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 */
018
019package org.apache.hadoop.metrics2.lib;
020
021import org.apache.hadoop.hbase.metrics.Interns;
022import org.apache.hadoop.hbase.metrics.Snapshot;
023import org.apache.hadoop.metrics2.MetricHistogram;
024import org.apache.hadoop.metrics2.MetricsInfo;
025import org.apache.hadoop.metrics2.MetricsRecordBuilder;
026import org.apache.yetus.audience.InterfaceAudience;
027
028/**
029 * Extended histogram implementation with metric range counters.
030 */
031@InterfaceAudience.Private
032public abstract class MutableRangeHistogram extends MutableHistogram implements MetricHistogram {
033
034  public MutableRangeHistogram(MetricsInfo info) {
035    this(info.name(), info.description());
036  }
037
038  public MutableRangeHistogram(String name, String description) {
039    super(name, description);
040  }
041
042  /**
043   * Returns the type of range histogram size or time 
044   */
045  public abstract String getRangeType();
046  
047  /**
048   * Returns the ranges to be counted 
049   */
050  public abstract long[] getRanges();
051
052  
053  @Override
054  public synchronized void snapshot(MetricsRecordBuilder metricsRecordBuilder, boolean all) {
055    // Get a reference to the old histogram.
056    Snapshot snapshot = histogram.snapshot();
057    if (snapshot != null) {
058      updateSnapshotMetrics(name, desc, histogram, snapshot, metricsRecordBuilder);
059      updateSnapshotRangeMetrics(metricsRecordBuilder, snapshot);
060    }
061  }
062
063  public void updateSnapshotRangeMetrics(MetricsRecordBuilder metricsRecordBuilder,
064                                         Snapshot snapshot) {
065    long priorRange = 0;
066    long cumNum = 0;
067
068    final long[] ranges = getRanges();
069    final String rangeType = getRangeType();
070    for (int i = 0; i < ranges.length - 1; i++) {
071      long val = snapshot.getCountAtOrBelow(ranges[i]);
072      if (val - cumNum > 0) {
073        metricsRecordBuilder.addCounter(
074            Interns.info(name + "_" + rangeType + "_" + priorRange + "-" + ranges[i], desc),
075            val - cumNum);
076      }
077      priorRange = ranges[i];
078      cumNum = val;
079    }
080    long val = snapshot.getCount();
081    if (val - cumNum > 0) {
082      metricsRecordBuilder.addCounter(
083          Interns.info(name + "_" + rangeType + "_" + ranges[ranges.length - 1] + "-inf", desc),
084          val - cumNum);
085    }
086  }  
087}