com.cloudera.livy.client.local.rpc.KryoMessageCodec.java Source code

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Here is the source code for com.cloudera.livy.client.local.rpc.KryoMessageCodec.java

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/*
 * 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.cloudera.livy.client.local.rpc;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.List;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.ByteBufferInputStream;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.esotericsoftware.shaded.org.objenesis.strategy.StdInstantiatorStrategy;
import com.google.common.base.Preconditions;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageCodec;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.cloudera.livy.client.common.Serializer;

/**
 * Codec that serializes / deserializes objects using Kryo. Objects are encoded with a 4-byte
 * header with the length of the serialized data.
 */
class KryoMessageCodec extends ByteToMessageCodec<Object> {

    private static final Logger LOG = LoggerFactory.getLogger(KryoMessageCodec.class);

    private final int maxMessageSize;
    private final Serializer serializer;
    private volatile EncryptionHandler encryptionHandler;

    public KryoMessageCodec(int maxMessageSize, Class<?>... messages) {
        this.maxMessageSize = maxMessageSize;
        this.serializer = new Serializer(messages);
        this.encryptionHandler = null;
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        if (in.readableBytes() < 4) {
            return;
        }

        in.markReaderIndex();
        int msgSize = in.readInt();
        checkSize(msgSize);

        if (in.readableBytes() < msgSize) {
            // Incomplete message in buffer.
            in.resetReaderIndex();
            return;
        }

        try {
            ByteBuffer nioBuffer = maybeDecrypt(in.nioBuffer(in.readerIndex(), msgSize));
            Object msg = serializer.deserialize(nioBuffer);
            LOG.debug("Decoded message of type {} ({} bytes)", msg != null ? msg.getClass().getName() : msg,
                    msgSize);
            out.add(msg);
        } finally {
            in.skipBytes(msgSize);
        }
    }

    @Override
    protected void encode(ChannelHandlerContext ctx, Object msg, ByteBuf buf) throws Exception {
        ByteBuffer msgData = maybeEncrypt(serializer.serialize(msg));
        LOG.debug("Encoded message of type {} ({} bytes)", msg.getClass().getName(), msgData.remaining());
        checkSize(msgData.remaining());

        buf.ensureWritable(msgData.remaining() + 4);
        buf.writeInt(msgData.remaining());
        buf.writeBytes(msgData);
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        if (encryptionHandler != null) {
            encryptionHandler.dispose();
        }
        super.channelInactive(ctx);
    }

    private void checkSize(int msgSize) {
        Preconditions.checkArgument(msgSize > 0, "Message size (%s bytes) must be positive.", msgSize);
        Preconditions.checkArgument(maxMessageSize <= 0 || msgSize <= maxMessageSize,
                "Message (%s bytes) exceeds maximum allowed size (%s bytes).", msgSize, maxMessageSize);
    }

    private ByteBuffer maybeEncrypt(ByteBuffer data) throws Exception {
        return doWrapOrUnWrap(data, true);
    }

    private ByteBuffer maybeDecrypt(ByteBuffer data) throws Exception {
        return doWrapOrUnWrap(data, false);
    }

    private ByteBuffer doWrapOrUnWrap(ByteBuffer data, boolean wrap) throws IOException {
        if (encryptionHandler == null) {
            return data;
        }

        byte[] byteData;
        int len = data.limit() - data.position();
        int offset;
        if (data.hasArray()) {
            byteData = data.array();
            offset = data.position() + data.arrayOffset();
            data.position(data.limit());
        } else {
            byteData = new byte[len];
            offset = 0;
            data.get(byteData);
        }

        byte[] result;
        if (wrap) {
            result = encryptionHandler.wrap(byteData, offset, len);
        } else {
            result = encryptionHandler.unwrap(byteData, offset, len);
        }
        return ByteBuffer.wrap(result);
    }

    void setEncryptionHandler(EncryptionHandler handler) {
        this.encryptionHandler = handler;
    }

    interface EncryptionHandler {

        byte[] wrap(byte[] data, int offset, int len) throws IOException;

        byte[] unwrap(byte[] data, int offset, int len) throws IOException;

        void dispose() throws IOException;

    }

}