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 com.fasterxml.jackson.annotation.JsonIgnoreProperties;
021import org.apache.hadoop.hbase.metrics.impl.FastLongHistogram;
022import org.apache.yetus.audience.InterfaceAudience;
023
024/**
025 * Snapshot of block cache age in cache.
026 * This object is preferred because we can control how it is serialized out when JSON'ing.
027 */
028@InterfaceAudience.Private
029@JsonIgnoreProperties({"ageHistogram", "snapshot"})
030public class AgeSnapshot {
031
032  private final FastLongHistogram ageHistogram;
033  private final long[] quantiles;
034
035  AgeSnapshot(final FastLongHistogram ageHistogram) {
036    this.ageHistogram = ageHistogram;
037    this.quantiles = ageHistogram.getQuantiles(new double[]{0.75, 0.95, 0.98, 0.99, 0.999});
038  }
039
040  public double get75thPercentile() {
041    return quantiles[0];
042  }
043
044  public double get95thPercentile() {
045    return quantiles[1];
046  }
047
048  public double get98thPercentile() {
049    return quantiles[2];
050  }
051
052  public double get99thPercentile() {
053    return quantiles[3];
054  }
055
056  public double get999thPercentile() {
057    return quantiles[4];
058  }
059
060
061  public double getMean() {
062    return this.ageHistogram.getMean();
063  }
064
065  public double getMax() {
066    return this.ageHistogram.getMax();
067  }
068
069  public double getMin() {
070    return this.ageHistogram.getMin();
071  }
072}