soju/rate.go
Simon Ser 578020e553 Add exponential backoff when re-connecting to upstream
The first reconnection attempt waits for 1min, the second the 2min,
and so on up to 10min. There's a 1min jitter so that multiple failed
connections don't try to reconnect at the exact same time.

Closes: https://todo.sr.ht/~emersion/soju/161
2021-12-02 12:14:35 +01:00

41 lines
603 B
Go

package soju
import (
"math/rand"
"time"
)
// backoffer implements a simple exponential backoff.
type backoffer struct {
min, max, jitter time.Duration
n int64
}
func newBackoffer(min, max, jitter time.Duration) *backoffer {
return &backoffer{min: min, max: max, jitter: jitter}
}
func (b *backoffer) Reset() {
b.n = 0
}
func (b *backoffer) Next() time.Duration {
if b.n == 0 {
b.n = 1
return 0
}
d := time.Duration(b.n) * b.min
if d > b.max {
d = b.max
} else {
b.n *= 2
}
if b.jitter != 0 {
d += time.Duration(rand.Int63n(int64(b.jitter)))
}
return d
}