while (edgeEnumerator.MoveNext())
{
if (vertex < edgeEnumerator.Neighbour)
{ // only check in on directions, all edges are added twice initially.
edges.Add(edgeEnumerator.Current);
}
}
}
// check witness paths.
for (var i = 0; i < edges.Count; i++)
{
var edge = edges[0];
while (witnessEdgeEnumerator.MoveNext())
{
if (witnessEdgeEnumerator.Neighbour == edge.Neighbour)
{ // this edge is witnessed, figure out how.
var forwardWitnessWeight = DirectedGraphExtensions.FromData(witnessEdgeEnumerator.Data0);
var backwardWitnessWeight = DirectedGraphExtensions.FromData(witnessEdgeEnumerator.Data1);
var weightAndDir = _weightHandler.GetEdgeWeight(edge);
var weight = _weightHandler.GetMetric(weightAndDir.Weight);
var witnessed = false;
if (weightAndDir.Direction.F &&
weight > forwardWitnessWeight)
{ // witnessed in forward direction.
weightAndDir.Direction = new Dir(false, weightAndDir.Direction.B);
witnessed = true;
}
if (weightAndDir.Direction.B &&
weight > backwardWitnessWeight)
{ // witnessed in backward direction.
weightAndDir.Direction = new Dir(weightAndDir.Direction.F, false);
witnessed = true;
}
if (witnessed)
{ // edge was witnessed, do something.
// remove the edge (in both directions)
_graph.RemoveEdge(vertex, edge.Neighbour);
_graph.RemoveEdge(edge.Neighbour, vertex);
if (weightAndDir.Direction.B || weightAndDir.Direction.F)
{ // add it again if there is something relevant still left.
_weightHandler.AddEdge(_graph, vertex, edge.Neighbour, Constants.NO_VERTEX,
weightAndDir.Direction.AsNullableBool(), weightAndDir.Weight);
weightAndDir.Direction.Reverse();
_weightHandler.AddEdge(_graph, edge.Neighbour, vertex, Constants.NO_VERTEX,
weightAndDir.Direction.AsNullableBool(), weightAndDir.Weight);
}
}
}
}
}
}
}
/// <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]);
}
}
}
}
