original_string: public static function get_site_identifier() {
          global $CFG;
          if (!is_null(self::$siteidentifier)) {
              return self::$siteidentifier;
          }
          // If site identifier hasn't been collected yet attempt to get it from the cache config.
          $factory = cache_factory::instance();
          // If the factory is initialising then we don't want to try to get it from the config or we risk
          // causing the cache to enter an infinite initialisation loop.
          if (!$factory->is_initialising()) {
              $config = $factory->create_config_instance();
              self::$siteidentifier = $config->get_site_identifier();
          }
          if (is_null(self::$siteidentifier)) {
              // If the site identifier is still null then config isn't aware of it yet.
              // We'll see if the CFG is loaded, and if not we will just use unknown.
              // It's very important here that we don't use get_config. We don't want an endless cache loop!
              if (!empty($CFG->siteidentifier)) {
                  self::$siteidentifier = self::update_site_identifier($CFG->siteidentifier);
              } else {
                  // It's not being recorded in MUC's config and the config data hasn't been loaded yet.
                  // Likely we are initialising.
                  return 'unknown';
              }
          }
          return self::$siteidentifier;
      }
code: public static function get_site_identifier() {
          global $CFG;
          if (!is_null(self::$siteidentifier)) {
              return self::$siteidentifier;
          }
          // If site identifier hasn't been collected yet attempt to get it from the cache config.
          $factory = cache_factory::instance();
          // If the factory is initialising then we don't want to try to get it from the config or we risk
          // causing the cache to enter an infinite initialisation loop.
          if (!$factory->is_initialising()) {
              $config = $factory->create_config_instance();
              self::$siteidentifier = $config->get_site_identifier();
          }
          if (is_null(self::$siteidentifier)) {
              // If the site identifier is still null then config isn't aware of it yet.
              // We'll see if the CFG is loaded, and if not we will just use unknown.
              // It's very important here that we don't use get_config. We don't want an endless cache loop!
              if (!empty($CFG->siteidentifier)) {
                  self::$siteidentifier = self::update_site_identifier($CFG->siteidentifier);
              } else {
                  // It's not being recorded in MUC's config and the config data hasn't been loaded yet.
                  // Likely we are initialising.
                  return 'unknown';
              }
          }
          return self::$siteidentifier;
      }
code_tokens: public static function get_site_identifier ( ) { global $ CFG ; if ( ! is_null ( self :: $ siteidentifier ) ) { return self :: $ siteidentifier ; } // If site identifier hasn't been collected yet attempt to get it from the cache config. $ factory = cache_factory :: instance ( ) ; // If the factory is initialising then we don't want to try to get it from the config or we risk // causing the cache to enter an infinite initialisation loop. if ( ! $ factory -> is_initialising ( ) ) { $ config = $ factory -> create_config_instance ( ) ; self :: $ siteidentifier = $ config -> get_site_identifier ( ) ; } if ( is_null ( self :: $ siteidentifier ) ) { // If the site identifier is still null then config isn't aware of it yet. // We'll see if the CFG is loaded, and if not we will just use unknown. // It's very important here that we don't use get_config. We don't want an endless cache loop! if ( ! empty ( $ CFG -> siteidentifier ) ) { self :: $ siteidentifier = self :: update_site_identifier ( $ CFG -> siteidentifier ) ; } else { // It's not being recorded in MUC's config and the config data hasn't been loaded yet. // Likely we are initialising. return 'unknown' ; } } return self :: $ siteidentifier ; }
docstring: Returns the site identifier.
  
  @return string
docstring_tokens: Returns the site identifier .