source: proiecte/ptvs/src/vnsim/applications/vitp/peer/Peer.java @ 31

/************************************************************************************
 * Copyright (C) 2008 by Politehnica University of Bucharest and Rutgers University
 * All rights reserved.
 * Refer to LICENSE for terms and conditions of use.
 ***********************************************************************************/
package vnsim.applications.vitp.peer;

import vnsim.applications.vitp.routing.*;
import vnsim.applications.vitp.services.*;
import vnsim.applications.vitp.ui.*;
import vnsim.applications.vitp.utils.*;

public class Peer {

        //a peer module, comunicating with a routing module (the layer below), 
        //a user interface (the layer above) and a services module, in order to 
        //properly serve VITP Requests

        public RoutingModule routingModule;
        private MessageProcessServices servicesModule;
        private UserInterface userInterfaceModule;

        public void attachModules(RoutingModule r, MessageProcessServices s, UserInterface ui){
                this.routingModule=r;
                this.servicesModule=s;
                this.userInterfaceModule=ui;
        }
        
        public boolean postMessageFromBelow(VITPMessage msg){
                //method to be called by the module below, in order to send a message
                //to this peer; returns true if the peer properly deals with the packet,
                //false otherwise

                //this peer has received a packet; there are several possibilities;

                //it could be a POST request or a reply; in that case, since it was 
                //delivered to me by the routing layer, it is for the local node, 
                //so it has to be delivered to the user interface

                //finally, it could be a GET request, in which case I have to try and satisfy
                //it, by using the services

                if(msg.isReply()) {
                        return userInterfaceModule.postMessage(msg);
                }
                if(msg.isRequest()) {
                        try{
                                VITPRequest req=(VITPRequest)msg;
                                if(req.isPost()) {
                                        //return userInterfaceModule.postMessage(msg);
                                        userInterfaceModule.postMessage(msg);
                                        return routingModule.postMessageFromAbove(msg);
                                } else {
                                        if(req.isGet()){
                                                //use the services to try and satisfy this request
                                                VITPMessage mes=servicesModule.satisfy(req);
                                                return routingModule.postMessageFromAbove(mes);
                                        } else {
                                                System.out.println("ERROR! Unknown method:="+req.getMethod());
                                                return false;
                                        }
                                }
                        } catch (Exception ex){
                                System.out.println("PEER_EXCEPTION:"+ex.toString());
                                ex.printStackTrace();
                                return false;
                        }
                }
                System.out.println("Discarding! Peer.postMessage could not decide on the following message:"+msg);
                System.out.println("***");
                return false;
        }

        public boolean postMessageFromAbove(VITPMessage msg){
                //method to be called by the module above, in order to send a message
                //to this peer; returns true if the peer properly deals with the packet,
                //false otherwise
        
                //this peer has received a message from the user interface; it should be
                //a request
                if(msg.isRequest()) {
                        msg.setMsgIdInval(); //invalidate the id; thus, the routing module will
                                                        //see the invalid id, and provide it a new one
                        return routingModule.postMessageFromAbove(msg);
                }
                return false;
        }
}