class MemoryQueue

Static queue implementation.

This allows "undelayed" variants of processes relying on the Queue interface. The queue data resides in memory. It should only be used for items that will be queued and dequeued within a given page request.

Hierarchy

class MemoryQueue implements BackdropQueueInterface

Expanded class hierarchy of MemoryQueue

File

core/modules/system/system.queue.inc, line 294: Queue functionality.

View source

class MemoryQueue implements BackdropQueueInterface {
  /**
   * The queue data.
   *
   * @var array
   */
  protected $queue;

  /**
   * Counter for item ids.
   *
   * @var int
   */
  protected $id_sequence;

  /**
   * Start working with a queue.
   *
   * @param $name
   *   Arbitrary string. The name of the queue to work with.
   */
  public function __construct($name) {
    $this->queue = array();
    $this->id_sequence = 0;
  }

  public function createItem($data) {
    $item = new stdClass();
    $item->item_id = $this->id_sequence++;
    $item->data = $data;
    $item->created = time();
    $item->expire = 0;
    $this->queue[$item->item_id] = $item;
    return TRUE;
  }

  public function numberOfItems() {
    return count($this->queue);
  }

  public function claimItem($lease_time = 30) {
    foreach ($this->queue as $key => $item) {
      if ($item->expire == 0) {
        $item->expire = time() + $lease_time;
        $this->queue[$key] = $item;
        return $item;
      }
    }
    return FALSE;
  }

  public function deleteItem($item) {
    unset($this->queue[$item->item_id]);
  }

  public function releaseItem($item) {
    if (isset($this->queue[$item->item_id]) && $this->queue[$item->item_id]->expire != 0) {
      $this->queue[$item->item_id]->expire = 0;
      return TRUE;
    }
    return FALSE;
  }

  public function createQueue() {
    // Nothing needed here.
  }

  public function deleteQueue() {
    $this->queue = array();
    $this->id_sequence = 0;
  }
}

Members

Name	Modifiers	Type	Description
MemoryQueue::$id_sequence	protected	property	Counter for item ids.
MemoryQueue::$queue	protected	property	The queue data.
MemoryQueue::claimItem	public	function	Claim an item in the queue for processing. Overrides BackdropQueueInterface::claimItem
MemoryQueue::createItem	public	function	Add a queue item and store it directly to the queue. Overrides BackdropQueueInterface::createItem
MemoryQueue::createQueue	public	function	Create a queue. Overrides BackdropQueueInterface::createQueue
MemoryQueue::deleteItem	public	function	Delete a finished item from the queue. Overrides BackdropQueueInterface::deleteItem
MemoryQueue::deleteQueue	public	function	Delete a queue and every item in the queue. Overrides BackdropQueueInterface::deleteQueue
MemoryQueue::numberOfItems	public	function	Retrieve the number of items in the queue. Overrides BackdropQueueInterface::numberOfItems
MemoryQueue::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 BackdropQueueInterface::releaseItem
MemoryQueue::__construct	public	function	Start working with a queue.

Hierarchy

Related topics

File

Members