Piwik\Site::clearCache PHP Method

    public static function clearCache()
    {
        self::$infoSites = array();
    }

 /**
  * When tracking data in the past (using Tracking API), this function
  * can be used to invalidate reports for the idSites and dates where new data
  * was added.
  * DEV: If you call this API, the UI should display the data correctly, but will process
  *      in real time, which could be very slow after large data imports.
  *      After calling this function via REST, you can manually force all data
  *      to be reprocessed by visiting the script as the Super User:
  *      http://example.net/piwik/misc/cron/archive.php?token_auth=$SUPER_USER_TOKEN_AUTH_HERE
  * REQUIREMENTS: On large piwik setups, you will need in PHP configuration: max_execution_time = 0
  *    We recommend to use an hourly schedule of the script.
  *    More information: http://piwik.org/setup-auto-archiving/
  *
  * @param string $idSites Comma separated list of idSite that have had data imported for the specified dates
  * @param string $dates Comma separated list of dates to invalidate for all these websites
  * @param string $period If specified (one of day, week, month, year, range) it will only invalidates archives for this period.
  *                      Note: because week, month, year, range reports aggregate day reports then you need to specifically invalidate day reports to see
  *                      other periods reports processed..
  * @throws Exception
  * @return array
  * @hideExceptForSuperUser
  */
 public function invalidateArchivedReports($idSites, $dates, $period = false)
 {
     $idSites = Site::getIdSitesFromIdSitesString($idSites);
     if (empty($idSites)) {
         throw new Exception("Specify a value for &idSites= as a comma separated list of website IDs, for which your token_auth has 'admin' permission");
     }
     Piwik::checkUserHasAdminAccess($idSites);
     $invalidator = new ArchiveInvalidator();
     $output = $invalidator->markArchivesAsInvalidated($idSites, $dates, $period);
     Site::clearCache();
     return $output;
 }