/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtMultimedia module of the Qt Toolkit.

**

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** 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

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

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** rights.  These rights are described in the Nokia Qt LGPL Exception

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**

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** $QT_END_LICENSE$

**

****************************************************************************/

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists for the convenience

// of other Qt classes.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

#ifndef QAUDIO_MAC_P_H

#define QAUDIO_MAC_P_H

#include <CoreAudio/CoreAudio.h>

#include <QtCore/qdebug.h>

#include <QtCore/qatomic.h>

#include <QtMultimedia/qaudioformat.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Multimedia)

extern QDebug operator<<(QDebug dbg, const QAudioFormat& audioFormat);

extern QAudioFormat toQAudioFormat(const AudioStreamBasicDescription& streamFormat);

extern AudioStreamBasicDescription toAudioStreamBasicDescription(QAudioFormat const& audioFormat);

class QAudioRingBuffer

{

public:

    typedef QPair<char*, int> Region;

    QAudioRingBuffer(int bufferSize);

    ~QAudioRingBuffer();

    Region acquireReadRegion(int size)

    {

        const int used = m_bufferUsed.fetchAndAddAcquire(0);

        if (used > 0) {

            const int readSize = qMin(size, qMin(m_bufferSize - m_readPos, used));

            return readSize > 0 ? Region(m_buffer + m_readPos, readSize) : Region(0, 0);

        }

        return Region(0, 0);

    }

    void releaseReadRegion(Region const& region)

    {

        m_readPos = (m_readPos + region.second) % m_bufferSize;

        m_bufferUsed.fetchAndAddRelease(-region.second);

    }

    Region acquireWriteRegion(int size)

    {

        const int free = m_bufferSize - m_bufferUsed.fetchAndAddAcquire(0);

        if (free > 0) {

            const int writeSize = qMin(size, qMin(m_bufferSize - m_writePos, free));

            return writeSize > 0 ? Region(m_buffer + m_writePos, writeSize) : Region(0, 0);

        }

        return Region(0, 0);

    }

    void releaseWriteRegion(Region const& region)

    {

        m_writePos = (m_writePos + region.second) % m_bufferSize;

        m_bufferUsed.fetchAndAddRelease(region.second);

    }

    int used() const;

    int free() const;

    int size() const;

    void reset();

private:

    int     m_bufferSize;

    int     m_readPos;

    int     m_writePos;

    char*   m_buffer;

    QAtomicInt  m_bufferUsed;

};

QT_END_NAMESPACE

QT_END_HEADER

#endif  // QAUDIO_MAC_P_H