1/*
2Copyright 2014 The Kubernetes Authors.
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8    http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15*/
16
17package clock
18
19import "time"
20
21// Clock allows for injecting fake or real clocks into code that
22// needs to do arbitrary things based on time.
23type Clock interface {
24	Now() time.Time
25	Since(time.Time) time.Duration
26	After(d time.Duration) <-chan time.Time
27	NewTimer(d time.Duration) Timer
28	Sleep(d time.Duration)
29	Tick(d time.Duration) <-chan time.Time
30}
31
32var _ = Clock(RealClock{})
33
34// RealClock really calls time.Now()
35type RealClock struct{}
36
37// Now returns the current time.
38func (RealClock) Now() time.Time {
39	return time.Now()
40}
41
42// Since returns time since the specified timestamp.
43func (RealClock) Since(ts time.Time) time.Duration {
44	return time.Since(ts)
45}
46
47// After is the same as time.After(d).
48func (RealClock) After(d time.Duration) <-chan time.Time {
49	return time.After(d)
50}
51
52// NewTimer is the same as time.NewTimer(d)
53func (RealClock) NewTimer(d time.Duration) Timer {
54	return &realTimer{
55		timer: time.NewTimer(d),
56	}
57}
58
59// Tick is the same as time.Tick(d)
60func (RealClock) Tick(d time.Duration) <-chan time.Time {
61	return time.Tick(d)
62}
63
64// Sleep is the same as time.Sleep(d)
65func (RealClock) Sleep(d time.Duration) {
66	time.Sleep(d)
67}
68
69// Timer allows for injecting fake or real timers into code that
70// needs to do arbitrary things based on time.
71type Timer interface {
72	C() <-chan time.Time
73	Stop() bool
74	Reset(d time.Duration) bool
75}
76
77var _ = Timer(&realTimer{})
78
79// realTimer is backed by an actual time.Timer.
80type realTimer struct {
81	timer *time.Timer
82}
83
84// C returns the underlying timer's channel.
85func (r *realTimer) C() <-chan time.Time {
86	return r.timer.C
87}
88
89// Stop calls Stop() on the underlying timer.
90func (r *realTimer) Stop() bool {
91	return r.timer.Stop()
92}
93
94// Reset calls Reset() on the underlying timer.
95func (r *realTimer) Reset(d time.Duration) bool {
96	return r.timer.Reset(d)
97}
98