/**
* Copyright (c) 2002-2012 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.cluster.statemachine;
import org.neo4j.cluster.com.message.Message;
import org.neo4j.cluster.com.message.MessageProcessor;
import org.neo4j.cluster.com.message.MessageType;
/**
* Implemented by states in a state machine. Each state must
* implement the handle method, to perform different things depending
* on the message that comes in. This should only be implemented as enums.
* <p/>
* A state is guaranteed to only have one handle at a time, i.e. access is serialized.
*/
public interface State<CONTEXT, MESSAGETYPE extends MessageType>
{
/**
* Handle a message. The state can use context for state storage/retrieval and it will also act
* as a facade to the rest of the system. The MessageProcessor is used to trigger new messages.
* When the handling is done the state returns the next state of the state machine.
*
* @param context that contains state and methods to access other parts of the system
* @param message that needs to be handled
* @param outgoing processor for new messages created by the handling of this message
* @return the new state
* @throws Throwable
*/
public State<?, ?> handle( CONTEXT context, Message<MESSAGETYPE> message, MessageProcessor outgoing ) throws
Throwable;
}