/*

  * 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 java.io.IOException;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;

 import org.apache.giraph.edge.Edge;

 import org.apache.giraph.io.EdgeReader;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 import org.apache.hadoop.mapreduce.InputSplit;

 import org.apache.hadoop.mapreduce.TaskAttemptContext;

 /**

  * Wraps {@link GiraphReader} for edges into {@link EdgeReader}

  *

  * @param <I> Vertex id

  * @param <E> Edge data

  */

 public class EdgeReaderWrapper<I extends WritableComparable,

     E extends Writable> extends EdgeReader<I, E> {

   /** Wrapped edge reader */

   private GiraphReader<EdgeWithSource<I, E>> edgeReader;

   /** {@link EdgeReader}-like wrapper of {@link #edgeReader} */

   private IteratorToReaderWrapper<EdgeWithSource<I, E>> iterator;

   /**

    * Constructor

    *

    * @param edgeReader GiraphReader for edges to wrap

    */

   public EdgeReaderWrapper(GiraphReader<EdgeWithSource<I, E>> edgeReader) {

     this.edgeReader = edgeReader;

     iterator = new IteratorToReaderWrapper<EdgeWithSource<I, E>>(edgeReader);

   }

   @Override

   public void setConf(

       ImmutableClassesGiraphConfiguration<I, Writable, E> conf) {

     super.setConf(conf);

     conf.configureIfPossible(edgeReader);

   }

   @Override

   public boolean nextEdge() throws IOException, InterruptedException {

     return iterator.nextObject();

   }

   @Override

   public I getCurrentSourceId() throws IOException, InterruptedException {

     return iterator.getCurrentObject().getSourceVertexId();

   }

   @Override

   public Edge<I, E> getCurrentEdge() throws IOException, InterruptedException {

     return iterator.getCurrentObject().getEdge();

   }

   @Override

   public void initialize(InputSplit inputSplit,

       TaskAttemptContext context) throws IOException, InterruptedException {

     edgeReader.initialize(inputSplit, context);

   }

   @Override

   public void close() throws IOException {

     edgeReader.close();

   }

   @Override

   public float getProgress() throws IOException, InterruptedException {

     return edgeReader.getProgress();

   }

 }