LCOV - code coverage report
Current view: top level - src/backend/utils/mb/conversion_procs/euc_tw_and_big5 - big5.c (source / functions) Hit Total Coverage
Test: PostgreSQL 18devel Lines: 45 74 60.8 %
Date: 2024-12-12 17:14:55 Functions: 3 3 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       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          90 : 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          90 :     low = 0;
     216          90 :     mid = high >> 1;
     217             : 
     218         198 :     for (; low <= high; mid = (low + high) >> 1)
     219             :     {
     220         198 :         if ((array[mid].code <= code) && (array[mid + 1].code > code))
     221             :         {
     222          90 :             if (0 == array[mid].peer)
     223           0 :                 return 0;
     224          90 :             if (code >= 0xa140U)
     225             :             {
     226             :                 /* big5 to cns */
     227          72 :                 tmp = ((code & 0xff00) - (array[mid].code & 0xff00)) >> 8;
     228          72 :                 high = code & 0x00ff;
     229          72 :                 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         144 :                 distance = tmp * 0x9d + high - low +
     241           0 :                     (high >= 0xa1 ? (low >= 0xa1 ? 0 : -0x22)
     242          72 :                      : (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          72 :                 tmp = (array[mid].peer & 0x00ff) + distance - 0x21;
     253          72 :                 tmp = (array[mid].peer & 0xff00) + ((tmp / 0x5e) << 8)
     254          72 :                     + 0x21 + tmp % 0x5e;
     255          72 :                 return tmp;
     256             :             }
     257             :             else
     258             :             {
     259             :                 /* cns to big5 */
     260          18 :                 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          18 :                 distance = tmp * 0x5e
     267          18 :                     + ((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          18 :                 low = array[mid].peer & 0x00ff;
     274          18 :                 tmp = low + distance - (low >= 0xa1 ? 0x62 : 0x40);
     275          18 :                 low = tmp % 0x9d;
     276          36 :                 tmp = (array[mid].peer & 0xff00) + ((tmp / 0x9d) << 8)
     277          18 :                     + (low > 0x3e ? 0x62 : 0x40) + low;
     278          18 :                 return tmp;
     279             :             }
     280             :         }
     281         108 :         else if (array[mid].code > code)
     282          72 :             high = mid - 1;
     283             :         else
     284          36 :             low = mid + 1;
     285             :     }
     286             : 
     287           0 :     return 0;
     288             : }
     289             : 
     290             : 
     291             : unsigned short
     292          72 : BIG5toCNS(unsigned short big5, unsigned char *lc)
     293             : {
     294          72 :     unsigned short cns = 0;
     295             :     int         i;
     296             : 
     297          72 :     if (big5 < 0xc940U)
     298             :     {
     299             :         /* level 1 */
     300             : 
     301         360 :         for (i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
     302             :         {
     303         288 :             if (b1c4[i][0] == big5)
     304             :             {
     305           0 :                 *lc = LC_CNS11643_4;
     306           0 :                 return (b1c4[i][1] | 0x8080U);
     307             :             }
     308             :         }
     309             : 
     310          72 :         if (0 < (cns = BinarySearchRange(big5Level1ToCnsPlane1, 23, big5)))
     311          72 :             *lc = LC_CNS11643_1;
     312             :     }
     313           0 :     else if (big5 == 0xc94aU)
     314             :     {
     315             :         /* level 2 */
     316           0 :         *lc = LC_CNS11643_1;
     317           0 :         cns = 0x4442;
     318             :     }
     319             :     else
     320             :     {
     321             :         /* level 2 */
     322           0 :         for (i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
     323             :         {
     324           0 :             if (b2c3[i][0] == big5)
     325             :             {
     326           0 :                 *lc = LC_CNS11643_3;
     327           0 :                 return (b2c3[i][1] | 0x8080U);
     328             :             }
     329             :         }
     330             : 
     331           0 :         if (0 < (cns = BinarySearchRange(big5Level2ToCnsPlane2, 46, big5)))
     332           0 :             *lc = LC_CNS11643_2;
     333             :     }
     334             : 
     335          72 :     if (0 == cns)
     336             :     {                           /* no mapping Big5 to CNS 11643-1992 */
     337           0 :         *lc = 0;
     338           0 :         return (unsigned short) '?';
     339             :     }
     340             : 
     341          72 :     return cns | 0x8080;
     342             : }
     343             : 
     344             : unsigned short
     345          18 : CNStoBIG5(unsigned short cns, unsigned char lc)
     346             : {
     347             :     int         i;
     348          18 :     unsigned int big5 = 0;
     349             : 
     350          18 :     cns &= 0x7f7f;
     351             : 
     352          18 :     switch (lc)
     353             :     {
     354          18 :         case LC_CNS11643_1:
     355          18 :             big5 = BinarySearchRange(cnsPlane1ToBig5Level1, 24, cns);
     356          18 :             break;
     357           0 :         case LC_CNS11643_2:
     358           0 :             big5 = BinarySearchRange(cnsPlane2ToBig5Level2, 47, cns);
     359           0 :             break;
     360           0 :         case LC_CNS11643_3:
     361           0 :             for (i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
     362             :             {
     363           0 :                 if (b2c3[i][1] == cns)
     364           0 :                     return b2c3[i][0];
     365             :             }
     366           0 :             break;
     367           0 :         case LC_CNS11643_4:
     368           0 :             for (i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
     369             :             {
     370           0 :                 if (b1c4[i][1] == cns)
     371           0 :                     return b1c4[i][0];
     372             :             }
     373             :         default:
     374           0 :             break;
     375             :     }
     376          18 :     return big5;
     377             : }

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