private void DeleteToken(ReteNode node, Token token)
{
if (node is Beta_Memory)
{
Beta_Memory b_node = (Beta_Memory)node;
b_node.Items.Remove(token);
}
else if (node is P_Node)
{
P_Node p_node = (P_Node)node;
//p_node.Items.Remove(tok);
// foamliu, 2008/11/23, for publishing (de)activation events.
p_node.RemoveToken(token);
}
else if (node is Negative_Node)
{
Negative_Node n_node = (Negative_Node)node;
n_node.Items.Remove(token);
}
else if (node is NCC_Node)
{
NCC_Node ncc_node = (NCC_Node)node;
ncc_node.Items.Remove(token);
}
}
/// <summary>
///
/// </summary>
/// <param name="current_node"></param>
/// <param name="condition">The NCC condition.</param>
/// <param name="conds_higher_up"></param>
/// <returns>Returns the NCC node</returns>
private ReteNode BuildOrShareNccNodes(ReteNode parent, NCCCondition condition, List <Condition> earlier_conds)
{
ReteNode bottom_of_subnetwork = BuildOrShareNetworkForConditions(parent, condition.SubConditions, earlier_conds);
// look for an existing node to share
foreach (ReteNode child in parent.Children)
{
NCC_Node ncc_child = child as NCC_Node;
if (null != ncc_child)
{
if (ncc_child.Partner.Parent == bottom_of_subnetwork)
{
return(child);
}
}
}
NCC_Node new_ncc_partner = new NCC_Node();
NCC_Partner_Node new_partner = new NCC_Partner_Node();
new_ncc_partner.Parent = parent;
// foamliu, 2008/11/21, more comments
// insert new at the tail of the list bottom_of_subnetwork.children, so the subnetwork comes first.
//
parent.Children.Add(new_ncc_partner);
new_partner.Parent = bottom_of_subnetwork;
bottom_of_subnetwork.Children.Insert(0, new_partner);
//new_ncc_partner.Children.Clear();
//new_partner.Children.Clear();
new_ncc_partner.Partner = new_partner;
new_partner.NCC_Node = new_ncc_partner;
//new_ncc_partner.Items.Clear();
//new_partner.New_Result_Buffer.Clear();
new_partner.Number_Of_Conjuncts = condition.SubConditions.Count;
// foamliu, 2008/11/21, more comments
// Note: we have to inform NCC node of existing matches before informing the partner, otherwise
// lots of matches would all get mixed together in the new-result-buffer.
//
UpdateNewNodeWithMatchesFromAbove(new_ncc_partner);
UpdateNewNodeWithMatchesFromAbove(new_partner);
return(new_ncc_partner);
}
private void NccNodeLeftActivation(NCC_Node node, Token t, WME w)
{
// build and store a new token, just like a beta memory would
Token new_token = Make_Token(node, t, w);
// insert new-token at the head of node.Items
node.Items.Insert(0, new_token);
// get initial ncc results
new_token.NCC_Results.Clear();
NCC_Partner_Node partner = node.Partner as NCC_Partner_Node;
//foreach (Token result in partner.New_Result_Buffer)
//{
// partner.New_Result_Buffer.Remove(result);
// new_token.NCC_Results.Insert(0, result);
// result.Owner = new_token;
//}
// foamliu, 2008/12/10, fix following error:
// System.InvalidOperationException : Collection was modified;
// enumeration operation may not execute.
while (partner.New_Result_Buffer.Count != 0)
{
Token result = partner.New_Result_Buffer[0];
partner.New_Result_Buffer.Remove(result);
new_token.NCC_Results.Insert(0, result);
result.Owner = new_token;
}
// if no ncc results, then inform children
if (0 == new_token.NCC_Results.Count)
{
foreach (ReteNode child in node.Children)
{
LeftActivation(child, new_token, null);
}
}
}
private void NccPartnerNodeLeftActivation(NCC_Partner_Node partner, Token t, WME w)
{
NCC_Node ncc_node = partner.NCC_Node as NCC_Node;
// build a result token <t,w>
Token new_result = Make_Token(partner, t, w);
// To find the appropriate owner token (into whose local memory we should put this
// result), first figure out what pair <owners-t,owners-w> would represent the owner. To
// do this, we start with the <t,w> pair we just received, and walk up the right number
// of links to find the pair that emerged from the join node for the preceding condition.
Token owners_t = t;
WME owners_w = w;
for (int i = 0; i < partner.Number_Of_Conjuncts; i++)
{
owners_w = owners_t.WME;
owners_t = owners_t.Parent;
}
// Look for this owner in the NCC node's memory. If we find it, add new-result to its
// local memory, and propagate (deletions) to the NCC node's children.
Token owner = ncc_node.FindOwner(owners_t, owners_w);
if (null != owner)
{
owner.NCC_Results.Add(new_result);
new_result.Owner = owner;
DeleteDescendentsOfToken(owner);
}
else
{
// We didn't find an appropriate owner token already in the NCC node's memory.
// This means the subnetwork has been activated for a new match for the preceding
// conditions, and this new result emerged from the bottom of the subnetwork, but
// the NCC node hasn't been activated for the new match yet. So, we just stuff the
// result in our temporary buffer.
partner.New_Result_Buffer.Insert(0, new_result);
}
}
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;
}