io.micrometer.tracing.test.simple.Clock Maven / Gradle / Ivy
/**
* Copyright 2022 the original author or authors.
*
* 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
*
* https://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.micrometer.tracing.test.simple;
/**
* Used to measure absolute and relative time.
*
* @author Jon Schneider
*/
public interface Clock {
/**
* Default, system clock.
*/
Clock SYSTEM = new Clock() {
@Override
public long wallTime() {
return System.currentTimeMillis();
}
@Override
public long monotonicTime() {
return System.nanoTime();
}
};
/**
* Current wall time in milliseconds since the epoch. Typically equivalent to
* System.currentTimeMillis. Should not be used to determine durations. Used for
* timestamping metrics being pushed to a monitoring system or for determination of
* step boundaries.
* @return Wall time in milliseconds
*/
long wallTime();
/**
* Current time from a monotonic clock source. The value is only meaningful when
* compared with another snapshot to determine the elapsed time for an operation. The
* difference between two samples will have a unit of nanoseconds. The returned value
* is typically equivalent to System.nanoTime.
* @return Monotonic time in nanoseconds
*/
long monotonicTime();
}