package com.codahale.metrics.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.concurrent.TimeUnit;

An annotation for marking a method as a gauge, which caches the result for a specified time.

Given a method like this:
 @CachedGauge(name = "queueSize", timeout = 30, timeoutUnit = TimeUnit.SECONDS) public int getQueueSize() { return queue.getSize(); } 

A gauge for the defining class with the name queueSize will be created which uses the annotated method's
return value as its value, and which caches the result for 30 seconds.
Since:
3.1/**
 * An annotation for marking a method as a gauge, which caches the result for a specified time.
 *
 * <p>
 * Given a method like this:
 * <pre><code>
 *     {@literal @}CachedGauge(name = "queueSize", timeout = 30, timeoutUnit = TimeUnit.SECONDS)
 *     public int getQueueSize() {
 *         return queue.getSize();
 *     }
 *
 * </code></pre>
 * <p>
 *
 * A gauge for the defining class with the name queueSize will be created which uses the annotated method's
 * return value as its value, and which caches the result for 30 seconds.
 *
 * @since 3.1
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.METHOD, ElementType.ANNOTATION_TYPE })
public @interface CachedGauge {

    
Returns:
The name of the counter./**
     * @return The name of the counter.
     */
    String name() default "";

    
Returns:
If true, use the given name as an absolute name. If false, use the given name relative to the annotated class./**
     * @return If {@code true}, use the given name as an absolute name. If {@code false}, use the given name
     * relative to the annotated class.
     */
    boolean absolute() default false;

    
Returns:
The amount of time to cache the result/**
     * @return The amount of time to cache the result
     */
    long timeout();

    
Returns:
The unit of timeout/**
     * @return The unit of timeout
     */
    TimeUnit timeoutUnit() default TimeUnit.MILLISECONDS;

}