<?php
// $Id: mongodb_queue.module,v 1.3 2010-04-01 03:59:27 chx Exp $

/**
 * Implement hook_cron.
 */
function mongodb_queue_cron() {
  // reset expired items.
  $aliases = variable_get('mongodb_connections', array());
  $aliases['default'] = TRUE;
  $update_query = array(
    'expire' => array('$gt' => 0, '$lt' < REQUEST_TIME),
  );
  foreach (array_keys($aliases) as $alias) {
    // Call mongodb()->selectConnection() directly to avoid prefixing and DB
    // mapping tricks mongodb_collection() plays,
    $db = mongodb($alias);
    $collection = $db->selectCollection('system.namespaces');
    $n = strlen($db) + 1;
    // We won't need to check for system collections because those start with
    // system. and we search for queue.
    $find = array('name' => new MongoRegex('/^' . $db .'\.queue\./'));
    $queues = $collection->find($find);
    foreach ($queues as $collection_data) {
      $collection_name = $collection_data['name'];
      // According to the PECL mongodb source $ means an index. Also check for
      // a valid collection name.
      if (strpos($collection_name, '$') === FALSE && substr($collection_name, 0, $n) == "$db.") {
        // Split off the name of the database.
        $db->selectCollection(substr($collection_data['name'], $n))
          ->update($update_query, array('$set' => array('expire' => 0)));
      }
    }
  }
}