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;
020
021import org.apache.hadoop.classification.InterfaceAudience;
022import org.apache.hadoop.classification.InterfaceStability;
023
024/**
025 * A visitor interface for metrics
026 */
027@InterfaceAudience.Public
028@InterfaceStability.Evolving
029public interface MetricsVisitor {
030  /**
031   * Callback for integer value gauges
032   * @param info  the metric info
033   * @param value of the metric
034   */
035  public void gauge(MetricsInfo info, int value);
036
037  /**
038   * Callback for long value gauges
039   * @param info  the metric info
040   * @param value of the metric
041   */
042  public void gauge(MetricsInfo info, long value);
043
044  /**
045   * Callback for float value gauges
046   * @param info  the metric info
047   * @param value of the metric
048   */
049  public void gauge(MetricsInfo info, float value);
050
051  /**
052   * Callback for double value gauges
053   * @param info  the metric info
054   * @param value of the metric
055   */
056  public void gauge(MetricsInfo info, double value);
057
058  /**
059   * Callback for integer value counters
060   * @param info  the metric info
061   * @param value of the metric
062   */
063  public void counter(MetricsInfo info, int value);
064
065  /**
066   * Callback for long value counters
067   * @param info  the metric info
068   * @param value of the metric
069   */
070  public void counter(MetricsInfo info, long value);
071}