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.io.hfile;
019
020import org.apache.hadoop.hbase.metrics.impl.FastLongHistogram;
021import org.apache.yetus.audience.InterfaceAudience;
022
023/**
024 * Snapshot of block cache age in cache.
025 * This object is preferred because we can control how it is serialized out when JSON'ing.
026 */
027@InterfaceAudience.Private
028public class AgeSnapshot {
029
030  private transient final FastLongHistogram ageHistogram;
031  private transient final long[] quantiles;
032
033  AgeSnapshot(final FastLongHistogram ageHistogram) {
034    this.ageHistogram = ageHistogram;
035    this.quantiles = ageHistogram.getQuantiles(new double[]{0.75, 0.95, 0.98, 0.99, 0.999});
036  }
037
038  public double get75thPercentile() {
039    return quantiles[0];
040  }
041
042  public double get95thPercentile() {
043    return quantiles[1];
044  }
045
046  public double get98thPercentile() {
047    return quantiles[2];
048  }
049
050  public double get99thPercentile() {
051    return quantiles[3];
052  }
053
054  public double get999thPercentile() {
055    return quantiles[4];
056  }
057
058
059  public double getMean() {
060    return this.ageHistogram.getMean();
061  }
062
063  public double getMax() {
064    return this.ageHistogram.getMax();
065  }
066
067  public double getMin() {
068    return this.ageHistogram.getMin();
069  }
070}