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Using Batch API to process Drupal Queue jobs

Thu, 12/09/2010 - 16:23 — infojunkie

Hot on the heels of Batch API / Search integration, here is a related recipe to interactively run Drupal Queue jobs using Batch API, instead of waiting for cron or another background process to activate them:

  • Set up the batch process. Here we just expose a new menu item that points to a simple function that sets up the batch process with a hard-coded queue name:
<?php
// @file mymodule.module

/**
* Implementation of hook_menu().
*/
function mymodule_menu() {
  $items = array();
  $items['admin/mymodule/queue'] = array(
    'title' => 'Run queued jobs',
    'page callback' => 'mymodule_queue',
    'access arguments' => array('administer site configuration'),
  );
  return $items;
}

function mymodule_queue() {
  $batch = array(
    'title' => t('Running queued jobs'),
    'operations' => array(
      array('_mymodule_queue_batch', array('my_job_queue')),
    ),
    'finished' => '_mymodule_queue_finished',
  );
  batch_set($batch);
  batch_process('');
  return '';
}

?>
  • Implement the batch process. This is the core function where we dequeue items from the given queue to process them:
<?php
// @file mymodule.module

function _mymodule_queue_batch($queue_name, &$context) {
  drupal_queue_include();

  // Grab the defined cron queues.
  $queues = module_invoke_all('cron_queue_info');
  drupal_alter('cron_queue_info', $queues);
  if (!($info = $queues[$queue_name])) return;
  $queue = DrupalQueue::get($queue_name);

  // Work off queues.
  if (!isset($context['sandbox']['completed'])) {
    $context['sandbox']['completed'] = 0;
    $context['sandbox']['total'] = $queue->numberOfItems();
  }

  $function = $info['worker callback'];
  $end = time() + (isset($info['time']) ? $info['time'] : 15);
  while (time() < $end && ($item = $queue->claimItem())) {
    $function($item->data);
    $queue->deleteItem($item);
    $context['sandbox']['completed']++;
  }

  // Update Batch API status.
  $context['finished'] = empty($context['sandbox']['total']) ? 1 : $context['sandbox']['completed'] / $context['sandbox']['total'];
  $context['message'] = t('Now processing queue !queue...', array('!queue' => $queue_name));
}

function _mymodule_queue_finished($success, $results, $operations) {
  drupal_set_message(t('Processed all jobs.'));
}

?>

That's it! The proverbial exercise to the reader is to show a list of queues, allowing the user to choose which one(s) to process, and creating a new batch operation for each selected queue. Enjoy!

Comments

Thu, 12/09/2010 - 19:42 — Dave Reid (not verified)

Or they could just install the Queue UI module. :) http://drupal.org/project/queue_ui

Thu, 12/09/2010 - 20:17 — infojunkie

Thanks for bringing this module to my attention. The code I describe here works with D6.

Thu, 12/09/2010 - 22:16 — Dave Reid (not verified)

Well, no reason it can't be backported for the D6 drupal_queue module integration. :)