/**
* 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.Descriptors.MethodDescriptor;
import com.google.protobuf.Message;
import com.google.protobuf.RpcCallback;
import com.google.protobuf.RpcController;
import com.google.protobuf.Service;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tajo.rpc.RpcProtos.RpcRequest;
import org.apache.tajo.rpc.RpcProtos.RpcResponse;
import org.jboss.netty.channel.*;
import java.lang.reflect.Method;
import java.net.InetSocketAddress;
public class AsyncRpcServer extends NettyServerBase {
private static final Log LOG = LogFactory.getLog(AsyncRpcServer.class);
private final Service service;
private final ChannelPipelineFactory pipeline;
public AsyncRpcServer(final Class<?> protocol,
final Object instance,
final InetSocketAddress bindAddress)
throws Exception {
super(protocol.getSimpleName(), bindAddress);
String serviceClassName = protocol.getName() + "$" +
protocol.getSimpleName() + "Service";
Class<?> serviceClass = Class.forName(serviceClassName);
Class<?> interfaceClass = Class.forName(serviceClassName + "$Interface");
Method method = serviceClass.getMethod("newReflectiveService", interfaceClass);
this.service = (Service) method.invoke(null, instance);
ServerHandler handler = new ServerHandler();
this.pipeline = new ProtoPipelineFactory(handler,
RpcRequest.getDefaultInstance());
super.init(this.pipeline);
}
private class ServerHandler extends SimpleChannelUpstreamHandler {
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e)
throws Exception {
final RpcRequest request = (RpcRequest) e.getMessage();
String methodName = request.getMethodName();
MethodDescriptor methodDescriptor = service.getDescriptorForType().
findMethodByName(methodName);
if (methodDescriptor == null) {
throw new RemoteCallException(request.getId(),
new NoSuchMethodException(methodName));
}
Message paramProto = null;
if (request.hasRequestMessage()) {
try {
paramProto = service.getRequestPrototype(methodDescriptor)
.newBuilderForType().mergeFrom(request.getRequestMessage()).
build();
} catch (Throwable t) {
throw new RemoteCallException(request.getId(), methodDescriptor, t);
}
}
final Channel channel = e.getChannel();
final RpcController controller = new NettyRpcController();
RpcCallback<Message> callback =
!request.hasId() ? null : new RpcCallback<Message>() {
public void run(Message returnValue) {
RpcResponse.Builder builder = RpcResponse.newBuilder()
.setId(request.getId());
if (returnValue != null) {
builder.setResponseMessage(returnValue.toByteString());
}
if (controller.failed()) {
builder.setErrorMessage(controller.errorText());
}
channel.write(builder.build());
}
};
service.callMethod(methodDescriptor, controller, paramProto, callback);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
throws Exception{
if (e.getCause() instanceof RemoteCallException) {
RemoteCallException callException = (RemoteCallException) e.getCause();
e.getChannel().write(callException.getResponse());
}
throw new RemoteException(e.getCause());
}
}
}