meerkat-java/destributed-key-generation/src/main/java/Communication/Network.java

package Communication;

import com.google.protobuf.InvalidProtocolBufferException;
import com.google.protobuf.Message;
import meerkat.protobuf.DKGMessages.*;
import java.util.Queue;
import java.util.concurrent.ArrayBlockingQueue;
/**
 * Created by Tzlil on 2/7/2016.
 * JointFeldamn protocol assumes all parties can communicate throw broadcast chanel
 * and private chanel (for each pair)
 * this class simulates it
 */
public class Network {

    protected final User[] users;
    protected final int n;
    protected final Queue<Integer> availableIDs;
    public static final int BROADCAST = 0;


    public Network(int n) {
        this.n = n;
        this.users = new User[n];
        this.availableIDs = new ArrayBlockingQueue<Integer>(n);
        for (int id = 1; id <= n; id++){
            availableIDs.add(id);
        }
    }

    public User connect(MailHandler mailHandler){
        Integer id = availableIDs.poll();
        if (id == null)
            return null;
        users[id - 1] = new User(id,this,mailHandler);
        return users[id - 1];
    }

    protected boolean sendMessage(User sender,int destination,Mail.Type type,Message message){
        if(destination < 1 || destination > n)
            return false;
        User user = users[destination - 1];
        if (user == null)
            return false;
        Mail mail = Mail.newBuilder()
                .setSender(sender.getID())
                .setDestination(destination)
                .setIsPrivate(true)
                .setType(type)
                .setMessage(message.toByteString())
                .build();
        return user.mailbox.add(mail);
    }

    protected void sendBroadcast(User sender,Mail.Type type,Message message){
        User user;
        Mail mail = Mail.newBuilder()
                .setSender(sender.getID())
                .setDestination(BROADCAST)
                .setIsPrivate(false)
                .setType(type)
                .setMessage(message.toByteString())
                .build();
        for (int i = 0 ; i < n ; i++){
            user = users[i];
            user.mailbox.add(mail);
        }
    }

}