/**
* 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 java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.neo4j.cluster.com.message.Message;
import org.neo4j.cluster.com.message.MessageProcessor;
import org.neo4j.cluster.com.message.MessageType;
/**
* Trigger messages when given state transitions occur
*/
public class StateMachineRules
implements StateTransitionListener
{
private final MessageProcessor outgoing;
private Map<State<?,?>,List<StateMachineRule>> rules = new HashMap<State<?, ?>, List<StateMachineRule>>( );
public StateMachineRules( MessageProcessor outgoing )
{
this.outgoing = outgoing;
}
public StateMachineRules rule( State<?, ?> oldState,
MessageType messageType,
State<?, ?> newState,
Message<?>... messages
)
{
List<StateMachineRule> fromRules = rules.get( oldState );
if (fromRules == null)
{
fromRules = new ArrayList<StateMachineRule>( );
rules.put( oldState, fromRules );
}
fromRules.add( new StateMachineRule( oldState, messageType, newState, messages ) );
return this;
}
@Override
public void stateTransition( StateTransition transition )
{
List<StateMachineRule> oldStateRules = rules.get( transition.getOldState() );
if (oldStateRules != null)
{
for( StateMachineRule oldStateRule : oldStateRules )
{
oldStateRule.stateTransition( transition );
}
}
}
private class StateMachineRule
implements StateTransitionListener
{
State<?,?> oldState;
MessageType messageType;
State<?,?> newState;
Message<?>[] messages;
private StateMachineRule( State<?, ?> oldState, MessageType messageType, State<?, ?> newState, Message<?>[] messages )
{
this.oldState = oldState;
this.messageType = messageType;
this.newState = newState;
this.messages = messages;
}
@Override
public void stateTransition( StateTransition transition )
{
if (oldState.equals( transition.getOldState() ) &&
transition.getMessage().getMessageType().equals( messageType ) &&
newState.equals( transition.getNewState() ))
{
for( Message<?> message : messages )
{
outgoing.process( message );
}
}
}
}
}