iconvdata/iso-ir-165.h

   1 /* Tables for conversion to and from ISO-IR-165.
   2    converting from UCS using gaps.
   3    Copyright (C) 2000, 2003 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #ifndef _ISO_IR_165_H
  23 #define _ISO_IR_165_H   1
  24
  25 #include <gconv.h>
  26 #include <stdint.h>
  27
  28 struct gap
  29 {
  30   uint16_t start;
  31   uint16_t end;
  32   int32_t idx;
  33 };
  34
  35 /* Table for ISO-IR-165 (CCITT Chinese) to UCS4 conversion.  */
  36 #define ISOIR165_FROMSIZE       0x2284
  37 extern const uint16_t __isoir165_to_tab[ISOIR165_FROMSIZE];
  38
  39
  40 /* XXX If we at some point need an offset value to decode the byte
  41    sequences another parameter can be added.  */
  42 static inline uint32_t
  43 __attribute ((always_inline))
  44 isoir165_to_ucs4 (const unsigned char **s, size_t avail)
  45 {
  46   unsigned char ch = *(*s);
  47   unsigned char ch2;
  48   uint32_t res;
  49
  50   if (ch <= 0x20 || ch >= 0x7f)
  51     return __UNKNOWN_10646_CHAR;
  52
  53   if (avail < 2)
  54     return 0;
  55
  56   ch2 = (*s)[1];
  57   if (ch2 <= 0x20 || ch2 >= 0x7f)
  58     return __UNKNOWN_10646_CHAR;
  59
  60   res = __isoir165_to_tab[(ch - 0x21) * 94 + (ch2 - 0x21)];
  61   if (res == 0)
  62     return __UNKNOWN_10646_CHAR;
  63
  64   *s += 2;
  65   return res;
  66 }
  67
  68
  69 /* Tables for ISO-IR-165 (CCITT Chinese) from UCS4 conversion.  */
  70 extern const struct gap __isoir165_from_idx[];
  71 extern const char __isoir165_from_tab[];
  72
  73 static inline size_t
  74 __attribute ((always_inline))
  75 ucs4_to_isoir165 (uint32_t wch, char *s, size_t avail)
  76 {
  77   unsigned int ch = (unsigned int) wch;
  78   const char *cp;
  79   const struct gap *rp = __isoir165_from_idx;
  80
  81   if (ch > 0xffe5)
  82     /* This is an illegal character.  */
  83     return __UNKNOWN_10646_CHAR;
  84
  85   while (ch > rp->end)
  86     ++rp;
  87   if (ch < rp->start)
  88     /* This is an illegal character.  */
  89     return __UNKNOWN_10646_CHAR;
  90
  91   /* The two bytes following the index given in this record give the
  92      encoding in ISO-IR-165.  Unless the bytes are zero.  */
  93   cp = &__isoir165_from_tab[(ch + rp->idx) * 2];
  94   if (*cp == '\0')
  95     /* This is an illegal character.  */
  96     return __UNKNOWN_10646_CHAR;
  97
  98   if (avail < 2)
  99     return 0;
 100
 101   s[0] = cp[0];
 102   s[1] = cp[1];
 103
 104   return 2;
 105 }
 106
 107 #endif  /* iso-ir-165.h */