Files
lk/lib/libc/bsearch.c
Travis Geiselbrecht d8fa82cb91 [formatting] run everything through codestyle
Almost nothing changes here except moving braces to the same line as the
function declaration. Everything else is largely whitespace changes and
a few dangling files with tab indents.

See scripts/codestyle
2019-06-19 21:02:24 -07:00

45 lines
1.5 KiB
C

/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <stdlib.h>
void *bsearch(const void *key, const void *base, size_t num_elems, size_t size,
int (*compare)(const void *, const void *)) {
size_t low = 0, high = num_elems - 1;
if (num_elems == 0) {
return NULL;
}
for (;;) {
size_t mid = low + ((high - low) / 2);
const void *mid_elem = ((unsigned char *) base) + mid*size;
int r = compare(key, mid_elem);
if (r < 0) {
if (mid == 0) {
return NULL;
}
high = mid - 1;
} else if (r > 0) {
low = mid + 1;
if (low < mid || low > high) {
return NULL;
}
} else {
return (void *) mid_elem;
}
}
}