class AcquiaPurgeQueueSmart in Acquia Purge 7

Efficient query bundling database queue that disregards expired queue items.

This backend drops items from the queue that have been sitting there twice as long as the sites TTL is configured to. All load balancers that once had the item in cache, are assumed to have already refreshed the item long ago.

Hierarchy

• class \SystemQueue implements DrupalReliableQueueInterface
  • class \AcquiaPurgeQueueEfficient implements AcquiaPurgeQueueInterface
    • class \AcquiaPurgeQueueSmart implements AcquiaPurgeQueueInterface

File

lib/queue/AcquiaPurgeQueueSmart.php, line 15

Contains SmartQueue.

class AcquiaPurgeQueueSmart extends AcquiaPurgeQueueEfficient implements AcquiaPurgeQueueInterface {

  /**
   * Time in seconds Varnish is caching pages generated by Drupal.
   *
   * @var int
   */
  protected $ttl = 0;

  /**
   * Construct a AcquiaPurgeQueueSmart instance.
   *
   * @param AcquiaPurgeStateStorageInterface $state
   *   The state storage required for the queue counters.
   */
  public function __construct(AcquiaPurgeStateStorageInterface $state) {
    parent::__construct($state);
    $this->ttl = (int) variable_get('page_cache_maximum_age', 0);
  }

  /**
   * Expire queue items that should have already expired externally.
   */
  protected function expireQueueItems() {

    // Do not bother expiry under the following conditions.
    $expired = time() - 2 * $this->ttl;
    if ($this->ttl < 20) {
      return;
    }
    if ($expired < 1 || $expired >= time()) {
      return;
    }

    // Delete items from the queue that expired and need no processing by AP.
    $deleted_items = db_delete('queue')
      ->condition('name', $this->name)
      ->condition('created', $expired, '<')
      ->execute();
    if ($deleted_items > 0) {
      watchdog('acquia_purge', "Disregarded %n expired items from the queue (smart queue backend).", array(
        '%n' => $deleted_items,
      ), WATCHDOG_INFO);
      $this
        ->total()
        ->decrease($deleted_items);
    }
  }

  /**
   * {@inheritdoc}
   */
  public function claimItem($lease_time = 30) {
    $this
      ->expireQueueItems();
    return parent::claimItem($lease_time);
  }

  /**
   * {@inheritdoc}
   */
  public function claimItemMultiple($claims = 10, $lease_time = 30) {
    $this
      ->expireQueueItems();
    return parent::claimItemMultiple($claims, $lease_time);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
AcquiaPurgeQueueEfficient::$class_queue_item	protected	property	The queue item class to spawn queue items with.
AcquiaPurgeQueueEfficient::$state	protected	property	The state storage which holds the counter state items.
AcquiaPurgeQueueEfficient::bad	public	function	Retrieve the failed purges counter. Overrides AcquiaPurgeQueueInterface::bad
AcquiaPurgeQueueEfficient::createItem	public	function	Add a queue item and store it directly to the queue. Overrides SystemQueue::createItem
AcquiaPurgeQueueEfficient::createItemMultiple	public	function	Add multiple items to the queue and store them efficiently. Overrides AcquiaPurgeQueueInterface::createItemMultiple
AcquiaPurgeQueueEfficient::deleteItemMultiple	public	function	Delete multiple items from the queue at once. Overrides AcquiaPurgeQueueInterface::deleteItemMultiple
AcquiaPurgeQueueEfficient::deleteQueue	public	function	Delete a queue and every item in the queue. Overrides SystemQueue::deleteQueue
AcquiaPurgeQueueEfficient::good	public	function	Retrieve the successful purges counter. Overrides AcquiaPurgeQueueInterface::good
AcquiaPurgeQueueEfficient::numberOfItems	public	function	Retrieve the number of items in the queue. Overrides SystemQueue::numberOfItems
AcquiaPurgeQueueEfficient::releaseItemMultiple	public	function	Release multiple items that the worker could not process. Overrides AcquiaPurgeQueueInterface::releaseItemMultiple
AcquiaPurgeQueueEfficient::total	public	function	Retrieve the total queue items counter. Overrides AcquiaPurgeQueueInterface::total
AcquiaPurgeQueueSmart::$ttl	protected	property	Time in seconds Varnish is caching pages generated by Drupal.
AcquiaPurgeQueueSmart::claimItem	public	function	SystemQueue::claimItem() doesn't included expired items in its query which means that it essentially breaks its own interface promise. Therefore we overload the implementation with one that does do this accurately. This should however flow back… Overrides AcquiaPurgeQueueEfficient::claimItem
AcquiaPurgeQueueSmart::claimItemMultiple	public	function	Claims multiple items from the queue for processing. Overrides AcquiaPurgeQueueEfficient::claimItemMultiple
AcquiaPurgeQueueSmart::expireQueueItems	protected	function	Expire queue items that should have already expired externally.
AcquiaPurgeQueueSmart::__construct	public	function	Construct a AcquiaPurgeQueueSmart instance. Overrides AcquiaPurgeQueueEfficient::__construct
SystemQueue::$name	protected	property	The name of the queue this instance is working with.
SystemQueue::createQueue	public	function	Create a queue. Overrides DrupalQueueInterface::createQueue
SystemQueue::deleteItem	public	function	Delete a finished item from the queue. Overrides DrupalQueueInterface::deleteItem
SystemQueue::releaseItem	public	function	Release an item that the worker could not process, so another worker can come in and process it before the timeout expires. Overrides DrupalQueueInterface::releaseItem