lib/hz.h

   1 /*
   2  * Copyright (C) 1999-2001, 2008, 2016 Free Software Foundation, Inc.
   3  * This file is part of the GNU LIBICONV Library.
   4  *
   5  * The GNU LIBICONV Library is free software; you can redistribute it
   6  * and/or modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either version 2.1
   8  * of the License, or (at your option) any later version.
   9  *
  10  * The GNU LIBICONV Library is distributed in the hope that it will be
  11  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
  17  * If not, see <https://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * HZ
  22  */
  23
  24 /* Specification: RFC 1842, RFC 1843 */
  25
  26 /*
  27  * The state is 1 in GB mode, 0 in ASCII mode.
  28  */
  29
  30 static int
  31 hz_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n)
  32 {
  33   state_t state = conv->istate;
  34   unsigned int count = 0;
  35   unsigned char c;
  36   for (;;) {
  37     c = *s;
  38     if (c == '~') {
  39       if (n < count+2)
  40         goto none;
  41       c = s[1];
  42       if (state == 0) {
  43         if (c == '~') {
  44           *pwc = (ucs4_t) '~';
  45           conv->istate = state;
  46           return count+2;
  47         }
  48         if (c == '{') {
  49           state = 1;
  50           s += 2; count += 2;
  51           if (n < count+1)
  52             goto none;
  53           continue;
  54         }
  55         if (c == '\n') {
  56           s += 2; count += 2;
  57           if (n < count+1)
  58             goto none;
  59           continue;
  60         }
  61       } else {
  62         if (c == '}') {
  63           state = 0;
  64           s += 2; count += 2;
  65           if (n < count+1)
  66             goto none;
  67           continue;
  68         }
  69       }
  70       goto ilseq;
  71     }
  72     break;
  73   }
  74   if (state == 0) {
  75     *pwc = (ucs4_t) c;
  76     conv->istate = state;
  77     return count+1;
  78   } else {
  79     int ret;
  80     if (n < count+2)
  81       goto none;
  82     ret = gb2312_mbtowc(conv,pwc,s,2);
  83     if (ret == RET_ILSEQ)
  84       goto ilseq;
  85     if (ret != 2) abort();
  86     conv->istate = state;
  87     return count+2;
  88   }
  89
  90 none:
  91   conv->istate = state;
  92   return RET_TOOFEW(count);
  93
  94 ilseq:
  95   conv->istate = state;
  96   return RET_SHIFT_ILSEQ(count);
  97 }
  98
  99 static int
 100 hz_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, size_t n)
 101 {
 102   state_t state = conv->ostate;
 103   unsigned char buf[2];
 104   int ret;
 105
 106   /* Code set 0 (ASCII or GB 1988-89) */
 107   ret = ascii_wctomb(conv,buf,wc,1);
 108   if (ret != RET_ILUNI) {
 109     if (ret != 1) abort();
 110     if (buf[0] < 0x80) {
 111       int count = (state ? 3 : 1);
 112       if (n < count)
 113         return RET_TOOSMALL;
 114       if (state) {
 115         r[0] = '~';
 116         r[1] = '}';
 117         r += 2;
 118         state = 0;
 119       }
 120       r[0] = buf[0];
 121       conv->ostate = state;
 122       return count;
 123     }
 124   }
 125
 126   /* Code set 1 (GB 2312-1980) */
 127   ret = gb2312_wctomb(conv,buf,wc,2);
 128   if (ret != RET_ILUNI) {
 129     if (ret != 2) abort();
 130     if (buf[0] < 0x80 && buf[1] < 0x80) {
 131       int count = (state ? 2 : 4);
 132       if (n < count)
 133         return RET_TOOSMALL;
 134       if (!state) {
 135         r[0] = '~';
 136         r[1] = '{';
 137         r += 2;
 138         state = 1;
 139       }
 140       r[0] = buf[0];
 141       r[1] = buf[1];
 142       conv->ostate = state;
 143       return count;
 144     }
 145   }
 146
 147   return RET_ILUNI;
 148 }
 149
 150 static int
 151 hz_reset (conv_t conv, unsigned char *r, size_t n)
 152 {
 153   state_t state = conv->ostate;
 154   if (state) {
 155     if (n < 2)
 156       return RET_TOOSMALL;
 157     r[0] = '~';
 158     r[1] = '}';
 159     /* conv->ostate = 0; will be done by the caller */
 160     return 2;
 161   } else
 162     return 0;
 163 }