Blame view

ffmpeg-4.2.2/libavutil/dynarray.h 2.66 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
  /*
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public License
   * as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public License
   * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #ifndef AVUTIL_DYNARRAY_H
  #define AVUTIL_DYNARRAY_H
  
  #include "log.h"
  #include "mem.h"
  
  /**
   * Add an element to a dynamic array.
   *
   * The array is reallocated when its number of elements reaches powers of 2.
   * Therefore, the amortized cost of adding an element is constant.
   *
   * In case of success, the pointer to the array is updated in order to
   * point to the new grown array, and the size is incremented.
   *
   * @param av_size_max  maximum size of the array, usually the MAX macro of
   *                     the type of the size
   * @param av_elt_size  size of the elements in the array, in bytes
   * @param av_array     pointer to the array, must be a lvalue
   * @param av_size      size of the array, must be an integer lvalue
   * @param av_success   statement to execute on success; at this point, the
   *                     size variable is not yet incremented
   * @param av_failure   statement to execute on failure; if this happens, the
   *                     array and size are not changed; the statement can end
   *                     with a return or a goto
   */
  #define FF_DYNARRAY_ADD(av_size_max, av_elt_size, av_array, av_size, \
                          av_success, av_failure) \
      do { \
          size_t av_size_new = (av_size); \
          if (!((av_size) & ((av_size) - 1))) { \
              av_size_new = (av_size) ? (av_size) << 1 : 1; \
              if (av_size_new > (av_size_max) / (av_elt_size)) { \
                  av_size_new = 0; \
              } else { \
                  void *av_array_new = \
                      av_realloc((av_array), av_size_new * (av_elt_size)); \
                  if (!av_array_new) \
                      av_size_new = 0; \
                  else \
                      (av_array) = av_array_new; \
              } \
          } \
          if (av_size_new) { \
              { av_success } \
              (av_size)++; \
          } else { \
              av_failure \
          } \
      } while (0)
  
  #endif /* AVUTIL_DYNARRAY_H */