/*

  * 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.io.formats;

 import org.apache.giraph.io.EdgeReader;

 import org.apache.giraph.io.ReverseEdgeDuplicator;

 import org.apache.hadoop.io.IntWritable;

 import org.apache.hadoop.io.NullWritable;

 import org.apache.hadoop.mapreduce.InputSplit;

 import org.apache.hadoop.mapreduce.TaskAttemptContext;

 import java.io.IOException;

 /**

  * Simple text-based {@link org.apache.giraph.io.EdgeInputFormat} for

  * unweighted graphs with int ids.

  *

  * Each line consists of: source_vertex, target_vertex

  *

  * This version also creates the reverse edges.

  */

 public class IntNullReverseTextEdgeInputFormat

     extends IntNullTextEdgeInputFormat {

   @Override

   public EdgeReader<IntWritable, NullWritable> createEdgeReader(

       InputSplit split, TaskAttemptContext context) throws IOException {

     EdgeReader<IntWritable, NullWritable> edgeReader =

         super.createEdgeReader(split, context);

     edgeReader.setConf(getConf());

     return new ReverseEdgeDuplicator<IntWritable, NullWritable>(edgeReader);

   }

 }