1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2011 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Eclipse Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.eclipse.org/org/documents/epl-v10.html *
11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
12 * *
13 * Information and Software Systems Research *
14 * AT&T Research *
15 * Florham Park NJ *
16 * *
17 * Glenn Fowler <gsf@research.att.com> *
18 * David Korn <dgk@research.att.com> *
19 * Phong Vo <kpv@research.att.com> *
20 * *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24 * Glenn Fowler
25 * AT&T Research
26 */
27
28 #include <ast.h>
29
30 /*
31 * return a pointer to the element matching
32 * name in the (*comparf*)() sorted tab of num elements of
33 * size siz where the first member of each
34 * element is a char*
35 *
36 * 0 returned if name not found
37 */
38
39 void*
strsearch(const void * tab,size_t num,size_t siz,Strcmp_f comparf,const char * name,void * context)40 strsearch(const void* tab, size_t num, size_t siz, Strcmp_f comparf, const char* name, void* context)
41 {
42 char* lo = (char *)tab;
43 char* hi = lo + (num - 1) * siz;
44 char* mid;
45 int v;
46 Strcmp_context_f comparf_c = (Strcmp_context_f)(uintptr_t)comparf;
47
48 while (lo <= hi)
49 {
50 mid = lo + (((hi - lo) / siz) / 2) * siz;
51 if (!(v = context ? (*comparf_c)(name, *((char**)mid), context) : (*comparf)(name, *((char**)mid))))
52 return (mid);
53 else if (v > 0)
54 lo = mid + siz;
55 else hi = mid - siz;
56 }
57 return (NULL);
58 }
59