SamoaSerializer.java

package com.yahoo.labs.samoa.topology.impl;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2013 - 2014 Yahoo! Inc.
 * %%
 * 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.
 * #L%
 */

import java.nio.ByteBuffer;

import org.apache.s4.base.SerializerDeserializer;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;
import com.yahoo.labs.samoa.learners.classifiers.trees.AttributeContentEvent;
import com.yahoo.labs.samoa.learners.classifiers.trees.ComputeContentEvent;

public class SamoaSerializer implements SerializerDeserializer{

	private ThreadLocal<Kryo> kryoThreadLocal;
    private ThreadLocal<Output> outputThreadLocal;

    private int initialBufferSize = 2048;
    private int maxBufferSize = 256 * 1024;

    public void setMaxBufferSize(int maxBufferSize) {
        this.maxBufferSize = maxBufferSize;
    }

    /**
     * 
     * @param classLoader
     *            classloader able to handle classes to serialize/deserialize. For instance, application-level events
     *            can only be handled by the application classloader.
     */
    @Inject
    public SamoaSerializer(@Assisted final ClassLoader classLoader) {
        kryoThreadLocal = new ThreadLocal<Kryo>() {

            @Override
            protected Kryo initialValue() {
                Kryo kryo = new Kryo();
                kryo.setClassLoader(classLoader);
                kryo.register(AttributeContentEvent.class, new AttributeContentEvent.AttributeCEFullPrecSerializer());
                kryo.register(ComputeContentEvent.class, new ComputeContentEvent.ComputeCEFullPrecSerializer());
                kryo.setRegistrationRequired(false);
                return kryo;
            }
        };

        outputThreadLocal = new ThreadLocal<Output>() {
            @Override
            protected Output initialValue() {
                Output output = new Output(initialBufferSize, maxBufferSize);
                return output;
            }
        };

    }

    @Override
    public Object deserialize(ByteBuffer rawMessage) {
        Input input = new Input(rawMessage.array());
        try {
            return kryoThreadLocal.get().readClassAndObject(input);
        } finally {
            input.close();
        }
    }

    @SuppressWarnings("resource")
    @Override
    public ByteBuffer serialize(Object message) {
        Output output = outputThreadLocal.get();
        try {
            kryoThreadLocal.get().writeClassAndObject(output, message);
            return ByteBuffer.wrap(output.toBytes());
        } finally {
            output.clear();
        }
    }
}