X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fhash-pjw.c;h=3328467e4522e882f8b61e55755f7e6cd15580df;hb=68126b9700a6cefbfe0f578fa7dbe71829c52e8f;hp=141b08b51f727c072e1fdb141ed355d02d959533;hpb=7aabcfc8f8c6964a2ca12c6c6765eb48fe24575c;p=gnulib.git diff --git a/lib/hash-pjw.c b/lib/hash-pjw.c index 141b08b51..3328467e4 100644 --- a/lib/hash-pjw.c +++ b/lib/hash-pjw.c @@ -1,5 +1,5 @@ /* hash-pjw.c -- compute a hash value from a NUL-terminated string. - Copyright 2001 Free Software Foundation, Inc. + Copyright (C) 2001, 2003 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -21,22 +21,22 @@ #include "hash-pjw.h" +#include + +#define SIZE_BITS (sizeof (size_t) * CHAR_BIT) + /* A hash function for NUL-terminated char* strings using - the method described in Aho, Sethi, & Ullman, p 436. */ + the method described by Bruno Haible. + See http://www.haible.de/bruno/hashfunc.html. */ -unsigned int -hash_pjw (const void *x, unsigned int tablesize) +size_t +hash_pjw (const void *x, size_t tablesize) { - const char *s = x; - unsigned int h = 0; - unsigned int g; - - while (*s != 0) - { - h = (h << 4) + *s++; - if ((g = h & (unsigned int) 0xf0000000) != 0) - h = (h ^ (g >> 24)) ^ g; - } - - return (h % tablesize); + const char *s; + size_t h = 0; + + for (s = x; *s; s++) + h = *s + ((h << 9) | (h >> (SIZE_BITS - 9))); + + return h % tablesize; }