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    
019    package org.apache.hadoop.metrics2;
020    
021    import org.apache.hadoop.classification.InterfaceAudience;
022    import org.apache.hadoop.classification.InterfaceStability;
023    
024    /**
025     * A visitor interface for metrics
026     */
027    @InterfaceAudience.Public
028    @InterfaceStability.Evolving
029    public 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    }