mirror of
https://github.com/v2fly/v2ray-core.git
synced 2024-09-05 19:44:32 -04:00
341 lines
7.4 KiB
Go
341 lines
7.4 KiB
Go
package kcp
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import (
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"sync"
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)
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type SendingWindow struct {
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start uint32
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cap uint32
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len uint32
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last uint32
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data []*DataSegment
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prev []uint32
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next []uint32
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totalInFlightSize uint32
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writer SegmentWriter
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onPacketLoss func(uint32)
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}
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func NewSendingWindow(size uint32, writer SegmentWriter, onPacketLoss func(uint32)) *SendingWindow {
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window := &SendingWindow{
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start: 0,
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cap: size,
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len: 0,
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last: 0,
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data: make([]*DataSegment, size),
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prev: make([]uint32, size),
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next: make([]uint32, size),
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writer: writer,
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onPacketLoss: onPacketLoss,
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}
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return window
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}
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func (this *SendingWindow) Len() int {
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return int(this.len)
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}
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func (this *SendingWindow) IsEmpty() bool {
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return this.len == 0
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}
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func (this *SendingWindow) Size() uint32 {
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return this.cap
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}
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func (this *SendingWindow) IsFull() bool {
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return this.len == this.cap
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}
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func (this *SendingWindow) Push(seg *DataSegment) {
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pos := (this.start + this.len) % this.cap
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this.data[pos] = seg
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if this.len > 0 {
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this.next[this.last] = pos
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this.prev[pos] = this.last
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}
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this.last = pos
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this.len++
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}
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func (this *SendingWindow) First() *DataSegment {
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return this.data[this.start]
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}
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func (this *SendingWindow) Clear(una uint32) {
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for !this.IsEmpty() && this.data[this.start].Number < una {
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this.Remove(0)
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}
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}
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func (this *SendingWindow) Remove(idx uint32) {
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if this.len == 0 {
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return
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}
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pos := (this.start + idx) % this.cap
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seg := this.data[pos]
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if seg == nil {
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return
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}
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this.totalInFlightSize--
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seg.Release()
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this.data[pos] = nil
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if pos == this.start && pos == this.last {
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this.len = 0
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this.start = 0
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this.last = 0
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} else if pos == this.start {
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delta := this.next[pos] - this.start
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if this.next[pos] < this.start {
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delta = this.next[pos] + this.cap - this.start
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}
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this.start = this.next[pos]
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this.len -= delta
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} else if pos == this.last {
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this.last = this.prev[pos]
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} else {
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this.next[this.prev[pos]] = this.next[pos]
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this.prev[this.next[pos]] = this.prev[pos]
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}
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}
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func (this *SendingWindow) HandleFastAck(number uint32) {
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if this.len == 0 {
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return
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}
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for i := this.start; ; i = this.next[i] {
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seg := this.data[i]
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if number-seg.Number > 0x7FFFFFFF {
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break
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}
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if number != seg.Number {
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seg.ackSkipped++
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}
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if i == this.last {
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break
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}
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}
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}
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func (this *SendingWindow) Flush(current uint32, resend uint32, rto uint32, maxInFlightSize uint32) {
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if this.IsEmpty() {
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return
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}
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var lost uint32
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var inFlightSize uint32
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for i := this.start; ; i = this.next[i] {
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segment := this.data[i]
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needsend := false
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if segment.transmit == 0 {
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needsend = true
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segment.transmit++
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segment.timeout = current + rto
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this.totalInFlightSize++
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} else if current-segment.timeout < 0x7FFFFFFF {
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needsend = true
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segment.transmit++
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segment.timeout = current + rto
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lost++
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} else if segment.ackSkipped >= resend {
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needsend = true
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segment.transmit++
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segment.ackSkipped = 0
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segment.timeout = current + rto
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}
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if needsend {
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segment.Timestamp = current
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this.writer.Write(segment)
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inFlightSize++
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if inFlightSize >= maxInFlightSize {
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break
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}
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}
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if i == this.last {
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break
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}
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}
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if this.onPacketLoss != nil && inFlightSize > 0 && this.totalInFlightSize != 0 {
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rate := lost * 100 / this.totalInFlightSize
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this.onPacketLoss(rate)
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}
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}
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type SendingWorker struct {
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sync.RWMutex
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conn *Connection
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window *SendingWindow
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firstUnacknowledged uint32
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nextNumber uint32
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remoteNextNumber uint32
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controlWindow uint32
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fastResend uint32
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}
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func NewSendingWorker(kcp *Connection) *SendingWorker {
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worker := &SendingWorker{
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conn: kcp,
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fastResend: 2,
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remoteNextNumber: 32,
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controlWindow: kcp.Config.GetSendingInFlightSize(),
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}
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worker.window = NewSendingWindow(kcp.Config.GetSendingBufferSize(), worker, worker.OnPacketLoss)
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return worker
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}
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func (this *SendingWorker) ProcessReceivingNext(nextNumber uint32) {
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this.Lock()
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defer this.Unlock()
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this.ProcessReceivingNextWithoutLock(nextNumber)
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}
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func (this *SendingWorker) ProcessReceivingNextWithoutLock(nextNumber uint32) {
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this.window.Clear(nextNumber)
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this.FindFirstUnacknowledged()
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}
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// Private: Visible for testing.
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func (this *SendingWorker) FindFirstUnacknowledged() {
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if !this.window.IsEmpty() {
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this.firstUnacknowledged = this.window.First().Number
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} else {
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this.firstUnacknowledged = this.nextNumber
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}
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}
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// Private: Visible for testing.
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func (this *SendingWorker) ProcessAck(number uint32) {
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// number < this.firstUnacknowledged || number >= this.nextNumber
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if number-this.firstUnacknowledged > 0x7FFFFFFF || number-this.nextNumber < 0x7FFFFFFF {
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return
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}
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this.window.Remove(number - this.firstUnacknowledged)
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this.FindFirstUnacknowledged()
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}
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func (this *SendingWorker) ProcessSegment(current uint32, seg *AckSegment) {
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defer seg.Release()
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this.Lock()
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defer this.Unlock()
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if this.remoteNextNumber < seg.ReceivingWindow {
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this.remoteNextNumber = seg.ReceivingWindow
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}
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this.ProcessReceivingNextWithoutLock(seg.ReceivingNext)
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if current-seg.Timestamp < 10000 {
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this.conn.roundTrip.Update(current-seg.Timestamp, current)
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}
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var maxack uint32
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for i := 0; i < int(seg.Count); i++ {
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number := seg.NumberList[i]
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this.ProcessAck(number)
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if maxack < number {
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maxack = number
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}
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}
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this.window.HandleFastAck(maxack)
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}
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func (this *SendingWorker) Push(b []byte) int {
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nBytes := 0
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this.Lock()
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defer this.Unlock()
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for len(b) > 0 && !this.window.IsFull() {
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var size int
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if len(b) > int(this.conn.mss) {
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size = int(this.conn.mss)
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} else {
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size = len(b)
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}
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seg := NewDataSegment()
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seg.Data = AllocateBuffer().Clear().Append(b[:size])
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seg.Number = this.nextNumber
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seg.timeout = 0
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seg.ackSkipped = 0
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seg.transmit = 0
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this.window.Push(seg)
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this.nextNumber++
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b = b[size:]
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nBytes += size
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}
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return nBytes
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}
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// Private: Visible for testing.
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func (this *SendingWorker) Write(seg Segment) {
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dataSeg := seg.(*DataSegment)
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dataSeg.Conv = this.conn.conv
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dataSeg.SendingNext = this.firstUnacknowledged
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dataSeg.Option = 0
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if this.conn.State() == StateReadyToClose {
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dataSeg.Option = SegmentOptionClose
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}
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this.conn.output.Write(dataSeg)
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}
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func (this *SendingWorker) OnPacketLoss(lossRate uint32) {
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if !this.conn.Config.Congestion || this.conn.roundTrip.Timeout() == 0 {
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return
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}
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if lossRate >= 15 {
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this.controlWindow = 3 * this.controlWindow / 4
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} else if lossRate <= 5 {
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this.controlWindow += this.controlWindow / 4
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}
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if this.controlWindow < 16 {
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this.controlWindow = 16
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}
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if this.controlWindow > 2*this.conn.Config.GetSendingInFlightSize() {
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this.controlWindow = 2 * this.conn.Config.GetSendingInFlightSize()
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}
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}
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func (this *SendingWorker) Flush(current uint32) {
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this.Lock()
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defer this.Unlock()
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cwnd := this.firstUnacknowledged + this.conn.Config.GetSendingInFlightSize()
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if cwnd > this.remoteNextNumber {
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cwnd = this.remoteNextNumber
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}
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if this.conn.Config.Congestion && cwnd > this.firstUnacknowledged+this.controlWindow {
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cwnd = this.firstUnacknowledged + this.controlWindow
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}
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if !this.window.IsEmpty() {
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this.window.Flush(current, this.conn.fastresend, this.conn.roundTrip.Timeout(), cwnd)
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}
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}
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func (this *SendingWorker) CloseWrite() {
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this.Lock()
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defer this.Unlock()
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this.window.Clear(0xFFFFFFFF)
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}
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func (this *SendingWorker) IsEmpty() bool {
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this.RLock()
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defer this.RUnlock()
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return this.window.IsEmpty()
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}
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