/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 package org.apache.shiro.session.mgt.eis;

 import org.apache.shiro.cache.AbstractCacheManager;

 import org.apache.shiro.cache.Cache;

 import org.apache.shiro.cache.CacheException;

 import org.apache.shiro.cache.MapCache;

 import org.apache.shiro.session.Session;

 import java.io.Serializable;

 import java.util.concurrent.ConcurrentHashMap;

 /**

  * SessionDAO implementation that relies on an enterprise caching product as the EIS system of record for all sessions.

  * It is expected that an injected {@link org.apache.shiro.cache.Cache Cache} or

  * {@link org.apache.shiro.cache.CacheManager CacheManager} is backed by an enterprise caching product that can support

  * all application sessions and/or provide disk paging for resilient data storage.

  * <h2>Production Note</h2>

  * This implementation defaults to using an in-memory map-based {@code CacheManager}, which is great for testing but

  * will typically not scale for production environments and could easily cause {@code OutOfMemoryException}s.  Just

  * don't forget to configure<b>*</b> an instance of this class with a production-grade {@code CacheManager} that can

  * handle disk paging for large numbers of sessions and you'll be fine.

  * <p/>

  * <b>*</b>If you configure Shiro's {@code SecurityManager} instance with such a {@code CacheManager}, it will be

  * automatically applied to an instance of this class and you won't need to explicitly set it in configuration.

  * <h3>Implementation Details</h3>

  * This implementation relies heavily on the {@link CachingSessionDAO parent class}'s transparent caching behavior for

  * all storage operations with the enterprise caching product.  Because the parent class uses a {@code Cache} or

  * {@code CacheManager} to perform caching, and the cache is considered the system of record, nothing further needs to

  * be done for the {@link #doReadSession}, {@link #doUpdate} and {@link #doDelete} method implementations.  This class

  * implements those methods as required by the parent class, but they essentially do nothing.

  *

  * @since 1.0

  */

 public class EnterpriseCacheSessionDAO extends CachingSessionDAO {

     public EnterpriseCacheSessionDAO() {

         setCacheManager(new AbstractCacheManager() {

             @Override

             protected Cache<Serializable, Session> createCache(String name) throws CacheException {

                 return new MapCache<Serializable, Session>(name, new ConcurrentHashMap<Serializable, Session>());

             }

         });

     }

     protected Serializable doCreate(Session session) {

         Serializable sessionId = generateSessionId(session);

         assignSessionId(session, sessionId);

         return sessionId;

     }

     protected Session doReadSession(Serializable sessionId) {

         return null; //should never execute because this implementation relies on parent class to access cache, which

         //is where all sessions reside - it is the cache implementation that determines if the

         //cache is memory only or disk-persistent, etc.

     }

     protected void doUpdate(Session session) {

         //does nothing - parent class persists to cache.

     }

     protected void doDelete(Session session) {

         //does nothing - parent class removes from cache.

     }

 }