simpler branch structure in init (16 bytes smaller object file)
[libav.git] / libavutil / fifo.c
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1/*
2 * A very simple circular buffer FIFO implementation
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4 * Copyright (c) 2006 Roman Shaposhnik
5 *
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6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
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9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
b78e7197 11 * version 2.1 of the License, or (at your option) any later version.
f5a478f6 12 *
b78e7197 13 * FFmpeg is distributed in the hope that it will be useful,
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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
b78e7197 19 * License along with FFmpeg; if not, write to the Free Software
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20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22#include "common.h"
23#include "fifo.h"
24
25int av_fifo_init(AVFifoBuffer *f, int size)
26{
0726982c 27 f->wptr = f->rptr =
f5a478f6 28 f->buffer = av_malloc(size);
4497712f 29 f->end = f->buffer + size;
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30 if (!f->buffer)
31 return -1;
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32 return 0;
33}
34
35void av_fifo_free(AVFifoBuffer *f)
36{
37 av_free(f->buffer);
38}
39
40int 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 */
51int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
52{
765d4f3b 53 return av_fifo_generic_read(f, buf_size, NULL, buf);
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54}
55
56/**
57 * Resizes a FIFO.
58 */
59void 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){
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63 int len= av_fifo_size(f);
64 AVFifoBuffer f2;
f5a478f6 65
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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;
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71 }
72}
73
74void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
75{
f5a478f6 76 while (size > 0) {
870a12d1 77 int len = FFMIN(f->end - f->wptr, size);
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78 memcpy(f->wptr, buf, len);
79 f->wptr += len;
80 if (f->wptr >= f->end)
81 f->wptr = f->buffer;
82 buf += len;
83 size -= len;
84 }
85}
86
87
be65b41f 88/** get data from the fifo (return -1 if not enough data) */
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89int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
90{
870a12d1 91 int size = av_fifo_size(f);
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92
93 if (size < buf_size)
94 return -1;
95 while (buf_size > 0) {
870a12d1 96 int len = FFMIN(f->end - f->rptr, buf_size);
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97 if(func) func(dest, f->rptr, len);
98 else{
99 memcpy(dest, f->rptr, len);
100 dest = (uint8_t*)dest + len;
101 }
3da97cfd 102 av_fifo_drain(f, len);
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103 buf_size -= len;
104 }
105 return 0;
106}
107
be65b41f 108/** discard data from the fifo */
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109void av_fifo_drain(AVFifoBuffer *f, int size)
110{
111 f->rptr += size;
112 if (f->rptr >= f->end)
113 f->rptr -= f->end - f->buffer;
114}