simplify
[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{
27 f->buffer = av_malloc(size);
28 if (!f->buffer)
29 return -1;
30 f->end = f->buffer + size;
31 f->wptr = f->rptr = f->buffer;
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{
f81b99b8 53 int size = av_fifo_size(f);
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54
55 if (size < buf_size)
56 return -1;
57 while (buf_size > 0) {
f81b99b8 58 int len = FFMIN(f->end - f->rptr, buf_size);
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59 memcpy(buf, f->rptr, len);
60 buf += len;
61 f->rptr += len;
62 if (f->rptr >= f->end)
63 f->rptr = f->buffer;
64 buf_size -= len;
65 }
66 return 0;
67}
68
69/**
70 * Resizes a FIFO.
71 */
72void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
73 unsigned int old_size= f->end - f->buffer;
74
75 if(old_size < new_size){
76 uint8_t *old= f->buffer;
77
78 f->buffer= av_realloc(f->buffer, new_size);
79
80 f->rptr += f->buffer - old;
81 f->wptr += f->buffer - old;
82
83 if(f->wptr < f->rptr){
84 memmove(f->rptr + new_size - old_size, f->rptr, f->buffer + old_size - f->rptr);
85 f->rptr += new_size - old_size;
86 }
87 f->end= f->buffer + new_size;
88 }
89}
90
91void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
92{
f5a478f6 93 while (size > 0) {
870a12d1 94 int len = FFMIN(f->end - f->wptr, size);
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95 memcpy(f->wptr, buf, len);
96 f->wptr += len;
97 if (f->wptr >= f->end)
98 f->wptr = f->buffer;
99 buf += len;
100 size -= len;
101 }
102}
103
104
105/* get data from the fifo (return -1 if not enough data) */
106int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
107{
870a12d1 108 int size = av_fifo_size(f);
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109
110 if (size < buf_size)
111 return -1;
112 while (buf_size > 0) {
870a12d1 113 int len = FFMIN(f->end - f->rptr, buf_size);
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114 func(dest, f->rptr, len);
115 f->rptr += len;
116 if (f->rptr >= f->end)
117 f->rptr = f->buffer;
118 buf_size -= len;
119 }
120 return 0;
121}
122
123/* discard data from the fifo */
124void av_fifo_drain(AVFifoBuffer *f, int size)
125{
126 f->rptr += size;
127 if (f->rptr >= f->end)
128 f->rptr -= f->end - f->buffer;
129}