DirectWriteBackHttpProxyBackendHandler.java

package io.urmia.proxy;

/**
 *
 * Copyright 2014 by Amin Abbaspour
 *
 * This file is part of Urmia.io
 *
 * Urmia.io is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Urmia.io is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Urmia.io.  If not, see <http://www.gnu.org/licenses/>.
 */

import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DirectWriteBackHttpProxyBackendHandler extends ChannelInboundHandlerAdapter {

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

    private final Channel inboundChannel;

    public DirectWriteBackHttpProxyBackendHandler(Channel inboundChannel) {
        this.inboundChannel = inboundChannel;
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info("backend active: {}", ctx);
        ctx.read();
        ctx.write(Unpooled.EMPTY_BUFFER);
    }

    @Override
    public void channelRead(final ChannelHandlerContext ctx, Object msg) throws Exception {

        inboundChannel.writeAndFlush(msg).addListener(new ChannelFutureListener() {
            @Override
            public void operationComplete(ChannelFuture future) throws Exception {
                if (future.isSuccess()) {
                    //log.info("success on write back to inbound");
                    ctx.channel().read();
                } else {
                    log.warn("fail on write to back to inbound: {}", future.cause());
                    future.channel().close();
                }
            }
        });

    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        log.info("backend channelInactive: {}. closing inbound", ctx);
        inboundChannel.close();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        log.warn("exceptionCaught", cause);
        inboundChannel.close();
    }
}