/**
    *
    * 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.regionserver.handler;
  
  import java.io.IOException;
  import java.util.concurrent.CountDownLatch;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.executor.EventHandler;
  import org.apache.hadoop.hbase.executor.EventType;
  import org.apache.hadoop.hbase.regionserver.KeyValueScanner;
  
  /**
   * Handler to seek storefiles in parallel.
   */
  @InterfaceAudience.Private
  public class ParallelSeekHandler extends EventHandler {
    private static final Log LOG = LogFactory.getLog(ParallelSeekHandler.class);
    private KeyValueScanner scanner;
    private Cell keyValue;
    private long readPoint;
    private CountDownLatch latch;
    private Throwable err = null;
  
    public ParallelSeekHandler(KeyValueScanner scanner,Cell keyValue, 
        long readPoint, CountDownLatch latch) {
      super(null, EventType.RS_PARALLEL_SEEK);
      this.scanner = scanner;
      this.keyValue = keyValue;
      this.readPoint = readPoint;
      this.latch = latch;
    }
  
    @Override
    public void process() {
      try {
        scanner.seek(keyValue);
      } catch (IOException e) {
        LOG.error("", e);
        setErr(e);
      } finally {
        latch.countDown();
      }
    }
  
    public Throwable getErr() {
      return err;
    }
  
    public void setErr(Throwable err) {
      this.err = err;
    }
  }