19ec13e63d0716e7515fbe86c0d82f08ce2e7ff9
[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 /**
49 * Get data from the fifo (returns -1 if not enough data).
50 */
51 int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
52 {
53 return av_fifo_generic_read(f, buf_size, NULL, buf);
54 }
55
56 /**
57 * Resizes a FIFO.
58 */
59 void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
60 unsigned int old_size= f->end - f->buffer;
61
62 if(old_size < new_size){
63 int len= av_fifo_size(f);
64 AVFifoBuffer f2;
65
66 av_fifo_init(&f2, new_size);
67 av_fifo_read(f, f2.buffer, len);
68 f2.wptr += len;
69 av_free(f->buffer);
70 *f= f2;
71 }
72 }
73
74 void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
75 {
76 av_fifo_generic_write(f, (void *)buf, size, NULL);
77 }
78
79 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
80 {
81 int total = size;
82 do {
83 int len = FFMIN(f->end - f->wptr, size);
84 if(func) {
85 if(func(src, f->wptr, len) <= 0)
86 break;
87 } else {
88 memcpy(f->wptr, src, len);
89 src = (uint8_t*)src + len;
90 }
91 f->wptr += len;
92 if (f->wptr >= f->end)
93 f->wptr = f->buffer;
94 size -= len;
95 } while (size > 0);
96 return total - size;
97 }
98
99
100 /** get data from the fifo (return -1 if not enough data) */
101 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
102 {
103 int size = av_fifo_size(f);
104
105 if (size < buf_size)
106 return -1;
107 do {
108 int len = FFMIN(f->end - f->rptr, buf_size);
109 if(func) func(dest, f->rptr, len);
110 else{
111 memcpy(dest, f->rptr, len);
112 dest = (uint8_t*)dest + len;
113 }
114 av_fifo_drain(f, len);
115 buf_size -= len;
116 } while (buf_size > 0);
117 return 0;
118 }
119
120 /** discard data from the fifo */
121 void av_fifo_drain(AVFifoBuffer *f, int size)
122 {
123 f->rptr += size;
124 if (f->rptr >= f->end)
125 f->rptr -= f->end - f->buffer;
126 }