60 lines
1.9 KiB
C
60 lines
1.9 KiB
C
|
/* Description of GNU message catalog format: string hashing function.
|
||
|
|
Copyright (C) 1995, 1997, 1998, 2000, 2001 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
This program is free software; you can redistribute it and/or modify it
|
||
|
|
under the terms of the GNU Library General Public License as published
|
||
|
|
by the Free Software Foundation; either version 2, or (at your option)
|
||
|
|
any later version.
|
||
|
|
|
||
|
|
This program 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
|
||
|
|
Library General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU Library General Public
|
||
|
|
License along with this program; 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__ || defined __GNUC__ || defined __SUNPRO_C || defined __cplusplus || __PROTOTYPES
|
||
|
|
# 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;
|
||
|
|
}
|