batch.queue.inc

<?php


/**
 * @file
 * Queue handlers used by the Batch API.
 *
 * These implementations:
 * - Ensure FIFO ordering.
 * - Allow an item to be repeatedly claimed until it is actually deleted (no
 *   notion of lease time or 'expire' date), to allow multipass operations.
 */

/**
 * Defines a batch queue.
 *
 * Stale items from failed batches are cleaned from the {queue} table on cron
 * using the 'created' date.
 */
class BatchQueue extends SystemQueue {
    
    /**
     * Overrides SystemQueue::claimItem().
     *
     * Unlike SystemQueue::claimItem(), this method provides a default lease
     * time of 0 (no expiration) instead of 30. This allows the item to be
     * claimed repeatedly until it is deleted.
     */
    public function claimItem($lease_time = 0) {
        $item = db_query_range('SELECT data, item_id FROM {queue} q WHERE name = :name ORDER BY item_id ASC', 0, 1, array(
            ':name' => $this->name,
        ))
            ->fetchObject();
        if ($item) {
            $item->data = unserialize($item->data);
            return $item;
        }
        return FALSE;
    }
    
    /**
     * Retrieves all remaining items in the queue.
     *
     * This is specific to Batch API and is not part of the DrupalQueueInterface.
     */
    public function getAllItems() {
        $result = array();
        $items = db_query('SELECT data FROM {queue} q WHERE name = :name ORDER BY item_id ASC', array(
            ':name' => $this->name,
        ))
            ->fetchAll();
        foreach ($items as $item) {
            $result[] = unserialize($item->data);
        }
        return $result;
    }

}

/**
 * Defines a batch queue for non-progressive batches.
 */
class BatchMemoryQueue extends MemoryQueue {
    
    /**
     * Overrides MemoryQueue::claimItem().
     *
     * Unlike MemoryQueue::claimItem(), this method provides a default lease
     * time of 0 (no expiration) instead of 30. This allows the item to be
     * claimed repeatedly until it is deleted.
     */
    public function claimItem($lease_time = 0) {
        if (!empty($this->queue)) {
            reset($this->queue);
            return current($this->queue);
        }
        return FALSE;
    }
    
    /**
     * Retrieves all remaining items in the queue.
     *
     * This is specific to Batch API and is not part of the DrupalQueueInterface.
     */
    public function getAllItems() {
        $result = array();
        foreach ($this->queue as $item) {
            $result[] = $item->data;
        }
        return $result;
    }

}