/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This 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 2.1 of
* the License, or (at your option) any later version.
*
* This software 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 this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.web.tomcat.service.session.notification;
/**
* Policy for determining whether the servlet spec notifications related
* to session events are allowed to be emitted on the local cluster node.
* <p>
* <strong>Note:</strong> The use of the word <strong>allowed</strong> above
* is intentional; if a given policy implementation returns <code>true</code>
* from one of the methods in this interface, that does not mean the listener
* will be invoked by the container, nor does the presence of a method in this
* interface imply that it will be invoked by the container in all cases. The
* only contract this interface creates is that before invoking a listener
* method, the container will invoke an implementation of this policy to
* get permission and will not invoke the listeners if this policy returns
* <code>false</code>. If the container does not support emitting notifications
* in certain cases, it may not bother checking if the notification is allowed,
* and even if it checks, it still will not emit the notification.
* </p>
* <p>
* An example of a case where the container may not support emitting a
* notification is for a session that has never been used locally.
* </p>
*
* @author Brian Stansberry
*/
public interface ClusteredSessionNotificationPolicy
{
/**
* Are invocations of <code>HttpSessionListener</code> callbacks
* allowed under the given conditions?
*
* @param status the status of the session
* @param cause the cause of the session notification
* @param local <code>true</code> if the event driving the notification
* originated on this node; <code>false</code> otherwise
*
* @return <code>true</code> if the notification is allowed,
* <code>false</code> if not
*/
boolean isHttpSessionListenerInvocationAllowed(ClusteredSessionManagementStatus status,
ClusteredSessionNotificationCause cause,
boolean local);
/**
* Under the given conditions, are invocations of
* <code>HttpSessionAttributeListener</code> callbacks allowed?
*
* @param status the status of the session
* @param cause the cause of the session notification
* @param attributeName value that would be passed to the <code>name</code>
* param of the <code>HttpSessionBindingEvent</code> if
* the listener were invoked
* @param local <code>true</code> if the event driving the notification
* originated on this node; <code>false</code> otherwise
*
* @return <code>true</code> if the notification is allowed,
* <code>false</code> if not
*/
boolean isHttpSessionAttributeListenerInvocationAllowed(ClusteredSessionManagementStatus status,
ClusteredSessionNotificationCause cause,
String attributeName,
boolean local);
/**
* Under the given conditions, are invocations of
* <code>HttpSessionBindingListener</code> callbacks allowed?
*
* @param status the status of the session
* @param cause the cause of the session notification
* @param attributeName value that would be passed to the <code>name</code>
* param of the <code>HttpSessionBindingEvent</code> if
* the listener were invoked
* @param local <code>true</code> if the event driving the notification
* originated on this node; <code>false</code> otherwise
*
* @return <code>true</code> if the notification is allowed,
* <code>false</code> if not
*/
boolean isHttpSessionBindingListenerInvocationAllowed(ClusteredSessionManagementStatus status,
ClusteredSessionNotificationCause cause,
String attributeName,
boolean local);
/**
* Under the given conditions, are invocations of
* <code>HttpSessionActivationListener</code> callbacks allowed?
*
* @param status the status of the session
* @param cause the cause of the session notification
* @param attributeName value that would be passed to the <code>name</code>
* param of the <code>HttpSessionEvent</code> if
* the listener were invoked
*
* @return <code>true</code> if the notification is allowed,
* <code>false</code> if not
*/
boolean isHttpSessionActivationListenerInvocationAllowed(ClusteredSessionManagementStatus status,
ClusteredSessionNotificationCause cause,
String attributeName);
/**
* Provides the policy information about the container's capabilities with
* respect to issuing notifications. Will be invoked by the container before
* the first invocation of any of the other methods in this interface.
*
* @param capability the capability, Will not be <code>null</code>.
*/
void setClusteredSessionNotificationCapability(ClusteredSessionNotificationCapability capability);
}