org.apache.tajo.rpc.NettyAsyncRpcProxy.java Source code

Introduction

Here is the source code for org.apache.tajo.rpc.NettyAsyncRpcProxy.java

Source

/**
 * 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.tajo.rpc;

import com.google.protobuf.ByteString;
import com.google.protobuf.Message;
import com.google.protobuf.RpcCallback;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jboss.netty.channel.*;
import org.apache.tajo.rpc.ProtoParamRpcProtos.Invocation;
import org.apache.tajo.rpc.ProtoParamRpcProtos.Response;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.net.InetSocketAddress;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

@Deprecated
public class NettyAsyncRpcProxy extends NettyClientBase {
    private static Log LOG = LogFactory.getLog(NettyAsyncRpcProxy.class);

    private final Class<?> protocol;
    private final ClientHandler handler;
    InetSocketAddress addr;

    private final AtomicInteger sequence = new AtomicInteger(0);
    private final Map<Integer, ResponseRpcCallback> requests = new ConcurrentHashMap<Integer, ResponseRpcCallback>();

    @SuppressWarnings("rawtypes")
    private final Map<String, Class> returnTypeMap = new HashMap<String, Class>();

    public NettyAsyncRpcProxy(Class<?> server, Class<?> client, InetSocketAddress addr) {
        this.protocol = client;

        this.handler = new ClientHandler();
        ChannelPipelineFactory pipeFactory = new ProtoPipelineFactory(handler, Response.getDefaultInstance());

        for (Method method : server.getMethods()) {
            returnTypeMap.put(method.getName(), method.getReturnType());
        }

        super.init(addr, pipeFactory);
    }

    public Object getProxy() {
        return Proxy.newProxyInstance(protocol.getClassLoader(), new Class[] { protocol },
                new Invoker(getChannel()));
    }

    public class Invoker implements InvocationHandler {
        private final Channel channel;

        public Invoker(Channel channel) {
            this.channel = channel;
        }

        @SuppressWarnings("rawtypes")
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

            int seqId = sequence.incrementAndGet();
            Invocation.Builder builder = Invocation.newBuilder();

            if (args != null) {
                for (int i = 1; i < args.length; i++) {
                    ByteString str = ((Message) args[i]).toByteString();
                    builder.addParam(str);
                }
            }
            Callback userCallBack = (Callback) args[0];
            ResponseRpcCallback rpcCallback = new ResponseRpcCallback(returnTypeMap.get(method.getName()),
                    userCallBack);

            Invocation request = builder.setId(seqId).setMethodName(method.getName()).build();
            requests.put(seqId, rpcCallback);
            this.channel.write(request);
            return null;
        }

        public void shutdown() {
            LOG.info("[RPC] Client terminates connection " + channel.getRemoteAddress());
            this.channel.close().awaitUninterruptibly();
            bootstrap.releaseExternalResources();
        }
    }

    private class ResponseRpcCallback implements RpcCallback<Response> {
        @SuppressWarnings("rawtypes")
        private final Callback callback;
        private Response response;
        private Class<?> retType;

        @SuppressWarnings("rawtypes")
        public ResponseRpcCallback(Class clazz, Callback callback) {
            this.callback = callback;
            this.retType = clazz;
        }

        @SuppressWarnings("unchecked")
        public void run(Response message) {
            response = message;

            Object retObj = null;
            if (response != null) {
                if (!response.getHasReturn()) {
                    if (response.hasExceptionMessage()) {
                        callback.onFailure(new RemoteException(response.getExceptionMessage()));
                        return;
                    }
                    retObj = null;
                } else {
                    try {
                        Method mtd = retType.getMethod("parseFrom", new Class[] { ByteString.class });
                        retObj = mtd.invoke(null, response.getReturnValue());
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }

            callback.onComplete(retObj);
        }
    }

    private class ClientHandler extends SimpleChannelUpstreamHandler {
        @Override
        public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
            Response response = (Response) e.getMessage();
            ResponseRpcCallback callback = requests.remove(response.getId());

            if (callback == null) {
                LOG.debug("dangling rpc call");
            } else {
                callback.run(response);
            }
        }

        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
            LOG.error("[RPC] ERROR " + e.getChannel().getRemoteAddress() + " " + e.getCause());
            e.getChannel().close();
        }
    }
}