/*
 * Copyright 2010-2013 Coda Hale and Yammer, Inc., 2014-2017 Dropwizard Team
 *
 * Licensed 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 io.dropwizard.metrics;

/**
 * A gauge metric is an instantaneous reading of a particular value. To instrument a queue's depth,
 * for example:<br>
 * <pre><code>
 * final Queue&lt;String&gt; queue = new ConcurrentLinkedQueue&lt;String&gt;();
 * final Gauge&lt;Integer&gt; queueDepth = new Gauge&lt;Integer&gt;() {
 *     public Integer getValue() {
 *         return queue.size();
 *     }
 * };
 * </code></pre>
 *
 * @param <T> the type of the metric's value
 */
public interface Gauge<T> extends Metric {
    /**
     * Returns the metric's current value.
     *
     * @return the metric's current value
     */
    T getValue();
}
