pa_ringbuffer.h

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#ifndef PA_RINGBUFFER_H
#define PA_RINGBUFFER_H
/*
 * $Id$
 * Portable Audio I/O Library
 * Ring Buffer utility.
 *
 * Author: Phil Burk, http://www.softsynth.com
 * modified for SMP safety on OS X by Bjorn Roche.
 * also allowed for const where possible.
 * modified for multiple-byte-sized data elements by Sven Fischer 
 *
 * Note that this is safe only for a single-thread reader
 * and a single-thread writer.
 *
 * This program is distributed with the PortAudio Portable Audio Library.
 * For more information see: http://www.portaudio.com
 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * The text above constitutes the entire PortAudio license; however, 
 * the PortAudio community also makes the following non-binding requests:
 *
 * Any person wishing to distribute modifications to the Software is
 * requested to send the modifications to the original developer so that
 * they can be incorporated into the canonical version. It is also 
 * requested that these non-binding requests be included along with the 
 * license above.
 */

#if defined(__APPLE__)
#include <sys/types.h>
typedef int32_t ring_buffer_size_t;
#elif defined( __GNUC__ )
typedef long ring_buffer_size_t;
#elif (_MSC_VER >= 1400)
typedef long ring_buffer_size_t;
#elif defined(_MSC_VER) || defined(__BORLANDC__)
typedef long ring_buffer_size_t;
#else
typedef long ring_buffer_size_t;
#endif



#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */

typedef struct PaUtilRingBuffer
{
    ring_buffer_size_t  bufferSize; 
    volatile ring_buffer_size_t  writeIndex; 
    volatile ring_buffer_size_t  readIndex;  
    ring_buffer_size_t  bigMask;    
    ring_buffer_size_t  smallMask;  
    ring_buffer_size_t  elementSizeBytes; 
    char  *buffer;    
}PaUtilRingBuffer;

ring_buffer_size_t PaUtil_InitializeRingBuffer( PaUtilRingBuffer *rbuf, ring_buffer_size_t elementSizeBytes, ring_buffer_size_t elementCount, void *dataPtr );

void PaUtil_FlushRingBuffer( PaUtilRingBuffer *rbuf );

ring_buffer_size_t PaUtil_GetRingBufferWriteAvailable( const PaUtilRingBuffer *rbuf );

ring_buffer_size_t PaUtil_GetRingBufferReadAvailable( const PaUtilRingBuffer *rbuf );

ring_buffer_size_t PaUtil_WriteRingBuffer( PaUtilRingBuffer *rbuf, const void *data, ring_buffer_size_t elementCount );

ring_buffer_size_t PaUtil_ReadRingBuffer( PaUtilRingBuffer *rbuf, void *data, ring_buffer_size_t elementCount );

ring_buffer_size_t PaUtil_GetRingBufferWriteRegions( PaUtilRingBuffer *rbuf, ring_buffer_size_t elementCount,
                                       void **dataPtr1, ring_buffer_size_t *sizePtr1,
                                       void **dataPtr2, ring_buffer_size_t *sizePtr2 );

ring_buffer_size_t PaUtil_AdvanceRingBufferWriteIndex( PaUtilRingBuffer *rbuf, ring_buffer_size_t elementCount );

ring_buffer_size_t PaUtil_GetRingBufferReadRegions( PaUtilRingBuffer *rbuf, ring_buffer_size_t elementCount,
                                      void **dataPtr1, ring_buffer_size_t *sizePtr1,
                                      void **dataPtr2, ring_buffer_size_t *sizePtr2 );

ring_buffer_size_t PaUtil_AdvanceRingBufferReadIndex( PaUtilRingBuffer *rbuf, ring_buffer_size_t elementCount );

#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* PA_RINGBUFFER_H */