refresher.h

//------------------------------------------------------------------------------
// refresher.h
//------------------------------------------------------------------------------
//
// 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 (at your option) 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., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301  USA
//
//------------------------------------------------------------------------------
// Copyright (C) 2009 "Zalewa" <zalewapl@gmail.com>
//------------------------------------------------------------------------------
#ifndef DOOMSEEKER_REFRESHER_REFRESHER_H
#define DOOMSEEKER_REFRESHER_REFRESHER_H

#include <QObject>
#include <QMutex>

#define gRefresher (Refresher::instance())

class MasterClient;
class Server;
class QHostAddress;

class Refresher : public QObject
{
        Q_OBJECT

        public:
                ~Refresher();

                void quit();

                void registerMaster(MasterClient* pMaster);

                bool registerServer(Server* server);

                void setDelayBetweenResends(int delay);

                bool start();

                static Refresher *instance();
                static bool isInstantiated();
                static void deinstantiate();

        signals:
                void block();

                void finishedQueryingMaster(MasterClient* master);

                void sleepingModeEnter();

                void sleepingModeExit();

        private:
                class Data;
                class MasterClientInfo;

                static const int MASTER_SERVER_TIMEOUT_DELAY = 10000;
                static Refresher *staticInstance;
                static QMutex instanceMutex;

                Data *d;

                Refresher();

                void concludeRefresh();
                bool isAnythingToRefresh() const;
                Server* findRefreshingServer(const QHostAddress& address, unsigned short port);

                void purgeNullServers();

                void readPendingDatagram();

                void startNewServerRefresh();
                void resendCurrentServerRefreshesIfTimeout();

                // TODO: Constify 'address' and 'packet' args.
                bool tryReadDatagramByMasterClient(QHostAddress& address,
                        unsigned short port, QByteArray& packet);
                bool tryReadDatagramByServer(const QHostAddress& address,
                        unsigned short port, QByteArray& packet);

                void unregisterMaster(MasterClient* pMaster);

        private slots:
                void attemptTimeoutMasters();
                void masterFinishedRefreshing();
                void readAllPendingDatagrams();
                void sendMasterQueries();
                void sendServerQueries();
};

#endif