/*

  * 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.giraph.writable.kryo.serializers;

 import java.util.Collections;

 import java.util.List;

 import com.esotericsoftware.kryo.Kryo;

 import com.esotericsoftware.kryo.Serializer;

 import com.esotericsoftware.kryo.io.Input;

 import com.esotericsoftware.kryo.io.Output;

 /**

  * Special serializer for Collections.nCopies

  *

  * @param <T> Element type

  */

 public class CollectionsNCopiesSerializer<T> extends Serializer<List<T>> {

   @Override

   public void write(Kryo kryo, Output output, List<T> object) {

     output.writeInt(object.size(), true);

     if (object.size() > 0) {

       kryo.writeClassAndObject(output, object.get(0));

     }

   }

   @Override

   public List<T> read(Kryo kryo, Input input, Class<List<T>> type) {

     int size = input.readInt(true);

     if (size > 0) {

       T object = (T) kryo.readClassAndObject(input);

       return Collections.nCopies(size, object);

     } else {

       return Collections.emptyList();

     }

   }

 }