kshareddatacache.h

Go to the documentation of this file.

/*
 * This file is part of the KDE project.
 * Copyright © 2010 Michael Pyne <mpyne@kde.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License version 2 as published by the Free Software Foundation.
 *
 * 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifndef KSHAREDDATACACHE_H
#define KSHAREDDATACACHE_H

#include <kdecore_export.h>

class QString;
class QByteArray;

class KDECORE_EXPORT KSharedDataCache
{
public:
    KSharedDataCache(const QString &cacheName,
                     unsigned defaultCacheSize,
                     unsigned expectedItemSize = 0);
    ~KSharedDataCache();

    enum EvictionPolicy
    {
        // The default value for data in our shared memory will be 0, so it is
        // important that whatever we want for the default value is also 0.
        NoEvictionPreference = 0,
        EvictLeastRecentlyUsed,
        EvictLeastOftenUsed,
        EvictOldest
    };

    EvictionPolicy evictionPolicy() const;

    void setEvictionPolicy(EvictionPolicy newPolicy);

    bool insert(const QString &key, const QByteArray &data);

    bool find(const QString &key, QByteArray *destination) const;

    void clear();

    static void deleteCache(const QString &cacheName);

    bool contains(const QString &key) const;

    unsigned totalSize() const;

    unsigned freeSize() const;

    unsigned timestamp() const;

    void setTimestamp(unsigned newTimestamp);

private:
    class Private;
    Private *d;
};

#endif