Base.php in Redis 7.2

File

lib/Redis/Queue/Base.php

<?php

/**
 * 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 *       time and released when leave is outdated.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.
 */
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;
  }

}

Classes

Name	Description
Redis_Queue_Base	Redis allows implementing reliable queues, here is the spec: