giochannel.c

嵌入式下基于MiniGUI的Web Browser

                if (oldlen < channel->encoded_read_buf->len)
                  status = G_IO_STATUS_NORMAL;
                else
                  {
                    g_set_error (err, G_CONVERT_ERROR,
                      G_CONVERT_ERROR_ILLEGAL_SEQUENCE,
                      _("Invalid byte sequence in conversion input"));
                    status = G_IO_STATUS_ERROR;
                  }
                lastchar = nextchar;
                break;
              default:
                nextchar = g_utf8_next_char (nextchar);
                break;
            }
        }

      if (lastchar > channel->read_buf->str)
        {
          gint copy_len = lastchar - channel->read_buf->str;

          g_string_append_len (channel->encoded_read_buf, channel->read_buf->str,
                               copy_len);
          g_string_erase (channel->read_buf, 0, copy_len);
        }
    }

  return status;
}

/**
 * g_io_channel_read_line:
 * @channel: a #GIOChannel
 * @str_return: The line read from the #GIOChannel, including the
 *              line terminator. This data should be freed with g_free()
 *              when no longer needed. This is a nul-terminated string. 
 *              If a @length of zero is returned, this will be %NULL instead.
 * @length: location to store length of the read data, or %NULL
 * @terminator_pos: location to store position of line terminator, or %NULL
 * @error: A location to return an error of type #GConvertError
 *         or #GIOChannelError
 *
 * Reads a line, including the terminating character(s),
 * from a #GIOChannel into a newly-allocated string.
 * @str_return will contain allocated memory if the return
 * is %G_IO_STATUS_NORMAL.
 *
 * Return value: the status of the operation.
 **/
GIOStatus
g_io_channel_read_line (GIOChannel *channel,
                        gchar     **str_return,
                        gsize      *length,
			gsize      *terminator_pos,
		        GError    **error)
{
  GIOStatus status;
  gsize got_length;
  
  g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail (str_return != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail ((error == NULL) || (*error == NULL),
			G_IO_STATUS_ERROR);
  g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);

  status = g_io_channel_read_line_backend (channel, &got_length, terminator_pos, error);

  if (length)
    *length = got_length;

  if (status == G_IO_STATUS_NORMAL)
    {
      g_assert (USE_BUF (channel));
      *str_return = g_strndup (USE_BUF (channel)->str, got_length);
      g_string_erase (USE_BUF (channel), 0, got_length);
    }
  else
    *str_return = NULL;
  
  return status;
}

/**
 * g_io_channel_read_line_string:
 * @channel: a #GIOChannel
 * @buffer: a #GString into which the line will be written.
 *          If @buffer already contains data, the old data will
 *          be overwritten.
 * @terminator_pos: location to store position of line terminator, or %NULL
 * @error: a location to store an error of type #GConvertError
 *         or #GIOChannelError
 *
 * Reads a line from a #GIOChannel, using a #GString as a buffer.
 *
 * Return value: the status of the operation.
 **/
GIOStatus
g_io_channel_read_line_string (GIOChannel *channel,
                               GString	  *buffer,
			       gsize      *terminator_pos,
                               GError	 **error)
{
  gsize length;
  GIOStatus status;

  g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail (buffer != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail ((error == NULL) || (*error == NULL),
			G_IO_STATUS_ERROR);
  g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);

  if (buffer->len > 0)
    g_string_truncate (buffer, 0); /* clear out the buffer */

  status = g_io_channel_read_line_backend (channel, &length, terminator_pos, error);

  if (status == G_IO_STATUS_NORMAL)
    {
      g_assert (USE_BUF (channel));
      g_string_append_len (buffer, USE_BUF (channel)->str, length);
      g_string_erase (USE_BUF (channel), 0, length);
    }

  return status;
}


static GIOStatus
g_io_channel_read_line_backend	(GIOChannel *channel,
				 gsize      *length,
				 gsize      *terminator_pos,
				 GError    **error)
{
  GIOStatus status;
  gsize checked_to, line_term_len, line_length, got_term_len;
  gboolean first_time = TRUE;

  if (!channel->use_buffer)
    {
      /* Can't do a raw read in read_line */
      g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
                   _("Can't do a raw read in g_io_channel_read_line_string"));
      return G_IO_STATUS_ERROR;
    }

  status = G_IO_STATUS_NORMAL;

  if (channel->line_term)
    line_term_len = channel->line_term_len;
  else
    line_term_len = 3;
    /* This value used for setting checked_to, it's the longest of the four
     * we autodetect for.
     */

  checked_to = 0;

  while (TRUE)
    {
      gchar *nextchar, *lastchar;
      GString *use_buf;

      if (!first_time || (BUF_LEN (USE_BUF (channel)) == 0))
        {
read_again:
          status = g_io_channel_fill_buffer (channel, error);
          switch (status)
            {
              case G_IO_STATUS_NORMAL:
                if (BUF_LEN (USE_BUF (channel)) == 0)
                  /* Can happen when using conversion and only read
                   * part of a character
                   */
                  {
                    first_time = FALSE;
                    continue;
                  }
                break;
              case G_IO_STATUS_EOF:
                if (BUF_LEN (USE_BUF (channel)) == 0)
                  {
                    if (length)
                      *length = 0;

                    if (channel->encoding && channel->read_buf->len != 0)
                      {
                        g_set_error (error, G_CONVERT_ERROR,
                                     G_CONVERT_ERROR_PARTIAL_INPUT,
                                     _("Leftover unconverted data in read buffer"));
                        return G_IO_STATUS_ERROR;
                      }
                    else
                      return G_IO_STATUS_EOF;
                  }
                break;
              default:
                if (length)
                  *length = 0;
                return status;
            }
        }

      g_assert (BUF_LEN (USE_BUF (channel)) != 0);

      use_buf = USE_BUF (channel); /* The buffer has been created by this point */

      first_time = FALSE;

      lastchar = use_buf->str + use_buf->len;

      for (nextchar = use_buf->str + checked_to; nextchar < lastchar;
           channel->encoding ? nextchar = g_utf8_next_char (nextchar) : nextchar++)
        {
          if (channel->line_term)
            {
              if (memcmp (channel->line_term, nextchar, line_term_len) == 0)
                {
                  line_length = nextchar - use_buf->str;
                  got_term_len = line_term_len;
                  goto done;
                }
            }
          else /* auto detect */
            {
              switch (*nextchar)
                {
                  case '\n': /* unix */
                    line_length = nextchar - use_buf->str;
                    got_term_len = 1;
                    goto done;
                  case '\r': /* Warning: do not use with sockets */
                    line_length = nextchar - use_buf->str;
                    if ((nextchar == lastchar - 1) && (status != G_IO_STATUS_EOF)
                       && (lastchar == use_buf->str + use_buf->len))
                      goto read_again; /* Try to read more data */
                    if ((nextchar < lastchar - 1) && (*(nextchar + 1) == '\n')) /* dos */
                      got_term_len = 2;
                    else /* mac */
                      got_term_len = 1;
                    goto done;
                  case '\xe2': /* Unicode paragraph separator */
                    if (strncmp ("\xe2\x80\xa9", nextchar, 3) == 0)
                      {
                        line_length = nextchar - use_buf->str;
                        got_term_len = 3;
                        goto done;
                      }
                    break;
                  case '\0': /* Embeded null in input */
                    line_length = nextchar - use_buf->str;
                    got_term_len = 1;
                    goto done;
                  default: /* no match */
                    break;
                }
            }
        }

      /* If encoding != NULL, valid UTF-8, didn't overshoot */
      g_assert (nextchar == lastchar);

      /* Check for EOF */

      if (status == G_IO_STATUS_EOF)
        {
          if (channel->encoding && channel->read_buf->len > 0)
            {
              g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_PARTIAL_INPUT,
                           _("Channel terminates in a partial character"));
              return G_IO_STATUS_ERROR;
            }
          line_length = use_buf->len;
          got_term_len = 0;
          break;
        }

      if (use_buf->len > line_term_len - 1)
	checked_to = use_buf->len - (line_term_len - 1);
      else
	checked_to = 0;
    }

done:

  if (terminator_pos)
    *terminator_pos = line_length;

  if (length)
    *length = line_length + got_term_len;

  return G_IO_STATUS_NORMAL;
}

/**
 * g_io_channel_read_to_end:
 * @channel: a #GIOChannel
 * @str_return: Location to store a pointer to a string holding
 *              the remaining data in the #GIOChannel. This data should
 *              be freed with g_free() when no longer needed. This
 *              data is terminated by an extra nul character, but there 
 *              may be other nuls in the intervening data.
 * @length: Location to store length of the data
 * @error: A location to return an error of type #GConvertError
 *         or #GIOChannelError
 *
 * Reads all the remaining data from the file.
 *
 * Return value: %G_IO_STATUS_NORMAL on success. This function never
 *               returns %G_IO_STATUS_EOF.
 **/
GIOStatus
g_io_channel_read_to_end (GIOChannel	*channel,
                          gchar        **str_return,
                          gsize		*length,
                          GError       **error)
{
  GIOStatus status;
    
  g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail ((error == NULL) || (*error == NULL),
    G_IO_STATUS_ERROR);
  g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);

  if (str_return)
    *str_return = NULL;
  if (length)
    *length = 0;

  if (!channel->use_buffer)
    {
      g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
                   _("Can't do a raw read in g_io_channel_read_to_end"));
      return G_IO_STATUS_ERROR;
    }

  do
    status = g_io_channel_fill_buffer (channel, error);
  while (status == G_IO_STATUS_NORMAL);

  if (status != G_IO_STATUS_EOF)
    return status;

  if (channel->encoding && channel->read_buf->len > 0)
    {
      g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_PARTIAL_INPUT,
                   _("Channel terminates in a partial character"));
      return G_IO_STATUS_ERROR;
    }

  if (USE_BUF (channel) == NULL)
    {
      /* length is already set to zero */
      if (str_return)
        *str_return = g_strdup ("");
    }
  else
    {
      if (length)
        *length = USE_BUF (channel)->len;

      if (str_return)
        *str_return = g_string_free (USE_BUF (channel), FALSE);
      else
        g_string_free (USE_BUF (channel), TRUE);

      if (channel->encoding)
	channel->encoded_read_buf = NULL;
      else
	channel->read_buf = NULL;
    }

  return G_IO_STATUS_NORMAL;
}

/**
 * g_io_channel_read_chars:
 * @channel: a #GIOChannel
 * @buf: a buffer to read data into
 * @count: the size of the buffer. Note that the buffer may
 *         not be complelely filled even if there is data
 *         in the buffer if the remaining data is not a
 *         complete character.
 * @bytes_read: The number of bytes read. This may be zero even on
 *              success if count < 6 and the channel's encoding is non-%NULL.
 *              This indicates that the next UTF-8 character is too wide for
 *              the buffer.
 * @error: A location to return an error of type #GConvertError
 *         or #GIOChannelError.
 *
 * Replacement for g_io_channel_read() with the new API.
 *
 * Return value: the status of the operation.
 **/
GIOStatus
g_io_channel_read_chars (GIOChannel	*channel,
                         gchar		*buf,
                         gsize		 count,
			 gsize          *bytes_read,
                         GError        **error)
{
  GIOStatus status;
  gsize got_bytes;

  g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
  g_return_val_if_fail ((error == NULL) || (*error == NULL),
			G_IO_STATUS_ERROR);
  g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);

  if (count == 0)
    {
      *bytes_read = 0;
      return G_IO_STATUS_NORMAL;
    }
  g_return_val_if_fail (buf != NULL, G_IO_STATUS_ERROR);

  if (!channel->use_buffer)
    {
      gsize tmp_bytes;
      
      g_assert (!channel->read_buf || channel->read_buf->len == 0);

      status = channel->funcs->io_read (channel, buf, count, &tmp_bytes, error);
      
      if (bytes_read)
	*bytes_read = tmp_bytes;

      return status;
    }

  status = G_IO_STATUS_NORMAL;

  while (BUF_LEN (USE_BUF (channel)) < count && status == G_IO_STATUS_NORMAL)
    status = g_io_channel_fill_buffer (channel, error);

  /* Only return an error if we have no data */