515b2d7f59f8ec90cac41294f5ce8c226aa3e28b
[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 AVFifoBuffer *av_fifo_alloc(unsigned int size)
26 {
27 AVFifoBuffer *f= av_mallocz(sizeof(AVFifoBuffer));
28 if(!f)
29 return NULL;
30 f->wptr = f->rptr =
31 f->buffer = av_malloc(size);
32 f->end = f->buffer + size;
33 if (!f->buffer)
34 av_freep(&f);
35 return f;
36 }
37
38 void av_fifo_free(AVFifoBuffer *f)
39 {
40 if(f){
41 av_free(f->buffer);
42 av_free(f);
43 }
44 }
45
46 int av_fifo_size(AVFifoBuffer *f)
47 {
48 return (uint32_t)(f->wndx - f->rndx);
49 }
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 #if LIBAVUTIL_VERSION_MAJOR < 50
57 void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
58 av_fifo_realloc2(f, new_size);
59 }
60 #endif
61
62 int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) {
63 unsigned int old_size= f->end - f->buffer;
64
65 if(old_size < new_size){
66 int len= av_fifo_size(f);
67 AVFifoBuffer *f2= av_fifo_alloc(new_size);
68
69 if (!f2)
70 return -1;
71 av_fifo_read(f, f2->buffer, len);
72 f2->wptr += len;
73 f2->wndx += len;
74 av_free(f->buffer);
75 *f= *f2;
76 av_free(f2);
77 }
78 return 0;
79 }
80
81 #if LIBAVUTIL_VERSION_MAJOR < 50
82 void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
83 {
84 av_fifo_generic_write(f, (void *)buf, size, NULL);
85 }
86 #endif
87
88 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
89 {
90 int total = size;
91 do {
92 int len = FFMIN(f->end - f->wptr, size);
93 if(func) {
94 if(func(src, f->wptr, len) <= 0)
95 break;
96 } else {
97 memcpy(f->wptr, src, len);
98 src = (uint8_t*)src + len;
99 }
100 // Write memory barrier needed for SMP here in theory
101 f->wptr += len;
102 if (f->wptr >= f->end)
103 f->wptr = f->buffer;
104 f->wndx += len;
105 size -= len;
106 } while (size > 0);
107 return total - size;
108 }
109
110
111 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
112 {
113 // Read memory barrier needed for SMP here in theory
114 do {
115 int len = FFMIN(f->end - f->rptr, buf_size);
116 if(func) func(dest, f->rptr, len);
117 else{
118 memcpy(dest, f->rptr, len);
119 dest = (uint8_t*)dest + len;
120 }
121 // memory barrier needed for SMP here in theory
122 av_fifo_drain(f, len);
123 buf_size -= len;
124 } while (buf_size > 0);
125 return 0;
126 }
127
128 /** Discard data from the FIFO. */
129 void av_fifo_drain(AVFifoBuffer *f, int size)
130 {
131 f->rptr += size;
132 if (f->rptr >= f->end)
133 f->rptr -= f->end - f->buffer;
134 f->rndx += size;
135 }