// Copyright 2010 The Bazel Authors. All Rights Reserved.
//
// 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 com.google.testing.junit.runner.util;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
/**
* A Ticker whose value can be advanced programmatically in test.
* <p> The ticker can be configured so that the time is incremented whenever {@link #read} is
* called.
*
* <p> This class is thread-safe.
*/
public class FakeTicker extends Ticker {
private final AtomicLong nanos = new AtomicLong();
private volatile long autoIncrementStepNanos;
/** Advances the ticker value by {@code time} in {@code timeUnit}. */
public FakeTicker advance(long time, TimeUnit timeUnit) {
return advance(timeUnit.toNanos(time));
}
/** Advances the ticker value by {@code nanoseconds}. */
public FakeTicker advance(long nanoseconds) {
nanos.addAndGet(nanoseconds);
return this;
}
/**
* Sets the increment applied to the ticker whenever it is queried.
*
* <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when
* queried.
*/
public FakeTicker setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit) {
if (autoIncrementStep < 0) {
throw new IllegalArgumentException("May not auto-increment by a negative amount");
}
this.autoIncrementStepNanos = timeUnit.toNanos(autoIncrementStep);
return this;
}
@Override
public long read() {
return nanos.getAndAdd(autoIncrementStepNanos);
}
}