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

   1 /* _PDCLIB_flushbuffer( struct _PDCLIB_file_t * )
   2
   3    This file is part of the Public Domain C Library (PDCLib).
   4    Permission is granted to use, modify, and / or redistribute at will.
   5 */
   6
   7 #include <stdio.h>
   8 #include <string.h>
   9
  10 #ifndef REGTEST
  11 #include "_PDCLIB_glue.h"
  12 #include "_PDCLIB_io.h"
  13
  14
  15 static int flushsubbuffer( FILE * stream, size_t length )
  16 {
  17     size_t justWrote;
  18     size_t written = 0;
  19     int rv = 0;
  20
  21 #if 0
  22     // Very useful for debugging buffering issues
  23     char l = '<', r = '>';
  24     stream->ops->write( stream->handle, &l,  1, &justWrote );
  25 #endif
  26
  27     while( written != length )
  28     {
  29         size_t toWrite = length - written;
  30
  31         bool res = stream->ops->write( stream->handle, stream->buffer + written,
  32                               toWrite, &justWrote);
  33         written += justWrote;
  34         stream->pos.offset += justWrote;
  35
  36         if (!res)
  37         {
  38             stream->status |= _PDCLIB_ERRORFLAG;
  39             rv = EOF;
  40             break;
  41         }
  42     }
  43
  44 #if 0
  45     stream->ops->write( stream->handle, &r,  1, &justWrote );
  46 #endif
  47
  48     stream->bufidx   -= written;
  49 #ifdef _PDCLIB_NEED_EOL_TRANSLATION
  50     stream->bufnlexp -= written;
  51 #endif
  52     memmove( stream->buffer, stream->buffer + written, stream->bufidx );
  53
  54     return rv;
  55 }
  56
  57 int _PDCLIB_flushbuffer( FILE * stream )
  58 {
  59 #ifdef _PDCLIB_NEED_EOL_TRANSLATION
  60     // if a text stream, and this platform needs EOL translation, well...
  61     if ( ! ( stream->status & _PDCLIB_FBIN ) )
  62     {
  63         // Special case: buffer is full and we start with a \n
  64         if ( stream->bufnlexp == 0
  65             && stream->bufidx == stream->bufend
  66             && stream->buffer[0] == '\n' )
  67         {
  68             char cr = '\r';
  69             size_t written = 0;
  70             bool res = stream->ops->write( stream->handle, &cr, 1, &written );
  71
  72             if (!res) {
  73                 stream->status |= _PDCLIB_ERRORFLAG;
  74                 return EOF;
  75             }
  76
  77         }
  78
  79         for ( ; stream->bufnlexp < stream->bufidx; stream->bufnlexp++ )
  80         {
  81             if (stream->buffer[stream->bufnlexp] == '\n' ) {
  82                 if ( stream->bufidx == stream->bufend ) {
  83                     // buffer is full. Need to print out everything up till now
  84                     if( flushsubbuffer( stream, stream->bufnlexp - 1 ) )
  85                     {
  86                         return EOF;
  87                     }
  88                 }
  89
  90                 // we have spare space in buffer. Shift everything 1char and
  91                 // insert \r
  92                 memmove( &stream->buffer[stream->bufnlexp + 1],
  93                          &stream->buffer[stream->bufnlexp],
  94                          stream->bufidx - stream->bufnlexp );
  95                 stream->buffer[stream->bufnlexp] = '\r';
  96
  97                 stream->bufnlexp++;
  98                 stream->bufidx++;
  99             }
 100         }
 101     }
 102 #endif
 103     return flushsubbuffer( stream, stream->bufidx );
 104 }
 105
 106 #endif
 107
 108
 109 #ifdef TEST
 110 #include "_PDCLIB_test.h"
 111
 112 int main( void )
 113 {
 114     /* Testing covered by ftell.c */
 115     return TEST_RESULTS;
 116 }
 117
 118 #endif
 119