com.google.common.testing.FakeTicker Maven / Gradle / Ivy
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/*
* Copyright (C) 2008 The Guava 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
*
* 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.common.testing;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Ticker;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
/**
* A Ticker whose value can be advanced programmatically in test.
*
* The ticker can be configured so that the time is incremented whenever {@link #read} is called:
* see {@link #setAutoIncrementStep}.
*
* This class is thread-safe.
*
* @author Jige Yu
* @since 10.0
*/
@Beta
@GwtCompatible
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.
*
*
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) {
checkArgument(autoIncrementStep >= 0, "May not auto-increment by a negative amount");
this.autoIncrementStepNanos = timeUnit.toNanos(autoIncrementStep);
return this;
}
@Override public long read() {
return nanos.getAndAdd(autoIncrementStepNanos);
}
}