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-rw-r--r--lib/intl/hash-string.h59
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/intl/hash-string.h b/lib/intl/hash-string.h
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+/* Description of GNU message catalog format: string hashing function.
+ Copyright (C) 1995, 1997, 1998, 2000, 2001 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 @@ */
+
+#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;
+}