/// <summary>
/// find and return the maximum cyclic throughput cost
/// </summary>
/// <param name="sort">topological sorted enumerable of vertices</param>
/// <param name="graph">a delay graph</param>
/// <param name="registered">a hash set containing registered vertices</param>
/// <returns>a value representing maximum throughput cost of all cycles</returns>
internal static long FindMaxThroughputCostCore(IEnumerable <DelayGraphVertex> sort, DelayGraph graph, HashSet <DelayGraphVertex> registered)
{
long maxCycleCost = 0;
var table = new WaveFrontDictionary <Dictionary <DelayGraphVertex, long> >();
foreach (var v in sort)
{
var inEdges = graph.GetForwardInEdges(v);
var outEdges = graph.GetForwardOutEdges(v);
var feedbackInEdges = graph.GetFeedbackInEdges(v);
var feedbackOutEdges = graph.GetFeedbackOutEdges(v);
int myRefCount = outEdges.Count();
long cost = GetThroughputCost(v, registered);
Dictionary <DelayGraphVertex, long> myData = null;
// first, consume predecessor's wavefront data, if any
foreach (var e in inEdges)
{
var p = e.Source;
var data = table.Use(p);
if (data == null)
{
continue;
}
// copy data into myData
myData = GetOrMakeMyData(table, v, myRefCount, myData);
UpdateMaxData(myData, data);
}
if (cost > 0 && myData != null)
{
// incr all costs in myData by cost
foreach (var p in myData.Keys.ToList())
{
myData[p] += cost;
}
}
if (feedbackInEdges.Any())
{
// v is start of cycle - enter v into myData
myData = GetOrMakeMyData(table, v, myRefCount, myData);
myData[v] = cost;
}
if (myData == null)
{
continue;
}
// update max cycle cost
foreach (var e in feedbackOutEdges)
{
var p = e.Target;
long cycleCost;
if (myData.TryGetValue(p, out cycleCost) &&
cycleCost > maxCycleCost)
{
maxCycleCost = cycleCost;
}
}
}
return(maxCycleCost);
}