private ReteNode BuildOrShareJoinNode(ReteNode parent, Alpha_Memory am, List <Test_At_Join_Node> tests)
{
// look for an existing node to share
foreach (ReteNode child in parent.Children)
{
Join_Node j_node = child as Join_Node;
if (null != j_node)
{
if (j_node.Amem.Equals(am) && Test_At_Join_Node.IsListEquals(j_node.Tests, tests))
{
return(child);
}
}
}
Join_Node new_j_node = new Join_Node();
new_j_node.Parent = parent;
// insert new at the head of the list parent.children
parent.Children.Insert(0, new_j_node);
// foamliu, 2008/11/29, new object, no need.
//new_j_node.Children.Clear();
new_j_node.Tests = tests;
new_j_node.Amem = am;
am.Successors.Insert(0, new_j_node);
return(new_j_node);
}
public void JoinNodeLeftActivation(Join_Node node, Token t)
{
foreach (WME w in node.Amem.Items)
{
if (PerformJoinTests(node.Tests, t, w))
{
foreach (ReteNode child in node.Children)
{
//if (child is Beta_Memory)
//{
// // left-activation (child, t, w)
// Beta_Memory_Left_Activation((Beta_Memory)child, t, w);
//}
//else if (child is P_Node)
//{
// P_Node_Left_Activation((P_Node)child, t, w);
//}
// foamliu, 2008/08/26, use a general method here
// to support both join-node and negative-node.
// foamliu, 2008/11/21, and ncc-node and ncc-partner-node.
//
LeftActivation(child, t, w);
}
}
}
}
public void JoinNodeRightActivation(Join_Node node, WME w)
{
// parent is the beta memory node
Beta_Memory parent = (Beta_Memory)node.Parent;
foreach (Token t in parent.Items)
{
//if (t is DummyTopToken)
//{
// Handle_Dummy_Top_Token(node, w);
// continue;
//}
if (PerformJoinTests(node.Tests, t, w))
{
foreach (ReteNode child in node.Children)
{
//if (child is Beta_Memory)
//{
// // left-activation (child, t, w)
// Beta_Memory_Left_Activation((Beta_Memory)child, t, w);
//}
//else if (child is P_Node)
//{
// P_Node_Left_Activation((P_Node)child, t, w);
//}
// foamliu, 2008/08/26, use a general method here
// to support both join-node and negative-node.
LeftActivation(child, t, w);
}
}
}
}
private void HandleDummyTopToken(Join_Node j_node, WME w)
{
foreach (ReteNode j_child in j_node.Children)
{
Beta_Memory b_node = j_child as Beta_Memory;
if (null != b_node)
{
Token new_token = new Token();
new_token.WME = w;
b_node.Items.Insert(0, new_token);
// for each child in node.children do left-activation (child, new-token)
foreach (ReteNode b_child in b_node.Children)
{
JoinNodeLeftActivation((Join_Node)b_child, new_token);
}
}
}
}
private void DeleteNodeAndAnyUnusedAncestors(ReteNode node)
{
// foamliu, 2008/11/20, for NCC nodes, delete the partner node too
NCC_Node ncc_node = node as NCC_Node;
if (null != ncc_node)
{
DeleteNodeAndAnyUnusedAncestors(ncc_node.Partner);
}
// foamliu, 2008/11/20, clean up any tokens the node contains
switch (node.Type)
{
case ReteNodeType.Beta_Memory:
Beta_Memory b_node = (Beta_Memory)node;
while (b_node.Items.Count != 0 && !(b_node.Items[0] is Dummy_Top_Token))
{
DeleteTokenAndDescendents(b_node.Items[0]);
}
break;
case ReteNodeType.Negative_Node:
Negative_Node n_node = (Negative_Node)node;
while (n_node.Items.Count != 0)
{
DeleteTokenAndDescendents(n_node.Items[0]);
}
break;
case ReteNodeType.NCC_Node:
while (ncc_node.Items.Count != 0)
{
DeleteTokenAndDescendents(ncc_node.Items[0]);
}
break;
default:
break;
}
NCC_Partner_Node par_node = node as NCC_Partner_Node;
if (null != par_node)
{
while (par_node.New_Result_Buffer.Count != 0)
{
DeleteTokenAndDescendents(par_node.New_Result_Buffer[0]);
}
}
// foamliu, 2008/11/20, for join and negative nodes, deal with the alpha memory
//
Join_Node j_node = node as Join_Node;
if (null != j_node)
{
j_node.Amem.Successors.Remove(node);
if (j_node.Amem.Successors.Count == 0)
{
DeleteAlphaMemory(j_node.Amem);
}
}
else if (node.Type == ReteNodeType.Negative_Node)
{
Negative_Node n_node = (Negative_Node)node;
n_node.Amem.Successors.Remove(node);
if (n_node.Amem.Successors.Count == 0)
{
DeleteAlphaMemory(n_node.Amem);
}
}
// foamliu, 2008/11/21, fix a null-ref bug.
if (null != node.Parent)
{
node.Parent.Children.Remove(node);
if (node.Parent.Children.Count == 0)
{
DeleteNodeAndAnyUnusedAncestors(node.Parent);
}
}
node = null;
}
