glibc/intl/hash-string.h
Andreas Jaeger 41bdb6e20c Update to LGPL v2.1.
2001-07-06  Paul Eggert  <eggert@twinsun.com>

	* manual/argp.texi: Remove ignored LGPL copyright notice; it's
	not appropriate for documentation anyway.
	* manual/libc-texinfo.sh: "Library General Public License" ->
	"Lesser General Public License".

2001-07-06  Andreas Jaeger  <aj@suse.de>

	* All files under GPL/LGPL version 2: Place under LGPL version
	2.1.
2001-07-06 04:58:11 +00:00

61 lines
1.8 KiB
C

/* Implements a string hashing function.
Copyright (C) 1995, 1997, 1998, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* @@ end of prolog @@ */
#ifndef PARAMS
# if __STDC__
# define PARAMS(Args) Args
# else
# define PARAMS(Args) ()
# endif
#endif
/* We assume to have `unsigned long int' value with at least 32 bits. */
#define HASHWORDBITS 32
/* Defines the so called `hashpjw' function by P.J. Weinberger
[see Aho/Sethi/Ullman, COMPILERS: Principles, Techniques and Tools,
1986, 1987 Bell Telephone Laboratories, Inc.] */
static unsigned long int hash_string PARAMS ((const char *__str_param));
static inline unsigned long int
hash_string (str_param)
const char *str_param;
{
unsigned long int hval, g;
const char *str = str_param;
/* Compute the hash value for the given string. */
hval = 0;
while (*str != '\0')
{
hval <<= 4;
hval += (unsigned long int) *str++;
g = hval & ((unsigned long int) 0xf << (HASHWORDBITS - 4));
if (g != 0)
{
hval ^= g >> (HASHWORDBITS - 8);
hval ^= g;
}
}
return hval;
}