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|
package probing
import (
"sync"
"time"
)
var (
// weight factor
α = 0.125
)
type Status interface {
Total() int64
Loss() int64
Health() bool
// Estimated smoothed round trip time
SRTT() time.Duration
// Estimated clock difference
ClockDiff() time.Duration
StopNotify() <-chan struct{}
}
type status struct {
mu sync.Mutex
srtt time.Duration
total int64
loss int64
health bool
clockdiff time.Duration
stopC chan struct{}
}
// SRTT = (1-α) * SRTT + α * RTT
func (s *status) SRTT() time.Duration {
s.mu.Lock()
defer s.mu.Unlock()
return s.srtt
}
func (s *status) Total() int64 {
s.mu.Lock()
defer s.mu.Unlock()
return s.total
}
func (s *status) Loss() int64 {
s.mu.Lock()
defer s.mu.Unlock()
return s.loss
}
func (s *status) Health() bool {
s.mu.Lock()
defer s.mu.Unlock()
return s.health
}
func (s *status) ClockDiff() time.Duration {
s.mu.Lock()
defer s.mu.Unlock()
return s.clockdiff
}
func (s *status) StopNotify() <-chan struct{} {
return s.stopC
}
func (s *status) record(rtt time.Duration, when time.Time) {
s.mu.Lock()
defer s.mu.Unlock()
s.total += 1
s.health = true
s.srtt = time.Duration((1-α)*float64(s.srtt) + α*float64(rtt))
s.clockdiff = time.Now().Sub(when) - s.srtt/2
}
func (s *status) recordFailure() {
s.mu.Lock()
defer s.mu.Unlock()
s.total++
s.health = false
s.loss += 1
}
func (s *status) reset() {
s.mu.Lock()
defer s.mu.Unlock()
s.srtt = 0
s.total = 0
s.health = false
s.clockdiff = 0
}
|
