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 java.util.concurrent.TimeUnit; 24 import java.util.concurrent.atomic.AtomicLong; 25 26 /** 27 * A Ticker whose value can be advanced programmatically in test. 28 * 29 * <p>The ticker can be configured so that the time is incremented whenever {@link #read} is called: 30 * see {@link #setAutoIncrementStep}. 31 * 32 * <p>This class is thread-safe. 33 * 34 * @author Jige Yu 35 * @since 10.0 36 */ 37 @GwtCompatible 38 public class FakeTicker extends Ticker { 39 40 private final AtomicLong nanos = new AtomicLong(); 41 private volatile long autoIncrementStepNanos; 42 43 /** Advances the ticker value by {@code time} in {@code timeUnit}. */ 44 @SuppressWarnings("GoodTime") // should accept a java.time.Duration advance(long time, TimeUnit timeUnit)45 public FakeTicker advance(long time, TimeUnit timeUnit) { 46 return advance(timeUnit.toNanos(time)); 47 } 48 49 /** Advances the ticker value by {@code nanoseconds}. */ 50 @SuppressWarnings("GoodTime") // should accept a java.time.Duration advance(long nanoseconds)51 public FakeTicker advance(long nanoseconds) { 52 nanos.addAndGet(nanoseconds); 53 return this; 54 } 55 56 /** 57 * Sets the increment applied to the ticker whenever it is queried. 58 * 59 * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when 60 * queried. 61 */ 62 @SuppressWarnings("GoodTime") // should accept a java.time.Duration setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit)63 public FakeTicker setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit) { 64 checkArgument(autoIncrementStep >= 0, "May not auto-increment by a negative amount"); 65 this.autoIncrementStepNanos = timeUnit.toNanos(autoIncrementStep); 66 return this; 67 } 68 69 @Override read()70 public long read() { 71 return nanos.getAndAdd(autoIncrementStepNanos); 72 } 73 } 74