/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * Licensed 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.catalina.cluster.session;
import org.apache.catalina.cluster.ClusterMessage;

/**
 *
 * <B>Class Description:</B><BR>
 * The SessionMessage class is a class that is used when a session has been
 * created, modified, expired in a Tomcat cluster node.<BR>
 *
 * The following events are currently available:
 * <ul>
 *   <li><pre>public static final int EVT_SESSION_CREATED</pre><li>
 *   <li><pre>public static final int EVT_SESSION_ACCESSED</pre><li>
 *   <li><pre>public static final int EVT_ATTRIBUTE_ADDED</pre><li>
 *   <li><pre>public static final int EVT_ATTRIBUTE_REMOVED</pre><li>
 *   <li><pre>public static final int EVT_SESSION_EXPIRED_WONOTIFY</pre><li>
 *   <li><pre>public static final int EVT_SESSION_EXPIRED_WNOTIFY</pre><li>
 *   <li><pre>public static final int EVT_GET_ALL_SESSIONS</pre><li>
 *   <li><pre>public static final int EVT_SET_USER_PRINCIPAL</pre><li>
 *   <li><pre>public static final int EVT_SET_SESSION_NOTE</pre><li>
 *   <li><pre>public static final int EVT_REMOVE_SESSION_NOTE</pre><li>
 * </ul>
 *
 */

public interface SessionMessage extends ClusterMessage, java.io.Serializable
{

    /**
     * Event type used when a session has been created on a node
     */
    public static final int EVT_SESSION_CREATED = 1;
    /**
     * Event type used when a session has expired
     */
    public static final int EVT_SESSION_EXPIRED = 2;

    /**
     * Event type used when a session has been accessed (ie, last access time
     * has been updated. This is used so that the replicated sessions will not expire
     * on the network
     */
    public static final int EVT_SESSION_ACCESSED = 3;
    /**
     * Event type used when a server comes online for the first time.
     * The first thing the newly started server wants to do is to grab the
     * all the sessions from one of the nodes and keep the same state in there
     */
    public static final int EVT_GET_ALL_SESSIONS = 4;
    /**
     * Event type used when an attribute has been added to a session,
     * the attribute will be sent to all the other nodes in the cluster
     */
    public static final int EVT_SESSION_DELTA  = 13;

    /**
     * When a session state is transferred, this is the event.
     */
    public static final int EVT_ALL_SESSION_DATA = 12;
    

    public String getContextName();
    
    public String getEventTypeString();
    
    /**
     * returns the event type
     * @return one of the event types EVT_XXXX
     */
    public int getEventType(); 
    /**
     * @return the serialized data for the session
     */
    public byte[] getSession();
    /**
     * @return the session ID for the session
     */
    public String getSessionID();
    

}//SessionMessage