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