001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.server.blockmanagement;
019
020public class BlockPlacementStatusDefault implements BlockPlacementStatus {
021
022  private int requiredRacks = 0;
023  private int currentRacks = 0;
024  
025  public BlockPlacementStatusDefault(int currentRacks, int requiredRacks){
026    this.requiredRacks = requiredRacks;
027    this.currentRacks = currentRacks;
028  }
029  
030  @Override
031  public boolean isPlacementPolicySatisfied() {
032    return requiredRacks <= currentRacks;
033  }
034
035  @Override
036  public String getErrorDescription() {
037    if (isPlacementPolicySatisfied()) {
038      return null;
039    }
040    return "Block should be additionally replicated on " + 
041        (requiredRacks - currentRacks) + " more rack(s).";
042  }
043
044}