001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to you under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.hadoop.hbase.quotas;
018
019import java.util.Iterator;
020import java.util.Map.Entry;
021
022import org.apache.hadoop.hbase.client.RegionInfo;
023import org.apache.yetus.audience.InterfaceAudience;
024
025/**
026 * A {@link RegionSizeStore} implementation that stores nothing.
027 */
028@InterfaceAudience.Private
029public final class NoOpRegionSizeStore implements RegionSizeStore {
030  private static final NoOpRegionSizeStore INSTANCE = new NoOpRegionSizeStore();
031
032  private NoOpRegionSizeStore() {}
033
034  public static NoOpRegionSizeStore getInstance() {
035    return INSTANCE;
036  }
037
038  @Override
039  public Iterator<Entry<RegionInfo,RegionSize>> iterator() {
040    return null;
041  }
042
043  @Override
044  public long heapSize() {
045    return 0;
046  }
047
048  @Override
049  public RegionSize getRegionSize(RegionInfo regionInfo) {
050    return null;
051  }
052
053  @Override
054  public void put(RegionInfo regionInfo, long size) {}
055
056  @Override
057  public void incrementRegionSize(RegionInfo regionInfo, long delta) {}
058
059  @Override
060  public RegionSize remove(RegionInfo regionInfo) {
061    return null;
062  }
063
064  @Override
065  public int size() {
066    return 0;
067  }
068
069  @Override
070  public boolean isEmpty() {
071    return true;
072  }
073
074  @Override
075  public void clear() {}
076}