SystemMessage.java

/**
 * Copyright (c) 2007-2009 Alysson Bessani, Eduardo Alchieri, Paulo Sousa, and the authors indicated in the @author tags
 * 
 * This file is part of SMaRt.
 * 
 * SMaRt 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, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * SMaRt 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 SMaRt.  If not, see <http://www.gnu.org/licenses/>.
 */

package bftsmart.communication;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

/**
 * This is the super-class for all other kinds of messages created by JBP
 * 
 */

public abstract class SystemMessage implements Externalizable {

    protected int sender; // ID of the process which sent the message
    public transient boolean authenticated; // set to TRUE if the message was received
                                            // with a (valid) mac, FALSE if no mac was given
                                            // note that if the message arrives with an
                                            // invalid MAC, it won't be delivered

    /**
     * Creates a new instance of SystemMessage
     */
    public SystemMessage(){}
    
    /**
     * Creates a new instance of SystemMessage
     * @param sender ID of the process which sent the message
     */
    public SystemMessage(int sender){
        this.sender = sender;
    }
    
    /**
     * Returns the ID of the process which sent the message
     * @return
     */
    public final int getSender() {
        return sender;
    }

    // This methods implement the Externalizable interface
    @Override
    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeInt(sender);
    }
    
    @Override
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        sender = in.readInt();
    }
}