1 /* 2 * Copyright (C) 2008 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.testing; 18 19 import static com.google.common.base.Preconditions.checkArgument; 20 21 import com.google.common.annotations.GwtCompatible; 22 import com.google.common.base.Ticker; 23 import com.google.errorprone.annotations.CanIgnoreReturnValue; 24 import java.util.concurrent.TimeUnit; 25 import java.util.concurrent.atomic.AtomicLong; 26 27 /** 28 * A Ticker whose value can be advanced programmatically in test. 29 * 30 * <p>The ticker can be configured so that the time is incremented whenever {@link #read} is called: 31 * see {@link #setAutoIncrementStep}. 32 * 33 * <p>This class is thread-safe. 34 * 35 * @author Jige Yu 36 * @since 10.0 37 */ 38 @ElementTypesAreNonnullByDefault 39 @GwtCompatible 40 public class FakeTicker extends Ticker { 41 42 private final AtomicLong nanos = new AtomicLong(); 43 private volatile long autoIncrementStepNanos; 44 45 /** Advances the ticker value by {@code time} in {@code timeUnit}. */ 46 @SuppressWarnings("GoodTime") // should accept a java.time.Duration 47 @CanIgnoreReturnValue advance(long time, TimeUnit timeUnit)48 public FakeTicker advance(long time, TimeUnit timeUnit) { 49 return advance(timeUnit.toNanos(time)); 50 } 51 52 /** Advances the ticker value by {@code nanoseconds}. */ 53 @SuppressWarnings("GoodTime") // should accept a java.time.Duration 54 @CanIgnoreReturnValue advance(long nanoseconds)55 public FakeTicker advance(long nanoseconds) { 56 nanos.addAndGet(nanoseconds); 57 return this; 58 } 59 60 /** 61 * Sets the increment applied to the ticker whenever it is queried. 62 * 63 * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when 64 * queried. 65 */ 66 @SuppressWarnings("GoodTime") // should accept a java.time.Duration 67 @CanIgnoreReturnValue setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit)68 public FakeTicker setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit) { 69 checkArgument(autoIncrementStep >= 0, "May not auto-increment by a negative amount"); 70 this.autoIncrementStepNanos = timeUnit.toNanos(autoIncrementStep); 71 return this; 72 } 73 74 @Override read()75 public long read() { 76 return nanos.getAndAdd(autoIncrementStepNanos); 77 } 78 } 79