src/siconv.c

   1 /* This file is part of the YAZ toolkit.
   2  * Copyright (C) 1995-2012 Index Data
   3  * See the file LICENSE for details.
   4  */
   5 /**
   6  * \file
   7  * \brief Implements simple ICONV
   8  *
   9  * This implements an interface similar to that of iconv and
  10  * is used by YAZ to interface with iconv (if present).
  11  * For systems where iconv is not present, this layer
  12  * provides a few important conversions: UTF-8, MARC-8, Latin-1.
  13  *
  14  */
  15
  16 #if HAVE_CONFIG_H
  17 #include <config.h>
  18 #endif
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <string.h>
  23
  24 #if HAVE_ICONV_H
  25 #include <iconv.h>
  26 #endif
  27
  28 #include <yaz/xmalloc.h>
  29 #include <yaz/errno.h>
  30 #include "iconv-p.h"
  31
  32 struct yaz_iconv_struct {
  33     int my_errno;
  34     int init_flag;
  35 #if 0
  36     size_t (*init_handle)(yaz_iconv_t cd, unsigned char *inbuf,
  37                             size_t inbytesleft, size_t *no_read);
  38     unsigned long (*read_handle)(yaz_iconv_t cd, unsigned char *inbuf,
  39                                  size_t inbytesleft, size_t *no_read);
  40 #endif
  41     size_t no_read_x;
  42     unsigned long unget_x;
  43 #if HAVE_ICONV_H
  44     iconv_t iconv_cd;
  45 #endif
  46     struct yaz_iconv_encoder_s encoder;
  47     struct yaz_iconv_decoder_s decoder;
  48 };
  49
  50
  51 int yaz_iconv_isbuiltin(yaz_iconv_t cd)
  52 {
  53     return cd->decoder.read_handle && cd->encoder.write_handle;
  54 }
  55
  56
  57 static int prepare_encoders(yaz_iconv_t cd, const char *tocode)
  58 {
  59     if (yaz_marc8_encoder(tocode, &cd->encoder))
  60         return 1;
  61     if (yaz_utf8_encoder(tocode, &cd->encoder))
  62         return 1;
  63     if (yaz_ucs4_encoder(tocode, &cd->encoder))
  64         return 1;
  65     if (yaz_iso_8859_1_encoder(tocode, &cd->encoder))
  66         return 1;
  67     if (yaz_iso_5428_encoder(tocode, &cd->encoder))
  68         return 1;
  69     if (yaz_advancegreek_encoder(tocode, &cd->encoder))
  70         return 1;
  71     if (yaz_wchar_encoder(tocode, &cd->encoder))
  72         return 1;
  73     return 0;
  74 }
  75
  76 static int prepare_decoders(yaz_iconv_t cd, const char *tocode)
  77 {
  78     if (yaz_marc8_decoder(tocode, &cd->decoder))
  79         return 1;
  80     if (yaz_iso5426_decoder(tocode, &cd->decoder))
  81         return 1;
  82     if (yaz_utf8_decoder(tocode, &cd->decoder))
  83         return 1;
  84     if (yaz_ucs4_decoder(tocode, &cd->decoder))
  85         return 1;
  86     if (yaz_iso_8859_1_decoder(tocode, &cd->decoder))
  87         return 1;
  88     if (yaz_iso_5428_decoder(tocode, &cd->decoder))
  89         return 1;
  90     if (yaz_advancegreek_decoder(tocode, &cd->decoder))
  91         return 1;
  92     if (yaz_wchar_decoder(tocode, &cd->decoder))
  93         return 1;
  94     if (yaz_danmarc_decoder(tocode, &cd->decoder))
  95         return 1;
  96     return 0;
  97 }
  98
  99 yaz_iconv_t yaz_iconv_open(const char *tocode, const char *fromcode)
 100 {
 101     yaz_iconv_t cd = (yaz_iconv_t) xmalloc(sizeof(*cd));
 102
 103     cd->encoder.data = 0;
 104     cd->encoder.write_handle = 0;
 105     cd->encoder.flush_handle = 0;
 106     cd->encoder.init_handle = 0;
 107     cd->encoder.destroy_handle = 0;
 108
 109     cd->decoder.data = 0;
 110     cd->decoder.read_handle = 0;
 111     cd->decoder.init_handle = 0;
 112     cd->decoder.destroy_handle = 0;
 113
 114     cd->my_errno = YAZ_ICONV_UNKNOWN;
 115
 116     /* a useful hack: if fromcode has leading @,
 117        the library not use YAZ's own conversions .. */
 118     if (fromcode[0] == '@')
 119         fromcode++;
 120     else
 121     {
 122         prepare_encoders(cd, tocode);
 123         prepare_decoders(cd, fromcode);
 124     }
 125     if (cd->decoder.read_handle && cd->encoder.write_handle)
 126     {
 127 #if HAVE_ICONV_H
 128         cd->iconv_cd = (iconv_t) (-1);
 129 #endif
 130         ;
 131     }
 132     else
 133     {
 134 #if HAVE_ICONV_H
 135         cd->iconv_cd = iconv_open(tocode, fromcode);
 136         if (cd->iconv_cd == (iconv_t) (-1))
 137         {
 138             yaz_iconv_close(cd);
 139             return 0;
 140         }
 141 #else
 142         yaz_iconv_close(cd);
 143         return 0;
 144 #endif
 145     }
 146     cd->init_flag = 1;
 147     return cd;
 148 }
 149
 150 size_t yaz_iconv(yaz_iconv_t cd, char **inbuf, size_t *inbytesleft,
 151                  char **outbuf, size_t *outbytesleft)
 152 {
 153     char *inbuf0 = 0;
 154     size_t r = 0;
 155
 156 #if HAVE_ICONV_H
 157     if (cd->iconv_cd != (iconv_t) (-1))
 158     {
 159         size_t r =
 160             iconv(cd->iconv_cd, inbuf, inbytesleft, outbuf, outbytesleft);
 161         if (r == (size_t)(-1))
 162         {
 163             switch (yaz_errno())
 164             {
 165             case E2BIG:
 166                 cd->my_errno = YAZ_ICONV_E2BIG;
 167                 break;
 168             case EINVAL:
 169                 cd->my_errno = YAZ_ICONV_EINVAL;
 170                 break;
 171             case EILSEQ:
 172                 cd->my_errno = YAZ_ICONV_EILSEQ;
 173                 break;
 174             default:
 175                 cd->my_errno = YAZ_ICONV_UNKNOWN;
 176             }
 177         }
 178         return r;
 179     }
 180 #endif
 181
 182     if (inbuf)
 183         inbuf0 = *inbuf;
 184
 185     if (cd->init_flag)
 186     {
 187         cd->my_errno = YAZ_ICONV_UNKNOWN;
 188
 189         if (cd->encoder.init_handle)
 190             (*cd->encoder.init_handle)(&cd->encoder);
 191
 192         cd->unget_x = 0;
 193         cd->no_read_x = 0;
 194
 195         if (cd->decoder.init_handle)
 196         {
 197             size_t no_read = 0;
 198             size_t r = (cd->decoder.init_handle)(
 199                 cd, &cd->decoder,
 200                 inbuf ? (unsigned char *) *inbuf : 0,
 201                 inbytesleft ? *inbytesleft : 0,
 202                 &no_read);
 203             if (r)
 204             {
 205                 if (cd->my_errno == YAZ_ICONV_EINVAL)
 206                     return r;
 207                 cd->init_flag = 0;
 208                 return r;
 209             }
 210             if (inbytesleft)
 211                 *inbytesleft -= no_read;
 212             if (inbuf)
 213                 *inbuf += no_read;
 214         }
 215     }
 216     cd->init_flag = 0;
 217
 218     if (!inbuf || !*inbuf)
 219     {
 220         if (outbuf && *outbuf)
 221         {
 222             if (cd->unget_x)
 223                 r = (*cd->encoder.write_handle)(cd, &cd->encoder,
 224                                                 cd->unget_x, outbuf, outbytesleft);
 225             if (cd->encoder.flush_handle)
 226                 r = (*cd->encoder.flush_handle)(cd, &cd->encoder,
 227                                                 outbuf, outbytesleft);
 228         }
 229         if (r == 0)
 230             cd->init_flag = 1;
 231         cd->unget_x = 0;
 232         return r;
 233     }
 234     while (1)
 235     {
 236         unsigned long x;
 237         size_t no_read;
 238
 239         if (cd->unget_x)
 240         {
 241             x = cd->unget_x;
 242             no_read = cd->no_read_x;
 243         }
 244         else
 245         {
 246             if (*inbytesleft == 0)
 247             {
 248                 r = *inbuf - inbuf0;
 249                 break;
 250             }
 251             x = (*cd->decoder.read_handle)(
 252                 cd, &cd->decoder,
 253                 (unsigned char *) *inbuf, *inbytesleft, &no_read);
 254             if (no_read == 0)
 255             {
 256                 r = (size_t)(-1);
 257                 break;
 258             }
 259         }
 260         if (x)
 261         {
 262             r = (*cd->encoder.write_handle)(cd, &cd->encoder,
 263                                             x, outbuf, outbytesleft);
 264             if (r)
 265             {
 266                 /* unable to write it. save it because read_handle cannot
 267                    rewind .. */
 268                 if (cd->my_errno == YAZ_ICONV_E2BIG)
 269                 {
 270                     cd->unget_x = x;
 271                     cd->no_read_x = no_read;
 272                     break;
 273                 }
 274             }
 275             cd->unget_x = 0;
 276         }
 277         *inbytesleft -= no_read;
 278         (*inbuf) += no_read;
 279     }
 280     return r;
 281 }
 282
 283 int yaz_iconv_error(yaz_iconv_t cd)
 284 {
 285     return cd->my_errno;
 286 }
 287
 288 int yaz_iconv_close(yaz_iconv_t cd)
 289 {
 290 #if HAVE_ICONV_H
 291     if (cd->iconv_cd != (iconv_t) (-1))
 292         iconv_close(cd->iconv_cd);
 293 #endif
 294     if (cd->encoder.destroy_handle)
 295         (*cd->encoder.destroy_handle)(&cd->encoder);
 296     if (cd->decoder.destroy_handle)
 297         (*cd->decoder.destroy_handle)(&cd->decoder);
 298     xfree(cd);
 299     return 0;
 300 }
 301
 302 void yaz_iconv_set_errno(yaz_iconv_t cd, int no)
 303 {
 304     cd->my_errno = no;
 305 }
 306
 307 /*
 308  * Local variables:
 309  * c-basic-offset: 4
 310  * c-file-style: "Stroustrup"
 311  * indent-tabs-mode: nil
 312  * End:
 313  * vim: shiftwidth=4 tabstop=8 expandtab
 314  */
 315