public WalkingVertex <TKey, TValue> CreateSecondPassVertex()
{
CheckNotSealed();
SecondPass = new WalkingVertex <TKey, TValue>(DependencyVertex, this);
return(SecondPass);
}
public void AddOutgoing(WalkingVertex <TKey, TValue> outgoingVertex)
{
CheckNotSealed();
_outgoing.Add(outgoingVertex);
outgoingVertex.IncomingCount++;
}
private static void CheckForLoop(WalkingVertex <TKey, TValue> vertex, Stack <WalkingVertex <TKey, TValue> > stackP, Stack <WalkingVertex <TKey, TValue> > stackS, ref int counter, ref int loopNumber)
{
vertex.Index = counter++;
stackP.Push(vertex);
stackS.Push(vertex);
foreach (var child in vertex.Outgoing)
{
if (child.Index == -1)
{
CheckForLoop(child, stackP, stackS, ref counter, ref loopNumber);
}
else if (child.LoopNumber == -1)
{
while (stackP.Peek().Index > child.Index)
{
stackP.Pop();
}
}
}
if (stackP.Count > 0 && vertex == stackP.Peek())
{
if (SetLoopNumber(vertex, stackS, loopNumber))
{
loopNumber++;
}
stackP.Pop();
}
}
private static ImmutableArray <WalkingVertex <TKey, TValue> > CreateWalkingGraph(ImmutableArray <DependencyVertex <TKey, TValue> > snapshot, ImmutableArray <DependencyVertex <TKey, TValue> > changedVertices)
{
var analysisGraph = ImmutableArray <WalkingVertex <TKey, TValue> > .Empty;
var nodesByVertexIndex = new Dictionary <int, WalkingVertex <TKey, TValue> >();
foreach (var vertex in changedVertices)
{
var node = new WalkingVertex <TKey, TValue>(snapshot[vertex.Index]);
analysisGraph = analysisGraph.Add(node);
nodesByVertexIndex[vertex.Index] = node;
}
var queue = new Queue <WalkingVertex <TKey, TValue> >(analysisGraph);
while (queue.Count > 0)
{
var node = queue.Dequeue();
foreach (var outgoingIndex in node.DependencyVertex.Outgoing)
{
if (!nodesByVertexIndex.TryGetValue(outgoingIndex, out var outgoingNode))
{
outgoingNode = new WalkingVertex <TKey, TValue>(snapshot[outgoingIndex]);
analysisGraph = analysisGraph.Add(outgoingNode);
nodesByVertexIndex[outgoingIndex] = outgoingNode;
queue.Enqueue(outgoingNode);
}
node.AddOutgoing(outgoingNode);
}
}
return(analysisGraph);
}
public WalkingVertex(DependencyVertex <TKey, TValue> vertex, WalkingVertex <TKey, TValue> firstPass = null)
{
DependencyVertex = vertex;
FirstPass = firstPass;
Index = -1;
LoopNumber = firstPass?.LoopNumber ?? -1;
_outgoing = new List <WalkingVertex <TKey, TValue> >();
}
private static void RemoveLoopEdges(WalkingVertex <TKey, TValue> vertex, ref int counter)
{
vertex.Index = counter++;
for (var i = vertex.Outgoing.Count - 1; i >= 0; i--)
{
var outgoing = vertex.Outgoing[i];
if (outgoing.Index == -1)
{
RemoveLoopEdges(outgoing, ref counter);
}
else if (outgoing.Index < vertex.Index)
{
vertex.RemoveOutgoingAt(i);
}
}
}
private static bool SetLoopNumber(WalkingVertex <TKey, TValue> vertex, Stack <WalkingVertex <TKey, TValue> > stackS, int loopIndex)
{
var count = 0;
WalkingVertex <TKey, TValue> loopVertex;
do
{
loopVertex = stackS.Pop();
loopVertex.LoopNumber = loopIndex;
count++;
} while (loopVertex != vertex);
if (count != 1)
{
return(true);
}
vertex.LoopNumber = -2;
return(false);
}
