Include a new SqlParallel queue type that enables multiple queue runners to process in parallel

CRM/Queue/Queue/SqlParallel.php

@@ -0,0 +1,210 @@
+<?php
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ * A queue implementation which stores items in the CiviCRM SQL database
+ */
+class CRM_Queue_Queue_SqlParallel extends CRM_Queue_Queue {
+
+  /**
+   * Create a reference to queue. After constructing the queue, one should
+   * usually call createQueue (if it's a new queue) or loadQueue (if it's
+   * known to be an existing queue).
+   *
+   * @param array $queueSpec
+   *   Array with keys:
+   *   - type: string, required, e.g. "interactive", "immediate", "stomp",
+   *     "beanstalk"
+   *   - name: string, required, e.g. "upgrade-tasks"
+   *   - reset: bool, optional; if a queue is found, then it should be
+   *     flushed; default to TRUE
+   *   - (additional keys depending on the queue provider).
+   */
+  public function __construct($queueSpec) {
+    parent::__construct($queueSpec);
+  }
+
+  /**
+   * Perform any registation or resource-allocation for a new queue
+   */
+  public function createQueue() {
+    // nothing to do -- just start CRUDing items in the appropriate table
+  }
+
+  /**
+   * Perform any loading or pre-fetch for an existing queue.
+   */
+  public function loadQueue() {
+    // nothing to do -- just start CRUDing items in the appropriate table
+  }
+
+  /**
+   * Release any resources claimed by the queue (memory, DB rows, etc)
+   */
+  public function deleteQueue() {
+    return CRM_Core_DAO::singleValueQuery("
+      DELETE FROM civicrm_queue_item
+      WHERE queue_name = %1
+    ", [
+      1 => [$this->getName(), 'String'],
+    ]);
+  }
+
+  /**
+   * Check if the queue exists.
+   *
+   * @return bool
+   */
+  public function existsQueue() {
+    return ($this->numberOfItems() > 0);
+  }
+
+  /**
+   * Add a new item to the queue.
+   *
+   * @param mixed $data
+   *   Serializable PHP object or array.
+   * @param array $options
+   *   Queue-dependent options; for example, if this is a
+   *   priority-queue, then $options might specify the item's priority.
+   */
+  public function createItem($data, $options = []) {
+    $dao = new CRM_Queue_DAO_QueueItem();
+    $dao->queue_name = $this->getName();
+    $dao->submit_time = CRM_Utils_Time::getTime('YmdHis');
+    $dao->data = serialize($data);
+    $dao->weight = CRM_Utils_Array::value('weight', $options, 0);
+    $dao->save();
+  }
+
+  /**
+   * Determine number of items remaining in the queue.
+   *
+   * @return int
+   */
+  public function numberOfItems() {
+    return CRM_Core_DAO::singleValueQuery("
+      SELECT count(*)
+      FROM civicrm_queue_item
+      WHERE queue_name = %1
+    ", [
+      1 => [$this->getName(), 'String'],
+    ]);
+  }
+
+  /**
+   * Get the next item.
+   *
+   * @param int $lease_time
+   *   Seconds.
+   *
+   * @return object
+   *   With key 'data' that matches the inputted data.
+   */
+  public function claimItem($lease_time = 3600) {
+
+    $result = NULL;
+    $dao = CRM_Core_DAO::executeQuery('LOCK TABLES civicrm_queue_item WRITE;');
+    $sql = "SELECT id, queue_name, submit_time, release_time, data
+        FROM civicrm_queue_item
+        WHERE queue_name = %1
+              AND release_time IS NULL
+        ORDER BY weight ASC, id ASC
+        LIMIT 1
+      ";
+    $params = [
+      1 => [$this->getName(), 'String'],
+    ];
+    $dao = CRM_Core_DAO::executeQuery($sql, $params, TRUE, 'CRM_Queue_DAO_QueueItem');
+    if (is_a($dao, 'DB_Error')) {
+      // FIXME - Adding code to allow tests to pass
+      CRM_Core_Error::fatal();
+    }
+
+    if ($dao->fetch()) {
+      $nowEpoch = CRM_Utils_Time::getTimeRaw();
+      CRM_Core_DAO::executeQuery("UPDATE civicrm_queue_item SET release_time = %1 WHERE id = %2", [
+        '1' => [date('YmdHis', $nowEpoch + $lease_time), 'String'],
+        '2' => [$dao->id, 'Integer'],
+      ]);
+      // (Comment by artfulrobot Sep 2019: Not sure what the below comment means, should be removed/clarified?)
+      // work-around: inconsistent date-formatting causes unintentional breakage
+      #        $dao->submit_time = date('YmdHis', strtotime($dao->submit_time));
+      #        $dao->release_time = date('YmdHis', $nowEpoch + $lease_time);
+      #        $dao->save();
+      $dao->data = unserialize($dao->data);
+      $result = $dao;
+    }
+
+    $dao = CRM_Core_DAO::executeQuery('UNLOCK TABLES;');
+
+    return $result;
+  }
+
+  /**
+   * Get the next item, even if there's an active lease
+   *
+   * @param int $lease_time
+   *   Seconds.
+   *
+   * @return object
+   *   With key 'data' that matches the inputted data.
+   */
+  public function stealItem($lease_time = 3600) {
+    $sql = "
+      SELECT id, queue_name, submit_time, release_time, data
+      FROM civicrm_queue_item
+      WHERE queue_name = %1
+      ORDER BY weight ASC, id ASC
+      LIMIT 1
+    ";
+    $params = [
+      1 => [$this->getName(), 'String'],
+    ];
+    $dao = CRM_Core_DAO::executeQuery($sql, $params, TRUE, 'CRM_Queue_DAO_QueueItem');
+    if ($dao->fetch()) {
+      $nowEpoch = CRM_Utils_Time::getTimeRaw();
+      CRM_Core_DAO::executeQuery("UPDATE civicrm_queue_item SET release_time = %1 WHERE id = %2", [
+        '1' => [date('YmdHis', $nowEpoch + $lease_time), 'String'],
+        '2' => [$dao->id, 'Integer'],
+      ]);
+      $dao->data = unserialize($dao->data);
+      return $dao;
+    }
+  }
+
+  /**
+   * Remove an item from the queue.
+   *
+   * @param CRM_Core_DAO $dao
+   *   The item returned by claimItem.
+   */
+  public function deleteItem($dao) {
+    $dao->delete();
+    $dao->free();
+  }
+
+  /**
+   * Return an item that could not be processed.
+   *
+   * @param CRM_Core_DAO $dao
+   *   The item returned by claimItem.
+   */
+  public function releaseItem($dao) {
+    $sql = "UPDATE civicrm_queue_item SET release_time = NULL WHERE id = %1";
+    $params = [
+      1 => [$dao->id, 'Integer'],
+    ];
+    CRM_Core_DAO::executeQuery($sql, $params);
+    $dao->free();
+  }
+
+}