1
/* Description of GNU message catalog format: string hashing function.
2
Copyright (C) 1995, 1997, 1998, 2000, 2001 Free Software Foundation, Inc.
4
This program is free software; you can redistribute it and/or modify
5
it under the terms of the GNU General Public License as published by
6
the Free Software Foundation; either version 2, or (at your option)
9
This program is distributed in the hope that it will be useful,
10
but WITHOUT ANY WARRANTY; without even the implied warranty of
11
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12
GNU General Public License for more details.
14
You should have received a copy of the GNU General Public License
15
along with this program; if not, write to the Free Software Foundation,
16
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18
/* We assume to have `unsigned long int' value with at least 32 bits. */
19
#define HASHWORDBITS 32
21
/* Defines the so called `hashpjw' function by P.J. Weinberger
22
[see Aho/Sethi/Ullman, COMPILERS: Principles, Techniques and Tools,
23
1986, 1987 Bell Telephone Laboratories, Inc.] */
24
static unsigned long int hash_string(const unsigned char *__str_param);
26
static inline unsigned long int
27
hash_string(const unsigned char *str_param)
29
unsigned long int hval, g;
30
const unsigned char *str = str_param;
32
/* Compute the hash value for the given string. */
34
while (*str != '\0') {
36
hval += (unsigned long int) *str++;
37
g = hval & ((unsigned long int) 0xf << (HASHWORDBITS - 4));
39
hval ^= g >> (HASHWORDBITS - 8);