/*
* 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.drill.exec.rpc;
import io.netty.buffer.ByteBuf;
/**
* Note that if a handler maintains any internal state, the state will be disposed if the handler on the connection
* changes. So handler should not maintain state.
*
* @param <S> server connection type
*/
public interface RequestHandler<S extends ServerConnection<S>> {
/**
* Handle request of given type (rpcType) with message (pBody) and optional data (dBody)
* on the connection, and return the appropriate response.
*
* The method must do one of three things:
* + use {@link ResponseSender#send send} the response
* + throw UserRpcException, in which case a response will be sent using {@link ResponseSender#send send}
* + throw an Exception, in which case, the connection will be dropped
*
* @param connection remote connection
* @param rpcType rpc type
* @param pBody message
* @param dBody data, maybe null
* @param sender used to {@link ResponseSender#send send} the response
* @return response to the request
* @throws RpcException
*/
void handle(S connection, int rpcType, ByteBuf pBody, ByteBuf dBody, ResponseSender sender)
throws RpcException;
}