is::_get_xml_chunk_mb_orig

function _get_xml_chunk_mb_orig($fp)
{
	if($this->buf_position >= $this->buf_len)
	{
		if(!feof($fp))
		{
			$this->buf = fread($fp, $this->read_size);
			$this->buf_position = 0;
			$this->buf_len = mb_orig_strlen($this->buf);
		}
		else
			return false;
	}

	//Skip line delimiters (ltrim)
	$xml_position = mb_orig_strpos($this->buf, "<", $this->buf_position);
	while($xml_position === $this->buf_position)
	{
		$this->buf_position++;
		$this->file_position++;
		//Buffer ended with white space so we can refill it
		if($this->buf_position >= $this->buf_len)
		{
			if(!feof($fp))
			{
				$this->buf = fread($fp, $this->read_size);
				$this->buf_position = 0;
				$this->buf_len = mb_orig_strlen($this->buf);
			}
			else
				return false;
		}
		$xml_position = mb_orig_strpos($this->buf, "<", $this->buf_position);
	}

	//Let's find next line delimiter
	while($xml_position===false)
	{
		$next_search = $this->buf_len;
		//Delimiter not in buffer so try to add more data to it
		if(!feof($fp))
		{
			$this->buf .= fread($fp, $this->read_size);
			$this->buf_len = mb_orig_strlen($this->buf);
		}
		else
			break;

		//Let's find xml tag start
		$xml_position = mb_orig_strpos($this->buf, "<", $next_search);
	}
	if($xml_position===false)
		$xml_position = $this->buf_len+1;

	$len = $xml_position-$this->buf_position;
	$this->file_position += $len;
	$result = mb_orig_substr($this->buf, $this->buf_position, $len);
	$this->buf_position = $xml_position;

	return $result;
}