Reorder arguments for av_fifo_generic_read to be more logical and
[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->buffer = av_malloc(size);
31 f->end = f->buffer + size;
32 av_fifo_reset(f);
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 void av_fifo_reset(AVFifoBuffer *f)
47 {
48 f->wptr = f->rptr = f->buffer;
49 f->wndx = f->rndx = 0;
50 }
51
52 int av_fifo_size(AVFifoBuffer *f)
53 {
54 return (uint32_t)(f->wndx - f->rndx);
55 }
56
57 int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) {
58 unsigned int old_size= f->end - f->buffer;
59
60 if(old_size < new_size){
61 int len= av_fifo_size(f);
62 AVFifoBuffer *f2= av_fifo_alloc(new_size);
63
64 if (!f2)
65 return -1;
66 av_fifo_generic_read(f, f2->buffer, len, NULL);
67 f2->wptr += len;
68 f2->wndx += len;
69 av_free(f->buffer);
70 *f= *f2;
71 av_free(f2);
72 }
73 return 0;
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 // Write memory barrier needed for SMP here in theory
89 f->wptr += len;
90 if (f->wptr >= f->end)
91 f->wptr = f->buffer;
92 f->wndx += len;
93 size -= len;
94 } while (size > 0);
95 return total - size;
96 }
97
98
99 int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int))
100 {
101 // Read memory barrier needed for SMP here in theory
102 do {
103 int len = FFMIN(f->end - f->rptr, buf_size);
104 if(func) func(dest, f->rptr, len);
105 else{
106 memcpy(dest, f->rptr, len);
107 dest = (uint8_t*)dest + len;
108 }
109 // memory barrier needed for SMP here in theory
110 av_fifo_drain(f, len);
111 buf_size -= len;
112 } while (buf_size > 0);
113 return 0;
114 }
115
116 /** Discard data from the FIFO. */
117 void av_fifo_drain(AVFifoBuffer *f, int size)
118 {
119 f->rptr += size;
120 if (f->rptr >= f->end)
121 f->rptr -= f->end - f->buffer;
122 f->rndx += size;
123 }