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.Beta;
22 import com.google.common.annotations.GwtCompatible;
23 import com.google.common.annotations.GwtIncompatible;
24 import com.google.common.base.Ticker;
25 import java.util.concurrent.TimeUnit;
26 import java.util.concurrent.atomic.AtomicLong;
27
28 /**
29 * A Ticker whose value can be advanced programmatically in test.
30 *
31 * <p>The ticker can be configured so that the time is incremented whenever {@link #read} is called:
32 * see {@link #setAutoIncrementStep}.
33 *
34 * <p>This class is thread-safe.
35 *
36 * @author Jige Yu
37 * @since 10.0
38 */
39 @Beta
40 @GwtCompatible
41 public class FakeTicker extends Ticker {
42
43 private final AtomicLong nanos = new AtomicLong();
44 private volatile long autoIncrementStepNanos;
45
46 /** Advances the ticker value by {@code time} in {@code timeUnit}. */
47 @SuppressWarnings("GoodTime") // should accept a java.time.Duration
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 public FakeTicker advance(long nanoseconds) {
55 nanos.addAndGet(nanoseconds);
56 return this;
57 }
58
59 /**
60 * Advances the ticker value by {@code duration}.
61 *
62 * @since 28.0
63 */
64 @GwtIncompatible
65 public FakeTicker advance(java.time.Duration duration) {
66 return advance(duration.toNanos());
67 }
68
69 /**
70 * Sets the increment applied to the ticker whenever it is queried.
71 *
72 * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when
73 * queried.
74 */
75 @SuppressWarnings("GoodTime") // should accept a java.time.Duration
76 public FakeTicker setAutoIncrementStep(long autoIncrementStep, TimeUnit timeUnit) {
77 checkArgument(autoIncrementStep >= 0, "May not auto-increment by a negative amount");
78 this.autoIncrementStepNanos = timeUnit.toNanos(autoIncrementStep);
79 return this;
80 }
81
82 /**
83 * Sets the increment applied to the ticker whenever it is queried.
84 *
85 * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when
86 * queried.
87 *
88 * @since 28.0
89 */
90 @GwtIncompatible
91 public FakeTicker setAutoIncrementStep(java.time.Duration autoIncrementStep) {
92 return setAutoIncrementStep(autoIncrementStep.toNanos(), TimeUnit.NANOSECONDS);
93 }
94
95 @Override
96 public long read() {
97 return nanos.getAndAdd(autoIncrementStepNanos);
98 }
99 }