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.metrics.impl; 019 020import org.apache.hadoop.hbase.metrics.Histogram; 021import org.apache.hadoop.hbase.metrics.Snapshot; 022import org.apache.yetus.audience.InterfaceAudience; 023 024/** 025 * Custom histogram implementation based on FastLongHistogram. Dropwizard-based histograms are slow 026 * compared to this implementation, so we are using our implementation here. See HBASE-15222. 027 */ 028@InterfaceAudience.Private 029public class HistogramImpl implements Histogram { 030 // Double buffer the two FastLongHistograms. 031 // As they are reset they learn how the buckets should be spaced 032 // So keep two around and use them 033 protected final FastLongHistogram histogram; 034 private final CounterImpl counter; 035 036 public HistogramImpl() { 037 this((long) Integer.MAX_VALUE << 2); 038 } 039 040 public HistogramImpl(long maxExpected) { 041 this(FastLongHistogram.DEFAULT_NBINS, 1, maxExpected); 042 } 043 044 public HistogramImpl(int numBins, long min, long maxExpected) { 045 this.counter = new CounterImpl(); 046 this.histogram = new FastLongHistogram(numBins, min, maxExpected); 047 } 048 049 protected HistogramImpl(CounterImpl counter, FastLongHistogram histogram) { 050 this.counter = counter; 051 this.histogram = histogram; 052 } 053 054 @Override 055 public void update(int value) { 056 counter.increment(); 057 histogram.add(value, 1); 058 } 059 060 @Override 061 public void update(long value) { 062 counter.increment(); 063 histogram.add(value, 1); 064 } 065 066 @Override 067 public long getCount() { 068 return counter.getCount(); 069 } 070 071 public long getMax() { 072 return this.histogram.getMax(); 073 } 074 075 public long getMin() { 076 return this.histogram.getMin(); 077 } 078 079 @Override 080 public Snapshot snapshot() { 081 return histogram.snapshotAndReset(); 082 } 083 084 public long[] getQuantiles(double[] quantiles) { 085 return histogram.getQuantiles(quantiles); 086 } 087}