c5db.control.SimpleControlClient.java Source code

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Here is the source code for c5db.control.SimpleControlClient.java

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/*
 * Copyright 2014 WANdisco
 *
 *  WANdisco 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 c5db.control;

import c5db.C5ServerConstants;
import c5db.interfaces.server.CommandRpcRequest;
import c5db.messages.generated.CommandReply;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpObjectAggregator;

import java.net.InetSocketAddress;

/**
 * A very simple control client that uses 1 shot HTTP requests to ask remote services
 * what to do.  Uses a ListenableFuture interface to convey replies back.
 * <p>
 * It doesn't do any timeouts, or anything of such a nature.
 */
public class SimpleControlClient {
    private final EventLoopGroup ioWorkerGroup;
    private final Bootstrap client = new Bootstrap();

    public SimpleControlClient(EventLoopGroup ioWorkerGroup) {

        this.ioWorkerGroup = ioWorkerGroup;

        createClient();
    }

    private void createClient() {
        client.group(ioWorkerGroup).channel(NioSocketChannel.class).option(ChannelOption.SO_REUSEADDR, true)
                .option(ChannelOption.TCP_NODELAY, true).handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ChannelPipeline pipeline = ch.pipeline();
                        //            pipeline.addLast("logger", new LoggingHandler(LogLevel.WARN));
                        pipeline.addLast("http-client", new HttpClientCodec());
                        pipeline.addLast("aggregator", new HttpObjectAggregator(C5ServerConstants.MAX_CALL_SIZE));

                        pipeline.addLast("encode", new ClientHttpProtostuffEncoder());
                        pipeline.addLast("decode", new ClientHttpProtostuffDecoder());

                        pipeline.addLast("translate", new ClientEncodeCommandRequest());
                    }
                });
    }

    public ListenableFuture<CommandReply> sendRequest(CommandRpcRequest<?> request,
            InetSocketAddress remoteAddress) {
        SettableFuture<CommandReply> replyMessageFuture = SettableFuture.create();
        ChannelFuture connectFuture = client.connect(remoteAddress);
        connectFuture.addListener(new ChannelFutureListener() {
            @Override
            public void operationComplete(ChannelFuture future) throws Exception {
                if (future.isSuccess()) {
                    future.channel().pipeline().addLast(new SimpleChannelInboundHandler<CommandReply>() {
                        @Override
                        protected void channelRead0(ChannelHandlerContext ctx, CommandReply msg) throws Exception {
                            replyMessageFuture.set(msg);
                            ctx.channel().close();
                        }
                    });

                    // connected is fine, flush message:
                    future.channel().writeAndFlush(request);
                } else {
                    replyMessageFuture.setException(future.cause());
                    future.channel().close();
                }
            }
        });

        return replyMessageFuture;
    }

}