com.torchmind.netty.msgpack.codec.MessageCodec.java Source code

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Here is the source code for com.torchmind.netty.msgpack.codec.MessageCodec.java

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/*
 * Copyright 2014 Johannes Donath <johannesd@torchmind.com>
 * 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.torchmind.netty.msgpack.codec;

import com.google.common.base.Preconditions;
import com.torchmind.netty.msgpack.registry.IMessageRegistry;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageCodec;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.NonNull;
import lombok.Setter;
import org.msgpack.MessagePack;

import java.util.List;

/**
 * @author Johannes Donath <johannesd@evil-co.com>
 * @copyright Copyright (C) 2014 Evil-Co <http://www.evil-co.com>
 */
public class MessageCodec extends ByteToMessageCodec<Object> {

    /**
     * Stores the active message registry.
     */
    @Getter
    @Setter
    @NonNull
    private IMessageRegistry registry;

    /**
     * Stores the msgpack instance.
     */
    @Getter(AccessLevel.PROTECTED)
    @Setter(AccessLevel.PROTECTED)
    @NonNull
    private MessagePack messagePack = new MessagePack();

    /**
     * Constructs a new MessageCodec instance.
     * @param messageRegistry The registry.
     */
    public MessageCodec(IMessageRegistry messageRegistry) {
        this.setRegistry(messageRegistry);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void encode(ChannelHandlerContext ctx, Object msg, ByteBuf out) throws Exception {
        // verify argument
        Preconditions.checkNotNull(msg, "msg");

        // search message identifier
        short identifier = this.getRegistry().getMessageID(msg.getClass());

        // send identifier
        out.writeShort(identifier);

        // encode message
        out.writeBytes(this.messagePack.write(msg));
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        // read identifier
        short identifier = in.readShort();

        // search message type
        Class<?> type = this.getRegistry().getMessageType(identifier);

        // read data
        byte[] data = new byte[in.readableBytes()];
        in.readBytes(data);

        // decode message
        out.add(this.messagePack.read(data, type));
    }
}