/*
    * 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.graph.Vertex;
  import org.apache.giraph.io.formats.TextVertexOutputFormat;
  import org.apache.hadoop.io.DoubleWritable;
  import org.apache.hadoop.io.LongWritable;
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.mapreduce.TaskAttemptContext;
  
  import java.io.IOException;
  
  /**
   * Output format for vertices with a long as id, a double as value and
   * null edges
   */
  public class VertexWithDoubleValueNullEdgeTextOutputFormat extends
      TextVertexOutputFormat<LongWritable, DoubleWritable, NullWritable> {
    @Override
    public TextVertexWriter createVertexWriter(TaskAttemptContext context)
      throws IOException, InterruptedException {
      return new VertexWithDoubleValueWriter();
    }
  
    /**
     * Vertex writer used with
     * {@link VertexWithDoubleValueNullEdgeTextOutputFormat}.
     */
    public class VertexWithDoubleValueWriter extends TextVertexWriter {
      @Override
      public void writeVertex(
          Vertex<LongWritable, DoubleWritable, NullWritable> vertex)
        throws IOException, InterruptedException {
        StringBuilder output = new StringBuilder();
        output.append(vertex.getId().get());
        output.append('\t');
        output.append(vertex.getValue().get());
        getRecordWriter().write(new Text(output.toString()), null);
      }
    }
  }