dynarray.h (2720B)
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 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 FF_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 */