com.googlecode.protobuf.pro.duplex.handler.ServerConnectRequestHandler.java Source code

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Here is the source code for com.googlecode.protobuf.pro.duplex.handler.ServerConnectRequestHandler.java

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/**
 *   Copyright 2010-2014 Peter Klauser
 *
 *   Licensed 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 com.googlecode.protobuf.pro.duplex.handler;

import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageDecoder;

import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.googlecode.protobuf.pro.duplex.PeerInfo;
import com.googlecode.protobuf.pro.duplex.RpcClient;
import com.googlecode.protobuf.pro.duplex.server.DuplexTcpServerPipelineFactory;
import com.googlecode.protobuf.pro.duplex.server.RpcClientRegistry;
import com.googlecode.protobuf.pro.duplex.wire.DuplexProtocol.ConnectErrorCode;
import com.googlecode.protobuf.pro.duplex.wire.DuplexProtocol.ConnectRequest;
import com.googlecode.protobuf.pro.duplex.wire.DuplexProtocol.ConnectResponse;
import com.googlecode.protobuf.pro.duplex.wire.DuplexProtocol.WirePayload;

/**
 * The ServerConnectRequestHandler handles the receipt of ConnectRequest
 * client requests, and uses the {@link RpcClientRegistry} to try to
 * register new clients. If the RpcClientRegistry allows the connection,
 * this handler sends back a ConnectResponse to the client.
 * 
 * Once a successful client handshake has been performed, this Handler
 * uses the {@link DuplexTcpServerPipelineFactory} to complete the
 * Channel's pipeline, which will remove this Handler ( since it's job is
 * done ) and place a {@link RpcClientHandler} and {@link RpcServerHandler}
 * into the pipeline.
 * 
 * @author Peter Klauser
 *
 */
@Sharable
public class ServerConnectRequestHandler extends MessageToMessageDecoder<WirePayload> {

    private static Logger log = LoggerFactory.getLogger(ServerConnectRequestHandler.class);

    private final DuplexTcpServerPipelineFactory pipelineFactory;

    public ServerConnectRequestHandler(DuplexTcpServerPipelineFactory pipelineFactory) {
        this.pipelineFactory = pipelineFactory;
    }

    /* (non-Javadoc)
     * @see io.netty.channel.ChannelInboundMessageHandlerAdapter#messageReceived(io.netty.channel.ChannelHandlerContext, java.lang.Object)
     */
    @Override
    protected void decode(ChannelHandlerContext ctx, WirePayload msg, List<Object> out) throws Exception {
        if (msg.hasConnectRequest()) {
            ConnectRequest connectRequest = msg.getConnectRequest();
            if (log.isDebugEnabled()) {
                log.debug("Received [" + connectRequest.getCorrelationId() + "]ConnectRequest.");
            }
            PeerInfo connectingClientInfo = new PeerInfo(connectRequest.getClientHostName(),
                    connectRequest.getClientPort(), connectRequest.getClientPID());
            ConnectResponse connectResponse = null;

            RpcClient rpcClient = new RpcClient(ctx.channel(), pipelineFactory.getServerInfo(),
                    connectingClientInfo, connectRequest.getCompress(), pipelineFactory.getLogger(),
                    pipelineFactory.getExtensionRegistry());
            if (pipelineFactory.getRpcClientRegistry().registerRpcClient(rpcClient)) {
                connectResponse = ConnectResponse.newBuilder().setCorrelationId(connectRequest.getCorrelationId())
                        .setServerPID(pipelineFactory.getServerInfo().getPid())
                        .setCompress(connectRequest.getCompress()).build();
                WirePayload payload = WirePayload.newBuilder().setConnectResponse(connectResponse).build();

                if (log.isDebugEnabled()) {
                    log.debug("Sending [" + connectResponse.getCorrelationId() + "]ConnectResponse.");
                }
                ctx.channel().writeAndFlush(payload);

                // now we swap this Handler out of the pipeline and complete the server side pipeline.
                RpcClientHandler clientHandler = pipelineFactory.completePipeline(rpcClient);
                clientHandler.notifyOpened();
            } else {
                connectResponse = ConnectResponse.newBuilder().setCorrelationId(connectRequest.getCorrelationId())
                        .setErrorCode(ConnectErrorCode.ALREADY_CONNECTED).build();
                WirePayload payload = WirePayload.newBuilder().setConnectResponse(connectResponse).build();

                if (log.isDebugEnabled()) {
                    log.debug("Sending [" + connectResponse.getCorrelationId()
                            + "]ConnectResponse. Already Connected.");
                }
                ChannelFuture future = ctx.channel().writeAndFlush(payload);
                future.addListener(ChannelFutureListener.CLOSE); // close after write response.
            }
        } else {
            out.add(msg);
        }
    }

    /* (non-Javadoc)
     * @see io.netty.channel.ChannelHandlerAdapter#exceptionCaught(io.netty.channel.ChannelHandlerContext, java.lang.Throwable)
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
        log.warn("Exception caught during RPC connection handshake.", cause);
        ctx.close();
    }

}