#ifndef _PD_RINGBUFFER_H #define _PD_RINGBUFFER_H #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /* * $Id: s_audio_paring.h,v 1.1.4.1.2.3 2006-01-24 01:29:54 xovo Exp $ * ringbuffer.h * Ring Buffer utility.. * * Author: Phil Burk, http://www.softsynth.com * * This program is distributed with the PortAudio Portable Audio Library. * For more information see: http://www.audiomulch.com/portaudio/ * 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. * * 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. * * 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. * */ #include #include #include #include typedef struct { long bufferSize; /* Number of bytes in FIFO. Power of 2. Set by RingBuffer_Init. */ /* These are declared volatile because they are written by a different thread than the reader. */ volatile long writeIndex; /* Index of next writable byte. Set by RingBuffer_AdvanceWriteIndex. */ volatile long readIndex; /* Index of next readable byte. Set by RingBuffer_AdvanceReadIndex. */ long bigMask; /* Used for wrapping indices with extra bit to distinguish full/empty. */ long smallMask; /* Used for fitting indices to buffer. */ char *buffer; } RingBuffer; /* * Initialize Ring Buffer. * numBytes must be power of 2, returns -1 if not. */ long PD_RingBuffer_Init( RingBuffer *rbuf, long numBytes, void *dataPtr ); /* Clear buffer. Should only be called when buffer is NOT being read. */ void PD_RingBuffer_Flush( RingBuffer *rbuf ); /* Return number of bytes available for writing. */ long PD_RingBuffer_GetWriteAvailable( RingBuffer *rbuf ); /* Return number of bytes available for read. */ long PD_RingBuffer_GetReadAvailable( RingBuffer *rbuf ); /* Return bytes written. */ long PD_RingBuffer_Write( RingBuffer *rbuf, const void *data, long numBytes ); /* Return bytes read. */ long PD_RingBuffer_Read( RingBuffer *rbuf, void *data, long numBytes ); /* Get address of region(s) to which we can write data. ** If the region is contiguous, size2 will be zero. ** If non-contiguous, size2 will be the size of second region. ** Returns room available to be written or numBytes, whichever is smaller. */ long PD_RingBuffer_GetWriteRegions( RingBuffer *rbuf, long numBytes, void **dataPtr1, long *sizePtr1, void **dataPtr2, long *sizePtr2 ); long PD_RingBuffer_AdvanceWriteIndex( RingBuffer *rbuf, long numBytes ); /* Get address of region(s) from which we can read data. ** If the region is contiguous, size2 will be zero. ** If non-contiguous, size2 will be the size of second region. ** Returns room available to be read or numBytes, whichever is smaller. */ long PD_RingBuffer_GetReadRegions( RingBuffer *rbuf, long numBytes, void **dataPtr1, long *sizePtr1, void **dataPtr2, long *sizePtr2 ); long PD_RingBuffer_AdvanceReadIndex( RingBuffer *rbuf, long numBytes ); #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* _PD_RINGBUFFER_H */