com.tongbanjie.tarzan.rpc.protocol.NettyDecoder.java Source code

Introduction

Here is the source code for com.tongbanjie.tarzan.rpc.protocol.NettyDecoder.java

Source

/**
 * 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 com.tongbanjie.tarzan.rpc.protocol;

import com.tongbanjie.tarzan.rpc.util.RpcHelper;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Netty? <p>
 * ??
 *
 * @author zixiao
 * @date 16/9/27
 * @see [/]?
 * @since [?/?] ?
 */
public class NettyDecoder extends LengthFieldBasedFrameDecoder {

    private static final Logger LOGGER = LoggerFactory.getLogger(NettyDecoder.class);

    private static final int FRAME_MAX_LENGTH = Integer
            .parseInt(System.getProperty("netty.frameMaxLength", "8388608"));

    public NettyDecoder() {
        super(FRAME_MAX_LENGTH, 0, Protocol.TOTAL_LENGTH_SIZE, 0, 4);
    }

    @Override
    public Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
        ByteBuf frame = null;
        try {
            frame = (ByteBuf) super.decode(ctx, in);
            if (null == frame) {
                return null;
            }
            return RpcCommand.decode(frame.nioBuffer());
        } catch (Exception e) {
            LOGGER.error("decode exception, " + RpcHelper.parseChannelRemoteAddr(ctx.channel()), e);
            RpcHelper.closeChannel(ctx.channel());
        } finally {
            if (null != frame) {
                frame.release();
            }
        }

        return null;
    }
}