Add ReserverInterface.

This interface allows implementations to define different behaviours
for reserving jobs from the queues.

Author: rayward

lib/Resque/Reserver/ReserverInterface.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Resque\Reserver;
+
+use Resque_Job;
+
+/**
+ * A reserver implements a specific behaviour for reserving jobs from its queues.
+ * Resque_Worker will call the reserve() method to obtain a reserved job.
+ */
+interface ReserverInterface
+{
+    /**
+     * Gets the queues to reserve jobs from.
+     *
+     * @return array
+     */
+    public function getQueues();
+
+    /**
+     * Reserves a job.
+     *
+     * @return Resque_Job|null A job instance or null if not job was available to reserve.
+     */
+    public function reserve();
+
+    /**
+     * If there was no job available to reserve, should the worker wait before attempting to reserve a job again?
+     *
+     * @return bool
+     */
+    public function waitAfterReservationAttempt();
+
+    /**
+     * Gets a friendly name of this reserver.
+     *
+     * @return string
+     */
+    public function getName();
+}