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 <QMutex>
#include <QObject>

#define gRefresher (Refresher::instance())

class MasterClient;
class Server;
class QHostAddress;

class Refresher : public QObject
{
        Q_OBJECT

public:
        ~Refresher() override;

        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