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Diffstat (limited to 'digikam/libs/threadimageio/loadingcache.h')
-rw-r--r-- | digikam/libs/threadimageio/loadingcache.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/digikam/libs/threadimageio/loadingcache.h b/digikam/libs/threadimageio/loadingcache.h new file mode 100644 index 0000000..26f89c8 --- /dev/null +++ b/digikam/libs/threadimageio/loadingcache.h @@ -0,0 +1,134 @@ +/* ============================================================ + * + * This file is a part of digiKam project + * http://www.digikam.org + * + * Date : 2006-01-11 + * Description : shared image loading and caching + * + * Copyright (C) 2005-2007 by Marcel Wiesweg <marcel.wiesweg@gmx.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 LOADING_CACHE_H +#define LOADING_CACHE_H + +#include <qptrlist.h> +#include <qcache.h> +#include <qdict.h> +#include <qmutex.h> + +#include "dimg.h" +#include "loadsavethread.h" + +namespace Digikam +{ + +class LoadingProcessListener +{ +public: + + virtual bool querySendNotifyEvent() = 0; + virtual QObject *eventReceiver() = 0; + virtual LoadSaveThread::AccessMode accessMode() = 0; + +}; + +class LoadingProcess +{ +public: + + virtual bool completed() = 0; + virtual QString filePath() = 0; + virtual QString cacheKey() = 0; + virtual void addListener(LoadingProcessListener *listener) = 0; + virtual void removeListener(LoadingProcessListener *listener) = 0; + virtual void notifyNewLoadingProcess(LoadingProcess *process, LoadingDescription description) = 0; + +}; + +class LoadingCachePriv; + +class LoadingCache : public QObject +{ + + Q_OBJECT + +public: + + static LoadingCache *cache(); + static void cleanUp(); + ~LoadingCache(); + + // all functions shall only be called when a CacheLock is held + class CacheLock + { + public: + CacheLock(LoadingCache *cache); + ~CacheLock(); + void wakeAll(); + void timedWait(); + private: + LoadingCache *m_cache; + }; + + // Retrieves an image for the given string from the cache, + // or 0 if no image is found. + DImg *retrieveImage(const QString &cacheKey); + // Returns whether the given DImg fits in the cache. + bool isCacheable(const DImg *img); + // Put image into for given string into the cache. + // Returns true if image has been put in the cache, false otherwise. + // Ownership of the DImg instance is passed to the cache. + // When it cannot be put in the cache it is deleted. + // The third parameter specifies a file path that will be watched. + // If this file changes, the object will be removed from the cache. + bool putImage(const QString &cacheKey, DImg *img, const QString &filePath); + void removeImage(const QString &cacheKey); + void removeImages(); + + // Find the loading process for given cacheKey, or 0 if not found + LoadingProcess *retrieveLoadingProcess(const QString &cacheKey); + // Add a loading process to the list. Only one loading process + // for the same cache key is registered at a time. + void addLoadingProcess(LoadingProcess *process); + // Remove loading process for given cache key + void removeLoadingProcess(LoadingProcess *process); + // Notify all currently registered loading processes + void notifyNewLoadingProcess(LoadingProcess *process, LoadingDescription description); + + void setCacheSize(int megabytes); + +protected: + + virtual void customEvent (QCustomEvent *event); + +private slots: + + void slotFileDirty(const QString &path); + +private: + + static LoadingCache *m_instance; + + LoadingCache(); + + friend class CacheLock; + LoadingCachePriv *d; + +}; + +} // namespace Digikam + +#endif |