| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.storm.metrics.hdrhistogram; |
| |
| import backtype.storm.metric.api.IMetric; |
| import org.HdrHistogram.Histogram; |
| |
| /** |
| * A metric wrapping an HdrHistogram. |
| */ |
| public class HistogramMetric implements IMetric { |
| private final Histogram _histo; |
| |
| |
| public HistogramMetric(final int numberOfSignificantValueDigits) { |
| this(null, numberOfSignificantValueDigits); |
| } |
| |
| public HistogramMetric(Long highestTrackableValue, final int numberOfSignificantValueDigits) { |
| this(null, highestTrackableValue, numberOfSignificantValueDigits); |
| } |
| |
| /** |
| * (From the Constructor of Histogram) |
| * Construct a Histogram given the Lowest and Highest values to be tracked and a number of significant |
| * decimal digits. Providing a lowestDiscernibleValue is useful is situations where the units used |
| * for the histogram's values are much smaller that the minimal accuracy required. E.g. when tracking |
| * time values stated in nanosecond units, where the minimal accuracy required is a microsecond, the |
| * proper value for lowestDiscernibleValue would be 1000. |
| * |
| * @param lowestDiscernibleValue The lowest value that can be discerned (distinguished from 0) by the |
| * histogram. Must be a positive integer that is {@literal >=} 1. May be |
| * internally rounded down to nearest power of 2 |
| * (if null 1 is used). |
| * @param highestTrackableValue The highest value to be tracked by the histogram. Must be a positive |
| * integer that is {@literal >=} (2 * lowestDiscernibleValue). |
| * (if null 2 * lowestDiscernibleValue is used and auto-resize is enabled) |
| * @param numberOfSignificantValueDigits Specifies the precision to use. This is the number of significant |
| * decimal digits to which the histogram will maintain value resolution |
| * and separation. Must be a non-negative integer between 0 and 5. |
| */ |
| public HistogramMetric(Long lowestDiscernibleValue, Long highestTrackableValue, |
| final int numberOfSignificantValueDigits) { |
| boolean autoResize = false; |
| if (lowestDiscernibleValue == null) lowestDiscernibleValue = 1L; |
| if (highestTrackableValue == null) { |
| highestTrackableValue = 2 * lowestDiscernibleValue; |
| autoResize = true; |
| } |
| _histo = new Histogram(lowestDiscernibleValue, highestTrackableValue, numberOfSignificantValueDigits); |
| if (autoResize) _histo.setAutoResize(true); |
| } |
| |
| public void recordValue(long val) { |
| _histo.recordValue(val); |
| } |
| |
| @Override |
| public Object getValueAndReset() { |
| Histogram copy = _histo.copy(); |
| _histo.reset(); |
| return copy; |
| } |
| } |