Make av_fifo*_read() ignore the available amount of data.
[libav.git] / libavutil / fifo.c
1 /*
2 * A very simple circular buffer FIFO implementation
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4 * Copyright (c) 2006 Roman Shaposhnik
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22 #include "common.h"
23 #include "fifo.h"
24
25 int av_fifo_init(AVFifoBuffer *f, int size)
26 {
27 f->wptr = f->rptr =
28 f->buffer = av_malloc(size);
29 f->end = f->buffer + size;
30 if (!f->buffer)
31 return -1;
32 return 0;
33 }
34
35 void av_fifo_free(AVFifoBuffer *f)
36 {
37 av_free(f->buffer);
38 }
39
40 int av_fifo_size(AVFifoBuffer *f)
41 {
42 int size = f->wptr - f->rptr;
43 if (size < 0)
44 size += f->end - f->buffer;
45 return size;
46 }
47
48 int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
49 {
50 return av_fifo_generic_read(f, buf_size, NULL, buf);
51 }
52
53 /**
54 * Resizes a FIFO.
55 */
56 void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
57 unsigned int old_size= f->end - f->buffer;
58
59 if(old_size < new_size){
60 int len= av_fifo_size(f);
61 AVFifoBuffer f2;
62
63 av_fifo_init(&f2, new_size);
64 av_fifo_read(f, f2.buffer, len);
65 f2.wptr += len;
66 av_free(f->buffer);
67 *f= f2;
68 }
69 }
70
71 void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
72 {
73 av_fifo_generic_write(f, (void *)buf, size, NULL);
74 }
75
76 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
77 {
78 int total = size;
79 do {
80 int len = FFMIN(f->end - f->wptr, size);
81 if(func) {
82 if(func(src, f->wptr, len) <= 0)
83 break;
84 } else {
85 memcpy(f->wptr, src, len);
86 src = (uint8_t*)src + len;
87 }
88 f->wptr += len;
89 if (f->wptr >= f->end)
90 f->wptr = f->buffer;
91 size -= len;
92 } while (size > 0);
93 return total - size;
94 }
95
96
97 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
98 {
99 do {
100 int len = FFMIN(f->end - f->rptr, buf_size);
101 if(func) func(dest, f->rptr, len);
102 else{
103 memcpy(dest, f->rptr, len);
104 dest = (uint8_t*)dest + len;
105 }
106 av_fifo_drain(f, len);
107 buf_size -= len;
108 } while (buf_size > 0);
109 return 0;
110 }
111
112 /** discard data from the fifo */
113 void av_fifo_drain(AVFifoBuffer *f, int size)
114 {
115 f->rptr += size;
116 if (f->rptr >= f->end)
117 f->rptr -= f->end - f->buffer;
118 }