/*
* Copyright (C) 2001 - 2009 ScalAgent Distributed Technologies
* Copyright (C) 1996 - 2000 BULL
* Copyright (C) 1996 - 2000 INRIA
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA.
*/
package fr.dyade.aaa.agent;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import org.objectweb.util.monolog.api.BasicLevel;
/**
* <code>Agent</code> used to allow remote agent creation. Every agent
* server hosts a factory agent, they all use a predefined stamp identifier
* <code>AgentId.factoryId</code>. The factory must be able to create all
* types of objects, actually it is supposed that the corresponding classes
* can be reached.<p>
* The agent creation process involves the following steps
* <ul>
* <li>locally creating the <code>Agent</code> object in memory ;
* <li>serializing the agent state, building an <code>AgentCreateRequest</code>
* notification with the resulting string, sending it to the target
* Factory agent ;
* <li>the factory agent building the object in memory from the serialized
* image, and saving it into operational storage ;
* <li>the factory agent calling the initialize method.
* </ul>
* The AgentDeleteRequest class of notification follows a similar process
* to remotely delete agents.
*/
final class AgentFactory extends Agent {
/** define serialVersionUID for interoperability */
private static final long serialVersionUID = 1L;
/**
* Allocates a new <code>AgentFactory</code> agent.
* An <code>AgentFactory</code> agent must be created on every agent
* server the first time it runs.
*/
AgentFactory(AgentId factoryId) {
super("AgentFactory#" + AgentServer.getServerId(), true, factoryId);
}
/**
* Returns log topic for factory agent.
*/
protected String getLogTopic() {
return Debug.A3Agent + ".AgentFactory.#" + AgentServer.getServerId();
}
/**
* Gives this agent an opportunity to initialize after having been
* deployed, and each time it is loaded into memory. Loads the list of
* agents with a <code>fixed</code> field set to <code>true</code>.
*
* @param firstTime true when first called by the factory
*
* @exception Exception
* unspecialized exception
*/
protected void agentInitialize(boolean firstTime) throws Exception {
super.agentInitialize(firstTime);
}
/**
* Reacts to notifications ... .
*
* @param from agent sending notification
* @param not notification to react to
*
* @exception Exception
* unspecialized exception
*/
public void react(AgentId from, Notification not) throws Exception {
if (not instanceof AgentCreateRequest) {
AgentCreateRequest cnot = (AgentCreateRequest) not;
try {
// Restore the new agent state.
ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(cnot.agentState, 0,
cnot.agentState.length));
Agent ag = (Agent) ois.readObject();
try {
ois.close();
} catch (IOException exc) {}
// Initializes and creates the agent
// TODO: (ThreadEngine) Thread.currentThread() ...
AgentServer.engine.createAgent(cnot.deploy, ag);
if (logmon.isLoggable(BasicLevel.DEBUG))
logmon.log(BasicLevel.DEBUG,
"AgentFactory" + id + ", create Agent" + ag.id + " [" + ag.name + "]");
if (cnot.reply != null) {
AgentCreateReply reply = new AgentCreateReply(ag.getId());
reply.setContext(cnot.getContext());
sendTo(cnot.reply, reply);
}
} catch (Throwable error) {
// If there is an explicit reply request send it the
// ExceptionNotification to the requester else to the
// sender.
cnot.agentState = null;
logmon.log(BasicLevel.ERROR,
"AgentFactory" + id + ", can't create Agent" + cnot.deploy,
error);
ExceptionNotification excNot =
new ExceptionNotification(getId(), cnot, new AgentException(error));
excNot.setContext(cnot.getContext());
if (cnot.reply != null) {
sendTo(cnot.reply, excNot);
} else {
sendTo(from, excNot);
}
}
} else if (not instanceof AgentDeleteRequest) {
try {
// TODO: (ThreadEngine) Thread.currentThread() ...
AgentServer.engine.deleteAgent(from);
if (((AgentDeleteRequest) not).reply != null)
sendTo(((AgentDeleteRequest) not).reply,
new DeleteAck(from, ((AgentDeleteRequest) not).extraInformation));
} catch (Exception exc) {
if (((AgentDeleteRequest) not).reply != null)
sendTo(((AgentDeleteRequest) not).reply, new DeleteAck(from, exc));
}
} else {
try {
super.react(from, not);
} catch (Exception exc) {
sendTo(from,
new ExceptionNotification(getId(), not, exc));
}
}
}
}