1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVUTIL_BUFFER_INTERNAL_H
20#define AVUTIL_BUFFER_INTERNAL_H
21
22#include <stdint.h>
23
24#include "buffer.h"
25
26/**
27 * The buffer is always treated as read-only.
28 */
29#define BUFFER_FLAG_READONLY      (1 << 0)
30/**
31 * The buffer was av_realloc()ed, so it is reallocatable.
32 */
33#define BUFFER_FLAG_REALLOCATABLE (1 << 1)
34
35struct AVBuffer {
36    uint8_t *data; /**< data described by this buffer */
37    int      size; /**< size of data in bytes */
38
39    /**
40     *  number of existing AVBufferRef instances referring to this buffer
41     */
42    volatile int refcount;
43
44    /**
45     * a callback for freeing the data
46     */
47    void (*free)(void *opaque, uint8_t *data);
48
49    /**
50     * an opaque pointer, to be used by the freeing callback
51     */
52    void *opaque;
53
54    /**
55     * A combination of BUFFER_FLAG_*
56     */
57    int flags;
58};
59
60typedef struct BufferPoolEntry {
61    uint8_t *data;
62
63    /*
64     * Backups of the original opaque/free of the AVBuffer corresponding to
65     * data. They will be used to free the buffer when the pool is freed.
66     */
67    void *opaque;
68    void (*free)(void *opaque, uint8_t *data);
69
70    AVBufferPool *pool;
71    struct BufferPoolEntry * volatile next;
72} BufferPoolEntry;
73
74struct AVBufferPool {
75    BufferPoolEntry * volatile pool;
76
77    /*
78     * This is used to track when the pool is to be freed.
79     * The pointer to the pool itself held by the caller is considered to
80     * be one reference. Each buffer requested by the caller increases refcount
81     * by one, returning the buffer to the pool decreases it by one.
82     * refcount reaches zero when the buffer has been uninited AND all the
83     * buffers have been released, then it's safe to free the pool and all
84     * the buffers in it.
85     */
86    volatile int refcount;
87
88    volatile int nb_allocated;
89
90    int size;
91    AVBufferRef* (*alloc)(int size);
92};
93
94#endif /* AVUTIL_BUFFER_INTERNAL_H */
95