/*
* Copyright 2007-2009 非也
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation。
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses.
*/
package org.fireflow.kernel.impl;
import java.util.ArrayList;
import java.util.List;
import org.fireflow.kernel.ILoopInstance;
import org.fireflow.kernel.INodeInstance;
import org.fireflow.kernel.IToken;
import org.fireflow.kernel.KernelException;
import org.fireflow.kernel.event.EdgeInstanceEvent;
import org.fireflow.kernel.event.IEdgeInstanceEventListener;
import org.fireflow.kernel.plugin.IKernelExtension;
import org.fireflow.kernel.plugin.IPlugable;
import org.fireflow.model.net.Loop;
/**
*
* @author 非也
* @version 1.0
* Created on Mar 18, 2009
*/
public class LoopInstance extends EdgeInstance implements ILoopInstance ,IPlugable{
public transient static final String Extension_Target_Name = "org.fireflow.kernel.LoopInstance";
public transient static List<String> Extension_Point_Names = new ArrayList<String>();
public transient static final String Extension_Point_LoopInstanceEventListener = "LoopInstanceEventListener";
static {
Extension_Point_Names.add(Extension_Point_LoopInstanceEventListener);
}
private transient Loop loop = null;
public LoopInstance(Loop lp){
this.loop = lp;
}
public String getId() {
return loop.getId();
}
public int getWeight() {
if (weight==0){
if (leavingNodeInstance instanceof SynchronizerInstance){
weight=((SynchronizerInstance)this.leavingNodeInstance).getVolume();
//如果后继结点是同步器节点，那么权值=后继结点的容量（这样就可以直接执行后继activity了）
}else if (leavingNodeInstance instanceof StartNodeInstance){
weight = ((StartNodeInstance)this.leavingNodeInstance).getVolume();
//如果后继结点是开始节点，那么权值=开始节点的容量
}else if (leavingNodeInstance instanceof EndNodeInstance){
weight = ((EndNodeInstance)this.leavingNodeInstance).getVolume();
//如果后继结点是结束节点，那么权值=结束节点的容量
}
}
return weight;
}
/* (non-Javadoc)
* @see org.fireflow.kernel.IEdgeInstance#take(org.fireflow.kernel.IToken)
*/
public boolean take(IToken token) throws KernelException {
boolean oldAlive = token.isAlive();
EdgeInstanceEvent e = new EdgeInstanceEvent(this);
e.setToken(token);
e.setEventType(EdgeInstanceEvent.ON_TAKING_THE_TOKEN);
for (int i = 0; this.eventListeners != null && i < this.eventListeners.size(); i++) {
IEdgeInstanceEventListener listener = this.eventListeners.get(i);
listener.onEdgeInstanceEventFired(e);
}
boolean newAlive = token.isAlive();
if (!newAlive){//循环条件不满足，则恢复token的alive标示
token.setAlive(oldAlive);
return newAlive;
}else{//否则流转到下一个节点
INodeInstance nodeInst = this.getLeavingNodeInstance();
token.setValue(this.getWeight());
nodeInst.fire(token);//触发同步器节点
return newAlive;
}
}
public Loop getLoop() {
return loop;
}
public void setLoop(Loop arg0){
this.loop = arg0;
}
@SuppressWarnings("static-access")
public String getExtensionTargetName() {
return this.Extension_Target_Name;
}
@SuppressWarnings("static-access")
public List<String> getExtensionPointNames() {
return this.Extension_Point_Names;
}
public void registExtension(IKernelExtension extension) throws RuntimeException {
if (!Extension_Target_Name.equals(extension.getExtentionTargetName())) {
return;
}
if (Extension_Point_LoopInstanceEventListener.equals(extension.getExtentionPointName())) {
if (extension instanceof IEdgeInstanceEventListener) {
this.eventListeners.add((IEdgeInstanceEventListener) extension);
} else {
throw new RuntimeException("Error:When construct the TransitionInstance,the extension MUST be a instance of ITransitionInstanceEventListener");
}
}
}
}