/**
 * 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.hadoop.hive.ql.io;

import java.io.IOException;

import org.apache.hadoop.hive.ql.exec.mr.ExecMapper;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordReader;

/**
 * HiveRecordReader is a simple wrapper on RecordReader. It allows us to stop
 * reading the data when some global flag ExecMapper.getDone() is set.
 */
public class HiveRecordReader<K extends WritableComparable, V extends Writable>
    extends HiveContextAwareRecordReader<K, V> {



  public HiveRecordReader(RecordReader recordReader)
      throws IOException {
    super(recordReader);
  }

  public HiveRecordReader(RecordReader recordReader, JobConf conf)
      throws IOException {
    super(recordReader, conf);
  }

  @Override
  public void doClose() throws IOException {
    recordReader.close();
  }

  public K createKey() {
    return (K) recordReader.createKey();
  }

  public V createValue() {
    return (V) recordReader.createValue();
  }

  public long getPos() throws IOException {
    return recordReader.getPos();
  }

  @Override
  public float getProgress() throws IOException {
    if (isSorted) {
      return super.getProgress();
    }

    return recordReader.getProgress();
  }

  @Override
  public boolean doNext(K key, V value) throws IOException {
    if (ExecMapper.getDone()) {
      return false;
    }
    return super.doNext(key, value);
  }

}
