1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
#ifndef _RINGBUFFER_H
#define _RINGBUFFER_H
#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */
/*
* $Id: ringbuffer.h,v 1.5 2006-08-11 20:09:07 millerpuckette 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 <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "ringbuffer.h"
#include <string.h>
typedef struct
{
long bufferSize; /* Number of bytes in FIFO. Power of 2. Set by RingBuffer_Init. */
long writeIndex; /* Index of next writable byte. Set by RingBuffer_AdvanceWriteIndex. */
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 RingBuffer_Init( RingBuffer *rbuf, long numBytes, void *dataPtr );
/* Clear buffer. Should only be called when buffer is NOT being read. */
void RingBuffer_Flush( RingBuffer *rbuf );
/* Return number of bytes available for writing. */
long RingBuffer_GetWriteAvailable( RingBuffer *rbuf );
/* Return number of bytes available for read. */
long RingBuffer_GetReadAvailable( RingBuffer *rbuf );
/* Return bytes written. */
long RingBuffer_Write( RingBuffer *rbuf, void *data, long numBytes );
/* Return bytes read. */
long 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 RingBuffer_GetWriteRegions( RingBuffer *rbuf, long numBytes,
void **dataPtr1, long *sizePtr1,
void **dataPtr2, long *sizePtr2 );
long 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 written or numBytes, whichever is smaller.
*/
long RingBuffer_GetReadRegions( RingBuffer *rbuf, long numBytes,
void **dataPtr1, long *sizePtr1,
void **dataPtr2, long *sizePtr2 );
long RingBuffer_AdvanceReadIndex( RingBuffer *rbuf, long numBytes );
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _RINGBUFFER_H */
|
