internal PeriodTraverseState(
DelayGraphVertex vertex,
int delayReturned,
Queue <DelayGraphEdge> unfinishedEdges,
int maxAmongOutgoingEdges)
{
Vertex = vertex;
DelayReturned = delayReturned;
UnfinishedEdges = unfinishedEdges;
MaxAmongOutgoingEdges = maxAmongOutgoingEdges;
StateWaitingOn = null;
}
private int TraverseForwardCalculatingPeriodIterative2(
DelayGraphVertex startingVertex, out bool foundCycle)
{
Stack <PeriodTraverseState> stack = new Stack <PeriodTraverseState>();
stack.Push(new PeriodTraverseState(startingVertex));
PeriodTraverseState currentState = null;
foundCycle = false;
while (stack.Any())
{
currentState = stack.Peek();
int alreadyComputedDelay = 0;
if (ComputedDelays.TryGetValue(currentState.Vertex, out alreadyComputedDelay)) // put in for reconvergent paths
{
currentState.DelayReturned = alreadyComputedDelay;
stack.Pop();
continue;
}
if (currentState.StateWaitingOn == null) // this state is used here just to tell if we are coming along here b/c we need to attend to unfinished business where we might have already set 'visited'
{
if (Visiting.Contains(currentState.Vertex)) // stop recursing if we're going along a loop, but still add up the delays of the loop
{
currentState.DelayReturned = 0;
foundCycle = true;
stack.Pop();
continue;
}
Visiting.Add(currentState.Vertex);
}
if (currentState.UnfinishedEdges == null)
{
IEnumerable <DelayGraphEdge> foundOutgoingEdges;
if (Graph.TryGetOutEdges(currentState.Vertex, out foundOutgoingEdges))
{
currentState.UnfinishedEdges = new Queue <DelayGraphEdge>(foundOutgoingEdges);
}
}
bool done = true;
while (currentState.UnfinishedEdges != null && currentState.UnfinishedEdges.Any())
{
var outEdge = currentState.UnfinishedEdges.Peek();
int delayOnThisPath;
if (Registered(outEdge.Target)) // stop recursing when we hit a register
{
delayOnThisPath = outEdge.Delay;
}
else if (Visiting.Contains(outEdge.Target))
{
// found a cycle
foundCycle = true;
delayOnThisPath = outEdge.Delay;
}
else
{
if (currentState.StateWaitingOn == null)
{
currentState.StateWaitingOn = new PeriodTraverseState(outEdge.Target);
stack.Push(currentState.StateWaitingOn);
done = false; // need to process what we just pushed
break;
}
else
{
delayOnThisPath = outEdge.Delay + currentState.StateWaitingOn.DelayReturned;
currentState.StateWaitingOn = null;
}
}
currentState.UnfinishedEdges.Dequeue();
currentState.MaxAmongOutgoingEdges = Math.Max(currentState.MaxAmongOutgoingEdges, delayOnThisPath);
}
if (done)
{
ComputedDelays[currentState.Vertex] = currentState.MaxAmongOutgoingEdges;
currentState.DelayReturned = currentState.MaxAmongOutgoingEdges;
Visiting.Remove(currentState.Vertex);
stack.Pop();
}
}
return(currentState.DelayReturned);
}