LoginService.java

package net.scapeemulator.game.net.login;

import java.util.ArrayDeque;
import java.util.Queue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
import net.scapeemulator.game.io.Serializer;
import net.scapeemulator.game.io.Serializer.SerializeResult;
import net.scapeemulator.game.model.MobList;
import net.scapeemulator.game.model.World;
import net.scapeemulator.game.model.player.Player;

public final class LoginService implements Runnable {

    private static abstract class Job {

        public abstract void perform(LoginService service);

    }

    private static class LoginJob extends Job {

        private final LoginSession session;
        private final LoginRequest request;

        public LoginJob(LoginSession session, LoginRequest request) {
            this.session = session;
            this.request = request;
        }

        @Override
        public void perform(LoginService service) {
            SerializeResult result = service.serializer.loadPlayer(request.getUsername(), request.getPassword());
            int status = result.getStatus();

            if (status != LoginResponse.STATUS_OK) {
                /* send failure response immediately */
                session.sendLoginFailure(status);
            } else {
                /* add to new player queue */
                synchronized (service.newPlayers) {
                    service.newPlayers.add(new SessionPlayerPair(session, result.getPlayer()));
                }
            }
        }

    }

    private static class LogoutJob extends Job {

        private final Player player;

        public LogoutJob(Player player) {
            this.player = player;
        }

        @Override
        public void perform(LoginService service) {
            service.serializer.savePlayer(player);
            player.unregister();
            World.getWorld().getPlayers().remove(player);
        }

    }

    private static class SessionPlayerPair {

        private final LoginSession session;
        private final Player player;

        public SessionPlayerPair(LoginSession session, Player player) {
            this.session = session;
            this.player = player;
        }

    }

    private final Serializer serializer;
    private final BlockingQueue<Job> jobs = new LinkedBlockingDeque<>();
    private final Queue<SessionPlayerPair> newPlayers = new ArrayDeque<>();
    private final Queue<Player> oldPlayers = new ArrayDeque<>();

    public LoginService(Serializer serializer) {
        this.serializer = serializer;
    }

    public void addLoginRequest(LoginSession session, LoginRequest request) {
        jobs.offer(new LoginJob(session, request));
    }

    public void addLogoutRequest(Player player) {
        player.setSession(null);
        synchronized (oldPlayers) {
            oldPlayers.add(player);
        }
    }

    public void registerNewPlayers(World world) {
        MobList<Player> players = world.getPlayers();

        synchronized (oldPlayers) {
            Player player;
            while ((player = oldPlayers.peek()) != null) {
                // TODO change this to check for logout conditions (combat)
                if (true) {
                    oldPlayers.poll();
                    jobs.add(new LogoutJob(player));
                }
            }
        }

        synchronized (newPlayers) {
            SessionPlayerPair pair;
            while ((pair = newPlayers.poll()) != null) {
                if (world.getPlayerByName(pair.player.getUsername()) != null) {
                    /* player is already online */
                    pair.session.sendLoginFailure(LoginResponse.STATUS_ALREADY_ONLINE);
                } else if (!players.add(pair.player)) {
                    /* world is full */
                    pair.session.sendLoginFailure(LoginResponse.STATUS_WORLD_FULL);
                } else {
                    /* send success packet & switch to GameSession */
                    pair.session.sendLoginSuccess(LoginResponse.STATUS_OK, pair.player);
                }
            }
        }
    }

    @Override
    public void run() {
        for (;;) {
            try {
                jobs.take().perform(this);
            } catch (InterruptedException e) {
                /* ignore */
            }
        }
    }

}