blob: e300af69c5a839ed24e2db48cbc93a8ff1a4e5f5 (
plain)
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
|
package minio
import "time"
// newRetryTimerContinous creates a timer with exponentially increasing delays forever.
func (c Client) newRetryTimerContinous(unit time.Duration, cap time.Duration, jitter float64, doneCh chan struct{}) <-chan int {
attemptCh := make(chan int)
// normalize jitter to the range [0, 1.0]
if jitter < NoJitter {
jitter = NoJitter
}
if jitter > MaxJitter {
jitter = MaxJitter
}
// computes the exponential backoff duration according to
// https://www.awsarchitectureblog.com/2015/03/backoff.html
exponentialBackoffWait := func(attempt int) time.Duration {
// 1<<uint(attempt) below could overflow, so limit the value of attempt
maxAttempt := 30
if attempt > maxAttempt {
attempt = maxAttempt
}
//sleep = random_between(0, min(cap, base * 2 ** attempt))
sleep := unit * time.Duration(1<<uint(attempt))
if sleep > cap {
sleep = cap
}
if jitter != NoJitter {
sleep -= time.Duration(c.random.Float64() * float64(sleep) * jitter)
}
return sleep
}
go func() {
defer close(attemptCh)
var nextBackoff int
for {
select {
// Attempts starts.
case attemptCh <- nextBackoff:
nextBackoff++
case <-doneCh:
// Stop the routine.
return
}
time.Sleep(exponentialBackoffWait(nextBackoff))
}
}()
return attemptCh
}
|
