xref: /titanic_51/usr/src/lib/libast/common/hash/strsum.c (revision 3e14f97f673e8a630f076077de35afdd43dc1587)

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2010 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Glenn Fowler
 * AT&T Bell Laboratories
 *
 * hash table library
 */

#include "hashlib.h"

/*
 * return a running 32 bit checksum of string s
 *
 * c is the return value from a previous
 * memsum() or strsum() call, 0 on the first call
 *
 * the result is the same on all implementations
 */

unsigned long
strsum(const char* as, register unsigned long c)
{
	register const unsigned char*	s = (const unsigned char*)as;
	register int			n;

	while (n = *s++) HASHPART(c, n);
#if LONG_MAX > 2147483647
	return(c & 0xffffffff);
#else
	return(c);
#endif
}