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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 */ |