/*
    * 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.chaos.actions;
  
  import java.io.IOException;
  import java.util.Random;
  
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Admin;
  import org.apache.hadoop.hbase.io.compress.Compression.Algorithm;
  import org.apache.hadoop.io.compress.Compressor;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Action that changes the compression algorithm on a column family from a list of tables.
   */
  public class ChangeCompressionAction extends Action {
    private final TableName tableName;
  
    private Admin admin;
    private Random random;
    private static final Logger LOG = LoggerFactory.getLogger(ChangeCompressionAction.class);
  
    public ChangeCompressionAction(TableName tableName) {
      this.tableName = tableName;
      this.random = new Random();
    }
  
    @Override protected Logger getLogger() {
      return LOG;
    }
  
    @Override
    public void init(ActionContext context) throws IOException {
      super.init(context);
      this.admin = context.getHBaseIntegrationTestingUtility().getHBaseAdmin();
    }
  
    @Override
    public void perform() throws Exception {
      HTableDescriptor tableDescriptor = admin.getTableDescriptor(tableName);
      HColumnDescriptor[] columnDescriptors = tableDescriptor.getColumnFamilies();
  
      if (columnDescriptors == null || columnDescriptors.length == 0) {
        return;
      }
  
      // Possible compression algorithms. If an algorithm is not supported,
      // modifyTable will fail, so there is no harm.
      Algorithm[] possibleAlgos = Algorithm.values();
  
      // Since not every compression algorithm is supported,
      // let's use the same algorithm for all column families.
  
      // If an unsupported compression algorithm is chosen, pick a different one.
      // This is to work around the issue that modifyTable() does not throw remote
      // exception.
      Algorithm algo;
      do {
        algo = possibleAlgos[random.nextInt(possibleAlgos.length)];
  
        try {
          Compressor c = algo.getCompressor();
  
          // call returnCompressor() to release the Compressor
          algo.returnCompressor(c);
          break;
        } catch (Throwable t) {
          getLogger().info("Performing action: Changing compression algorithms to " + algo +
                  " is not supported, pick another one");
        }
      } while (true);
  
      getLogger().debug("Performing action: Changing compression algorithms on "
        + tableName.getNameAsString() + " to " + algo);
      for (HColumnDescriptor descriptor : columnDescriptors) {
        if (random.nextBoolean()) {
          descriptor.setCompactionCompressionType(algo);
        } else {
         descriptor.setCompressionType(algo);
       }
     }
 
     // Don't try the modify if we're stopping
     if (context.isStopping()) {
       return;
     }
 
     admin.modifyTable(tableName, tableDescriptor);
   }
 }