Caching.php

  <?php
  
  /**
   * Clears entire WP Engine cache
   * @return void
   */
  public function wpeCacheFlush() {

    // Only initiates a cache clear if the $cleared property is false
    if (!self::$cleared) {
      // Don't cause a fatal error if there is no WpeCommon class
      if (!class_exists('WpeCommon')) {
        return false;
      }

      if (method_exists('WpeCommon', 'purge_memcached')) {
        \WpeCommon::purge_memcached();
        AdminNotice::log('WpeCommon::purge_memcached triggered');
      }

      if (method_exists('WpeCommon', 'clear_maxcdn_cache')) {
        \WpeCommon::clear_maxcdn_cache();
      }

      if (method_exists('WpeCommon', 'purge_varnish_cache')) {
        \WpeCommon::purge_varnish_cache();
        AdminNotice::log('WpeCommon::purge_varnish_cache triggered');
      }

      global $wp_object_cache;

      // Check for valid cache. Sometimes this is broken -- we don't know why! -- and it crashes when we flush.
      // If there's no cache, we don't need to flush anyway.
      $error = '';

      if ($wp_object_cache && is_object($wp_object_cache)) {
        try {
          wp_cache_flush();
        } catch (\Exception $ex) {
          $error = "Warning: error flushing WordPress object cache: " . $ex->getMessage();
        }
      }

      // Log our response to the debug.log
      if (!empty($error)) {
        AdminNotice::displayError($error);
        AdminNotice::log($error);

      } else {
        $success = __('All WP Engine caches have been cleared successfully.', 'to4-framework');

        AdminNotice::log($success);
        AdminNotice::displaySuccess($success);
      }

      self::$cleared = true;
    }
  }
  
  /**
   * Trigger entire WPE cache include memcache, Varnish, and object cache,
   * and CF cache if on live WPE site, and if cache clearing is enabled in settings
   * @param string $log_message (optional) Add additional message for debugging
   * @param boolean $rest (optional) Setting to true enables CF cache clearing for custom REST API endpoints
   */
  public function globalCacheFlush($log_message = null, $rest = false) {

    // Send cache setting status and what type of cache clear has been triggered to admin_notice
    self::logCacheClearStatus();

    AdminNotice::log($log_message);
    //AdminNotice::displayInfo($log_message);

    // We'll only perform this on WPE servers if cache purge is enabled in our settings
    if ( (1 == $this->isThisWpe()) && (1 == self::$cachePurgeOptions) ) {
      // Trigger cache clear
      $this->wpeCacheFlush();
      $this->cfCacheFlushAll();

    }
  }