/**
    *
    * 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.master.normalizer;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.client.Admin;
  
  import java.io.IOException;
  
  /**
   * Normalization plan to merge regions (smallest region in the table with its smallest neighbor).
   */
  @InterfaceAudience.Private
  public class MergeNormalizationPlan implements NormalizationPlan {
    private static final Log LOG = LogFactory.getLog(MergeNormalizationPlan.class.getName());
  
    private final HRegionInfo firstRegion;
    private final HRegionInfo secondRegion;
  
    public MergeNormalizationPlan(HRegionInfo firstRegion, HRegionInfo secondRegion) {
      this.firstRegion = firstRegion;
      this.secondRegion = secondRegion;
    }
  
    @Override
    public PlanType getType() {
      return PlanType.MERGE;
    }
  
    HRegionInfo getFirstRegion() {
      return firstRegion;
    }
  
    HRegionInfo getSecondRegion() {
      return secondRegion;
    }
  
    @Override
    public String toString() {
      return "MergeNormalizationPlan{" +
        "firstRegion=" + firstRegion +
        ", secondRegion=" + secondRegion +
        '}';
    }
  
    /**
     * {@inheritDoc}
     */
    @Override
    public void execute(Admin admin) {
      LOG.info("Executing merging normalization plan: " + this);
      try {
        admin.mergeRegions(firstRegion.getEncodedNameAsBytes(),
          secondRegion.getEncodedNameAsBytes(), true);
      } catch (IOException ex) {
        LOG.error("Error during region merge: ", ex);
      }
    }
  }