예제 #1
0
파일: fileops.c 프로젝트: Kampi/Zybo-Linux
int
_IO_new_file_close_it (_IO_FILE *fp)
{
  int write_status;
  if (!_IO_file_is_open (fp))
    return EOF;

  if ((fp->_flags & _IO_NO_WRITES) == 0
      && (fp->_flags & _IO_CURRENTLY_PUTTING) != 0)
    write_status = _IO_do_flush (fp);
  else
    write_status = 0;

  _IO_unsave_markers (fp);

  int close_status = ((fp->_flags2 & _IO_FLAGS2_NOCLOSE) == 0
		      ? _IO_SYSCLOSE (fp) : 0);

  /* Free buffer. */
#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
  if (fp->_mode > 0)
    {
      if (_IO_have_wbackup (fp))
	_IO_free_wbackup_area (fp);
      _IO_wsetb (fp, NULL, NULL, 0);
      _IO_wsetg (fp, NULL, NULL, NULL);
      _IO_wsetp (fp, NULL, NULL);
    }
#endif
  _IO_setb (fp, NULL, NULL, 0);
  _IO_setg (fp, NULL, NULL, NULL);
  _IO_setp (fp, NULL, NULL);

  _IO_un_link ((struct _IO_FILE_plus *) fp);
  fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS;
  fp->_fileno = -1;
  fp->_offset = _IO_pos_BAD;

  return close_status ? close_status : write_status;
}
예제 #2
0
파일: wfileops.c 프로젝트: siddhesh/glibc
_IO_off64_t
_IO_wfile_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
{
  _IO_off64_t result;
  _IO_off64_t delta, new_offset;
  long int count;

  /* Short-circuit into a separate function.  We don't want to mix any
     functionality and we don't want to touch anything inside the FILE
     object. */
  if (mode == 0)
    return do_ftell_wide (fp);

  /* POSIX.1 8.2.3.7 says that after a call the fflush() the file
     offset of the underlying file must be exact.  */
  int must_be_exact = ((fp->_wide_data->_IO_read_base
			== fp->_wide_data->_IO_read_end)
		       && (fp->_wide_data->_IO_write_base
			   == fp->_wide_data->_IO_write_ptr));

  bool was_writing = ((fp->_wide_data->_IO_write_ptr
		       > fp->_wide_data->_IO_write_base)
		      || _IO_in_put_mode (fp));

  /* Flush unwritten characters.
     (This may do an unneeded write if we seek within the buffer.
     But to be able to switch to reading, we would need to set
     egptr to pptr.  That can't be done in the current design,
     which assumes file_ptr() is eGptr.  Anyway, since we probably
     end up flushing when we close(), it doesn't make much difference.)
     FIXME: simulate mem-mapped files. */
  if (was_writing && _IO_switch_to_wget_mode (fp))
    return WEOF;

  if (fp->_wide_data->_IO_buf_base == NULL)
    {
      /* It could be that we already have a pushback buffer.  */
      if (fp->_wide_data->_IO_read_base != NULL)
	{
	  free (fp->_wide_data->_IO_read_base);
	  fp->_flags &= ~_IO_IN_BACKUP;
	}
      _IO_doallocbuf (fp);
      _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
      _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
      _IO_wsetp (fp, fp->_wide_data->_IO_buf_base,
		 fp->_wide_data->_IO_buf_base);
      _IO_wsetg (fp, fp->_wide_data->_IO_buf_base,
		 fp->_wide_data->_IO_buf_base, fp->_wide_data->_IO_buf_base);
    }

  switch (dir)
    {
      struct _IO_codecvt *cv;
      int clen;

    case _IO_seek_cur:
      /* Adjust for read-ahead (bytes is buffer).  To do this we must
	 find out which position in the external buffer corresponds to
	 the current position in the internal buffer.  */
      cv = fp->_codecvt;
      clen = (*cv->__codecvt_do_encoding) (cv);

      if (mode != 0 || !was_writing)
	{
	  if (clen > 0)
	    {
	      offset -= (fp->_wide_data->_IO_read_end
			 - fp->_wide_data->_IO_read_ptr) * clen;
	      /* Adjust by readahead in external buffer.  */
	      offset -= fp->_IO_read_end - fp->_IO_read_ptr;
	    }
	  else
	    {
	      int nread;

	      delta = (fp->_wide_data->_IO_read_ptr
		       - fp->_wide_data->_IO_read_base);
	      fp->_wide_data->_IO_state = fp->_wide_data->_IO_last_state;
	      nread = (*cv->__codecvt_do_length) (cv,
						  &fp->_wide_data->_IO_state,
						  fp->_IO_read_base,
						  fp->_IO_read_end, delta);
	      fp->_IO_read_ptr = fp->_IO_read_base + nread;
	      fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_read_ptr;
	      offset -= fp->_IO_read_end - fp->_IO_read_base - nread;
	    }
	}

      if (fp->_offset == _IO_pos_BAD)
	goto dumb;

      /* Make offset absolute, assuming current pointer is file_ptr(). */
      offset += fp->_offset;

      dir = _IO_seek_set;
      break;
    case _IO_seek_set:
      break;
    case _IO_seek_end:
      {
	struct stat64 st;
	if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
	  {
	    offset += st.st_size;
	    dir = _IO_seek_set;
	  }
	else
	  goto dumb;
      }
    }
  /* At this point, dir==_IO_seek_set. */

  /* If destination is within current buffer, optimize: */
  if (fp->_offset != _IO_pos_BAD && fp->_IO_read_base != NULL
      && !_IO_in_backup (fp))
    {
      _IO_off64_t start_offset = (fp->_offset
				  - (fp->_IO_read_end - fp->_IO_buf_base));
      if (offset >= start_offset && offset < fp->_offset)
	{
	  _IO_setg (fp, fp->_IO_buf_base,
		    fp->_IO_buf_base + (offset - start_offset),
		    fp->_IO_read_end);
	  _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
	  _IO_wsetg (fp, fp->_wide_data->_IO_buf_base,
		     fp->_wide_data->_IO_buf_base,
		     fp->_wide_data->_IO_buf_base);
	  _IO_wsetp (fp, fp->_wide_data->_IO_buf_base,
		     fp->_wide_data->_IO_buf_base);

	  if (adjust_wide_data (fp, false))
	    goto dumb;

	  _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
	  goto resync;
	}
    }

  if (fp->_flags & _IO_NO_READS)
    goto dumb;

  /* Try to seek to a block boundary, to improve kernel page management. */
  new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1);
  delta = offset - new_offset;
  if (delta > fp->_IO_buf_end - fp->_IO_buf_base)
    {
      new_offset = offset;
      delta = 0;
    }
  result = _IO_SYSSEEK (fp, new_offset, 0);
  if (result < 0)
    return EOF;
  if (delta == 0)
    count = 0;
  else
    {
      count = _IO_SYSREAD (fp, fp->_IO_buf_base,
			   (must_be_exact
			    ? delta : fp->_IO_buf_end - fp->_IO_buf_base));
      if (count < delta)
	{
	  /* We weren't allowed to read, but try to seek the remainder. */
	  offset = count == EOF ? delta : delta-count;
	  dir = _IO_seek_cur;
	  goto dumb;
	}
    }
  _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta,
	    fp->_IO_buf_base + count);
  _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
  _IO_wsetg (fp, fp->_wide_data->_IO_buf_base,
	     fp->_wide_data->_IO_buf_base, fp->_wide_data->_IO_buf_base);
  _IO_wsetp (fp, fp->_wide_data->_IO_buf_base, fp->_wide_data->_IO_buf_base);

  if (adjust_wide_data (fp, true))
    goto dumb;

  fp->_offset = result + count;
  _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
  return offset;
 dumb:

  _IO_unsave_markers (fp);
  result = _IO_SYSSEEK (fp, offset, dir);
  if (result != EOF)
    {
      _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
      fp->_offset = result;
      _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
      _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
      _IO_wsetg (fp, fp->_wide_data->_IO_buf_base,
		 fp->_wide_data->_IO_buf_base, fp->_wide_data->_IO_buf_base);
      _IO_wsetp (fp, fp->_wide_data->_IO_buf_base,
		 fp->_wide_data->_IO_buf_base);
    }
  return result;

resync:
  /* We need to do it since it is possible that the file offset in
     the kernel may be changed behind our back. It may happen when
     we fopen a file and then do a fork. One process may access the
     file and the kernel file offset will be changed. */
  if (fp->_offset >= 0)
    _IO_SYSSEEK (fp, fp->_offset, 0);

  return offset;
}