// It returns -2 of obj is a dead end
// Returns n >= 0, if all paths starting at 'obj' end in objects already
// visited. 'n' is the index of a node in rootInfo.Path, which is the closest
// visited node found
// Returns -1 otherwise.
// This return value is used to detect dead ends.
int FindRoot(RootInfo rootInfo, PathTree pathTree, int obj)
{
if (rootInfo.DeadEnds.ContainsKey(obj))
{
return(-2);
}
int curval;
if (rootInfo.Visited.TryGetValue(obj, out curval))
{
// The object has already been visited
if (rootInfo.Path.Count >= curval)
{
return(rootInfo.Path.IndexOf(obj));
}
}
rootInfo.Visited [obj] = rootInfo.Path.Count;
int treePos = pathTree.GetObjectNode(obj);
if (treePos != -1)
{
// If this object already has partial paths to roots,
// reuse them.
FindTreeRoot(rootInfo.Path, rootInfo.Roots, pathTree, treePos);
return(-1);
}
rootInfo.Path.Add(obj);
bool hasrefs = false;
int findresult = int.MaxValue;
foreach (int oref in GetReferencers(obj))
{
hasrefs = true;
if (!rootInfo.BaseObjects.ContainsKey(oref))
{
int fr = FindRoot(rootInfo, pathTree, oref);
if (fr != -2 && fr < findresult)
{
findresult = fr;
}
}
}
if (!hasrefs)
{
// A root
rootInfo.Visited.Remove(obj);
RegisterPath(rootInfo.Roots, rootInfo.Path, obj);
findresult = -1;
}
rootInfo.Path.RemoveAt(rootInfo.Path.Count - 1);
// If all children paths end in nodes already visited, it means that it is a dead end.
if (findresult >= rootInfo.Path.Count)
{
rootInfo.DeadEnds [obj] = obj;
// Console.WriteLine ("de: " + findresult);
}
return(findresult);
}
