ResultSerializer.java

package com.splout.db.engine;

/*
 * #%L
 * Splout SQL commons
 * %%
 * Copyright (C) 2012 - 2014 Datasalt Systems S.L.
 * %%
 * 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.io.ByteArrayOutputStream;
import java.nio.ByteBuffer;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.splout.db.common.QueryResult;

/**
 * Abstraction that permits serializing classes like {@link ResultAndCursorId}
 * and {@link QueryResult} in a binary format.
 * By default we use Kryo.
 */
public class ResultSerializer {

  public final static ThreadLocal<Kryo> localKryo = new ThreadLocal<Kryo>() {

    protected Kryo initialValue() {
      return new Kryo();
    };
  };

  @SuppressWarnings("serial")
  public static class SerializationException extends Exception {

    public SerializationException(String why) {
      super(why);
    }

    public SerializationException(Throwable t) {
      super(t);
    }

    public SerializationException(String why, Throwable t) {
      super(why, t);
    }
  }
  
  public static byte[] serializeToByteArray(Object result) throws SerializationException {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    Output output = new Output(stream);
    localKryo.get().writeObject(output, result);
    output.flush();
    return stream.toByteArray();
  }

  public static ByteBuffer serialize(Object result) throws SerializationException {
    return ByteBuffer.wrap(serializeToByteArray(result));
  }
  
  public static <T> T deserialize(ByteBuffer serialized, Class<T> clzz) {
    return ResultSerializer.localKryo.get().readObject(new Input(serialized.array(), serialized.position(), serialized.remaining()),
        clzz);
  }

  public static QueryResult deserialize(ByteBuffer serialized) throws SerializationException {
    return ResultSerializer.localKryo.get().readObject(new Input(serialized.array(), serialized.position(), serialized.remaining()),
        QueryResult.class);
  }
}