| 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 */ |