Remove av_fifo_read, API is already broken and major version will be bumped soon.
[libav.git] / libavutil / fifo.h
1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 /**
20 * @file libavutil/fifo.h
21 * a very simple circular buffer FIFO implementation
22 */
23
24 #ifndef AVUTIL_FIFO_H
25 #define AVUTIL_FIFO_H
26
27 #include <stdint.h>
28 #include "avutil.h"
29 #include "common.h"
30
31 typedef struct AVFifoBuffer {
32 uint8_t *buffer;
33 uint8_t *rptr, *wptr, *end;
34 uint32_t rndx, wndx;
35 } AVFifoBuffer;
36
37 /**
38 * Initializes an AVFifoBuffer.
39 * @param size of FIFO
40 * @return AVFifoBuffer or NULL if mem allocation failure
41 */
42 AVFifoBuffer *av_fifo_alloc(unsigned int size);
43
44 /**
45 * Frees an AVFifoBuffer.
46 * @param *f AVFifoBuffer to free
47 */
48 void av_fifo_free(AVFifoBuffer *f);
49
50 /**
51 * Returns the amount of data in bytes in the AVFifoBuffer, that is the
52 * amount of data you can read from it.
53 * @param *f AVFifoBuffer to read from
54 * @return size
55 */
56 int av_fifo_size(AVFifoBuffer *f);
57
58 /**
59 * Feeds data from an AVFifoBuffer to a user-supplied callback.
60 * @param *f AVFifoBuffer to read from
61 * @param buf_size number of bytes to read
62 * @param *func generic read function
63 * @param *dest data destination
64 */
65 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest);
66
67 #if LIBAVUTIL_VERSION_MAJOR < 50
68 /**
69 * Writes data into an AVFifoBuffer.
70 * @param *f AVFifoBuffer to write to
71 * @param *buf data source
72 * @param size data size
73 */
74 attribute_deprecated void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size);
75 #endif
76
77 /**
78 * Feeds data from a user-supplied callback to an AVFifoBuffer.
79 * @param *f AVFifoBuffer to write to
80 * @param *src data source
81 * @param size number of bytes to write
82 * @param *func generic write function; the first parameter is src,
83 * the second is dest_buf, the third is dest_buf_size.
84 * func must return the number of bytes written to dest_buf, or <= 0 to
85 * indicate no more data available to write.
86 * If func is NULL, src is interpreted as a simple byte array for source data.
87 * @return the number of bytes written to the FIFO
88 */
89 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
90
91 #if LIBAVUTIL_VERSION_MAJOR < 50
92 /**
93 * Resizes an AVFifoBuffer.
94 * @param *f AVFifoBuffer to resize
95 * @param size new AVFifoBuffer size in bytes
96 * @see av_fifo_realloc2()
97 */
98 attribute_deprecated void av_fifo_realloc(AVFifoBuffer *f, unsigned int size);
99 #endif
100
101 /**
102 * Resizes an AVFifoBuffer.
103 * @param *f AVFifoBuffer to resize
104 * @param size new AVFifoBuffer size in bytes
105 * @return <0 for failure, >=0 otherwise
106 */
107 int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size);
108
109 /**
110 * Reads and discards the specified amount of data from an AVFifoBuffer.
111 * @param *f AVFifoBuffer to read from
112 * @param size amount of data to read in bytes
113 */
114 void av_fifo_drain(AVFifoBuffer *f, int size);
115
116 static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs)
117 {
118 uint8_t *ptr = f->rptr + offs;
119 if (ptr >= f->end)
120 ptr -= f->end - f->buffer;
121 return *ptr;
122 }
123 #endif /* AVUTIL_FIFO_H */