/**
* 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.BlockingService;
import com.google.protobuf.Descriptors.MethodDescriptor;
import com.google.protobuf.Message;
import com.google.protobuf.RpcController;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jboss.netty.channel.*;
import org.apache.tajo.rpc.RpcProtos.RpcRequest;
import org.apache.tajo.rpc.RpcProtos.RpcResponse;
import java.lang.reflect.Method;
import java.net.InetSocketAddress;
public class BlockingRpcServer extends NettyServerBase {
private static Log LOG = LogFactory.getLog(BlockingRpcServer.class);
private final BlockingService service;
private final ChannelPipelineFactory pipeline;
public BlockingRpcServer(final Class<?> protocol,
final Object instance,
final InetSocketAddress bindAddress)
throws Exception {
super(protocol.getSimpleName(), bindAddress);
String serviceClassName = protocol.getName() + "$" +
protocol.getSimpleName() + "Service";
Class<?> serviceClass = Class.forName(serviceClassName);
Class<?> interfaceClass = Class.forName(serviceClassName +
"$BlockingInterface");
Method method = serviceClass.getMethod(
"newReflectiveBlockingService", interfaceClass);
this.service = (BlockingService) method.invoke(null, instance);
this.pipeline = new ProtoPipelineFactory(new ServerHandler(),
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);
}
}
Message returnValue;
RpcController controller = new NettyRpcController();
try {
returnValue = service.callBlockingMethod(methodDescriptor,
controller, paramProto);
} catch (Throwable t) {
throw new RemoteCallException(request.getId(), methodDescriptor, t);
}
RpcResponse.Builder builder =
RpcResponse.newBuilder().setId(request.getId());
if (returnValue != null) {
builder.setResponseMessage(returnValue.toByteString());
}
if (controller.failed()) {
builder.setErrorMessage(controller.errorText());
}
e.getChannel().write(builder.build());
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
if (e.getCause() instanceof RemoteCallException) {
RemoteCallException callException = (RemoteCallException) e.getCause();
e.getChannel().write(callException.getResponse());
}
throw new RemoteException(e.getCause());
}
}
}