com.spotify.ffwd.protobuf.ProtobufLengthPrefixedProtocolServer.java Source code

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Here is the source code for com.spotify.ffwd.protobuf.ProtobufLengthPrefixedProtocolServer.java

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/*-
 * -\-\-
 * FastForward Protobuf Module
 * --
 * Copyright (C) 2016 - 2018 Spotify AB
 * --
 * 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.spotify.ffwd.protobuf;

import com.google.inject.Inject;
import com.spotify.ffwd.protocol.ProtocolServer;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInboundHandler;
import io.netty.channel.ChannelInitializer;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;

/**
 * Decode a stream of data which is length-prefixed.
 * <p>
 * Should only be used with TCP-based protocols.
 *
 * @author udoprog
 */
public class ProtobufLengthPrefixedProtocolServer implements ProtocolServer {
    private static final int MAX_LENGTH = 0xffffff;

    @Inject
    private ChannelInboundHandler handler;

    @Inject
    private ProtobufDecoder decoder;

    @Override
    public final ChannelInitializer<Channel> initializer() {
        return new ChannelInitializer<Channel>() {
            @Override
            protected void initChannel(Channel ch) throws Exception {
                ch.pipeline().addLast(new LengthFieldBasedFrameDecoder(MAX_LENGTH, 0, 4), decoder, handler);
            }
        };
    }
}