/****************************************************************************
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** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the QtAddOn.JsonDb module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** use the contact form at http://qt.digia.com/contact-us.
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** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
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** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/

#ifndef QBTREELOCKER_H
#define QBTREELOCKER_H

#include <QByteArray>
#include "qbtreedata.h"

class QBtree;
class QBtreeTxn;

class QBtreeReadLocker
{
public:
    explicit QBtreeReadLocker(QBtree *db);
    ~QBtreeReadLocker();

    inline bool isValid() const { return mTxn != 0; }

    bool get(const QByteArray &baKey, QByteArray *baValue) const;
    bool get(const char *key, int keySize, QBtreeData *value) const;
    bool get(const QBtreeData &key, QBtreeData *value) const;

    quint32 tag() const;

    void abort();

private:
    QBtreeTxn *mTxn;

    // forbid copy constructor
    QBtreeReadLocker(const QBtreeReadLocker &);
    void operator=(const QBtreeReadLocker &);
};

class QBtreeWriteLockerPrivate;
class QBtreeWriteLocker
{
public:
    explicit QBtreeWriteLocker(QBtree *db);
    ~QBtreeWriteLocker();

    bool isValid() const;

    bool get(const QByteArray &baKey, QByteArray *baValue) const;
    bool get(const char *key, int keySize, QBtreeData *value) const;
    bool get(const QBtreeData &key, QBtreeData *value) const;
    bool put(const QByteArray &baKey, const QByteArray &baValue);
    bool put(const char *key, int keySize, const char *value, int valueSize);
    bool put(const QBtreeData &baKey, const QBtreeData &baValue);
    bool remove(const QByteArray &baKey);
    bool remove(const QBtreeData &baKey);
    bool remove(const char *key, int keySize);

    quint32 tag() const;

    void abort();
    bool commit(quint32 tag);

    void setAutoCommitTag(quint32 tag);
    quint32 autoCommitTag() const;
    void unsetAutoCommitTag();

private:
    QBtreeWriteLockerPrivate *d_ptr;

    // forbid copy constructor
    QBtreeWriteLocker(const QBtreeWriteLocker &);
    void operator=(const QBtreeWriteLocker &);
};

#endif // QBTREELOCKER_H