drupal-civicrm/sites/all/modules/civicrm/CRM/Queue/Service.php
2018-01-14 13:10:16 +00:00

173 lines
5.4 KiB
PHP

<?php
/*
+--------------------------------------------------------------------+
| CiviCRM version 4.7 |
+--------------------------------------------------------------------+
| Copyright CiviCRM LLC (c) 2004-2017 |
+--------------------------------------------------------------------+
| This file is a part of CiviCRM. |
| |
| CiviCRM is free software; you can copy, modify, and distribute it |
| under the terms of the GNU Affero General Public License |
| Version 3, 19 November 2007 and the CiviCRM Licensing Exception. |
| |
| CiviCRM is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| See the GNU Affero General Public License for more details. |
| |
| You should have received a copy of the GNU Affero General Public |
| License and the CiviCRM Licensing Exception along |
| with this program; if not, contact CiviCRM LLC |
| at info[AT]civicrm[DOT]org. If you have questions about the |
| GNU Affero General Public License or the licensing of CiviCRM, |
| see the CiviCRM license FAQ at http://civicrm.org/licensing |
+--------------------------------------------------------------------+
*/
/**
* The queue service provides an interface for creating or locating
* queues. Note that this approach hides the details of data-storage:
* different queue-providers may store the queue content in different
* ways (in memory, in SQL, or in an external service).
*
* @code
* $queue = CRM_Queue_Service::singleton()->create(array(
* 'type' => 'interactive',
* 'name' => 'upgrade-tasks',
* ));
* $queue->createItem($myData);
*
* // Some time later...
* $item = $queue->claimItem();
* if ($item) {
* if (my_process($item->data)) {
* $queue->deleteItem($item);
* } else {
* $queue->releaseItem($item);
* }
* }
* @endcode
*/
class CRM_Queue_Service {
protected static $_singleton;
/**
* FIXME: Singleton pattern should be removed when dependency-injection
* becomes available.
*
* @param bool $forceNew
* TRUE if a new instance must be created.
*
* @return \CRM_Queue_Service
*/
public static function &singleton($forceNew = FALSE) {
if ($forceNew || !self::$_singleton) {
self::$_singleton = new CRM_Queue_Service();
}
return self::$_singleton;
}
/**
* @var array (string $queueName => CRM_Queue_Queue)
*/
public $queues;
/**
*/
public function __construct() {
$this->queues = array();
}
/**
* Create a queue. If one already exists, then it will be reused.
*
* @param array $queueSpec
* Array with keys:
* - type: string, required, e.g. "interactive", "immediate", "stomp",
* "beanstalk"
* - name: string, required, e.g. "upgrade-tasks"
* - reset: bool, optional; if a queue is found, then it should be
* flushed; default to TRUE
* - (additional keys depending on the queue provider).
*
* @return CRM_Queue_Queue
*/
public function create($queueSpec) {
if (@is_object($this->queues[$queueSpec['name']]) && empty($queueSpec['reset'])) {
return $this->queues[$queueSpec['name']];
}
$queue = $this->instantiateQueueObject($queueSpec);
$exists = $queue->existsQueue();
if (!$exists) {
$queue->createQueue();
}
elseif (@$queueSpec['reset']) {
$queue->deleteQueue();
$queue->createQueue();
}
else {
$queue->loadQueue();
}
$this->queues[$queueSpec['name']] = $queue;
return $queue;
}
/**
* Look up an existing queue.
*
* @param array $queueSpec
* Array with keys:
* - type: string, required, e.g. "interactive", "immediate", "stomp",
* "beanstalk"
* - name: string, required, e.g. "upgrade-tasks"
* - (additional keys depending on the queue provider).
*
* @return CRM_Queue_Queue
*/
public function load($queueSpec) {
if (is_object($this->queues[$queueSpec['name']])) {
return $this->queues[$queueSpec['name']];
}
$queue = $this->instantiateQueueObject($queueSpec);
$queue->loadQueue();
$this->queues[$queueSpec['name']] = $queue;
return $queue;
}
/**
* Convert a queue "type" name to a class name.
*
* @param string $type
* E.g. "interactive", "immediate", "stomp", "beanstalk".
*
* @return string
* Class-name
*/
protected function getQueueClass($type) {
$type = preg_replace('/[^a-zA-Z0-9]/', '', $type);
$className = 'CRM_Queue_Queue_' . $type;
// FIXME: when used with class-autoloader, this may be unnecessary
if (!class_exists($className)) {
$classFile = 'CRM/Queue/Queue/' . $type . '.php';
require_once $classFile;
}
return $className;
}
/**
* @param array $queueSpec
* See create().
*
* @return CRM_Queue_Queue
*/
protected function instantiateQueueObject($queueSpec) {
// note: you should probably never do anything else here
$class = new ReflectionClass($this->getQueueClass($queueSpec['type']));
return $class->newInstance($queueSpec);
}
}