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
25int av_fifo_init(AVFifoBuffer *f, unsigned int size)
26{
27    size= FFMAX(size, size+1);
28    f->wptr = f->rptr =
29    f->buffer = av_malloc(size);
30    f->end = f->buffer + size;
31    if (!f->buffer)
32        return -1;
33    return 0;
34}
35
36void av_fifo_free(AVFifoBuffer *f)
37{
38    av_free(f->buffer);
39}
40
41int av_fifo_size(AVFifoBuffer *f)
42{
43    int size = f->wptr - f->rptr;
44    if (size < 0)
45        size += f->end - f->buffer;
46    return size;
47}
48
49int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
50{
51    return av_fifo_generic_read(f, buf_size, NULL, buf);
52}
53
54#if LIBAVUTIL_VERSION_MAJOR < 50
55void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
56    av_fifo_realloc2(f, new_size);
57}
58#endif
59
60int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) {
61    unsigned int old_size= f->end - f->buffer;
62
63    if(old_size <= new_size){
64        int len= av_fifo_size(f);
65        AVFifoBuffer f2;
66
67        if (av_fifo_init(&f2, new_size) < 0)
68            return -1;
69        av_fifo_read(f, f2.buffer, len);
70        f2.wptr += len;
71        av_free(f->buffer);
72        *f= f2;
73    }
74    return 0;
75}
76
77#if LIBAVUTIL_VERSION_MAJOR < 50
78void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
79{
80    av_fifo_generic_write(f, (void *)buf, size, NULL);
81}
82#endif
83
84int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
85{
86    int total = size;
87    do {
88        int len = FFMIN(f->end - f->wptr, size);
89        if(func) {
90            if(func(src, f->wptr, len) <= 0)
91                break;
92        } else {
93            memcpy(f->wptr, src, len);
94            src = (uint8_t*)src + len;
95        }
96        f->wptr += len;
97        if (f->wptr >= f->end)
98            f->wptr = f->buffer;
99        size -= len;
100    } while (size > 0);
101    return total - size;
102}
103
104
105int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
106{
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. */
121void 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}
127