/*

  * 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.iterables;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;

 import org.apache.giraph.io.MappingReader;

 import org.apache.giraph.mapping.MappingEntry;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 import org.apache.hadoop.mapreduce.InputSplit;

 import org.apache.hadoop.mapreduce.TaskAttemptContext;

 import java.io.IOException;

 /**

  * Wraps {@link GiraphReader} for mapping into

  * {@link org.apache.giraph.io.MappingReader}

  *

  * @param <I> vertexId type

  * @param <V> vertexValue type

  * @param <E> edgeValue type

  * @param <B> mappingTarget type

  */

 public class MappingReaderWrapper<I extends WritableComparable,

   V extends Writable, E extends  Writable, B extends Writable>

   extends MappingReader<I, V, E, B> {

   /** Wrapped mapping reader */

   private GiraphReader<MappingEntry<I, B>> mappingReader;

   /**

    * {@link org.apache.giraph.io.MappingReader}-like wrapper of

    * {@link #mappingReader}

    */

   private IteratorToReaderWrapper<MappingEntry<I, B>> iterator;

   /**

    * Constructor

    *

    * @param mappingReader user supplied mappingReader

    */

   public MappingReaderWrapper(GiraphReader<MappingEntry<I, B>> mappingReader) {

     this.mappingReader = mappingReader;

     iterator = new IteratorToReaderWrapper<>(mappingReader);

   }

   @Override

   public void setConf(

       ImmutableClassesGiraphConfiguration<I, V, E> conf) {

     super.setConf(conf);

     conf.configureIfPossible(mappingReader);

   }

   @Override

   public boolean nextEntry() throws IOException, InterruptedException {

     return iterator.nextObject();

   }

   @Override

   public MappingEntry<I, B> getCurrentEntry()

     throws IOException, InterruptedException {

     return iterator.getCurrentObject();

   }

   @Override

   public void initialize(InputSplit inputSplit,

     TaskAttemptContext context) throws IOException, InterruptedException {

     mappingReader.initialize(inputSplit, context);

   }

   @Override

   public void close() throws IOException {

     mappingReader.close();

   }

   @Override

   public float getProgress() throws IOException, InterruptedException {

     return mappingReader.getProgress();

   }

 }