/// <summary>
/// Returns the number of references to the node represented by 'nodeIndex'. The count will max out at 255 (but not wrap)
/// </summary>
public byte RefCount(NodeIndex nodeIndex)
{
if (m_refCounts == null)
{
// Do the expensive operation of walking the graph collecting refcounts.
m_refCounts = new byte[(int)m_graph.NodeIndexLimit];
m_refCounts[(int)m_graph.RootIndex] = 1;
var nodeStorage = m_graph.AllocNodeStorage(); // Need for enumeration below.
var nodesToVisit = new Queue <NodeIndex>(1000);
nodesToVisit.Enqueue(m_graph.RootIndex);
while (nodesToVisit.Count > 0)
{
var curNodeIndex = nodesToVisit.Dequeue();
var curNode = m_graph.GetNode(curNodeIndex, nodeStorage);
for (var childIndex = curNode.GetFirstChildIndex(); childIndex != NodeIndex.Invalid; childIndex = curNode.GetNextChildIndex())
{
byte val = m_refCounts[(int)childIndex];
if (val == 0)
{
nodesToVisit.Enqueue(childIndex);
}
val++; if (val == 0)
{
val = 255; // increment, but never wrap-around.
}
m_refCounts[(int)childIndex] = val;
}
}
var singletons = 0;
var orphans = 0;
var max = 0;
var totalRefs = 0.0;
foreach (var refCount in m_refCounts)
{
totalRefs += refCount;
if (refCount == 1)
{
singletons++;
}
else if (refCount == 0)
{
orphans++;
}
else if (refCount == 255)
{
max++;
}
}
Trace.WriteLine("Total = " + m_refCounts.Length);
Trace.WriteLine("Singletons = " + singletons);
Trace.WriteLine("Orphans = " + orphans);
Trace.WriteLine("Max = " + max);
Trace.WriteLine("Average = " + (totalRefs / m_refCounts.Length).ToString("f2"));
Trace.WriteLine("");
}
return(m_refCounts[(int)nodeIndex]);
}
