Update.

[thirdparty/glibc.git] / wctype / cname-lookup.h

/* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.

   The GNU C Library 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 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <endian.h>
#include "../locale/localeinfo.h"

/* Some words on the runtime of this functions.  Although there is a
   loop in the function the runtime is asymptotically quasi constant.
   The reason is that even for the largest character sets HASH_LAYERS
   will not grow beyond 15 (a guess!).  */
#ifndef USE_IN_EXTENDED_LOCALE_MODEL
static __inline size_t
cname_lookup (wint_t wc)
#else
static __inline size_t
cname_lookup (wint_t wc, __locale_t locale)
#endif
{
  unsigned int hash_size, hash_layers;
  size_t result, cnt;

#ifndef USE_IN_EXTENDED_LOCALE_MODEL
  extern unsigned int *__ctype_names;
  hash_size = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_HASH_SIZE);
  hash_layers = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_HASH_LAYERS);
#else
  struct locale_data *current = locale->__locales[LC_CTYPE];
#if BYTE_ORDER == BIG_ENDIAN
  unsigned int *__ctype_names =
    (unsigned int *) current->values[_NL_ITEM_INDEX (_NL_CTYPE_NAMES_EB)].string;
#elif BYTE_ORDER == LITTLE_ENDIAN
  unsigned int *__ctype_names =
    (unsigned int *) current->values[_NL_ITEM_INDEX (_NL_CTYPE_NAMES_EL)].string;
#else
# error bizarre byte order
#endif
  hash_size =
    current->values[_NL_ITEM_INDEX (_NL_CTYPE_HASH_SIZE)].word;
  hash_layers =
    current->values[_NL_ITEM_INDEX (_NL_CTYPE_HASH_LAYERS)].word;
#endif

  result = wc % hash_size;
  for (cnt = 0; cnt < hash_layers; ++cnt)
    {
      if (__ctype_names[result] == wc)
	break;
      result += hash_size;
    }

  return cnt < hash_layers ? result : ~((size_t) 0);
}