CXMLFileStream::getXmlChunk

private function getXmlChunk()
{
	if ($this->bufPosition >= $this->bufLen)
	{
		if (is_resource($this->fileHandler) && !feof($this->fileHandler))
		{
			$this->buf = fread($this->fileHandler, $this->readSize);
			$this->bufPosition = 0;
			$this->bufLen = strlen($this->buf);
		}
		else
		{
			return false;
		}
	}

	//Skip line delimiters (ltrim)
	$xml_position = strpos($this->buf, "<", $this->bufPosition);
	while ($xml_position === $this->bufPosition)
	{
		$this->bufPosition++;
		$this->filePosition++;
		//Buffer ended with white space so we can refill it
		if ($this->bufPosition >= $this->bufLen)
		{
			if (!feof($this->fileHandler))
			{
				$this->buf = fread($this->fileHandler, $this->readSize);
				$this->bufPosition = 0;
				$this->bufLen = strlen($this->buf);
			}
			else
			{
				return false;
			}
		}
		$xml_position = strpos($this->buf, "<", $this->bufPosition);
	}

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

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

	$len = $xml_position-$this->bufPosition;
	$this->filePosition += $len;
	$result = substr($this->buf, $this->bufPosition, $len);
	$this->bufPosition = $xml_position;

	return $result;
}