class Memory in Drupal 8

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 \Drupal\Core\Queue\Memory implements QueueInterface

Related topics

Queue operations

Queue items to allow later processing.

1 file declares its use of Memory

QueueTest.php in core/tests/Drupal/KernelTests/Core/Queue/QueueTest.php

File

core/lib/Drupal/Core/Queue/Memory.php, line 14

Namespace

Drupal\Core\Queue

class Memory implements QueueInterface {

  /**
   * The queue data.
   *
   * @var array
   */
  protected $queue;

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

  /**
   * Constructs a Memory object.
   *
   * @param string $name
   *   An arbitrary string. The name of the queue to work with.
   */
  public function __construct($name) {
    $this->queue = [];
    $this->idSequence = 0;
  }

  /**
   * {@inheritdoc}
   */
  public function createItem($data) {
    $item = new \stdClass();
    $item->item_id = $this->idSequence++;
    $item->data = $data;
    $item->created = time();
    $item->expire = 0;
    $this->queue[$item->item_id] = $item;
    return $item->item_id;
  }

  /**
   * {@inheritdoc}
   */
  public function numberOfItems() {
    return count($this->queue);
  }

  /**
   * {@inheritdoc}
   */
  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;
  }

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

  /**
   * {@inheritdoc}
   */
  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;
  }

  /**
   * {@inheritdoc}
   */
  public function createQueue() {

    // Nothing needed here.
  }

  /**
   * {@inheritdoc}
   */
  public function deleteQueue() {
    $this->queue = [];
    $this->idSequence = 0;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
Memory::$idSequence	protected	property	Counter for item ids.
Memory::$queue	protected	property	The queue data.
Memory::claimItem	public	function	Claims an item in the queue for processing. Overrides QueueInterface::claimItem	1
Memory::createItem	public	function	Adds a queue item and store it directly to the queue. Overrides QueueInterface::createItem
Memory::createQueue	public	function	Creates a queue. Overrides QueueInterface::createQueue
Memory::deleteItem	public	function	Deletes a finished item from the queue. Overrides QueueInterface::deleteItem
Memory::deleteQueue	public	function	Deletes a queue and every item in the queue. Overrides QueueInterface::deleteQueue
Memory::numberOfItems	public	function	Retrieves the number of items in the queue. Overrides QueueInterface::numberOfItems
Memory::releaseItem	public	function	Releases an item that the worker could not process. Overrides QueueInterface::releaseItem
Memory::__construct	public	function	Constructs a Memory object.