FifoBuffer.h

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/*
 * FifoBuffer.h - FIFO fixed-size buffer
 *
 * Copyright (c) 2007 Javier Serrano Polo <jasp00/at/users.sourceforge.net>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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 of the License, 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.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef LMMS_FIFO_BUFFER_H
#define LMMS_FIFO_BUFFER_H
 
#include <QSemaphore>
 
 
namespace lmms
{
 
 
template<typename T>
class FifoBuffer
{
public:
        FifoBuffer(int size) :
                m_readSem(size),
                m_writeSem(size),
                m_readIndex(0),
                m_writeIndex(0),
                m_size(size)
        {
                m_buffer = new T[size];
                m_readSem.acquire(size);
        }
 
        ~FifoBuffer()
        {
                delete[] m_buffer;
                m_readSem.release(m_size);
        }
 
        void write(T element)
        {
                m_writeSem.acquire();
                m_buffer[m_writeIndex++] = element;
                m_writeIndex %= m_size;
                m_readSem.release();
        }
 
        T read()
        {
                m_readSem.acquire();
                T element = m_buffer[m_readIndex++];
                m_readIndex %= m_size;
                m_writeSem.release();
                return element;
        }
 
        void waitUntilRead()
        {
                m_writeSem.acquire(m_size);
                m_writeSem.release(m_size);
        }
 
        bool available()
        {
                return m_readSem.available();
        }
 
 
private:
        QSemaphore m_readSem;
        QSemaphore m_writeSem;
        int m_readIndex;
        int m_writeIndex;
        int m_size;
        T * m_buffer;
} ;
 
 
} // namespace lmms
 
#endif // LMMS_FIFO_BUFFER_H