/*
 * Copyright (C) 2005-2013 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */
package org.alfresco.repo.cache;

/**
 * Basic cache API
 * 
 * @author Andy
 *
 */
public interface RefreshableCache <T> 
{
    /**
     * Get the cache.
     * If there is no cache value this call will block.
     * If the underlying cache is being refreshed, the old cache value will be returned until the refresh is complete.
     * 
     * @return
     */
    public T get();
    
    /**
     * Refresh the cache asynchronously.
     */
    public void refresh();

//    /**
//     * Register to be informed when the cache is updated in the background.
//     * 
//     * Note: it is up to the implementation to provide any transactional wrapping.
//     * Transactional wrapping is not required to invalidate a shared cache entry directly via a transactional cache 
//     * @param listener
//     */
//    void register(RefreshableCacheListener listener);
}