mirror of
https://github.com/MetaCubeX/mihomo.git
synced 2024-09-12 11:52:33 +00:00
86 lines
2.1 KiB
Go
86 lines
2.1 KiB
Go
|
package congestion
|
||
|
|
||
|
import (
|
||
|
"github.com/lucas-clemente/quic-go/congestion"
|
||
|
"math"
|
||
|
"time"
|
||
|
)
|
||
|
|
||
|
const (
|
||
|
maxBurstPackets = 10
|
||
|
minPacingDelay = time.Millisecond
|
||
|
)
|
||
|
|
||
|
// The pacer implements a token bucket pacing algorithm.
|
||
|
type pacer struct {
|
||
|
budgetAtLastSent congestion.ByteCount
|
||
|
maxDatagramSize congestion.ByteCount
|
||
|
lastSentTime time.Time
|
||
|
getBandwidth func() congestion.ByteCount // in bytes/s
|
||
|
}
|
||
|
|
||
|
func newPacer(getBandwidth func() congestion.ByteCount) *pacer {
|
||
|
p := &pacer{
|
||
|
budgetAtLastSent: maxBurstPackets * initMaxDatagramSize,
|
||
|
maxDatagramSize: initMaxDatagramSize,
|
||
|
getBandwidth: getBandwidth,
|
||
|
}
|
||
|
return p
|
||
|
}
|
||
|
|
||
|
func (p *pacer) SentPacket(sendTime time.Time, size congestion.ByteCount) {
|
||
|
budget := p.Budget(sendTime)
|
||
|
if size > budget {
|
||
|
p.budgetAtLastSent = 0
|
||
|
} else {
|
||
|
p.budgetAtLastSent = budget - size
|
||
|
}
|
||
|
p.lastSentTime = sendTime
|
||
|
}
|
||
|
|
||
|
func (p *pacer) Budget(now time.Time) congestion.ByteCount {
|
||
|
if p.lastSentTime.IsZero() {
|
||
|
return p.maxBurstSize()
|
||
|
}
|
||
|
budget := p.budgetAtLastSent + (p.getBandwidth()*congestion.ByteCount(now.Sub(p.lastSentTime).Nanoseconds()))/1e9
|
||
|
return minByteCount(p.maxBurstSize(), budget)
|
||
|
}
|
||
|
|
||
|
func (p *pacer) maxBurstSize() congestion.ByteCount {
|
||
|
return maxByteCount(
|
||
|
congestion.ByteCount((minPacingDelay+time.Millisecond).Nanoseconds())*p.getBandwidth()/1e9,
|
||
|
maxBurstPackets*p.maxDatagramSize,
|
||
|
)
|
||
|
}
|
||
|
|
||
|
// TimeUntilSend returns when the next packet should be sent.
|
||
|
// It returns the zero value of time.Time if a packet can be sent immediately.
|
||
|
func (p *pacer) TimeUntilSend() time.Time {
|
||
|
if p.budgetAtLastSent >= p.maxDatagramSize {
|
||
|
return time.Time{}
|
||
|
}
|
||
|
return p.lastSentTime.Add(maxDuration(
|
||
|
minPacingDelay,
|
||
|
time.Duration(math.Ceil(float64(p.maxDatagramSize-p.budgetAtLastSent)*1e9/
|
||
|
float64(p.getBandwidth())))*time.Nanosecond,
|
||
|
))
|
||
|
}
|
||
|
|
||
|
func (p *pacer) SetMaxDatagramSize(s congestion.ByteCount) {
|
||
|
p.maxDatagramSize = s
|
||
|
}
|
||
|
|
||
|
func maxByteCount(a, b congestion.ByteCount) congestion.ByteCount {
|
||
|
if a < b {
|
||
|
return b
|
||
|
}
|
||
|
return a
|
||
|
}
|
||
|
|
||
|
func minByteCount(a, b congestion.ByteCount) congestion.ByteCount {
|
||
|
if a < b {
|
||
|
return a
|
||
|
}
|
||
|
return b
|
||
|
}
|