/**
    * 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.hbase.mapreduce;
  
  import java.io.IOException;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.wal.WAL;
  import org.apache.hadoop.hbase.regionserver.wal.HLogKey;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.mapreduce.InputFormat;
  import org.apache.hadoop.mapreduce.InputSplit;
  import org.apache.hadoop.mapreduce.JobContext;
  import org.apache.hadoop.mapreduce.RecordReader;
  import org.apache.hadoop.mapreduce.TaskAttemptContext;
  
  /**
   * Simple {@link InputFormat} for {@link WAL} files.
   * @deprecated use {@link WALInputFormat}
   */
  @Deprecated
  @InterfaceAudience.Public
  public class HLogInputFormat extends InputFormat<HLogKey, WALEdit> {
    private static final Log LOG = LogFactory.getLog(HLogInputFormat.class);
    public static final String START_TIME_KEY = "hlog.start.time";
    public static final String END_TIME_KEY = "hlog.end.time";
  
    // Delegate to WALInputFormat for implementation.
    private final WALInputFormat delegate = new WALInputFormat();
  
    /**
     * {@link RecordReader} that pulls out the legacy HLogKey format directly.
     */
    static class HLogKeyRecordReader extends WALInputFormat.WALRecordReader<HLogKey> {
      @Override
      public HLogKey getCurrentKey() throws IOException, InterruptedException {
        if (!(currentEntry.getKey() instanceof HLogKey)) {
          final IllegalStateException exception = new IllegalStateException(
              "HLogInputFormat only works when given entries that have HLogKey for keys. This" +
              " one had '" + currentEntry.getKey().getClass() + "'");
          LOG.error("The deprecated HLogInputFormat has to work with the deprecated HLogKey class, " +
              " but HBase internals read the wal entry using some other class." +
              " This is a bug; please file an issue or email the developer mailing list. It is " +
              "likely that you would not have this problem if you updated to use WALInputFormat. " +
              "You will need the following exception details when seeking help from the HBase " +
              "community.",
              exception);
          throw exception;
        }
        return (HLogKey)currentEntry.getKey();
      }
    }
  
    @Override
    public List<InputSplit> getSplits(JobContext context) throws IOException,
        InterruptedException {
      return delegate.getSplits(context, START_TIME_KEY, END_TIME_KEY);
    }
  
    @Override
    public RecordReader<HLogKey, WALEdit> createRecordReader(InputSplit split,
        TaskAttemptContext context) throws IOException, InterruptedException {
      return new HLogKeyRecordReader();
    }
  }