pd.if.org Git - pdclib/blob - functions/stdio/fread.c

   1 /* ----------------------------------------------------------------------------
   2  * $Id$
   3  * ----------------------------------------------------------------------------
   4  * Public Domain C Library - http://pdclib.sourceforge.net
   5  * This code is Public Domain. Use, modify, and redistribute at will.
   6  * --------------------------------------------------------------------------*/
   7
   8 size_t fread( void * restrict ptr, size_t size, size_t nelem, FILE * restrict stream ) { /* TODO */ };
   9
  10 /* PDPC code - unreviewed, verbatim.
  11 Read the note in fopen.c.
  12 {
  13     size_t toread;
  14     size_t elemRead;
  15     size_t actualRead;
  16 #ifdef __OS2__
  17     APIRET rc;
  18     ULONG tempRead;
  19 #endif
  20 #ifdef __MSDOS__
  21     int errind;
  22     size_t tempRead;
  23 #endif
  24
  25     if (nmemb == 1)
  26     {
  27         toread = size;
  28     }
  29     else if (size == 1)
  30     {
  31         toread = nmemb;
  32     }
  33     else
  34     {
  35         toread = size * nmemb;
  36     }
  37     if (toread < stream->szfbuf)
  38     {
  39         stream->quickBin = 0;
  40     }
  41     if (!stream->quickBin)
  42     {
  43         if (stream->textMode)
  44         {
  45             freadSlowT(ptr, stream, toread, &actualRead);
  46         }
  47         else
  48         {
  49             if (toread <= (stream->endbuf - stream->upto))
  50             {
  51                 memcpy(ptr, stream->upto, toread);
  52                 actualRead = toread;
  53                 stream->upto += toread;
  54             }
  55             else
  56             {
  57                 freadSlowB(ptr, stream, toread, &actualRead);
  58             }
  59         }
  60         if (nmemb == 1)
  61         {
  62             if (actualRead == size)
  63             {
  64                 elemRead = 1;
  65             }
  66             else
  67             {
  68                 elemRead = 0;
  69             }
  70         }
  71         else if (size == 1)
  72         {
  73             elemRead = actualRead;
  74         }
  75         else
  76         {
  77             elemRead = actualRead / size;
  78         }
  79         return (elemRead);
  80     }
  81     else
  82     {
  83 #ifdef __OS2__
  84         rc = DosRead(stream->hfile, ptr, toread, &tempRead);
  85         if (rc != 0)
  86         {
  87             actualRead = 0;
  88             stream->errorInd = 1;
  89             errno = rc;
  90         }
  91         else
  92         {
  93             actualRead = tempRead;
  94         }
  95 #endif
  96 #ifdef __MSDOS__
  97         tempRead = __read(stream->hfile, ptr, toread, &errind);
  98         if (errind)
  99         {
 100             errno = tempRead;
 101             actualRead = 0;
 102             stream->errorInd = 1;
 103         }
 104         else
 105         {
 106             actualRead = tempRead;
 107         }
 108 #endif
 109         if (nmemb == 1)
 110         {
 111             if (actualRead == size)
 112             {
 113                 elemRead = 1;
 114             }
 115             else
 116             {
 117                 elemRead = 0;
 118                 stream->eofInd = 1;
 119             }
 120         }
 121         else if (size == 1)
 122         {
 123             elemRead = actualRead;
 124             if (nmemb != actualRead)
 125             {
 126                 stream->eofInd = 1;
 127             }
 128         }
 129         else
 130         {
 131             elemRead = actualRead / size;
 132             if (toread != actualRead)
 133             {
 134                 stream->eofInd = 1;
 135             }
 136         }
 137         stream->bufStartR += actualRead;
 138         return (elemRead);
 139     }
 140 }
 141
 142
 143 /*
 144 while toread has not been satisfied
 145 {
 146     scan stuff out of buffer, replenishing buffer as required
 147 }
 148 */
 149
 150 static void freadSlowT(void *ptr,
 151                        FILE *stream,
 152                        size_t toread,
 153                        size_t *actualRead)
 154 {
 155     int finReading = 0;
 156     size_t avail;
 157     size_t need;
 158     char *p;
 159     size_t got;
 160 #ifdef __OS2__
 161     ULONG tempRead;
 162     APIRET rc;
 163 #endif
 164 #ifdef __MSDOS__
 165     size_t tempRead;
 166     int errind;
 167 #endif
 168
 169     *actualRead = 0;
 170     while (!finReading)
 171     {
 172         if (stream->upto == stream->endbuf)
 173         {
 174             stream->bufStartR += (stream->upto - stream->fbuf);
 175 #ifdef __OS2__
 176             rc = DosRead(stream->hfile,
 177                          stream->fbuf,
 178                          stream->szfbuf,
 179                          &tempRead);
 180             if (rc != 0)
 181             {
 182                 tempRead = 0;
 183                 stream->errorInd = 1;
 184                 errno = rc;
 185             }
 186 #endif
 187 #ifdef __MSDOS__
 188             tempRead = __read(stream->hfile,
 189                               stream->fbuf,
 190                               stream->szfbuf,
 191                               &errind);
 192             if (errind)
 193             {
 194                 errno = tempRead;
 195                 tempRead = 0;
 196                 stream->errorInd = 1;
 197             }
 198 #endif
 199             if (tempRead == 0)
 200             {
 201                 stream->eofInd = 1;
 202                 break;
 203             }
 204             stream->endbuf = stream->fbuf + tempRead;
 205             *stream->endbuf = '\n';
 206             stream->upto = stream->fbuf;
 207         }
 208         avail = (size_t)(stream->endbuf - stream->upto) + 1;
 209         need = toread - *actualRead;
 210         p = memchr(stream->upto, '\n', avail);
 211         got = (size_t)(p - stream->upto);
 212         if (need < got)
 213         {
 214             memcpy((char *)ptr + *actualRead, stream->upto, need);
 215             stream->upto += need;
 216             *actualRead += need;
 217         }
 218         else
 219         {
 220             memcpy((char *)ptr + *actualRead, stream->upto, got);
 221             stream->upto += got;
 222             *actualRead += got;
 223             if (p != stream->endbuf)
 224             {
 225                 if (*(stream->upto - 1) == '\r')
 226                 {
 227                     *((char *)ptr + *actualRead - 1) = '\n';
 228                 }
 229                 else
 230                 {
 231                     *((char *)ptr + *actualRead) = '\n';
 232                     *actualRead += 1;
 233                 }
 234                 stream->upto++;
 235             }
 236             else
 237             {
 238                 if (*(stream->upto - 1) == '\r')
 239                 {
 240                     *actualRead -= 1;
 241                 }
 242             }
 243         }
 244         if (*actualRead == toread)
 245         {
 246             finReading = 1;
 247         }
 248     }
 249     return;
 250 }
 251
 252 static void freadSlowB(void *ptr,
 253                        FILE *stream,
 254                        size_t toread,
 255                        size_t *actualRead)
 256 {
 257     size_t avail;
 258 #ifdef __OS2__
 259     ULONG tempRead;
 260     APIRET rc;
 261 #endif
 262 #ifdef __MSDOS__
 263     size_t tempRead;
 264     int errind;
 265 #endif
 266
 267     avail = (size_t)(stream->endbuf - stream->upto);
 268     memcpy(ptr, stream->upto, avail);
 269     *actualRead = avail;
 270     stream->bufStartR += (stream->endbuf - stream->fbuf);
 271     if (toread >= stream->szfbuf)
 272     {
 273         stream->upto = stream->endbuf;
 274         stream->quickBin = 1;
 275 #ifdef __OS2__
 276         rc = DosRead(stream->hfile,
 277                      (char *)ptr + *actualRead,
 278                      toread - *actualRead,
 279                      &tempRead);
 280         if (rc != 0)
 281         {
 282             tempRead = 0;
 283             stream->errorInd = 1;
 284             errno = rc;
 285         }
 286 #endif
 287 #ifdef __MSDOS__
 288         tempRead = __read(stream->hfile,
 289                           (char *)ptr + *actualRead,
 290                           toread - *actualRead,
 291                           &errind);
 292         if (errind)
 293         {
 294             errno = tempRead;
 295             tempRead = 0;
 296             stream->errorInd = 1;
 297         }
 298 #endif
 299         else if (tempRead != (toread - *actualRead))
 300         {
 301             stream->eofInd = 1;
 302         }
 303         *actualRead += tempRead;
 304         stream->bufStartR += tempRead;
 305     }
 306     else
 307     {
 308         size_t left;
 309
 310         stream->upto = stream->fbuf;
 311 #ifdef __OS2__
 312         rc = DosRead(stream->hfile,
 313                      stream->fbuf,
 314                      stream->szfbuf,
 315                      &tempRead);
 316         left = toread - *actualRead;
 317         if (rc != 0)
 318         {
 319             tempRead = 0;
 320             stream->errorInd = 1;
 321             errno = rc;
 322         }
 323 #endif
 324 #ifdef __MSDOS__
 325         tempRead = __read(stream->hfile,
 326                           stream->fbuf,
 327                           stream->szfbuf,
 328                           &errind);
 329         left = toread - *actualRead;
 330         if (errind)
 331         {
 332             errno = tempRead;
 333             tempRead = 0;
 334             stream->errorInd = 1;
 335         }
 336 #endif
 337         else if (tempRead < left)
 338         {
 339             stream->eofInd = 1;
 340         }
 341         stream->endbuf = stream->fbuf + tempRead;
 342         *stream->endbuf = '\n';
 343         avail = (size_t)(stream->endbuf - stream->upto);
 344         if (avail > left)
 345         {
 346             avail = left;
 347         }
 348         memcpy((char *)ptr + *actualRead,
 349                stream->upto,
 350                avail);
 351         stream->upto += avail;
 352         *actualRead += avail;
 353     }
 354     return;
 355 }
 356 #endif
 357 */