src/basic/sort-util.c

   1 #include "sort-util.h"
   2 #include "alloc-util.h"
   3
   4 /* hey glibc, APIs with callbacks without a user pointer are so useless */
   5 void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
   6                  __compar_d_fn_t compar, void *arg) {
   7         size_t l, u, idx;
   8         const void *p;
   9         int comparison;
  10
  11         assert(!size_multiply_overflow(nmemb, size));
  12
  13         l = 0;
  14         u = nmemb;
  15         while (l < u) {
  16                 idx = (l + u) / 2;
  17                 p = (const uint8_t*) base + idx * size;
  18                 comparison = compar(key, p, arg);
  19                 if (comparison < 0)
  20                         u = idx;
  21                 else if (comparison > 0)
  22                         l = idx + 1;
  23                 else
  24                         return (void *)p;
  25         }
  26         return NULL;
  27 }