abstract class Redis_Queue_Base in Redis 7.2

Redis allows implementing reliable queues, here is the spec:

• For each queue, you have 4 different HASH:

• One for queued items queue:NAME:queued

• One for claimed items being processed: queue:NAME:claimed

• One for claimed items leave time: queue:NAME:leave Items from this one will be arbitrarily fetched at cron time and released when leave is outdated.

• One containing the item values and other valuable stateful information: queue:NAME:data ;

• For example, current job maximum identifier (auto increment emulation) will be stored in the "sequence" HASH key

• All other keys within the HASH will be the items themselves, keys for those will always be numeric

• Each time a queue will be emptied, even during a pragmatic process, it will be automatically deleted, reseting the sequence counter to the 0 value each time

• Algorithm is a variation of the one described in "Reliable queue" section of http://redis.io/commands/rpoplpush and partial port of what you can find in the http://drupal.org/project/redis_queue module.

You will find the driver specific implementation in the Redis_Queue_* classes as they may differ in how the API handles transaction, pipelining and return values.

Hierarchy

• class \Redis_AbstractBackend
  • class \Redis_Queue_Base implements DrupalReliableQueueInterface

File

lib/Redis/Queue/Base.php, line 37

abstract class Redis_Queue_Base extends Redis_AbstractBackend implements DrupalReliableQueueInterface {

  /**
   * Key prefix for queue data.
   */
  const QUEUE_KEY_PREFIX = 'queue';

  /**
   * Data HASH sequence key name.
   */
  const QUEUE_HKEY_SEQ = 'seq';

  /**
   * Queue name
   *
   * @var string
   */
  protected $name;

  /**
   * Get data HASH key
   *
   * Key will already be prefixed
   *
   * @return string
   */
  public function getKeyForData() {
    return $this
      ->getKey(self::QUEUE_KEY_PREFIX, $this->name, 'data');
  }

  /**
   * Get queued items LIST key
   *
   * Key will already be prefixed
   *
   * @return string
   */
  public function getKeyForQueue() {
    return $this
      ->getKey(self::QUEUE_KEY_PREFIX, $this->name, 'queued');
  }

  /**
   * Get claimed LIST key
   *
   * Key will already be prefixed
   *
   * @return string
   */
  public function getKeyForClaimed() {
    return $this
      ->getKey(self::QUEUE_KEY_PREFIX, $this->name, 'claimed');
  }

  /**
   * Default contructor
   *
   * Beware that DrupalQueueInterface does not defines the __construct
   * method in the interface yet is being used from DrupalQueue::get()
   *
   * @param unknown $name
   */
  public function __construct($name) {
    $this->name = $name;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DrupalQueueInterface::claimItem	public	function	Claim an item in the queue for processing.	2
DrupalQueueInterface::createItem	public	function	Add a queue item and store it directly to the queue.	2
DrupalQueueInterface::createQueue	public	function	Create a queue.	2
DrupalQueueInterface::deleteItem	public	function	Delete a finished item from the queue.	2
DrupalQueueInterface::deleteQueue	public	function	Delete a queue and every item in the queue.	2
DrupalQueueInterface::numberOfItems	public	function	Retrieve the number of items in the queue.	2
DrupalQueueInterface::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.	2
Redis_AbstractBackend::$globalPrefix	protected static	property
Redis_AbstractBackend::$prefix	private	property
Redis_AbstractBackend::getClient	public	function	Get redis client
Redis_AbstractBackend::getDefaultPrefix	public static	function	Get global default prefix
Redis_AbstractBackend::getGlobalPrefix	public static	function	Get site default global prefix
Redis_AbstractBackend::getKey	public	function	Get full key name using the set prefix	2
Redis_AbstractBackend::getPrefix	final public	function	Get prefix
Redis_AbstractBackend::KEY_SEPARATOR		constant	Key components name separator
Redis_AbstractBackend::setPrefix	final public	function	Set prefix
Redis_Queue_Base::$name	protected	property	Queue name
Redis_Queue_Base::getKeyForClaimed	public	function	Get claimed LIST key
Redis_Queue_Base::getKeyForData	public	function	Get data HASH key
Redis_Queue_Base::getKeyForQueue	public	function	Get queued items LIST key
Redis_Queue_Base::QUEUE_HKEY_SEQ		constant	Data HASH sequence key name.
Redis_Queue_Base::QUEUE_KEY_PREFIX		constant	Key prefix for queue data.
Redis_Queue_Base::__construct	public	function	Default contructor Overrides Redis_AbstractBackend::__construct