CRM/Queue/Queue.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | Copyright CiviCRM LLC. All rights reserved.                        |
   5  |                                                                    |
   6  | This work is published under the GNU AGPLv3 license with some      |
   7  | permitted exceptions and without any warranty. For full license    |
   8  | and copyright information, see https://civicrm.org/licensing       |
   9  +--------------------------------------------------------------------+
  10  */
  11
  12 /**
  13  * A queue is an object (usually backed by some persistent data store)
  14  * which stores a list of tasks or messages for use by other processes.
  15  *
  16  * This would ideally be an interface, but it's handy to specify the
  17  * "function __construct()" and the "$name" handling
  18  *
  19  * Note: This interface closely parallels the DrupalQueueInterface.
  20  */
  21 abstract class CRM_Queue_Queue {
  22
  23   const DEFAULT_LEASE_TIME = 3600;
  24
  25   /**
  26    * @var string
  27    */
  28   private $_name;
  29
  30   /**
  31    * @var array{name: string, type: string, runner: string, batch_limit: int, lease_time: ?int, retry_limit: int, retry_interval: ?int}
  32    * @see \CRM_Queue_Service::create()
  33    */
  34   protected $queueSpec;
  35
  36   /**
  37    * Create a reference to queue. After constructing the queue, one should
  38    * usually call createQueue (if it's a new queue) or loadQueue (if it's
  39    * known to be an existing queue).
  40    *
  41    * @param array{name: string, type: string, runner: string, batch_limit: int, lease_time: ?int, retry_limit: int, retry_interval: ?int} $queueSpec
  42    *   Ex: ['name' => 'my-import', 'type' => 'SqlParallel']
  43    *   The full definition of queueSpec is defined in CRM_Queue_Service.
  44    * @see \CRM_Queue_Service::create()
  45    */
  46   public function __construct($queueSpec) {
  47     $this->_name = $queueSpec['name'];
  48     $this->queueSpec = $queueSpec;
  49     unset($this->queueSpec['status']);
  50     // Status may be meaningfully + independently toggled (eg when using type=SqlParallel,error=abort).
  51     // Retaining a copy of 'status' in here would be misleading.
  52   }
  53
  54   /**
  55    * Determine whether this queue is currently active.
  56    *
  57    * @return bool
  58    *   TRUE if runners should continue claiming new tasks from this queue
  59    * @throws \CRM_Core_Exception
  60    */
  61   public function isActive(): bool {
  62     $status = CRM_Core_DAO::getFieldValue('CRM_Queue_DAO_Queue', $this->_name, 'status', 'name', TRUE);
  63     // Note: In the future, we may want to incorporate other data (like maintenance-mode or upgrade-status) in deciding active queues.
  64     return ($status === 'active');
  65   }
  66
  67   /**
  68    * Change the status of the queue.
  69    *
  70    * @param string $status
  71    *   Ex: 'active', 'draft', 'aborted'
  72    */
  73   public function setStatus(string $status): void {
  74     CRM_Core_DAO::executeQuery('UPDATE civicrm_queue SET status = %1 WHERE name = %2', [
  75       1 => ['aborted', 'String'],
  76       2 => [$this->getName(), 'String'],
  77     ]);
  78   }
  79
  80   /**
  81    * Determine the string name of this queue.
  82    *
  83    * @return string
  84    */
  85   public function getName() {
  86     return $this->_name;
  87   }
  88
  89   /**
  90    * Get a property from the queueSpec.
  91    *
  92    * @param string $field
  93    * @return mixed|null
  94    */
  95   public function getSpec(string $field) {
  96     return $this->queueSpec[$field] ?? NULL;
  97   }
  98
  99   /**
 100    * Perform any registation or resource-allocation for a new queue
 101    */
 102   abstract public function createQueue();
 103
 104   /**
 105    * Perform any loading or pre-fetch for an existing queue.
 106    */
 107   abstract public function loadQueue();
 108
 109   /**
 110    * Release any resources claimed by the queue (memory, DB rows, etc)
 111    */
 112   abstract public function deleteQueue();
 113
 114   /**
 115    * Check if the queue exists.
 116    *
 117    * @return bool
 118    */
 119   abstract public function existsQueue();
 120
 121   /**
 122    * Add a new item to the queue.
 123    *
 124    * @param mixed $data
 125    *   Serializable PHP object or array.
 126    * @param array $options
 127    *   Queue-dependent options; for example, if this is a
 128    *   priority-queue, then $options might specify the item's priority.
 129    */
 130   abstract public function createItem($data, $options = []);
 131
 132   /**
 133    * Determine number of items remaining in the queue.
 134    *
 135    * @return int
 136    */
 137   abstract public function numberOfItems();
 138
 139   /**
 140    * Get the next item.
 141    *
 142    * @param int|null $lease_time
 143    *   Hold a lease on the claimed item for $X seconds.
 144    *   If NULL, inherit a default.
 145    * @return object
 146    *   with key 'data' that matches the inputted data
 147    */
 148   abstract public function claimItem($lease_time = NULL);
 149
 150   /**
 151    * Get the next item, even if there's an active lease
 152    *
 153    * @param int $lease_time
 154    *   Seconds.
 155    *
 156    * @return object
 157    *   with key 'data' that matches the inputted data
 158    */
 159   abstract public function stealItem($lease_time = NULL);
 160
 161   /**
 162    * Remove an item from the queue.
 163    *
 164    * @param object $item
 165    *   The item returned by claimItem.
 166    */
 167   abstract public function deleteItem($item);
 168
 169   /**
 170    * Get the full data for an item.
 171    *
 172    * This is a passive peek - it does not claim/steal/release anything.
 173    *
 174    * @param int|string $id
 175    *   The unique ID of the task within the queue.
 176    * @return CRM_Queue_DAO_QueueItem|object|null $dao
 177    */
 178   abstract public function fetchItem($id);
 179
 180   /**
 181    * Return an item that could not be processed.
 182    *
 183    * @param object $item
 184    *   The item returned by claimItem.
 185    */
 186   abstract public function releaseItem($item);
 187
 188 }