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 java.util.concurrent.ConcurrentHashMap;
023import org.apache.hadoop.hbase.client.RegionInfo;
024import org.apache.hadoop.hbase.util.Bytes;
025import org.apache.hadoop.hbase.util.ClassSize;
026import org.apache.yetus.audience.InterfaceAudience;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030/**
031 * A {@link RegionSizeStore} implementation backed by a ConcurrentHashMap. We expected similar
032 * amounts of reads and writes to the "store", so using a RWLock is not going to provide any
033 * exceptional gains.
034 */
035@InterfaceAudience.Private
036public class RegionSizeStoreImpl implements RegionSizeStore {
037  private static final Logger LOG = LoggerFactory.getLogger(RegionSizeStoreImpl.class);
038  private static final long sizeOfEntry =
039    ClassSize.align(ClassSize.CONCURRENT_HASHMAP_ENTRY + ClassSize.OBJECT + Bytes.SIZEOF_LONG
040    // TODO Have RegionInfo implement HeapSize. 100B is an approximation based on a heapdump.
041      + ClassSize.OBJECT + 100);
042  private final ConcurrentHashMap<RegionInfo, RegionSize> store;
043
044  public RegionSizeStoreImpl() {
045    store = new ConcurrentHashMap<>();
046  }
047
048  @Override
049  public Iterator<Entry<RegionInfo, RegionSize>> iterator() {
050    return store.entrySet().iterator();
051  }
052
053  @Override
054  public RegionSize getRegionSize(RegionInfo regionInfo) {
055    return store.get(regionInfo);
056  }
057
058  @Override
059  public void put(RegionInfo regionInfo, long size) {
060    if (LOG.isTraceEnabled()) {
061      LOG.trace("Setting space quota size for " + regionInfo + " to " + size);
062    }
063    // Atomic. Either sets the new size for the first time, or replaces the existing value.
064    store.compute(regionInfo,
065      (key, value) -> value == null ? new RegionSizeImpl(size) : value.setSize(size));
066  }
067
068  @Override
069  public void incrementRegionSize(RegionInfo regionInfo, long delta) {
070    if (LOG.isTraceEnabled()) {
071      LOG.trace("Updating space quota size for " + regionInfo + " with a delta of " + delta);
072    }
073    // Atomic. Recomputes the stored value with the delta if there is one, otherwise use the delta.
074    store.compute(regionInfo,
075      (key, value) -> value == null ? new RegionSizeImpl(delta) : value.incrementSize(delta));
076  }
077
078  @Override
079  public RegionSize remove(RegionInfo regionInfo) {
080    return store.remove(regionInfo);
081  }
082
083  @Override
084  public long heapSize() {
085    // Will have to iterate over each element if RegionInfo implements HeapSize, for now it's just
086    // a simple calculation.
087    return sizeOfEntry * store.size();
088  }
089
090  @Override
091  public int size() {
092    return store.size();
093  }
094
095  @Override
096  public boolean isEmpty() {
097    return store.isEmpty();
098  }
099
100  @Override
101  public void clear() {
102    store.clear();
103  }
104}