1 /* Access functions for KS C 5601-1992 based encoding conversion.
2    Copyright (C) 1998-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the 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    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 C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _KSC5601_H
20 #define _KSC5601_H	1
21 
22 #define KSC5601_HANGUL 2350
23 #define KSC5601_HANJA  4888
24 #define KSC5601_SYMBOL  989
25 
26 #include <gconv.h>
27 #include <stdint.h>
28 
29 /* Structure to map from UCS to KSC.  This structure should be packed
30    on all platforms.  */
31 struct map
32 {
33   uint16_t ucs;
34   char val[2];
35 };
36 
37 /* Conversion table.  */
38 extern const uint16_t __ksc5601_hangul_to_ucs[KSC5601_HANGUL];
39 extern const uint16_t __ksc5601_sym_to_ucs[];
40 extern const struct map __ksc5601_sym_from_ucs[KSC5601_SYMBOL];
41 extern const uint16_t __ksc5601_hanja_to_ucs[KSC5601_HANJA];
42 extern const struct map __ksc5601_hanja_from_ucs[KSC5601_HANJA];
43 
44 
uint32_t(always_inline)45 static inline uint32_t
46 __attribute ((always_inline))
47 ksc5601_to_ucs4 (const unsigned char **s, size_t avail, unsigned char offset)
48 {
49   unsigned char ch = **s;
50   unsigned char ch2;
51   int idx;
52 
53   if (avail < 2)
54     return 0;
55 
56   /* row 94(0x7e) and row 41(0x49) are user-defined area in KS C 5601 */
57 
58   if (ch < offset || (ch - offset) <= 0x20 || (ch - offset) >= 0x7e
59       || (ch - offset) == 0x49)
60     return __UNKNOWN_10646_CHAR;
61 
62   ch2 = (*s)[1];
63   if (ch2 < offset || (ch2 - offset) <= 0x20 || (ch2 - offset) >= 0x7f)
64     return __UNKNOWN_10646_CHAR;
65 
66   idx = (ch - offset - 0x21) * 94 + (ch2 - offset - 0x21);
67 
68   /* 1410 = 15 * 94 , 3760 = 40 * 94
69      Hangul in KS C 5601 : row 16 - row 40 */
70 
71   *s += 2;
72 
73   if (idx >= 1410 && idx < 1410 + KSC5601_HANGUL)
74     return (__ksc5601_hangul_to_ucs[idx - 1410]
75 	    ?: (*s -= 2, __UNKNOWN_10646_CHAR));
76   else if (idx >= 3854)
77     /* Hanja : row 42 - row 93 : 3854 = 94 * (42-1) */
78    return (__ksc5601_hanja_to_ucs[idx - 3854]
79 	   ?: (*s -= 2, __UNKNOWN_10646_CHAR));
80   else if (idx <= 1114)
81     return __ksc5601_sym_to_ucs[idx] ?: (*s -= 2, __UNKNOWN_10646_CHAR);
82 
83   *s -= 2;
84   return __UNKNOWN_10646_CHAR;
85 }
86 
size_t(always_inline)87 static inline size_t
88 __attribute ((always_inline))
89 ucs4_to_ksc5601_hangul (uint32_t wch, unsigned char *s, size_t avail)
90 {
91   int l = 0;
92   int u = KSC5601_HANGUL - 1;
93   uint32_t try;
94 
95   while (l <= u)
96     {
97       int m = (l + u) / 2;
98       try = (uint32_t) __ksc5601_hangul_to_ucs[m];
99       if (try > wch)
100 	u = m - 1;
101       else if (try < wch)
102 	l= m + 1;
103       else
104 	{
105 	  if (avail < 2)
106 	    return 0;
107 
108 	  s[0] = (m / 94) + 0x30;
109 	  s[1] = (m % 94) + 0x21;
110 
111 	  return 2;
112 	}
113     }
114 
115   return __UNKNOWN_10646_CHAR;
116 }
117 
118 
size_t(always_inline)119 static inline size_t
120 __attribute ((always_inline))
121 ucs4_to_ksc5601_hanja (uint32_t wch, unsigned char *s, size_t avail)
122 {
123   int l = 0;
124   int u = KSC5601_HANJA - 1;
125   uint32_t try;
126 
127   while (l <= u)
128     {
129       int m = (l + u) / 2;
130       try = (uint32_t) __ksc5601_hanja_from_ucs[m].ucs;
131       if (try > wch)
132 	u=m-1;
133       else if (try < wch)
134 	l = m + 1;
135       else
136 	{
137 	  if (avail < 2)
138 	    return 0;
139 
140 	  s[0] = __ksc5601_hanja_from_ucs[m].val[0];
141 	  s[1] = __ksc5601_hanja_from_ucs[m].val[1];
142 
143 	  return 2;
144 	}
145     }
146 
147   return __UNKNOWN_10646_CHAR;
148 }
149 
size_t(always_inline)150 static inline  size_t
151 __attribute ((always_inline))
152 ucs4_to_ksc5601_sym (uint32_t wch, unsigned char *s, size_t avail)
153 {
154   int l = 0;
155   int u = KSC5601_SYMBOL - 1;
156   uint32_t try;
157 
158   while (l <= u)
159     {
160       int m = (l + u) / 2;
161       try = __ksc5601_sym_from_ucs[m].ucs;
162       if (try > wch)
163 	u = m - 1;
164       else if (try < wch)
165 	l = m + 1;
166       else
167 	{
168 	  if (avail < 2)
169 	    return 0;
170 
171 	  s[0] = __ksc5601_sym_from_ucs[m].val[0];
172 	  s[1] = __ksc5601_sym_from_ucs[m].val[1];
173 
174 	  return 2;
175 	}
176     }
177 
178   return __UNKNOWN_10646_CHAR;
179 }
180 
181 
size_t(always_inline)182 static inline size_t
183 __attribute ((always_inline))
184 ucs4_to_ksc5601 (uint32_t wch, unsigned char *s, size_t avail)
185 {
186   if (wch >= 0xac00 && wch <= 0xd7a3)
187     return ucs4_to_ksc5601_hangul (wch, s, avail);
188   else if ((wch >= 0x4e00 && wch <= 0x9fff)
189 	   || (wch >= 0xf900 && wch <= 0xfa0b))
190     return ucs4_to_ksc5601_hanja (wch, s, avail);
191   else
192     return ucs4_to_ksc5601_sym (wch, s, avail);
193 }
194 
195 #endif /* ksc5601.h */
196