001/*
002 * Copyright (C) 2008 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.testing;
018
019import static com.google.common.base.Preconditions.checkArgument;
020
021import com.google.common.annotations.GwtCompatible;
022import com.google.common.annotations.GwtIncompatible;
023import com.google.common.annotations.J2ktIncompatible;
024import com.google.common.base.Ticker;
025import com.google.errorprone.annotations.CanIgnoreReturnValue;
026import java.util.concurrent.TimeUnit;
027import java.util.concurrent.atomic.AtomicLong;
028
029/**
030 * A Ticker whose value can be advanced programmatically in test.
031 *
032 * <p>The ticker can be configured so that the time is incremented whenever {@link #read} is called:
033 * see {@link #setAutoIncrementStep}.
034 *
035 * <p>This class is thread-safe.
036 *
037 * @author Jige Yu
038 * @since 10.0
039 */
040@ElementTypesAreNonnullByDefault
041@GwtCompatible
042public class FakeTicker extends Ticker {
043
044  private final AtomicLong nanos = new AtomicLong();
045  private volatile long autoIncrementStepNanos;
046
047  /** Advances the ticker value by {@code time} in {@code timeUnit}. */
048  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
049  @CanIgnoreReturnValue
050  public FakeTicker advance(long time, TimeUnit timeUnit) {
051    return advance(timeUnit.toNanos(time));
052  }
053
054  /** Advances the ticker value by {@code nanoseconds}. */
055  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
056  @CanIgnoreReturnValue
057  public FakeTicker advance(long nanoseconds) {
058    nanos.addAndGet(nanoseconds);
059    return this;
060  }
061
062  /**
063   * Advances the ticker value by {@code duration}.
064   *
065   * @since 28.0
066   */
067  @GwtIncompatible
068  @J2ktIncompatible
069  @CanIgnoreReturnValue
070  public FakeTicker advance(java.time.Duration duration) {
071    return advance(duration.toNanos());
072  }
073
074  /**
075   * Sets the increment applied to the ticker whenever it is queried.
076   *
077   * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when
078   * queried.
079   */
080  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
081  @CanIgnoreReturnValue
082  public FakeTicker setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit) {
083    checkArgument(autoIncrementStep >= 0, "May not auto-increment by a negative amount");
084    this.autoIncrementStepNanos = timeUnit.toNanos(autoIncrementStep);
085    return this;
086  }
087
088  /**
089   * Sets the increment applied to the ticker whenever it is queried.
090   *
091   * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when
092   * queried.
093   *
094   * @since 28.0
095   */
096  @GwtIncompatible
097  @J2ktIncompatible
098  @CanIgnoreReturnValue
099  public FakeTicker setAutoIncrementStep(java.time.Duration autoIncrementStep) {
100    return setAutoIncrementStep(autoIncrementStep.toNanos(), TimeUnit.NANOSECONDS);
101  }
102
103  @Override
104  public long read() {
105    return nanos.getAndAdd(autoIncrementStepNanos);
106  }
107}