48 lines
1.3 KiB
Go
48 lines
1.3 KiB
Go
package throttling
|
|
|
|
import (
|
|
"time"
|
|
)
|
|
|
|
// Throttling notifications to prometheus and web clients
|
|
// TO be used in a single-threaded manner.
|
|
type Throttler[T any] struct {
|
|
minDelay time.Duration
|
|
// ucntion to call to implement the notification.
|
|
notifier func(t *T)
|
|
lastReportedTime time.Time
|
|
pendingValue *T
|
|
}
|
|
|
|
func NewThrottler[T any](notifier func(t *T), minDelay time.Duration) Throttler[T] {
|
|
throttler := Throttler[T]{
|
|
minDelay: minDelay,
|
|
notifier: notifier,
|
|
lastReportedTime: time.Time{},
|
|
pendingValue: nil,
|
|
}
|
|
return throttler
|
|
}
|
|
|
|
// Notify there is a new value. Performs notification if it was long enough ago
|
|
// for the last notification to be sent. If not, it is stored as a pending event to
|
|
// be sent later. New events that come in before a notification is sent override the
|
|
// pending event.
|
|
func (throttler *Throttler[T]) Notify(value *T) {
|
|
if clock.time().Sub(throttler.lastReportedTime) >= throttler.minDelay {
|
|
throttler.notifier(value)
|
|
throttler.lastReportedTime = clock.time()
|
|
throttler.pendingValue = nil
|
|
return
|
|
}
|
|
throttler.pendingValue = value
|
|
}
|
|
|
|
// To be called periodically. It sends out any pending events if the time the last
|
|
// notification was sent is long enough ago.
|
|
func (throttler *Throttler[T]) Ping() {
|
|
if throttler.pendingValue != nil {
|
|
throttler.Notify(throttler.pendingValue)
|
|
}
|
|
}
|