public DFSTEdge(DFSTNode start, DFSTNode end)
{
base();
this.set_Start(start);
this.set_End(end);
return;
}
private void DFSBuild(DFSTNode currentNode)
{
dummyVar0 = this.traversedNodes.Add(currentNode);
dummyVar1 = this.currentPath.Add(currentNode);
V_0 = LogicalFlowUtilities.GetTraversableSuccessors(currentNode.get_Construct()).GetEnumerator();
try
{
while (V_0.MoveNext())
{
V_1 = V_0.get_Current();
if (!this.constructToNodeMap.TryGetValue(V_1, out V_2))
{
continue;
}
if (this.traversedNodes.Contains(V_2))
{
if (!this.currentPath.Contains(V_2))
{
if (!this.IsAncestor(V_2, currentNode))
{
dummyVar10 = V_2.get_CrossEdgePredecessors().Add(currentNode);
dummyVar11 = currentNode.get_CrossEdgeSuccessors().Add(V_2);
dummyVar12 = this.theTree.get_CrossEdges().Add(new DFSTEdge(currentNode, V_2));
}
else
{
dummyVar7 = V_2.get_ForwardEdgePredecessors().Add(currentNode);
dummyVar8 = currentNode.get_ForwardEdgeSucessors().Add(V_2);
dummyVar9 = this.theTree.get_ForwardEdges().Add(new DFSTEdge(currentNode, V_2));
}
}
else
{
dummyVar4 = V_2.get_BackEdgePredecessors().Add(currentNode);
dummyVar5 = currentNode.get_BackEdgeSuccessors().Add(V_2);
dummyVar6 = this.theTree.get_BackEdges().Add(new DFSTEdge(currentNode, V_2));
}
}
else
{
V_2.set_Predecessor(currentNode);
dummyVar2 = currentNode.get_TreeEdgeSuccessors().Add(V_2);
dummyVar3 = this.theTree.get_TreeEdges().Add(new DFSTEdge(currentNode, V_2));
this.DFSBuild(V_2);
}
}
}
finally
{
if (V_0 != null)
{
V_0.Dispose();
}
}
dummyVar13 = this.currentPath.Remove(currentNode);
this.theTree.get_ReversePostOrder().Add(currentNode);
return;
}
/// <summary>
/// Recursively traverses the nodes and adds them to the tree. Also determines the type of each edge.
/// </summary>
/// <param name="currentNode"></param>
private void DFSBuild(DFSTNode currentNode)
{
traversedNodes.Add(currentNode);
//The current path is the set of all nodes on the DFS tree path from the root to the current node.
currentPath.Add(currentNode);
foreach (ISingleEntrySubGraph successorConstruct in LogicalFlowUtilities.GetTraversableSuccessors(currentNode.Construct))
{
DFSTNode successor;
if (!constructToNodeMap.TryGetValue(successorConstruct, out successor))
{
//Special case for interval constructs
continue;
}
if (!traversedNodes.Contains(successor))
{
//If the successor is not traversed then the edge between the two nodes is a tree edge.
successor.Predecessor = currentNode;
currentNode.TreeEdgeSuccessors.Add(successor);
theTree.TreeEdges.Add(new DFSTEdge(currentNode, successor));
//We continue the build from this successor.
DFSBuild(successor);
}
else if (currentPath.Contains(successor))
{
//If the successor is traversed and is on the current path then the edge between the nodes is a back edge.
successor.BackEdgePredecessors.Add(currentNode);
currentNode.BackEdgeSuccessors.Add(successor);
theTree.BackEdges.Add(new DFSTEdge(currentNode, successor));
}
else if (IsAncestor(successor, currentNode))
{
//If the successor is traversed and the current node is its ancestor, then the edge is a forward edge.
successor.ForwardEdgePredecessors.Add(currentNode);
currentNode.ForwardEdgeSucessors.Add(successor);
theTree.ForwardEdges.Add(new DFSTEdge(currentNode, successor));
}
else
{
//Otherwise the edge between the nodes is a cross edge.
successor.CrossEdgePredecessors.Add(currentNode);
currentNode.CrossEdgeSuccessors.Add(successor);
theTree.CrossEdges.Add(new DFSTEdge(currentNode, successor));
}
}
currentPath.Remove(currentNode);
//Adding the nodes in post order.
theTree.ReversePostOrder.Add(currentNode);
}
private bool IsAncestor(DFSTNode node, DFSTNode supposedAncestor)
{
V_0 = (DFSTNode)node.get_Predecessor();
while (V_0 != null)
{
if (V_0 == supposedAncestor)
{
return(true);
}
V_0 = (DFSTNode)V_0.get_Predecessor();
}
return(false);
}
/// <summary>
/// Builds the tree starting from the graph's entry.
/// </summary>
private void TraverseAndBuildTree()
{
theTree = new DFSTree(constructToNodeMap);
DFSTNode root = constructToNodeMap[this.entry];
DFSBuild(root);
//Since the nodes were added in postorder we must reverse them to get ... the reverse postorder.
theTree.ReversePostOrder.Reverse();
theTree.ReversePostOrder.TrimExcess();
AssignOrderIndices();
}
/// <summary>
/// Determines whether <paramref name="supposedAncestor"/> is on the tree path from the root to <paramref name="node"/>
/// </summary>
/// <param name="node"></param>
/// <param name="supposedAncestor"></param>
/// <returns></returns>
private bool IsAncestor(DFSTNode node, DFSTNode supposedAncestor)
{
DFSTNode currentAncestor = (DFSTNode)node.Predecessor;
while (currentAncestor != null)
{
if (currentAncestor == supposedAncestor)
{
return(true);
}
currentAncestor = (DFSTNode)currentAncestor.Predecessor;
}
return(false);
}
public List <DFSTNode> GetPath(DFSTNode ancestorNode, DFSTNode descenderNode)
{
V_0 = new List <DFSTNode>();
V_1 = descenderNode;
while (V_1 != null && V_1 != ancestorNode)
{
V_0.Add(V_1);
V_1 = (DFSTNode)V_1.get_Predecessor();
}
if (V_1 == null)
{
throw new Exception("No path between the two nodes.");
}
V_0.Add(V_1);
V_0.Reverse();
return(V_0);
}
/// <summary>
/// Gets the path in the tree between two nodes. The <paramref name="ancestorNode"/>
/// must be on the path from the root to the <paramref name="descenderNode"/>.
/// </summary>
/// <param name="ancestorNode"></param>
/// <param name="descenderNode"></param>
/// <returns></returns>
public List <DFSTNode> GetPath(DFSTNode ancestorNode, DFSTNode descenderNode)
{
List <DFSTNode> path = new List <DFSTNode>();
DFSTNode currentNodeOnPath = descenderNode;
while (currentNodeOnPath != null && currentNodeOnPath != ancestorNode)
{
path.Add(currentNodeOnPath);
currentNodeOnPath = (DFSTNode)currentNodeOnPath.Predecessor;
}
if (currentNodeOnPath != null)
{
path.Add(currentNodeOnPath);
}
else
{
//sanity check
throw new Exception("No path between the two nodes.");
}
path.Reverse();
return(path);
}
public DFSTEdge(DFSTNode start, DFSTNode end)
{
Start = start;
End = end;
}