mirror of
https://github.com/jech/galene.git
synced 2024-11-13 20:25:57 +01:00
103 lines
2.3 KiB
Go
103 lines
2.3 KiB
Go
// Package estimator implements a packet and byte rate estimator.
|
|
|
|
package estimator
|
|
|
|
import (
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/jech/galene/rtptime"
|
|
)
|
|
|
|
type Estimator struct {
|
|
interval uint64
|
|
|
|
mu sync.Mutex
|
|
time uint64
|
|
bytes uint32
|
|
packets uint32
|
|
totalBytes uint64
|
|
totalPackets uint64
|
|
rate uint32
|
|
packetRate uint32
|
|
}
|
|
|
|
// New creates a new estimator that estimates rate over the last interval.
|
|
func New(interval time.Duration) *Estimator {
|
|
return new(rtptime.Now(rtptime.JiffiesPerSec), interval)
|
|
}
|
|
|
|
func new(now uint64, interval time.Duration) *Estimator {
|
|
return &Estimator{
|
|
interval: uint64(
|
|
rtptime.FromDuration(interval, rtptime.JiffiesPerSec),
|
|
),
|
|
time: now,
|
|
}
|
|
}
|
|
|
|
// called locked
|
|
func (e *Estimator) swap(now uint64) {
|
|
jiffies := now - e.time
|
|
bytes := e.bytes
|
|
e.bytes = 0
|
|
packets := e.packets
|
|
e.packets = 0
|
|
e.totalBytes += uint64(bytes)
|
|
e.totalPackets += uint64(packets)
|
|
|
|
var rate, packetRate uint32
|
|
if jiffies >= rtptime.JiffiesPerSec/1000 {
|
|
rate = uint32((uint64(bytes)*rtptime.JiffiesPerSec + jiffies/2) / jiffies)
|
|
packetRate = uint32((uint64(packets)*rtptime.JiffiesPerSec + jiffies/2) / jiffies)
|
|
}
|
|
e.rate = rate
|
|
e.packetRate = packetRate
|
|
e.time = now
|
|
}
|
|
|
|
// Accumulate records one packet of size bytes
|
|
func (e *Estimator) Accumulate(bytes uint32) {
|
|
e.mu.Lock()
|
|
if e.bytes < ^uint32(0)-bytes {
|
|
e.bytes += bytes
|
|
}
|
|
if e.packets < ^uint32(0)-1 {
|
|
e.packets += 1
|
|
}
|
|
e.mu.Unlock()
|
|
}
|
|
|
|
// called locked
|
|
func (e *Estimator) estimate(now uint64) (uint32, uint32) {
|
|
if now < e.time {
|
|
// time went backwards
|
|
if e.time-now > e.interval {
|
|
e.time = now
|
|
e.packets = 0
|
|
e.bytes = 0
|
|
}
|
|
} else if now-e.time >= e.interval {
|
|
e.swap(now)
|
|
}
|
|
|
|
return e.rate, e.packetRate
|
|
}
|
|
|
|
// Estimate returns an estimate of the rate over the last interval.
|
|
// It starts a new interval if the last interval is larger than the value
|
|
// passed to New. It returns the byte rate and the packet rate, in units
|
|
// per second.
|
|
func (e *Estimator) Estimate() (uint32, uint32) {
|
|
e.mu.Lock()
|
|
defer e.mu.Unlock()
|
|
return e.estimate(rtptime.Now(rtptime.JiffiesPerSec))
|
|
}
|
|
|
|
// Totals returns the total number of bytes and packets accumulated.
|
|
func (e *Estimator) Totals() (uint64, uint64) {
|
|
e.mu.Lock()
|
|
defer e.mu.Unlock()
|
|
return e.totalPackets + uint64(e.packets),
|
|
e.totalBytes + uint64(e.bytes)
|
|
}
|