loadingcache.h

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/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2006-01-11
 * Description : shared image loading and caching
 *
 * Copyright (C) 2005-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
 *
 * This program is free software; you can redistribute it
 * and/or modify it under the terms of the GNU General
 * Public License as published by the Free Software Foundation;
 * either version 2, or (at your option)
 * any later version.
 *
 * This program 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 General Public License for more details.
 *
 * ============================================================ */
 
#ifndef DIGIKAM_LOADING_CACHE_H
#define DIGIKAM_LOADING_CACHE_H
 
// Qt includes
 
#include <QPixmap>
 
// Local includes
 
#include "dimg.h"
#include "loadsavethread.h"
#include "digikam_export.h"
 
namespace Digikam
{
 
class ICCSettingsContainer;
 
class LoadingProcessListener
{
public:
 
    LoadingProcessListener();
    virtual ~LoadingProcessListener();
    virtual bool querySendNotifyEvent()                                                     const = 0;
    virtual void setResult(const LoadingDescription& loadingDescription, const DImg& img)         = 0;
    virtual LoadSaveNotifier* loadSaveNotifier()                                            const = 0;
    virtual LoadSaveThread::AccessMode accessMode()                                         const = 0;
 
private:
 
    // Disable
    LoadingProcessListener(const LoadingProcessListener&)            = delete;
    LoadingProcessListener& operator=(const LoadingProcessListener&) = delete;
};
 
// --------------------------------------------------------------------------------------------------------------
 
class LoadingProcess
{
public:
 
    LoadingProcess();
    virtual ~LoadingProcess();
    virtual bool completed()                                                                             const = 0;
    virtual QString cacheKey()                                                                           const = 0;
    virtual void addListener(LoadingProcessListener* const listener)                                           = 0;
    virtual void removeListener(LoadingProcessListener* const listener)                                        = 0;
    virtual void notifyNewLoadingProcess(LoadingProcess* const process, const LoadingDescription& description) = 0;
 
private:
 
    // Disable
    LoadingProcess(const LoadingProcess&)            = delete;
    LoadingProcess& operator=(const LoadingProcess&) = delete;
};
 
// --------------------------------------------------------------------------------------------------------------
 
class DIGIKAM_EXPORT LoadingCacheFileWatch : public QObject
{
    Q_OBJECT
 
public:
 
    LoadingCacheFileWatch();
    ~LoadingCacheFileWatch() override;
 
    void addedImage(const QString& filePath);
    void checkFileWatch(const QString& filePath);
 
protected:
 
    void notifyFileChanged(const QString& filePath);
 
protected:
 
    friend class LoadingCache;
 
    QMap<QString, QPair<qint64, QDateTime> > m_watchMap;
    class LoadingCache*                      m_cache;
 
private:
 
    // Disable
    LoadingCacheFileWatch(const LoadingCacheFileWatch&)            = delete;
    LoadingCacheFileWatch& operator=(const LoadingCacheFileWatch&) = delete;
    LoadingCacheFileWatch(QObject*)                                = delete;
};
 
// --------------------------------------------------------------------------------------------------------------
 
class DIGIKAM_EXPORT LoadingCache : public QObject
{
    Q_OBJECT
 
public:
 
    class DIGIKAM_EXPORT CacheLock
    {
    public:
 
        explicit CacheLock(LoadingCache* const cache);
        ~CacheLock();
        void wakeAll();
        void timedWait();
 
    private:
 
        LoadingCache* m_cache;
    };
 
public:
 
    static LoadingCache* cache();
    static void cleanUp();
 
    DImg* retrieveImage(const QString& cacheKey) const;
 
    bool isCacheable(const DImg& img) const;
 
    bool putImage(const QString& cacheKey, const DImg& img, const QString& filePath) const;
 
    void removeImage(const QString& cacheKey);
 
    void removeImages();
 
    // ------- Loading process management -----------------------------------
 
    LoadingProcess* retrieveLoadingProcess(const QString& cacheKey) const;
 
    void addLoadingProcess(LoadingProcess* const process);
 
    void removeLoadingProcess(LoadingProcess* const process);
 
    void notifyNewLoadingProcess(LoadingProcess* const process, const LoadingDescription& description);
 
    void setCacheSize(int megabytes);
 
    // ------- Thumbnail cache -----------------------------------
 
    const QImage* retrieveThumbnail(const QString& cacheKey) const;
    const QPixmap* retrieveThumbnailPixmap(const QString& cacheKey) const;
    bool  hasThumbnailPixmap(const QString& cacheKey) const;
 
    void putThumbnail(const QString& cacheKey, const QImage& thumb, const QString& filePath);
    void putThumbnail(const QString& cacheKey, const QPixmap& thumb, const QString& filePath);
 
    void removeThumbnail(const QString& cacheKey);
 
    void removeThumbnails();
 
    void setThumbnailCacheSize(int numberOfQImages, int numberOfQPixmaps);
 
    // ------- File Watch Management -----------------------------------
 
    void setFileWatch(LoadingCacheFileWatch* const watch);
 
    QStringList imageFilePathsInCache()     const;
    QStringList thumbnailFilePathsInCache() const;
 
    void notifyFileChanged(const QString& filePath, bool notify = true);
 
Q_SIGNALS:
 
    void fileChanged(const QString& filePath);
 
private Q_SLOTS:
 
    void iccSettingsChanged(const ICCSettingsContainer& current, const ICCSettingsContainer& previous);
 
private:
 
    // Disabled
    LoadingCache();
    explicit LoadingCache(QObject*)              = delete;
    ~LoadingCache() override;
 
    LoadingCache(const LoadingCache&)            = delete;
    LoadingCache& operator=(const LoadingCache&) = delete;
 
private:
 
    friend class LoadingCacheFileWatch;
    friend class CacheLock;
 
private:
 
    static LoadingCache* m_instance;
 
    class Private;
    Private* const d;
};
 
} // namespace Digikam
 
#endif // DIGIKAM_LOADING_CACHE_H