58 lines
1.3 KiB
Go
58 lines
1.3 KiB
Go
package slack
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import (
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"math/rand"
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"time"
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)
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// This one was ripped from https://github.com/jpillora/backoff/blob/master/backoff.go
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// Backoff is a time.Duration counter. It starts at Min. After every
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// call to Duration() it is multiplied by Factor. It is capped at
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// Max. It returns to Min on every call to Reset(). Used in
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// conjunction with the time package.
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type backoff struct {
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attempts int
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// Initial value to scale out
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Initial time.Duration
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// Jitter value randomizes an additional delay between 0 and Jitter
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Jitter time.Duration
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// Max maximum values of the backoff
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Max time.Duration
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}
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// Returns the current value of the counter and then multiplies it
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// Factor
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func (b *backoff) Duration() (dur time.Duration) {
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// Zero-values are nonsensical, so we use
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// them to apply defaults
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if b.Max == 0 {
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b.Max = 10 * time.Second
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}
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if b.Initial == 0 {
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b.Initial = 100 * time.Millisecond
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}
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// calculate this duration
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if dur = time.Duration(1 << uint(b.attempts)); dur > 0 {
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dur = dur * b.Initial
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} else {
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dur = b.Max
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}
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if b.Jitter > 0 {
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dur = dur + time.Duration(rand.Intn(int(b.Jitter)))
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}
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// bump attempts count
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b.attempts++
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return dur
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}
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//Resets the current value of the counter back to Min
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func (b *backoff) Reset() {
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b.attempts = 0
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}
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