/*
* 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.tinkerpop.gremlin.process.computer;
import java.util.Iterator;
/**
* The {@link Messenger} serves as the routing system for messages between vertices. For distributed systems,
* the messenger can implement a "message passing" engine (distributed memory). For single machine systems, the
* messenger can implement a "state sharing" engine (shared memory). Each messenger is tied to the particular
* vertex distributing the message.
*
* @author Marko A. Rodriguez (http://markorodriguez.com)
* @author Matthias Broecheler (me@matthiasb.com)
*/
public interface Messenger<M> {
/**
* Receive all incoming messages to the currently executing vertex.
*
* @return the messages for the vertex
*/
public Iterator<M> receiveMessages();
/**
* The currently executing vertex can send a message with provided {@link MessageScope}.
*
* @param messageScope the message scope of the message being sent
* @param message the message to send
*/
public void sendMessage(final MessageScope messageScope, final M message);
}