com.github.spapageo.jannel.channel.MessageEncoder.java Source code

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Here is the source code for com.github.spapageo.jannel.channel.MessageEncoder.java

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/*
 * The MIT License (MIT)
 * Copyright (c) 2016 Spyros Papageorgiou
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.github.spapageo.jannel.channel;

import com.github.spapageo.jannel.msg.Message;
import com.github.spapageo.jannel.transcode.Transcoder;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;

/**
 * This encoder will be run before the LengthFieldAppender that read a whole message and its job is
 * to convert a Message to a ByteBuf
 */
@ChannelHandler.Sharable
public class MessageEncoder extends MessageToByteEncoder<Message> {

    private final Transcoder transcoder;

    /**
     * Construct a new message encoding handler
     * @param transcoder the transcoder to use for encoding the messages
     */
    public MessageEncoder(Transcoder transcoder) {
        this.transcoder = transcoder;
    }

    @Override
    protected void encode(ChannelHandlerContext ctx, Message msg, ByteBuf out) throws Exception {
        out.writeInt(msg.getType().value());
        transcoder.encode(msg, out);
    }
}