| /* Description of GNU message catalog format: string hashing function. |
| Copyright (C) 1995, 1997-1998, 2000-2003 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 @@ */ |
| |
| /* 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 inline unsigned long int |
| hash_string (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 char) *str++; |
| g = hval & ((unsigned long int) 0xf << (HASHWORDBITS - 4)); |
| if (g != 0) |
| { |
| hval ^= g >> (HASHWORDBITS - 8); |
| hval ^= g; |
| } |
| } |
| return hval; |
| } |