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.metrics2.lib;
019
020import java.util.concurrent.atomic.LongAdder;
021import org.apache.hadoop.metrics2.MetricsInfo;
022import org.apache.hadoop.metrics2.MetricsRecordBuilder;
023import org.apache.yetus.audience.InterfaceAudience;
024
025@InterfaceAudience.Private
026public class MutableFastCounter extends MutableCounter {
027
028  private final LongAdder counter;
029
030  protected MutableFastCounter(MetricsInfo info, long iVal) {
031    super(info);
032    counter = new LongAdder();
033    counter.add(iVal);
034  }
035
036  @Override
037  public void incr() {
038    counter.increment();
039    setChanged();
040  }
041
042  /**
043   * Increment the value by a delta
044   * @param delta of the increment
045   */
046  public void incr(long delta) {
047    counter.add(delta);
048    setChanged();
049  }
050
051  @Override
052  public void snapshot(MetricsRecordBuilder builder, boolean all) {
053    if (all || changed()) {
054      builder.addCounter(info(), value());
055      clearChanged();
056    }
057  }
058
059  public long value() {
060    return counter.sum();
061  }
062}