QGCTileCacheWorker.h

/****************************************************************************
 *
 *   (c) 2009-2016 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 *
 * QGroundControl is licensed according to the terms in the file
 * COPYING.md in the root of the source code directory.
 *
 ****************************************************************************/


/**
 * @file
 *   @brief Map Tile Cache Worker Thread
 *
 *   @author Gus Grubba <mavlink@grubba.com>
 *
 */

#ifndef QGC_TILE_CACHE_WORKER_H
#define QGC_TILE_CACHE_WORKER_H

#include <QString>
#include <QThread>
#include <QQueue>
#include <QMutex>
#include <QWaitCondition>
#include <QMutexLocker>
#include <QtSql/QSqlDatabase>

#include "QGCLoggingCategory.h"

Q_DECLARE_LOGGING_CATEGORY(QGCTileCacheLog)

class QGCMapTask;
class QGCCachedTileSet;

//-----------------------------------------------------------------------------
class QGCCacheWorker : public QThread
{
    Q_OBJECT
public:
    QGCCacheWorker  ();
    ~QGCCacheWorker ();

    void    quit            ();
    bool    enqueueTask     (QGCMapTask* task);
    void    setDatabaseFile (const QString& path);

protected:
    void    run             ();

private:
    void        _saveTile               (QGCMapTask* mtask);
    void        _getTile                (QGCMapTask* mtask);
    void        _getTileSets            (QGCMapTask* mtask);
    void        _createTileSet          (QGCMapTask* mtask);
    void        _getTileDownloadList    (QGCMapTask* mtask);
    void        _updateTileDownloadState(QGCMapTask* mtask);
    void        _deleteTileSet          (QGCMapTask* mtask);
    void        _resetCacheDatabase     (QGCMapTask* mtask);
    void        _pruneCache             (QGCMapTask* mtask);

    quint64     _findTile               (const QString hash);
    bool        _findTileSetID          (const QString name, quint64& setID);
    void        _updateSetTotals        (QGCCachedTileSet* set);
    bool        _init                   ();
    void        _createDB               ();
    quint64     _getDefaultTileSet      ();
    void        _updateTotals           ();

signals:
    void        updateTotals            (quint32 totaltiles, quint64 totalsize, quint32 defaulttiles, quint64 defaultsize);

private:
    QQueue<QGCMapTask*>     _taskQueue;
    QMutex                  _mutex;
    QMutex                  _waitmutex;
    QWaitCondition          _waitc;
    QString                 _databasePath;
    QSqlDatabase*           _db;
    bool                    _valid;
    bool                    _failed;
    quint64                 _defaultSet;
    quint64                 _totalSize;
    quint32                 _totalCount;
    quint64                 _defaultSize;
    quint32                 _defaultCount;
    time_t                  _lastUpdate;
    int                     _updateTimeout;
};

#endif // QGC_TILE_CACHE_WORKER_H