1/*
2 * conversion between BIG5 and Mule Internal Code(CNS 116643-1992
3 * plane 1 and plane 2).
4 * This program is partially copied from lv(Multilingual file viewer)
5 * and slightly modified. lv is written and copyrighted by NARITA Tomio
6 * (nrt@web.ad.jp).
7 *
8 * 1999/1/15 Tatsuo Ishii
9 *
10 * src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
11 */
12
13/* can be used in either frontend or backend */
14#include "postgres_fe.h"
15
16#include "mb/pg_wchar.h"
17
18typedef struct
19{
20 unsigned short code,
21 peer;
22} codes_t;
23
24/* map Big5 Level 1 to CNS 11643-1992 Plane 1 */
25static const codes_t big5Level1ToCnsPlane1[25] = { /* range */
26 {0xA140, 0x2121},
27 {0xA1F6, 0x2258},
28 {0xA1F7, 0x2257},
29 {0xA1F8, 0x2259},
30 {0xA2AF, 0x2421},
31 {0xA3C0, 0x4221},
32 {0xa3e1, 0x0000},
33 {0xA440, 0x4421},
34 {0xACFE, 0x5753},
35 {0xacff, 0x0000},
36 {0xAD40, 0x5323},
37 {0xAFD0, 0x5754},
38 {0xBBC8, 0x6B51},
39 {0xBE52, 0x6B50},
40 {0xBE53, 0x6F5C},
41 {0xC1AB, 0x7536},
42 {0xC2CB, 0x7535},
43 {0xC2CC, 0x7737},
44 {0xC361, 0x782E},
45 {0xC3B9, 0x7865},
46 {0xC3BA, 0x7864},
47 {0xC3BB, 0x7866},
48 {0xC456, 0x782D},
49 {0xC457, 0x7962},
50 {0xc67f, 0x0000}
51};
52
53/* map CNS 11643-1992 Plane 1 to Big5 Level 1 */
54static const codes_t cnsPlane1ToBig5Level1[26] = { /* range */
55 {0x2121, 0xA140},
56 {0x2257, 0xA1F7},
57 {0x2258, 0xA1F6},
58 {0x2259, 0xA1F8},
59 {0x234f, 0x0000},
60 {0x2421, 0xA2AF},
61 {0x2571, 0x0000},
62 {0x4221, 0xA3C0},
63 {0x4242, 0x0000},
64 {0x4421, 0xA440},
65 {0x5323, 0xAD40},
66 {0x5753, 0xACFE},
67 {0x5754, 0xAFD0},
68 {0x6B50, 0xBE52},
69 {0x6B51, 0xBBC8},
70 {0x6F5C, 0xBE53},
71 {0x7535, 0xC2CB},
72 {0x7536, 0xC1AB},
73 {0x7737, 0xC2CC},
74 {0x782D, 0xC456},
75 {0x782E, 0xC361},
76 {0x7864, 0xC3BA},
77 {0x7865, 0xC3B9},
78 {0x7866, 0xC3BB},
79 {0x7962, 0xC457},
80 {0x7d4c, 0x0000}
81};
82
83/* map Big5 Level 2 to CNS 11643-1992 Plane 2 */
84static const codes_t big5Level2ToCnsPlane2[48] = { /* range */
85 {0xC940, 0x2121},
86 {0xc94a, 0x0000},
87 {0xC94B, 0x212B},
88 {0xC96C, 0x214D},
89 {0xC9BE, 0x214C},
90 {0xC9BF, 0x217D},
91 {0xC9ED, 0x224E},
92 {0xCAF7, 0x224D},
93 {0xCAF8, 0x2439},
94 {0xD77A, 0x3F6A},
95 {0xD77B, 0x387E},
96 {0xDBA7, 0x3F6B},
97 {0xDDFC, 0x4176},
98 {0xDDFD, 0x4424},
99 {0xE8A3, 0x554C},
100 {0xE976, 0x5723},
101 {0xEB5B, 0x5A29},
102 {0xEBF1, 0x554B},
103 {0xEBF2, 0x5B3F},
104 {0xECDE, 0x5722},
105 {0xECDF, 0x5C6A},
106 {0xEDAA, 0x5D75},
107 {0xEEEB, 0x642F},
108 {0xEEEC, 0x6039},
109 {0xF056, 0x5D74},
110 {0xF057, 0x6243},
111 {0xF0CB, 0x5A28},
112 {0xF0CC, 0x6337},
113 {0xF163, 0x6430},
114 {0xF16B, 0x6761},
115 {0xF16C, 0x6438},
116 {0xF268, 0x6934},
117 {0xF269, 0x6573},
118 {0xF2C3, 0x664E},
119 {0xF375, 0x6762},
120 {0xF466, 0x6935},
121 {0xF4B5, 0x664D},
122 {0xF4B6, 0x6962},
123 {0xF4FD, 0x6A4C},
124 {0xF663, 0x6A4B},
125 {0xF664, 0x6C52},
126 {0xF977, 0x7167},
127 {0xF9C4, 0x7166},
128 {0xF9C5, 0x7234},
129 {0xF9C6, 0x7240},
130 {0xF9C7, 0x7235},
131 {0xF9D2, 0x7241},
132 {0xf9d6, 0x0000}
133};
134
135/* map CNS 11643-1992 Plane 2 to Big5 Level 2 */
136static const codes_t cnsPlane2ToBig5Level2[49] = { /* range */
137 {0x2121, 0xC940},
138 {0x212B, 0xC94B},
139 {0x214C, 0xC9BE},
140 {0x214D, 0xC96C},
141 {0x217D, 0xC9BF},
142 {0x224D, 0xCAF7},
143 {0x224E, 0xC9ED},
144 {0x2439, 0xCAF8},
145 {0x387E, 0xD77B},
146 {0x3F6A, 0xD77A},
147 {0x3F6B, 0xDBA7},
148 {0x4424, 0x0000},
149 {0x4176, 0xDDFC},
150 {0x4177, 0x0000},
151 {0x4424, 0xDDFD},
152 {0x554B, 0xEBF1},
153 {0x554C, 0xE8A3},
154 {0x5722, 0xECDE},
155 {0x5723, 0xE976},
156 {0x5A28, 0xF0CB},
157 {0x5A29, 0xEB5B},
158 {0x5B3F, 0xEBF2},
159 {0x5C6A, 0xECDF},
160 {0x5D74, 0xF056},
161 {0x5D75, 0xEDAA},
162 {0x6039, 0xEEEC},
163 {0x6243, 0xF057},
164 {0x6337, 0xF0CC},
165 {0x642F, 0xEEEB},
166 {0x6430, 0xF163},
167 {0x6438, 0xF16C},
168 {0x6573, 0xF269},
169 {0x664D, 0xF4B5},
170 {0x664E, 0xF2C3},
171 {0x6761, 0xF16B},
172 {0x6762, 0xF375},
173 {0x6934, 0xF268},
174 {0x6935, 0xF466},
175 {0x6962, 0xF4B6},
176 {0x6A4B, 0xF663},
177 {0x6A4C, 0xF4FD},
178 {0x6C52, 0xF664},
179 {0x7166, 0xF9C4},
180 {0x7167, 0xF977},
181 {0x7234, 0xF9C5},
182 {0x7235, 0xF9C7},
183 {0x7240, 0xF9C6},
184 {0x7241, 0xF9D2},
185 {0x7245, 0x0000}
186};
187
188/* Big Five Level 1 Correspondence to CNS 11643-1992 Plane 4 */
189static const unsigned short b1c4[][2] = {
190 {0xC879, 0x2123},
191 {0xC87B, 0x2124},
192 {0xC87D, 0x212A},
193 {0xC8A2, 0x2152}
194};
195
196/* Big Five Level 2 Correspondence to CNS 11643-1992 Plane 3 */
197static const unsigned short b2c3[][2] = {
198 {0xF9D6, 0x4337},
199 {0xF9D7, 0x4F50},
200 {0xF9D8, 0x444E},
201 {0xF9D9, 0x504A},
202 {0xF9DA, 0x2C5D},
203 {0xF9DB, 0x3D7E},
204 {0xF9DC, 0x4B5C}
205};
206
207static unsigned short BinarySearchRange
208 (const codes_t *array, int high, unsigned short code)
209{
210 int low,
211 mid,
212 distance,
213 tmp;
214
215 low = 0;
216 mid = high >> 1;
217
218 for (; low <= high; mid = (low + high) >> 1)
219 {
220 if ((array[mid].code <= code) && (array[mid + 1].code > code))
221 {
222 if (0 == array[mid].peer)
223 return 0;
224 if (code >= 0xa140U)
225 {
226 /* big5 to cns */
227 tmp = ((code & 0xff00) - (array[mid].code & 0xff00)) >> 8;
228 high = code & 0x00ff;
229 low = array[mid].code & 0x00ff;
230
231 /*
232 * NOTE: big5 high_byte: 0xa1-0xfe, low_byte: 0x40-0x7e,
233 * 0xa1-0xfe (radicals: 0x00-0x3e, 0x3f-0x9c) big5 radix is
234 * 0x9d. [region_low, region_high] We
235 * should remember big5 has two different regions (above).
236 * There is a bias for the distance between these regions.
237 * 0xa1 - 0x7e + bias = 1 (Distance between 0xa1 and 0x7e is
238 * 1.) bias = - 0x22.
239 */
240 distance = tmp * 0x9d + high - low +
241 (high >= 0xa1 ? (low >= 0xa1 ? 0 : -0x22)
242 : (low >= 0xa1 ? +0x22 : 0));
243
244 /*
245 * NOTE: we have to convert the distance into a code point.
246 * The code point's low_byte is 0x21 plus mod_0x5e. In the
247 * first, we extract the mod_0x5e of the starting code point,
248 * subtracting 0x21, and add distance to it. Then we calculate
249 * again mod_0x5e of them, and restore the final codepoint,
250 * adding 0x21.
251 */
252 tmp = (array[mid].peer & 0x00ff) + distance - 0x21;
253 tmp = (array[mid].peer & 0xff00) + ((tmp / 0x5e) << 8)
254 + 0x21 + tmp % 0x5e;
255 return tmp;
256 }
257 else
258 {
259 /* cns to big5 */
260 tmp = ((code & 0xff00) - (array[mid].code & 0xff00)) >> 8;
261
262 /*
263 * NOTE: ISO charsets ranges between 0x21-0xfe (94charset).
264 * Its radix is 0x5e. But there is no distance bias like big5.
265 */
266 distance = tmp * 0x5e
267 + ((int) (code & 0x00ff) - (int) (array[mid].code & 0x00ff));
268
269 /*
270 * NOTE: Similar to big5 to cns conversion, we extract
271 * mod_0x9d and restore mod_0x9d into a code point.
272 */
273 low = array[mid].peer & 0x00ff;
274 tmp = low + distance - (low >= 0xa1 ? 0x62 : 0x40);
275 low = tmp % 0x9d;
276 tmp = (array[mid].peer & 0xff00) + ((tmp / 0x9d) << 8)
277 + (low > 0x3e ? 0x62 : 0x40) + low;
278 return tmp;
279 }
280 }
281 else if (array[mid].code > code)
282 high = mid - 1;
283 else
284 low = mid + 1;
285 }
286
287 return 0;
288}
289
290
291unsigned short
292BIG5toCNS(unsigned short big5, unsigned char *lc)
293{
294 unsigned short cns = 0;
295 int i;
296
297 if (big5 < 0xc940U)
298 {
299 /* level 1 */
300
301 for (i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
302 {
303 if (b1c4[i][0] == big5)
304 {
305 *lc = LC_CNS11643_4;
306 return (b1c4[i][1] | 0x8080U);
307 }
308 }
309
310 if (0 < (cns = BinarySearchRange(big5Level1ToCnsPlane1, 23, big5)))
311 *lc = LC_CNS11643_1;
312 }
313 else if (big5 == 0xc94aU)
314 {
315 /* level 2 */
316 *lc = LC_CNS11643_1;
317 cns = 0x4442;
318 }
319 else
320 {
321 /* level 2 */
322 for (i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
323 {
324 if (b2c3[i][0] == big5)
325 {
326 *lc = LC_CNS11643_3;
327 return (b2c3[i][1] | 0x8080U);
328 }
329 }
330
331 if (0 < (cns = BinarySearchRange(big5Level2ToCnsPlane2, 46, big5)))
332 *lc = LC_CNS11643_2;
333 }
334
335 if (0 == cns)
336 { /* no mapping Big5 to CNS 11643-1992 */
337 *lc = 0;
338 return (unsigned short) '?';
339 }
340
341 return cns | 0x8080;
342}
343
344unsigned short
345CNStoBIG5(unsigned short cns, unsigned char lc)
346{
347 int i;
348 unsigned int big5 = 0;
349
350 cns &= 0x7f7f;
351
352 switch (lc)
353 {
354 case LC_CNS11643_1:
355 big5 = BinarySearchRange(cnsPlane1ToBig5Level1, 24, cns);
356 break;
357 case LC_CNS11643_2:
358 big5 = BinarySearchRange(cnsPlane2ToBig5Level2, 47, cns);
359 break;
360 case LC_CNS11643_3:
361 for (i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
362 {
363 if (b2c3[i][1] == cns)
364 return b2c3[i][0];
365 }
366 break;
367 case LC_CNS11643_4:
368 for (i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
369 {
370 if (b1c4[i][1] == cns)
371 return b1c4[i][0];
372 }
373 default:
374 break;
375 }
376 return big5;
377}
378