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 java.util.concurrent.atomic.LongAdder;
022
023import org.apache.hadoop.metrics2.MetricsInfo;
024import org.apache.hadoop.metrics2.MetricsRecordBuilder;
025import org.apache.yetus.audience.InterfaceAudience;
026
027@InterfaceAudience.Private
028public class MutableFastCounter extends MutableCounter {
029
030  private final LongAdder counter;
031
032  protected MutableFastCounter(MetricsInfo info, long iVal) {
033    super(info);
034    counter = new LongAdder();
035    counter.add(iVal);
036  }
037
038  @Override
039  public void incr() {
040    counter.increment();
041    setChanged();
042  }
043
044  /**
045   * Increment the value by a delta
046   * @param delta of the increment
047   */
048  public void incr(long delta) {
049    counter.add(delta);
050    setChanged();
051  }
052
053  @Override
054  public void snapshot(MetricsRecordBuilder builder, boolean all) {
055    if (all || changed()) {
056      builder.addCounter(info(), value());
057      clearChanged();
058    }
059  }
060
061  public long value() {
062    return counter.sum();
063  }
064}