1/*
2 * Copyright (C) 1999-2001 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 Library General Public
7 * License as published by the Free Software Foundation; either version 2
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 * 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 LIBICONV Library; see the file COPYING.LIB.
17 * If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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
30static int
31hz_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int 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      return RET_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      return RET_ILSEQ;
85    if (ret != 2) abort();
86    conv->istate = state;
87    return count+2;
88  }
89
90none:
91  conv->istate = state;
92  return RET_TOOFEW(count);
93}
94
95static int
96hz_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
97{
98  state_t state = conv->ostate;
99  unsigned char buf[2];
100  int ret;
101
102  /* Code set 0 (ASCII or GB 1988-89) */
103  ret = ascii_wctomb(conv,buf,wc,1);
104  if (ret != RET_ILUNI) {
105    if (ret != 1) abort();
106    if (buf[0] < 0x80) {
107      int count = (state ? 3 : 1);
108      if (n < count)
109        return RET_TOOSMALL;
110      if (state) {
111        r[0] = '~';
112        r[1] = '}';
113        r += 2;
114        state = 0;
115      }
116      r[0] = buf[0];
117      conv->ostate = state;
118      return count;
119    }
120  }
121
122  /* Code set 1 (GB 2312-1980) */
123  ret = gb2312_wctomb(conv,buf,wc,2);
124  if (ret != RET_ILUNI) {
125    if (ret != 2) abort();
126    if (buf[0] < 0x80 && buf[1] < 0x80) {
127      int count = (state ? 2 : 4);
128      if (n < count)
129        return RET_TOOSMALL;
130      if (!state) {
131        r[0] = '~';
132        r[1] = '{';
133        r += 2;
134        state = 1;
135      }
136      r[0] = buf[0];
137      r[1] = buf[1];
138      conv->ostate = state;
139      return count;
140    }
141  }
142
143  return RET_ILUNI;
144}
145
146static int
147hz_reset (conv_t conv, unsigned char *r, int n)
148{
149  state_t state = conv->ostate;
150  if (state) {
151    if (n < 2)
152      return RET_TOOSMALL;
153    r[0] = '~';
154    r[1] = '}';
155    /* conv->ostate = 0; will be done by the caller */
156    return 2;
157  } else
158    return 0;
159}
160