/**
    *
    * 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.handler;
  
  import java.io.IOException;
  import java.util.List;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.InvalidFamilyOperationException;
  import org.apache.hadoop.hbase.Server;
  import org.apache.hadoop.hbase.executor.EventType;
  import org.apache.hadoop.hbase.master.HMaster;
  import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
  import org.apache.hadoop.hbase.master.MasterServices;
  
  /**
   * Handles adding a new family to an existing table.
   */
  @InterfaceAudience.Private
  public class TableAddFamilyHandler extends TableEventHandler {
  
    private final HColumnDescriptor familyDesc;
  
    public TableAddFamilyHandler(TableName tableName, HColumnDescriptor familyDesc,
        Server server, final MasterServices masterServices) {
      super(EventType.C_M_ADD_FAMILY, tableName, server, masterServices);
      this.familyDesc = familyDesc;
    }
  
    @Override
    protected void prepareWithTableLock() throws IOException {
      super.prepareWithTableLock();
      HTableDescriptor htd = getTableDescriptor();
      if (htd.hasFamily(familyDesc.getName())) {
        throw new InvalidFamilyOperationException("Family '" +
          familyDesc.getNameAsString() + "' already exists so cannot be added");
      }
    }
  
    @Override
    protected void handleTableOperation(List<HRegionInfo> hris)
    throws IOException {
      MasterCoprocessorHost cpHost = ((HMaster) this.server)
          .getMasterCoprocessorHost();
      if(cpHost != null){
        cpHost.preAddColumnHandler(this.tableName, this.familyDesc);
      }
      // Update table descriptor
      this.masterServices.getMasterFileSystem().addColumn(tableName, familyDesc);
      if(cpHost != null){
        cpHost.postAddColumnHandler(this.tableName, this.familyDesc);
      }
    }
  
    @Override
    public String toString() {
      String name = "UnknownServerName";
      if(server != null && server.getServerName() != null) {
        name = server.getServerName().toString();
      }
      String family = "UnknownFamily";
      if(familyDesc != null) {
        family = familyDesc.getNameAsString();
      }
      return getClass().getSimpleName() + "-" + name + "-" +
                                getSeqid() + "-" + tableName + "-" + family;
    }
  
  }