/*

  * 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.examples;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfigurable;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;

 import org.apache.giraph.edge.Edge;

 import org.apache.giraph.edge.EdgeFactory;

 import org.apache.giraph.graph.Vertex;

 import org.apache.giraph.io.formats.TextVertexInputFormat;

 import org.apache.hadoop.io.DoubleWritable;

 import org.apache.hadoop.io.LongWritable;

 import org.apache.hadoop.io.NullWritable;

 import org.apache.hadoop.mapreduce.InputSplit;

 import org.apache.hadoop.mapreduce.TaskAttemptContext;

 import com.google.common.collect.Lists;

 import java.io.IOException;

 import java.util.List;

 import java.util.regex.Pattern;

 /**

  * Input format for unweighted graphs with long ids.

  */

 public class LongDoubleNullTextInputFormat

     extends TextVertexInputFormat<LongWritable, DoubleWritable, NullWritable>

     implements ImmutableClassesGiraphConfigurable<LongWritable, DoubleWritable,

     NullWritable> {

   /** Configuration. */

   private ImmutableClassesGiraphConfiguration<LongWritable, DoubleWritable,

       NullWritable> conf;

   @Override

   public TextVertexReader createVertexReader(InputSplit split,

                                              TaskAttemptContext context)

     throws IOException {

     return new LongDoubleNullDoubleVertexReader();

   }

   @Override

   public void setConf(ImmutableClassesGiraphConfiguration<LongWritable,

       DoubleWritable, NullWritable> configuration) {

     this.conf = configuration;

   }

   @Override

   public ImmutableClassesGiraphConfiguration<LongWritable, DoubleWritable,

       NullWritable> getConf() {

     return conf;

   }

   /**

    * Vertex reader associated with

    * {@link LongDoubleNullTextInputFormat}.

    */

   public class LongDoubleNullDoubleVertexReader extends

       TextVertexInputFormat<LongWritable, DoubleWritable,

           NullWritable>.TextVertexReader {

     /** Separator of the vertex and neighbors */

     private final Pattern separator = Pattern.compile("[\t ]");

     @Override

     public Vertex<LongWritable, DoubleWritable, NullWritable>

     getCurrentVertex() throws IOException, InterruptedException {

       Vertex<LongWritable, DoubleWritable, NullWritable>

           vertex = conf.createVertex();

       String[] tokens =

           separator.split(getRecordReader().getCurrentValue().toString());

       List<Edge<LongWritable, NullWritable>> edges =

           Lists.newArrayListWithCapacity(tokens.length - 1);

       for (int n = 1; n < tokens.length; n++) {

         edges.add(EdgeFactory.create(

             new LongWritable(Long.parseLong(tokens[n])),

             NullWritable.get()));

       }

       LongWritable vertexId = new LongWritable(Long.parseLong(tokens[0]));

       vertex.initialize(vertexId, new DoubleWritable(), edges);

       return vertex;

     }

     @Override

     public boolean nextVertex() throws IOException, InterruptedException {

       return getRecordReader().nextKeyValue();

     }

   }

 }