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Diffstat (limited to 'src/lib/libc/stdlib/bsearch.c')
-rw-r--r-- | src/lib/libc/stdlib/bsearch.c | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/src/lib/libc/stdlib/bsearch.c b/src/lib/libc/stdlib/bsearch.c deleted file mode 100644 index 6df44d6b4f..0000000000 --- a/src/lib/libc/stdlib/bsearch.c +++ /dev/null | |||
@@ -1,69 +0,0 @@ | |||
1 | /* $OpenBSD: bsearch.c,v 1.9 2021/12/02 20:58:01 cheloha Exp $ */ | ||
2 | /* | ||
3 | * Copyright (c) 1990 Regents of the University of California. | ||
4 | * All rights reserved. | ||
5 | * | ||
6 | * Redistribution and use in source and binary forms, with or without | ||
7 | * modification, are permitted provided that the following conditions | ||
8 | * are met: | ||
9 | * 1. Redistributions of source code must retain the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer. | ||
11 | * 2. Redistributions in binary form must reproduce the above copyright | ||
12 | * notice, this list of conditions and the following disclaimer in the | ||
13 | * documentation and/or other materials provided with the distribution. | ||
14 | * 3. Neither the name of the University nor the names of its contributors | ||
15 | * may be used to endorse or promote products derived from this software | ||
16 | * without specific prior written permission. | ||
17 | * | ||
18 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | ||
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | ||
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
28 | * SUCH DAMAGE. | ||
29 | */ | ||
30 | |||
31 | #include <stdlib.h> | ||
32 | |||
33 | /* | ||
34 | * Perform a binary search. | ||
35 | * | ||
36 | * The code below is a bit sneaky. After a comparison fails, we | ||
37 | * divide the work in half by moving either left or right. If lim | ||
38 | * is odd, moving left simply involves halving lim: e.g., when lim | ||
39 | * is 5 we look at item 2, so we change lim to 2 so that we will | ||
40 | * look at items 0 & 1. If lim is even, the same applies. If lim | ||
41 | * is odd, moving right again involves halving lim, this time moving | ||
42 | * the base up one item past p: e.g., when lim is 5 we change base | ||
43 | * to item 3 and make lim 2 so that we will look at items 3 and 4. | ||
44 | * If lim is even, however, we have to shrink it by one before | ||
45 | * halving: e.g., when lim is 4, we still looked at item 2, so we | ||
46 | * have to make lim 3, then halve, obtaining 1, so that we will only | ||
47 | * look at item 3. | ||
48 | */ | ||
49 | void * | ||
50 | bsearch(const void *key, const void *base0, size_t nmemb, size_t size, | ||
51 | int (*compar)(const void *, const void *)) | ||
52 | { | ||
53 | const char *base = base0; | ||
54 | const void *p; | ||
55 | size_t lim; | ||
56 | int cmp; | ||
57 | |||
58 | for (lim = nmemb; lim != 0; lim >>= 1) { | ||
59 | p = base + (lim >> 1) * size; | ||
60 | cmp = (*compar)(key, p); | ||
61 | if (cmp == 0) | ||
62 | return ((void *)p); | ||
63 | if (cmp > 0) { /* key > p: move right */ | ||
64 | base = (char *)p + size; | ||
65 | lim--; | ||
66 | } /* else move left */ | ||
67 | } | ||
68 | return (NULL); | ||
69 | } | ||