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#ifndef PA_RINGBUFFER_H
#define PA_RINGBUFFER_H
/*
* $Id: pa_ringbuffer.h,v 1.3 2007-12-28 03:43:01 millerpuckette Exp $
* 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.
* 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.
*/
/** @file
@ingroup common_src
*/
#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */
typedef struct PaUtilRingBuffer
{
long bufferSize; /* Number of bytes in FIFO. Power of 2. Set by PaUtil_InitRingBuffer. */
long writeIndex; /* Index of next writable byte. Set by PaUtil_AdvanceRingBufferWriteIndex. */
long readIndex; /* Index of next readable byte. Set by PaUtil_AdvanceRingBufferReadIndex. */
long bigMask; /* Used for wrapping indices with extra bit to distinguish full/empty. */
long smallMask; /* Used for fitting indices to buffer. */
char *buffer;
}PaUtilRingBuffer;
/** Initialize Ring Buffer.
@param rbuf The ring buffer.
@param numBytes The number of bytes in the buffer and must be power of 2.
@param dataPtr A pointer to a previously allocated area where the data
will be maintained. It must be numBytes long.
@return -1 if numBytes is not a power of 2, otherwise 0.
*/
long PaUtil_InitializeRingBuffer( PaUtilRingBuffer *rbuf, long numBytes, void *dataPtr );
/** Clear buffer. Should only be called when buffer is NOT being read.
@param rbuf The ring buffer.
*/
void PaUtil_FlushRingBuffer( PaUtilRingBuffer *rbuf );
/** Retrieve the number of bytes available in the ring buffer for writing.
@param rbuf The ring buffer.
@return The number of bytes available for writing.
*/
long PaUtil_GetRingBufferWriteAvailable( PaUtilRingBuffer *rbuf );
/** Retrieve the number of bytes available in the ring buffer for reading.
@param rbuf The ring buffer.
@return The number of bytes available for reading.
*/
long PaUtil_GetRingBufferReadAvailable( PaUtilRingBuffer *rbuf );
/** Write data to the ring buffer.
@param rbuf The ring buffer.
@param data The address of new data to write to the buffer.
@param numBytes The number of bytes to be written.
@return The number of bytes written.
*/
long PaUtil_WriteRingBuffer( PaUtilRingBuffer *rbuf, const void *data, long numBytes );
/** Read data from the ring buffer.
@param rbuf The ring buffer.
@param data The address where the data should be stored.
@param numBytes The number of bytes to be read.
@return The number of bytes read.
*/
long PaUtil_ReadRingBuffer( PaUtilRingBuffer *rbuf, void *data, long numBytes );
/** Get address of region(s) to which we can write data.
@param rbuf The ring buffer.
@param numBytes The number of bytes desired.
@param dataPtr1 The address where the first (or only) region pointer will be
stored.
@param sizePtr1 The address where the first (or only) region length will be
stored.
@param dataPtr2 The address where the second region pointer will be stored if
the first region is too small to satisfy numBytes.
@param sizePtr2 The address where the second region length will be stored if
the first region is too small to satisfy numBytes.
@return The room available to be written or numBytes, whichever is smaller.
*/
long PaUtil_GetRingBufferWriteRegions( PaUtilRingBuffer *rbuf, long numBytes,
void **dataPtr1, long *sizePtr1,
void **dataPtr2, long *sizePtr2 );
/** Advance the write index to the next location to be written.
@param rbuf The ring buffer.
@param numBytes The number of bytes to advance.
@return The new position.
*/
long PaUtil_AdvanceRingBufferWriteIndex( PaUtilRingBuffer *rbuf, long numBytes );
/** Get address of region(s) from which we can write data.
@param rbuf The ring buffer.
@param numBytes The number of bytes desired.
@param dataPtr1 The address where the first (or only) region pointer will be
stored.
@param sizePtr1 The address where the first (or only) region length will be
stored.
@param dataPtr2 The address where the second region pointer will be stored if
the first region is too small to satisfy numBytes.
@param sizePtr2 The address where the second region length will be stored if
the first region is too small to satisfy numBytes.
@return The number of bytes available for reading.
*/
long PaUtil_GetRingBufferReadRegions( PaUtilRingBuffer *rbuf, long numBytes,
void **dataPtr1, long *sizePtr1,
void **dataPtr2, long *sizePtr2 );
/** Advance the read index to the next location to be read.
@param rbuf The ring buffer.
@param numBytes The number of bytes to advance.
@return The new position.
*/
long PaUtil_AdvanceRingBufferReadIndex( PaUtilRingBuffer *rbuf, long numBytes );
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* PA_RINGBUFFER_H */
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