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 | |
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 | |