com.alibaba.metrics.Gauge Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.metrics;
/**
*
* A gauge metric is an instantaneous reading of a particular value. To instrument a queue's depth,
* for example:
*
* final Queue<String> queue = new ConcurrentLinkedQueue<String>();
* final Gauge<Integer> queueDepth = new Gauge<Integer>() {
* public Integer getValue() {
* return queue.size();
* }
* };
*
* 一种实时数据的度量，反映的是瞬态的数据，不具有累加性。
* 具体的实现由具体定义，例如，获取当前jvm的活跃线程数
*
*
* @param the type of the metric's value
*/
public interface Gauge extends Metric {
/**
* Returns the metric's current value.
*
* @return the metric's current value
*/
T getValue();
}