wctype/cname-lookup.h

   1 /* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <endian.h>
  21 #include "../locale/localeinfo.h"
  22
  23 /* Some words on the runtime of this functions.  Although there is a
  24    loop in the function the runtime is asymptotically quasi constant.
  25    The reason is that even for the largest character sets HASH_LAYERS
  26    will not grow beyond 15 (a guess!).  */
  27 #ifndef USE_IN_EXTENDED_LOCALE_MODEL
  28 static __inline size_t
  29 cname_lookup (wint_t wc)
  30 #else
  31 static __inline size_t
  32 cname_lookup (wint_t wc, __locale_t locale)
  33 #endif
  34 {
  35   unsigned int hash_size, hash_layers;
  36   size_t result, cnt;
  37
  38 #ifndef USE_IN_EXTENDED_LOCALE_MODEL
  39   extern unsigned int *__ctype_names;
  40   hash_size = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_HASH_SIZE);
  41   hash_layers = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_HASH_LAYERS);
  42 #else
  43   struct locale_data *current = locale->__locales[LC_CTYPE];
  44 #if BYTE_ORDER == BIG_ENDIAN
  45   unsigned int *__ctype_names =
  46     (unsigned int *) current->values[_NL_ITEM_INDEX (_NL_CTYPE_NAMES_EB)].string;
  47 #elif BYTE_ORDER == LITTLE_ENDIAN
  48   unsigned int *__ctype_names =
  49     (unsigned int *) current->values[_NL_ITEM_INDEX (_NL_CTYPE_NAMES_EL)].string;
  50 #else
  51 # error bizarre byte order
  52 #endif
  53   hash_size =
  54     current->values[_NL_ITEM_INDEX (_NL_CTYPE_HASH_SIZE)].word;
  55   hash_layers =
  56     current->values[_NL_ITEM_INDEX (_NL_CTYPE_HASH_LAYERS)].word;
  57 #endif
  58
  59   result = wc % hash_size;
  60   for (cnt = 0; cnt < hash_layers; ++cnt)
  61     {
  62       if (__ctype_names[result] == wc)
  63         break;
  64       result += hash_size;
  65     }
  66
  67   return cnt < hash_layers ? result : ~((size_t) 0);
  68 }