| 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 | |