1 /*
2 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stddef.h>
11 #include "internal/cryptlib.h"
12
ossl_bsearch(const void * key,const void * base,int num,int size,int (* cmp)(const void *,const void *),int flags)13 const void *ossl_bsearch(const void *key, const void *base, int num,
14 int size, int (*cmp) (const void *, const void *),
15 int flags)
16 {
17 const char *base_ = base;
18 int l, h, i = 0, c = 0;
19 const char *p = NULL;
20
21 if (num == 0)
22 return NULL;
23 l = 0;
24 h = num;
25 while (l < h) {
26 i = (l + h) / 2;
27 p = &(base_[i * size]);
28 c = (*cmp) (key, p);
29 if (c < 0)
30 h = i;
31 else if (c > 0)
32 l = i + 1;
33 else
34 break;
35 }
36 if (c != 0 && !(flags & OSSL_BSEARCH_VALUE_ON_NOMATCH))
37 p = NULL;
38 else if (c == 0 && (flags & OSSL_BSEARCH_FIRST_VALUE_ON_MATCH)) {
39 while (i > 0 && (*cmp) (key, &(base_[(i - 1) * size])) == 0)
40 i--;
41 p = &(base_[i * size]);
42 }
43 return p;
44 }
45