tachyon.network.protocol.RPCMessageEncoder.java Source code

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Here is the source code for tachyon.network.protocol.RPCMessageEncoder.java

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/*
 * Licensed to the University of California, Berkeley 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 tachyon.network.protocol;

import java.util.List;

import com.google.common.base.Preconditions;
import com.google.common.primitives.Longs;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.FileRegion;
import io.netty.handler.codec.MessageToMessageEncoder;

import tachyon.network.protocol.databuffer.DataBuffer;

/**
 * Simple Netty encoder for RPCMessages.
 */
@ChannelHandler.Sharable
public final class RPCMessageEncoder extends MessageToMessageEncoder<RPCMessage> {

    @Override
    protected void encode(ChannelHandlerContext ctx, RPCMessage in, List<Object> out) throws Exception {
        RPCRequest.Type type = in.getType();

        long bodyBytes = 0;
        DataBuffer payload = null;

        if (in.hasPayload()) {
            payload = in.getPayloadDataBuffer();
            bodyBytes = payload.getLength();
        }

        int lengthBytes = Longs.BYTES;
        int typeBytes = type.getEncodedLength();
        int messageBytes = in.getEncodedLength();

        int headerBytes = lengthBytes + typeBytes + messageBytes;
        long frameBytes = headerBytes + bodyBytes;

        // Write the header info into a buffer.
        // The format is: [frame length][message type][message][(optional) data]
        ByteBuf buffer = ctx.alloc().buffer();
        buffer.writeLong(frameBytes);
        type.encode(buffer);
        in.encode(buffer);

        // Output the header buffer.
        out.add(buffer);

        if (payload != null && bodyBytes > 0) {
            Object output = payload.getNettyOutput();
            Preconditions.checkArgument(output instanceof ByteBuf || output instanceof FileRegion,
                    "The payload must be a ByteBuf or a FileRegion.");
            out.add(output);
        }

    }
}