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big5.c
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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 
18 typedef struct
19 {
20  unsigned short code,
21  peer;
22 } codes_t;
23 
24 /* map Big5 Level 1 to CNS 11643-1992 Plane 1 */
25 static 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 */
54 static 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 */
84 static 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 */
136 static 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 */
189 static 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 */
197 static 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 
207 static 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 
291 unsigned short
292 BIG5toCNS(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 
344 unsigned short
345 CNStoBIG5(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 }
#define LC_CNS11643_1
Definition: pg_wchar.h:134
static unsigned short BinarySearchRange(const codes_t *array, int high, unsigned short code)
Definition: big5.c:208
static const codes_t big5Level2ToCnsPlane2[48]
Definition: big5.c:84
#define LC_CNS11643_4
Definition: pg_wchar.h:203
static const codes_t cnsPlane2ToBig5Level2[49]
Definition: big5.c:136
Definition: big5.c:18
static const codes_t big5Level1ToCnsPlane1[25]
Definition: big5.c:25
unsigned short code
Definition: big5.c:20
unsigned short CNStoBIG5(unsigned short cns, unsigned char lc)
Definition: big5.c:345
unsigned short peer
Definition: big5.c:20
static const codes_t cnsPlane1ToBig5Level1[26]
Definition: big5.c:54
unsigned short BIG5toCNS(unsigned short big5, unsigned char *lc)
Definition: big5.c:292
#define LC_CNS11643_2
Definition: pg_wchar.h:135
#define LC_CNS11643_3
Definition: pg_wchar.h:202
static const unsigned short b1c4[][2]
Definition: big5.c:189
int i
static const unsigned short b2c3[][2]
Definition: big5.c:197