forked from grab/async
/
jitter.go
64 lines (49 loc) · 1.74 KB
/
jitter.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
// Copyright (c) 2022 James Tran Dung, All rights reserved.
// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file
package async
import (
"context"
"math/rand"
"time"
)
// DoJitter adds a random jitter before executing doFn, then returns the jitter duration.
// Why jitter?
//
// http://highscalability.com/blog/2012/4/17/youtube-strategy-adding-jitter-isnt-a-bug.html
func DoJitter(doFn func(), maxJitterDurationInMilliseconds int) int {
randomJitterDuration := waitForRandomJitter(maxJitterDurationInMilliseconds)
doFn()
return randomJitterDuration
}
// AddJitterT adds a random jitter before executing the given Task. Why jitter?
//
// http://highscalability.com/blog/2012/4/17/youtube-strategy-adding-jitter-isnt-a-bug.html
func AddJitterT[T any](t Task[T], maxJitterDurationInMilliseconds int) Task[T] {
return NewTask(
func(ctx context.Context) (T, error) {
waitForRandomJitter(maxJitterDurationInMilliseconds)
t.ExecuteSync(ctx)
return t.Outcome()
},
)
}
// AddJitterST adds a random jitter before executing the given SilentTask. Why jitter?
//
// http://highscalability.com/blog/2012/4/17/youtube-strategy-adding-jitter-isnt-a-bug.html
func AddJitterST(t SilentTask, maxJitterDurationInMilliseconds int) SilentTask {
return NewSilentTask(
func(ctx context.Context) error {
waitForRandomJitter(maxJitterDurationInMilliseconds)
t.ExecuteSync(ctx)
return t.Error()
},
)
}
func waitForRandomJitter(maxJitterDurationInMilliseconds int) int {
rand.Seed(time.Now().UnixNano())
min := 0
max := maxJitterDurationInMilliseconds
randomJitterDuration := rand.Intn(max-min+1) + min
<-time.After(time.Duration(randomJitterDuration) * time.Millisecond)
return randomJitterDuration
}