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.hbase.quotas;
019
020import java.util.Iterator;
021import java.util.Map.Entry;
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
035  @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "MS_EXPOSE_REP",
036      justification = "singleton pattern")
037  public static NoOpRegionSizeStore getInstance() {
038    return INSTANCE;
039  }
040
041  @Override
042  public Iterator<Entry<RegionInfo, RegionSize>> iterator() {
043    return null;
044  }
045
046  @Override
047  public long heapSize() {
048    return 0;
049  }
050
051  @Override
052  public RegionSize getRegionSize(RegionInfo regionInfo) {
053    return null;
054  }
055
056  @Override
057  public void put(RegionInfo regionInfo, long size) {
058  }
059
060  @Override
061  public void incrementRegionSize(RegionInfo regionInfo, long delta) {
062  }
063
064  @Override
065  public RegionSize remove(RegionInfo regionInfo) {
066    return null;
067  }
068
069  @Override
070  public int size() {
071    return 0;
072  }
073
074  @Override
075  public boolean isEmpty() {
076    return true;
077  }
078
079  @Override
080  public void clear() {
081  }
082}