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Diffstat (limited to 'intl/hash-string.c')
-rw-r--r-- | intl/hash-string.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/intl/hash-string.c b/intl/hash-string.c new file mode 100644 index 0000000000..e4b0f8fe57 --- /dev/null +++ b/intl/hash-string.c @@ -0,0 +1,47 @@ +/* Implements a string hashing function. + Copyright (C) 1995, 1997, 1998, 2000, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include "hash-string.h" + + +/* 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.] */ +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; +} |