64 lines
1.4 KiB
Go
64 lines
1.4 KiB
Go
package retryutil
|
|
|
|
import (
|
|
"fmt"
|
|
"time"
|
|
)
|
|
|
|
// RetryTicker is a wrapper aroung time.Tick,
|
|
// that allows to mock its implementation
|
|
type RetryTicker interface {
|
|
Stop()
|
|
Tick()
|
|
}
|
|
|
|
// Ticker is a real implementation of RetryTicker interface
|
|
type Ticker struct {
|
|
ticker *time.Ticker
|
|
}
|
|
|
|
// Stop is a convenience wrapper around ticker.Stop
|
|
func (t *Ticker) Stop() { t.ticker.Stop() }
|
|
|
|
// Tick is a convenience wrapper around ticker.C
|
|
func (t *Ticker) Tick() { <-t.ticker.C }
|
|
|
|
// Retry is a wrapper around RetryWorker that provides a real RetryTicker
|
|
func Retry(interval time.Duration, timeout time.Duration, f func() (bool, error)) error {
|
|
//TODO: make the retry exponential
|
|
if timeout < interval {
|
|
return fmt.Errorf("timeout(%s) should be greater than interval(%v)", timeout, interval)
|
|
}
|
|
tick := &Ticker{time.NewTicker(interval)}
|
|
return RetryWorker(interval, timeout, tick, f)
|
|
}
|
|
|
|
// RetryWorker calls ConditionFunc until either:
|
|
// * it returns boolean true
|
|
// * a timeout expires
|
|
// * an error occurs
|
|
func RetryWorker(
|
|
interval time.Duration,
|
|
timeout time.Duration,
|
|
tick RetryTicker,
|
|
f func() (bool, error)) error {
|
|
|
|
maxRetries := int(timeout / interval)
|
|
defer tick.Stop()
|
|
|
|
for i := 0; ; i++ {
|
|
ok, err := f()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if ok {
|
|
return nil
|
|
}
|
|
if i+1 == maxRetries {
|
|
break
|
|
}
|
|
tick.Tick()
|
|
}
|
|
return fmt.Errorf("still failing after %d retries", maxRetries)
|
|
}
|