/* Implements hashing function for string with known length.

   Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.

   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, see

   <http://www.gnu.org/licenses/>.  */

#include <sys/types.h>

/* We assume to have `size_t' 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 size_t hash_string (const char *__str_param, size_t __len);

static inline size_t

hash_string (const char *str_param, size_t len)

{

  size_t hval, g;

  const char *end_str = str_param + len;

  /* Compute the hash value for the given string.  */

  hval = len;

  while (str_param != end_str)

    {

      hval <<= 4;

      hval += (size_t) *str_param++;

      g = hval & ((size_t) 0xf << (HASHWORDBITS - 4));

      if (g != 0)

	{

	  hval ^= g >> (HASHWORDBITS - 8);

	  hval ^= g;

	}

    }

  return hval;

}