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/* hash-string.h - Description of GNU message catalog format: string hashing function. */
/* Copyright (C) 1995, 1997, 1998, 2000, 2001, 2005-2009 Free Software Foundation, Inc.
This file is part of GNU Bash.
Bash is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Bash 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Bash. If not, see <http://www.gnu.org/licenses/>.
*/
/* @@ 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;
}
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