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 License
6 * 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
12 * GNU Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public License
15 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVUTIL_DYNARRAY_H
20#define AVUTIL_DYNARRAY_H
21
22#include "log.h"
23#include "mem.h"
24
25/**
26 * Add an element of to a dynamic array.
27 *
28 * The array is reallocated when its number of elements reaches powers of 2.
29 * Therefore, the amortized cost of adding an element is constant.
30 *
31 * In case of success, the pointer to the array is updated in order to
32 * point to the new grown array, and the size is incremented.
33 *
34 * @param av_size_max  maximum size of the array, usually the MAX macro of
35 *                     the type of the size
36 * @param av_elt_size  size of the elements in the array, in bytes
37 * @param av_array     pointer to the array, must be a lvalue
38 * @param av_size      size of the array, must be an integer lvalue
39 * @param av_success   statement to execute on success; at this point, the
40 *                     size variable is not yet incremented
41 * @param av_failure   statement to execute on failure; if this happens, the
42 *                     array and size are not changed; the statement can end
43 *                     with a return or a goto
44 */
45#define AV_DYNARRAY_ADD(av_size_max, av_elt_size, av_array, av_size, \
46                        av_success, av_failure) \
47    do { \
48        size_t av_size_new = (av_size); \
49        if (!((av_size) & ((av_size) - 1))) { \
50            av_size_new = (av_size) ? (av_size) << 1 : 1; \
51            if (av_size_new > (av_size_max) / (av_elt_size)) { \
52                av_size_new = 0; \
53            } else { \
54                void *av_array_new = \
55                    av_realloc((av_array), av_size_new * (av_elt_size)); \
56                if (!av_array_new) \
57                    av_size_new = 0; \
58                else \
59                    (av_array) = av_array_new; \
60            } \
61        } \
62        if (av_size_new) { \
63            { av_success } \
64            (av_size)++; \
65        } else { \
66            av_failure \
67        } \
68    } while (0)
69
70#endif /* AVUTIL_DYNARRAY_H */
71