computing.queue.inc in Drupal Computing 7.2

File

computing.queue.inc

<?php

/**
 * This file provides Queue support, an extra layer to handle computing records.
 * The only benefit here is to provide an interface for Queue, perhaps people don't need it.
 */
class ComputingQueue implements DrupalReliableQueueInterface {
  protected $app_name;

  // singleton design pattern.
  private function __construct($app_name) {

    // we don't validate $app_name against "computing_application" entity.
    $this->app_name = $app_name;
  }

  /**
   * Factory method.
   * @param $app_name
   * @return object
   */
  public static function get($app_name) {
    static $queues;
    if (!isset($queues[$app_name])) {
      $object = new ComputingQueue($app_name);
      $queues[$app_name] = $object;
    }
    return $queues[$app_name];
  }

  ///////////////////////////// below are methods defined in DrupalReliableQueueInterface
  public function createItem($data) {
    if (is_object($data)) {
      $data = (array) $data;
    }
    $options = array_diff_key($data, array_flip(array(
      'application',
      'command',
      'label',
      'input',
    )));
    return (bool) computing_create($data['application'], $data['command'], $data['label'], $data['input'], $options);
  }
  public function numberOfItems() {
    return db_query("SELECT COUNT(id) FROM {computing_record} WHERE application = :name AND status = 'RDY'", array(
      ':name' => $this->app_name,
    ))
      ->fetchField();
  }
  public function claimItem($lease_time = 3600) {

    //$lease_time: not used.
    return computing_claim($this->app_name);
  }
  public function deleteItem($item) {

    // we'll not physically delete the item, but just mark the item as "ABD".
    if (!is_object($item)) {
      $item = (object) $item;
    }

    // this is to follow the definition in the interface.
    if (computing_update_field($item->id, 'status', 'ABD')) {
      return computing_load($item->id);
    }
    else {
      return FALSE;
    }
  }
  public function releaseItem($item) {
    if (!is_object($item)) {
      $item = (object) $item;
    }
    return computing_release($item->id);
  }
  public function createQueue() {

    // nothing to be done here as the 'computing' table/entity_type is created in installation.
  }
  public function deleteQueue() {

    // we won't delete any data here. keep everything for archival purpose.
  }

}

Classes

Name	Description
ComputingQueue	This file provides Queue support, an extra layer to handle computing records. The only benefit here is to provide an interface for Queue, perhaps people don't need it.