mirror of
https://github.com/v2fly/v2ray-core.git
synced 2024-12-23 02:26:49 -05:00
388 lines
7.8 KiB
Go
388 lines
7.8 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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inuse []bool
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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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inuse: make([]bool, 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 (v *SendingWindow) Release() {
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if v == nil {
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return
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}
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v.len = 0
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for _, seg := range v.data {
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seg.Release()
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}
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}
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func (v *SendingWindow) Len() int {
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return int(v.len)
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}
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func (v *SendingWindow) IsEmpty() bool {
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return v.len == 0
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}
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func (v *SendingWindow) Size() uint32 {
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return v.cap
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}
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func (v *SendingWindow) IsFull() bool {
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return v.len == v.cap
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}
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func (v *SendingWindow) Push(number uint32, data []byte) {
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pos := (v.start + v.len) % v.cap
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v.data[pos].SetData(data)
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v.data[pos].Number = number
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v.data[pos].timeout = 0
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v.data[pos].transmit = 0
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v.inuse[pos] = true
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if v.len > 0 {
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v.next[v.last] = pos
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v.prev[pos] = v.last
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}
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v.last = pos
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v.len++
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}
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func (v *SendingWindow) FirstNumber() uint32 {
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return v.data[v.start].Number
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}
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func (v *SendingWindow) Clear(una uint32) {
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for !v.IsEmpty() && v.data[v.start].Number < una {
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v.Remove(0)
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}
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}
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func (v *SendingWindow) Remove(idx uint32) bool {
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if v.IsEmpty() {
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return false
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}
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pos := (v.start + idx) % v.cap
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if !v.inuse[pos] {
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return false
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}
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v.inuse[pos] = false
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v.totalInFlightSize--
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if pos == v.start && pos == v.last {
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v.len = 0
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v.start = 0
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v.last = 0
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} else if pos == v.start {
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delta := v.next[pos] - v.start
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if v.next[pos] < v.start {
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delta = v.next[pos] + v.cap - v.start
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}
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v.start = v.next[pos]
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v.len -= delta
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} else if pos == v.last {
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v.last = v.prev[pos]
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} else {
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v.next[v.prev[pos]] = v.next[pos]
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v.prev[v.next[pos]] = v.prev[pos]
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}
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return true
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}
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func (v *SendingWindow) HandleFastAck(number uint32, rto uint32) {
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if v.IsEmpty() {
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return
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}
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v.Visit(func(seg *DataSegment) bool {
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if number == seg.Number || number-seg.Number > 0x7FFFFFFF {
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return false
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}
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if seg.transmit > 0 && seg.timeout > rto/3 {
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seg.timeout -= rto / 3
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}
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return true
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})
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}
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func (v *SendingWindow) Visit(visitor func(seg *DataSegment) bool) {
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if v.IsEmpty() {
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return
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}
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for i := v.start; ; i = v.next[i] {
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if !visitor(&v.data[i]) || i == v.last {
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break
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}
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}
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}
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func (v *SendingWindow) Flush(current uint32, rto uint32, maxInFlightSize uint32) {
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if v.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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v.Visit(func(segment *DataSegment) bool {
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if current-segment.timeout >= 0x7FFFFFFF {
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return true
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}
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if segment.transmit == 0 {
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// First time
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v.totalInFlightSize++
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} else {
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lost++
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}
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segment.timeout = current + rto
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segment.Timestamp = current
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segment.transmit++
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v.writer.Write(segment)
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inFlightSize++
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if inFlightSize >= maxInFlightSize {
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return false
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}
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return true
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})
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if v.onPacketLoss != nil && inFlightSize > 0 && v.totalInFlightSize != 0 {
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rate := lost * 100 / v.totalInFlightSize
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v.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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firstUnacknowledgedUpdated bool
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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 (v *SendingWorker) Release() {
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v.Lock()
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v.window.Release()
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v.Unlock()
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}
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func (v *SendingWorker) ProcessReceivingNext(nextNumber uint32) {
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v.Lock()
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defer v.Unlock()
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v.ProcessReceivingNextWithoutLock(nextNumber)
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}
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func (v *SendingWorker) ProcessReceivingNextWithoutLock(nextNumber uint32) {
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v.window.Clear(nextNumber)
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v.FindFirstUnacknowledged()
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}
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// Private: Visible for testing.
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func (v *SendingWorker) FindFirstUnacknowledged() {
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first := v.firstUnacknowledged
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if !v.window.IsEmpty() {
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v.firstUnacknowledged = v.window.FirstNumber()
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} else {
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v.firstUnacknowledged = v.nextNumber
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}
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if first != v.firstUnacknowledged {
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v.firstUnacknowledgedUpdated = true
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}
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}
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func (v *SendingWorker) processAck(number uint32) bool {
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// number < v.firstUnacknowledged || number >= v.nextNumber
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if number-v.firstUnacknowledged > 0x7FFFFFFF || number-v.nextNumber < 0x7FFFFFFF {
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return false
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}
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removed := v.window.Remove(number - v.firstUnacknowledged)
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if removed {
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v.FindFirstUnacknowledged()
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}
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return removed
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}
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func (v *SendingWorker) ProcessSegment(current uint32, seg *AckSegment, rto uint32) {
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defer seg.Release()
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v.Lock()
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defer v.Unlock()
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if v.remoteNextNumber < seg.ReceivingWindow {
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v.remoteNextNumber = seg.ReceivingWindow
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}
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v.ProcessReceivingNextWithoutLock(seg.ReceivingNext)
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if seg.IsEmpty() {
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return
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}
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var maxack uint32
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var maxackRemoved bool
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for _, number := range seg.NumberList {
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removed := v.processAck(number)
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if maxack < number {
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maxack = number
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maxackRemoved = removed
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}
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}
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if maxackRemoved {
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v.window.HandleFastAck(maxack, rto)
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if current-seg.Timestamp < 10000 {
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v.conn.roundTrip.Update(current-seg.Timestamp, current)
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}
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}
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}
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func (v *SendingWorker) Push(b []byte) int {
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nBytes := 0
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v.Lock()
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defer v.Unlock()
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for len(b) > 0 && !v.window.IsFull() {
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var size int
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if len(b) > int(v.conn.mss) {
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size = int(v.conn.mss)
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} else {
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size = len(b)
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}
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v.window.Push(v.nextNumber, b[:size])
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v.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 (v *SendingWorker) Write(seg Segment) error {
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dataSeg := seg.(*DataSegment)
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dataSeg.Conv = v.conn.conv
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dataSeg.SendingNext = v.firstUnacknowledged
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dataSeg.Option = 0
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if v.conn.State() == StateReadyToClose {
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dataSeg.Option = SegmentOptionClose
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}
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return v.conn.output.Write(dataSeg)
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}
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func (v *SendingWorker) OnPacketLoss(lossRate uint32) {
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if !v.conn.Config.Congestion || v.conn.roundTrip.Timeout() == 0 {
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return
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}
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if lossRate >= 15 {
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v.controlWindow = 3 * v.controlWindow / 4
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} else if lossRate <= 5 {
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v.controlWindow += v.controlWindow / 4
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}
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if v.controlWindow < 16 {
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v.controlWindow = 16
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}
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if v.controlWindow > 2*v.conn.Config.GetSendingInFlightSize() {
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v.controlWindow = 2 * v.conn.Config.GetSendingInFlightSize()
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}
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}
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func (v *SendingWorker) Flush(current uint32) {
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v.Lock()
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cwnd := v.firstUnacknowledged + v.conn.Config.GetSendingInFlightSize()
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if cwnd > v.remoteNextNumber {
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cwnd = v.remoteNextNumber
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}
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if v.conn.Config.Congestion && cwnd > v.firstUnacknowledged+v.controlWindow {
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cwnd = v.firstUnacknowledged + v.controlWindow
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}
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if !v.window.IsEmpty() {
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v.window.Flush(current, v.conn.roundTrip.Timeout(), cwnd)
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v.firstUnacknowledgedUpdated = false
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}
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updated := v.firstUnacknowledgedUpdated
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v.firstUnacknowledgedUpdated = false
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v.Unlock()
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if updated {
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v.conn.Ping(current, CommandPing)
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}
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}
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func (v *SendingWorker) CloseWrite() {
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v.Lock()
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defer v.Unlock()
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v.window.Clear(0xFFFFFFFF)
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}
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func (v *SendingWorker) IsEmpty() bool {
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v.RLock()
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defer v.RUnlock()
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return v.window.IsEmpty()
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}
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func (v *SendingWorker) UpdateNecessary() bool {
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return !v.IsEmpty()
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}
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func (w *SendingWorker) FirstUnacknowledged() uint32 {
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w.RLock()
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defer w.RUnlock()
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return w.firstUnacknowledged
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}
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