package org.apache.helix.ipc;
/*
* 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.
*/
import io.netty.buffer.ByteBuf;
import org.apache.helix.resolver.HelixAddress;
import java.util.UUID;
/**
* Allows message passing among instances in Helix clusters.
* <p>
* Messages are sent asynchronously using {@link #send}, and handled by callbacks registered via
* {@link #registerCallback}
* </p>
*/
public interface HelixIPCService {
static final String IPC_HOST = "IPC_HOST";
static final String IPC_PORT = "IPC_PORT";
/** Starts service (must call before {@link #send}) */
void start() throws Exception;
/** Shuts down service and releases any resources */
void shutdown() throws Exception;
/** Sends a message to one or more instances that map to a cluster scope. */
void send(HelixAddress destination, int messageType, UUID messageId, ByteBuf message);
/** Registers a callback for a given message type */
void registerCallback(int messageType, HelixIPCCallback callback);
}