/**
 * 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 org.apache.apex.malhar.lib.codec;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import com.datatorrent.api.StreamCodec;
import com.datatorrent.netlet.util.Slice;

/**
 * This codec is used for serializing the objects of class which implements
 * java.io.Serializable. It's not optimized for speed and should be used as the
 * last resort if you know that the slowness of it is not going to prevent you
 * from operating your application in realtime.
 *
 * @param <T>
 *          Type of the object which gets serialized/deserialized using this
 *          codec.
 * @since 0.3.3
 */
public class JavaSerializationStreamCodec<T extends Serializable> implements StreamCodec<T>, Serializable
{
  @Override
  public Object fromByteArray(Slice fragment)
  {
    ByteArrayInputStream bis = new ByteArrayInputStream(fragment.buffer,
        fragment.offset, fragment.length);
    try {
      ObjectInputStream ois = new ObjectInputStream(bis);
      return ois.readObject();
    } catch (Exception ioe) {
      throw new RuntimeException(ioe);
    }
  }

  @Override
  public Slice toByteArray(T object)
  {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    try {
      ObjectOutputStream oos = new ObjectOutputStream(bos);
      oos.writeObject(object);
      oos.flush();
      byte[] buffer = bos.toByteArray();
      return new Slice(buffer, 0, buffer.length);
    } catch (IOException ex) {
      throw new RuntimeException(ex);
    }
  }

  @Override
  public int getPartition(T o)
  {
    return o.hashCode();
  }
}
