include/fifo_buffer.h

   1 /*
   2  * fifo_buffer.h - FIFO fixed-size buffer
   3  *
   4  * Copyright (c) 2007 Javier Serrano Polo <jasp00/at/users.sourceforge.net>
   5  *
   6  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public
  19  * License along with this program (see COPYING); if not, write to the
  20  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  * Boston, MA 02110-1301 USA.
  22  *
  23  */
  24
  25 #ifndef _FIFO_BUFFER_H
  26 #define _FIFO_BUFFER_H
  27
  28 #include <QtCore/QSemaphore>
  29
  30
  31 template<typename T>
  32 class fifoBuffer
  33 {
  34 public:
  35         fifoBuffer( int _size ) :
  36                 m_reader_sem( _size ),
  37                 m_writer_sem( _size ),
  38                 m_reader_index( 0 ),
  39                 m_writer_index( 0 ),
  40                 m_size( _size )
  41         {
  42                 m_buffer = new T[_size];
  43                 m_reader_sem.acquire( _size );
  44         }
  45
  46         ~fifoBuffer()
  47         {
  48                 delete[] m_buffer;
  49                 m_reader_sem.release( m_size );
  50         }
  51
  52         void write( T _element )
  53         {
  54                 m_writer_sem.acquire();
  55                 m_buffer[m_writer_index++] = _element;
  56                 m_writer_index %= m_size;
  57                 m_reader_sem.release();
  58         }
  59
  60         T read()
  61         {
  62                 m_reader_sem.acquire();
  63                 T element = m_buffer[m_reader_index++];
  64                 m_reader_index %= m_size;
  65                 m_writer_sem.release();
  66                 return( element );
  67         }
  68
  69         bool available()
  70         {
  71                 return( m_reader_sem.available() );
  72         }
  73
  74
  75 private:
  76         QSemaphore m_reader_sem;
  77         QSemaphore m_writer_sem;
  78         int m_reader_index;
  79         int m_writer_index;
  80         int m_size;
  81         T * m_buffer;
  82
  83 } ;
  84
  85
  86
  87
  88 #endif