org.apache.pulsar.broker.protocol.ProtocolHandler Maven / Gradle / Ivy
/**
* 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.pulsar.broker.protocol;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import java.net.InetSocketAddress;
import java.util.Map;
import org.apache.pulsar.broker.ServiceConfiguration;
import org.apache.pulsar.broker.service.BrokerService;
import org.apache.pulsar.common.classification.InterfaceAudience;
import org.apache.pulsar.common.classification.InterfaceStability;
/**
* The protocol handler interface for support additional protocols on Pulsar brokers.
*/
@InterfaceAudience.LimitedPrivate
@InterfaceStability.Evolving
public interface ProtocolHandler extends AutoCloseable {
/**
* Returns the unique protocol name. For example, `kafka-v2` for protocol handler for Kafka v2 protocol.
*/
String protocolName();
/**
* Verify if the protocol can speak the given protocol.
*
* @param protocol the protocol to verify
* @return true if the protocol handler can handle the given protocol, otherwise false.
*/
boolean accept(String protocol);
/**
* Initialize the protocol handler when the protocol is constructed from reflection.
*
* The initialize should initialize all the resources required for serving the protocol
* handler but don't start those resources until {@link #start(BrokerService)} is called.
*
* @param conf broker service configuration
* @throws Exception when fail to initialize the protocol handler.
*/
void initialize(ServiceConfiguration conf) throws Exception;
/**
* Retrieve the protocol related data to advertise as part of
* {@link org.apache.pulsar.policies.data.loadbalancer.LocalBrokerData}.
*
*
For example, when implementing a Kafka protocol handler, you need to advertise
* corresponding Kafka listeners so that Pulsar brokers understand how to give back
* the listener information when handling metadata requests.
*
*
NOTE: this method is called after {@link #initialize(ServiceConfiguration)}
* and before {@link #start(BrokerService)}.
*
* @return the protocol related data to be advertised as part of LocalBrokerData.
*/
String getProtocolDataToAdvertise();
/**
* Start the protocol handler with the provided broker service.
*
*
The broker service provides the accesses to the Pulsar components such as load
* manager, namespace service, managed ledger and etc.
*
* @param service the broker service to start with.
*/
void start(BrokerService service);
/**
* Create the list of channel initializers for the ports that this protocol handler
* will listen on.
*
*
NOTE: this method is called after {@link #start(BrokerService)}.
*
* @return the list of channel initializers for the ports that this protocol handler listens on.
*/
Map> newChannelInitializers();
@Override
void close();
}