granicus.if.org Git - postgresql/blob - src/backend/utils/adt/ascii.c

   1 /*-----------------------------------------------------------------------
   2  * ascii.c
   3  *       The PostgreSQL routine for string to ascii conversion.
   4  *
   5  *       Portions Copyright (c) 1999-2006, PostgreSQL Global Development Group
   6  *
   7  * IDENTIFICATION
   8  *        $PostgreSQL: pgsql/src/backend/utils/adt/ascii.c,v 1.29 2006/07/14 14:52:23 momjian Exp $
   9  *
  10  *-----------------------------------------------------------------------
  11  */
  12 #include "postgres.h"
  13
  14 #include "mb/pg_wchar.h"
  15 #include "utils/ascii.h"
  16
  17 static void pg_to_ascii(unsigned char *src, unsigned char *src_end,
  18                         unsigned char *dest, int enc);
  19 static text *encode_to_ascii(text *data, int enc);
  20
  21
  22 /* ----------
  23  * to_ascii
  24  * ----------
  25  */
  26 static void
  27 pg_to_ascii(unsigned char *src, unsigned char *src_end, unsigned char *dest, int enc)
  28 {
  29         unsigned char *x;
  30         const unsigned char *ascii;
  31         int                     range;
  32
  33         /*
  34          * relevant start for an encoding
  35          */
  36 #define RANGE_128       128
  37 #define RANGE_160       160
  38
  39         if (enc == PG_LATIN1)
  40         {
  41                 /*
  42                  * ISO-8859-1 <range: 160 -- 255>
  43                  */
  44                 ascii = (const unsigned char *) "  cL Y  \"Ca  -R     'u .,      ?AAAAAAACEEEEIIII NOOOOOxOUUUUYTBaaaaaaaceeeeiiii nooooo/ouuuuyty";
  45                 range = RANGE_160;
  46         }
  47         else if (enc == PG_LATIN2)
  48         {
  49                 /*
  50                  * ISO-8859-2 <range: 160 -- 255>
  51                  */
  52                 ascii = (const unsigned char *) " A L LS \"SSTZ-ZZ a,l'ls ,sstz\"zzRAAAALCCCEEEEIIDDNNOOOOxRUUUUYTBraaaalccceeeeiiddnnoooo/ruuuuyt.";
  53                 range = RANGE_160;
  54         }
  55         else if (enc == PG_LATIN9)
  56         {
  57                 /*
  58                  * ISO-8859-15 <range: 160 -- 255>
  59                  */
  60                 ascii = (const unsigned char *) "  cL YS sCa  -R     Zu .z   EeY?AAAAAAACEEEEIIII NOOOOOxOUUUUYTBaaaaaaaceeeeiiii nooooo/ouuuuyty";
  61                 range = RANGE_160;
  62         }
  63         else if (enc == PG_WIN1250)
  64         {
  65                 /*
  66                  * Window CP1250 <range: 128 -- 255>
  67                  */
  68                 ascii = (const unsigned char *) "  ' \"    %S<STZZ `'\"\".--  s>stzz   L A  \"CS  -RZ  ,l'u .,as L\"lzRAAAALCCCEEEEIIDDNNOOOOxRUUUUYTBraaaalccceeeeiiddnnoooo/ruuuuyt ";
  69                 range = RANGE_128;
  70         }
  71         else
  72         {
  73                 ereport(ERROR,
  74                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  75                                  errmsg("encoding conversion from %s to ASCII not supported",
  76                                                 pg_encoding_to_char(enc))));
  77                 return;                                 /* keep compiler quiet */
  78         }
  79
  80         /*
  81          * Encode
  82          */
  83         for (x = src; x < src_end; x++)
  84         {
  85                 if (*x < 128)
  86                         *dest++ = *x;
  87                 else if (*x < range)
  88                         *dest++ = ' ';          /* bogus 128 to 'range' */
  89                 else
  90                         *dest++ = ascii[*x - range];
  91         }
  92 }
  93
  94 /* ----------
  95  * encode text
  96  *
  97  * The text datum is overwritten in-place, therefore this coding method
  98  * cannot support conversions that change the string length!
  99  * ----------
 100  */
 101 static text *
 102 encode_to_ascii(text *data, int enc)
 103 {
 104         pg_to_ascii((unsigned char *) VARDATA(data),            /* src */
 105                                 (unsigned char *) (data) + VARSIZE(data),               /* src end */
 106                                 (unsigned char *) VARDATA(data),                /* dest */
 107                                 enc);                   /* encoding */
 108
 109         return data;
 110 }
 111
 112 /* ----------
 113  * convert to ASCII - enc is set as 'name' arg.
 114  * ----------
 115  */
 116 Datum
 117 to_ascii_encname(PG_FUNCTION_ARGS)
 118 {
 119         text       *data = PG_GETARG_TEXT_P_COPY(0);
 120         int                     enc = pg_char_to_encoding(NameStr(*PG_GETARG_NAME(1)));
 121
 122         PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 123 }
 124
 125 /* ----------
 126  * convert to ASCII - enc is set as int4
 127  * ----------
 128  */
 129 Datum
 130 to_ascii_enc(PG_FUNCTION_ARGS)
 131 {
 132         text       *data = PG_GETARG_TEXT_P_COPY(0);
 133         int                     enc = PG_GETARG_INT32(1);
 134
 135         PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 136 }
 137
 138 /* ----------
 139  * convert to ASCII - current enc is DatabaseEncoding
 140  * ----------
 141  */
 142 Datum
 143 to_ascii_default(PG_FUNCTION_ARGS)
 144 {
 145         text       *data = PG_GETARG_TEXT_P_COPY(0);
 146         int                     enc = GetDatabaseEncoding();
 147
 148         PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 149 }