$sha1Hash = wfBaseConvert( $sha1Hash, 16, 36, 31 );
$contentType = $this->getContentType( $params['dst'], null, $params['src'] );
$sha1Hash = wfBaseConvert( $sha1Hash, 16, 36, 31 );
$contentType = $this->getContentType( $params['dst'], null, $params['src'] );