initial message templates support
[claws.git] / intl / hash-string.h
blob37d4ce1a2c3d2c05d1e9d6a90d64e055613c74ad
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)
7 any later version.
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 /* @@ end of prolog @@ */
20 #ifndef PARAMS
21 # if __STDC__
22 # define PARAMS(Args) Args
23 # else
24 # define PARAMS(Args) ()
25 # endif
26 #endif
28 /* We assume to have `unsigned long int' value with at least 32 bits. */
29 #define HASHWORDBITS 32
32 /* Defines the so called `hashpjw' function by P.J. Weinberger
33 [see Aho/Sethi/Ullman, COMPILERS: Principles, Techniques and Tools,
34 1986, 1987 Bell Telephone Laboratories, Inc.] */
35 static unsigned long int hash_string PARAMS ((const char *__str_param));
37 static inline unsigned long int
38 hash_string (str_param)
39 const char *str_param;
41 unsigned long int hval, g;
42 const char *str = str_param;
44 /* Compute the hash value for the given string. */
45 hval = 0;
46 while (*str != '\0')
48 hval <<= 4;
49 hval += (unsigned long int) *str++;
50 g = hval & ((unsigned long int) 0xf << (HASHWORDBITS - 4));
51 if (g != 0)
53 hval ^= g >> (HASHWORDBITS - 8);
54 hval ^= g;
57 return hval;