base64_encode and serialize php function params

While browsing [Moodle's][1] source code I stumbled across this: **repository/recent/lib.php** public function get_listing($encodedpath = '', $page = '') { global $OUTPUT; $ret = array(); $ret['dynload'] = true; $ret['nosearch'] = true; $ret['nologin'] = true; $list = array(); $files = $this->get_recent_files(0, $this->number); try { foreach ($files as $file) { $params = base64_encode(serialize($file)); // Check that file exists and accessible $filesize = $this->get_file_size($params); if ($file['filename'] == 'image.png') { var_dump($filesize); } if (!empty($filesize)) { $node = array( 'title' => $file['filename'], 'size' => $filesize, 'date' => '', 'source'=> $params, 'thumbnail' => $OUTPUT->pix_url(file_extension_icon($file['filename'], 32))->out(false), ); $list[] = $node; } } } catch (Exception $e) { throw new repository_exception('emptyfilelist', 'repository_recent'); } $ret['list'] = array_filter($list, array($this, 'filter')); return $ret; } **repository/lib.php** public function get_file_size($source) { $browser = get_file_browser(); $params = unserialize(base64_decode($source)); $contextid = clean_param($params['contextid'], PARAM_INT); $fileitemid = clean_param($params['itemid'], PARAM_INT); $filename = clean_param($params['filename'], PARAM_FILE); $filepath = clean_param($params['filepath'], PARAM_PATH); $filearea = clean_param($params['filearea'], PARAM_AREA); $component = clean_param($params['component'], PARAM_COMPONENT); $context = get_context_instance_by_id($contextid); $file_info = $browser->get_file_info($context, $component, $filearea, $fileitemid, $filepath, $filename); if (!empty($file_info)) { $filesize = $file_info->get_filesize(); } else { $filesize = null; } return $filesize; } My question is what is the purpose of base64 encoding and serializing this when it's immediately undone once inside the function? Is there a valid reason for doing this or is this just over engineered? [1]: https://github.com/moodle/moodle