926 lines
23 KiB
Go
926 lines
23 KiB
Go
package main
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import (
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"crypto/rand"
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"encoding/binary"
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"fmt"
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"io"
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"net"
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"sort"
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"sync"
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"sync/atomic"
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"time"
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"dragontcp/internal/cover"
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"dragontcp/internal/protocol"
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"dragontcp/internal/wire"
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)
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type chunkClientOptions struct {
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startSize int
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minSize int
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maxSize int
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adaptive bool
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adaptSuccesses int
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adaptLog bool
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pollers int
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reconnectEvery int
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pollDelay time.Duration
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txnTimeout time.Duration
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tcpBuffer int
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minPipeline int
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maxPipeline int
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headerMask byte
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coverProfile cover.Profile
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skipPathProbe bool
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}
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type adaptiveSizer struct {
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mu sync.Mutex
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name string
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current int
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min int
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max int
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adaptive bool
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adaptSuccesses int
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successes int
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good int
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bad int
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logChanges bool
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}
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func newAdaptiveSizer(name string, start int, opts chunkClientOptions) *adaptiveSizer {
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if start < opts.minSize {
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start = opts.minSize
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}
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if start > opts.maxSize {
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start = opts.maxSize
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}
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return &adaptiveSizer{
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name: name,
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current: start,
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min: opts.minSize,
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max: opts.maxSize,
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adaptive: opts.adaptive,
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adaptSuccesses: func() int {
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if opts.adaptSuccesses > 0 {
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return opts.adaptSuccesses
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}
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return 64
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}(),
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logChanges: opts.adaptLog,
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}
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}
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func (s *adaptiveSizer) Current() int {
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s.mu.Lock()
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defer s.mu.Unlock()
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return s.current
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}
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func (s *adaptiveSizer) Success(attempted int) {
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s.mu.Lock()
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defer s.mu.Unlock()
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if !s.adaptive || attempted != s.current || s.current >= s.max {
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return
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}
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if attempted > s.good {
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s.good = attempted
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}
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s.successes++
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growAfter := s.adaptSuccesses
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if s.bad > 0 && s.bad-s.good <= 64 {
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growAfter *= 8
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}
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if s.successes < growAfter {
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return
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}
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s.successes = 0
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old := s.current
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next := 0
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if s.bad > old+1 {
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next = old + (s.bad-old)/2
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} else {
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if s.bad > 0 {
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s.bad = 0
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}
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step := old / 4
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if step < 32 {
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step = 32
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}
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next = old + step
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}
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if next > s.max {
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next = s.max
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}
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if next <= old {
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return
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}
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s.current = next
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if s.logChanges {
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fmt.Printf("adaptive %s chunk: %d -> %d after stable success\n", s.name, old, next)
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}
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}
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func (s *adaptiveSizer) Failure(attempted int) (int, int) {
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return s.FailureReason(attempted, nil)
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}
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func (s *adaptiveSizer) FailureReason(attempted int, cause error) (int, int) {
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s.mu.Lock()
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defer s.mu.Unlock()
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old := s.current
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if !s.adaptive || attempted != s.current {
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return old, old
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}
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s.successes = 0
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if s.bad == 0 || attempted < s.bad {
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s.bad = attempted
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}
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next := attempted / 2
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if s.good > 0 && s.good < attempted {
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next = s.good
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} else {
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s.good = 0
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}
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if next < s.min {
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next = s.min
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}
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if next >= attempted && attempted > s.min {
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next = attempted - 1
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}
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if next < s.min {
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next = s.min
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}
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s.current = next
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if s.logChanges && old != next {
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if cause != nil {
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fmt.Printf("adaptive %s chunk: %d -> %d after transport failure: %v\n", s.name, old, next, cause)
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} else {
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fmt.Printf("adaptive %s chunk: %d -> %d after transport failure\n", s.name, old, next)
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}
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}
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return old, next
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}
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type physicalConn struct {
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conn net.Conn
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requests int
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}
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type requestLane struct {
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mu sync.Mutex
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serverAddr string
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tcpBuffer int
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reconnectEvery int
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timeout time.Duration
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headerMask byte
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coverProfile cover.Profile
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autoReconnect bool
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pc *physicalConn
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closed bool
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}
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func newRequestLane(serverAddr string, tcpBuffer, reconnectEvery int, timeout time.Duration, headerMask byte, coverProfile cover.Profile) *requestLane {
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autoReconnect := reconnectEvery == 1
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if autoReconnect {
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// Auto starts persistent. If a request fails only after this lane has
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// already completed traffic on the connection, it learns that reuse is
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// unsafe and switches itself to one request per connection.
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reconnectEvery = 0
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}
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return &requestLane{
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serverAddr: serverAddr,
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tcpBuffer: tcpBuffer,
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reconnectEvery: reconnectEvery,
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timeout: timeout,
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headerMask: headerMask,
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coverProfile: coverProfile,
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autoReconnect: autoReconnect,
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}
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}
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func (l *requestLane) transportFailureLocked(reused bool) {
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if l.autoReconnect && reused {
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l.reconnectEvery = 1
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}
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l.discardLocked()
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}
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func (l *requestLane) discardLocked() {
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if l.pc != nil {
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_ = l.pc.conn.Close()
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l.pc = nil
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}
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}
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func (l *requestLane) closeAfterLocked() {
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if l.pc != nil && l.reconnectEvery > 0 && l.pc.requests >= l.reconnectEvery {
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l.discardLocked()
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}
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}
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func (l *requestLane) ensureLocked() error {
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if l.closed {
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return net.ErrClosed
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}
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if l.pc != nil {
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if l.reconnectEvery <= 0 || l.pc.requests < l.reconnectEvery {
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return nil
|
|
}
|
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l.discardLocked()
|
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}
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d := net.Dialer{Timeout: 10 * time.Second, KeepAlive: 30 * time.Second}
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conn, err := d.Dial("tcp", l.serverAddr)
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if err != nil {
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return err
|
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}
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if err := cover.WritePreface(conn, l.coverProfile); err != nil {
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_ = conn.Close()
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return err
|
|
}
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protocol.TuneTCP(conn)
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protocol.TuneTCPBuffer(conn, l.tcpBuffer)
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l.pc = &physicalConn{conn: conn}
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return nil
|
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}
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func (l *requestLane) Close() {
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l.mu.Lock()
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l.closed = true
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l.discardLocked()
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l.mu.Unlock()
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}
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func (l *requestLane) single(mode byte, sid wire.SessionID, seq uint64, payload []byte) (byte, []byte, error) {
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l.mu.Lock()
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defer l.mu.Unlock()
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timeout := l.timeout
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if timeout <= 0 {
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timeout = 5 * time.Second
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}
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var lastErr error
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for attempt := 0; attempt < 2; attempt++ {
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if err := l.ensureLocked(); err != nil {
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// A dial timeout is a dead path for this logical tunnel. Do not
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// spend another timeout replaying the same request.
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if isTransportTimeout(err) {
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return 0, nil, err
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}
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lastErr = err
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continue
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}
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reused := l.pc.requests > 0
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_ = l.pc.conn.SetDeadline(time.Now().Add(timeout))
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if err := wire.WriteRequestProfileEncoding(l.pc.conn, mode, sid, seq, payload, l.headerMask, l.coverProfile.Clear); err != nil {
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l.transportFailureLocked(reused)
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if isTransportTimeout(err) {
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return 0, nil, err
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}
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lastErr = err
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continue
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}
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status, body, err := wire.ReadResponseProfile(l.pc.conn, l.headerMask)
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if err != nil {
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l.transportFailureLocked(reused)
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if isTransportTimeout(err) {
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return 0, nil, err
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}
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lastErr = err
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continue
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}
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l.pc.requests++
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_ = l.pc.conn.SetDeadline(time.Time{})
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l.closeAfterLocked()
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if status != wire.StatusError && len(body) > 0 && !l.coverProfile.Clear {
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body = wire.DecodeMaskedResponse(status, body, sid, mode, seq)
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}
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return status, body, nil
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}
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return 0, nil, fmt.Errorf("request failed after reconnect: %w", lastErr)
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}
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// download sends one compact request and consumes up to count response records.
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// startOffset is also the response keystream sequence. Each DATA response advances
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// it by exactly the returned byte count.
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func (l *requestLane) download(sid wire.SessionID, startOffset, ackOffset uint64, maxChunk, count int) ([][]byte, byte, error) {
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l.mu.Lock()
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defer l.mu.Unlock()
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timeout := l.timeout
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if timeout <= 0 {
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timeout = 5 * time.Second
|
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}
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payload := make([]byte, 14)
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binary.BigEndian.PutUint64(payload[0:8], ackOffset)
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binary.BigEndian.PutUint32(payload[8:12], uint32(maxChunk))
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binary.BigEndian.PutUint16(payload[12:14], uint16(count))
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var lastErr error
|
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for attempt := 0; attempt < 2; attempt++ {
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if err := l.ensureLocked(); err != nil {
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if isTransportTimeout(err) {
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return nil, 0, err
|
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}
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lastErr = err
|
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continue
|
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}
|
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reused := l.pc.requests > 0
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_ = l.pc.conn.SetDeadline(time.Now().Add(timeout))
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if err := wire.WriteRequestProfileEncoding(l.pc.conn, wire.ModeDownload, sid, startOffset, payload, l.headerMask, l.coverProfile.Clear); err != nil {
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l.transportFailureLocked(reused)
|
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if isTransportTimeout(err) {
|
|
return nil, 0, err
|
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}
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lastErr = err
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continue
|
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}
|
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|
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out := make([][]byte, 0, count)
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offset := startOffset
|
|
lastStatus := wire.StatusOK
|
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for i := 0; i < count; i++ {
|
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status, body, err := wire.ReadResponseProfile(l.pc.conn, l.headerMask)
|
|
if err != nil {
|
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l.transportFailureLocked(reused)
|
|
if isTransportTimeout(err) {
|
|
return nil, 0, err
|
|
}
|
|
lastErr = err
|
|
goto retry
|
|
}
|
|
lastStatus = status
|
|
switch status {
|
|
case wire.StatusData:
|
|
if !l.coverProfile.Clear {
|
|
body = wire.DecodeMaskedResponse(status, body, sid, wire.ModeDownload, offset)
|
|
}
|
|
if len(body) == 0 {
|
|
l.discardLocked()
|
|
return out, status, fmt.Errorf("empty DATA response")
|
|
}
|
|
out = append(out, body)
|
|
offset += uint64(len(body))
|
|
case wire.StatusWait, wire.StatusEOF:
|
|
i = count // stop after this response
|
|
case wire.StatusError:
|
|
l.discardLocked()
|
|
return out, status, fmt.Errorf("%s", string(body))
|
|
default:
|
|
l.discardLocked()
|
|
return out, status, fmt.Errorf("unknown response status %d", status)
|
|
}
|
|
if status == wire.StatusWait || status == wire.StatusEOF {
|
|
break
|
|
}
|
|
}
|
|
|
|
l.pc.requests++
|
|
_ = l.pc.conn.SetDeadline(time.Time{})
|
|
l.closeAfterLocked()
|
|
return out, lastStatus, nil
|
|
retry:
|
|
}
|
|
return nil, 0, fmt.Errorf("download request failed after reconnect: %w", lastErr)
|
|
}
|
|
|
|
type pathProfile struct {
|
|
upload int
|
|
download int
|
|
persistent bool
|
|
at time.Time
|
|
}
|
|
|
|
var profileState struct {
|
|
sync.Mutex
|
|
key string
|
|
p pathProfile
|
|
}
|
|
|
|
var probeSeq atomic.Uint64
|
|
|
|
func randomSessionID() (wire.SessionID, error) {
|
|
var sid wire.SessionID
|
|
_, err := rand.Read(sid[:])
|
|
return sid, err
|
|
}
|
|
|
|
func probePattern(n int) []byte {
|
|
out := make([]byte, n)
|
|
for i := range out {
|
|
out[i] = byte((i*31 + 17) & 0xff)
|
|
}
|
|
return out
|
|
}
|
|
|
|
func makeProbePayload(kind byte, value, total int, token string) []byte {
|
|
base := 11 + len(token)
|
|
if total < base {
|
|
total = base
|
|
}
|
|
out := make([]byte, total)
|
|
copy(out[:4], wire.ProbeMagic[:])
|
|
out[4] = kind
|
|
binary.BigEndian.PutUint16(out[5:7], uint16(len(token)))
|
|
binary.BigEndian.PutUint32(out[7:11], uint32(value))
|
|
copy(out[11:11+len(token)], token)
|
|
for i := base; i < len(out); i++ {
|
|
out[i] = byte((i*31 + 17) & 0xff)
|
|
}
|
|
return out
|
|
}
|
|
|
|
func probeOne(serverAddr, token string, opts chunkClientOptions, kind byte, candidate int) bool {
|
|
sid, err := randomSessionID()
|
|
if err != nil {
|
|
return false
|
|
}
|
|
timeout := opts.txnTimeout
|
|
if timeout <= 0 || timeout > 2500*time.Millisecond {
|
|
timeout = 2500 * time.Millisecond
|
|
}
|
|
lane := newRequestLane(serverAddr, opts.tcpBuffer, 1, timeout, opts.headerMask, opts.coverProfile)
|
|
defer lane.Close()
|
|
seq := probeSeq.Add(1)
|
|
|
|
total := 0
|
|
value := candidate
|
|
if kind == wire.ProbeUpload {
|
|
total = candidate
|
|
}
|
|
payload := makeProbePayload(kind, value, total, token)
|
|
status, body, err := lane.single(wire.ModeProbe, sid, seq, payload)
|
|
if err != nil {
|
|
return false
|
|
}
|
|
if kind == wire.ProbeUpload {
|
|
return status == wire.StatusOK
|
|
}
|
|
if kind == wire.ProbeDownload {
|
|
if status != wire.StatusData || len(body) != candidate {
|
|
return false
|
|
}
|
|
want := probePattern(candidate)
|
|
for i := range body {
|
|
if body[i] != want[i] {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
return status == wire.StatusOK
|
|
}
|
|
|
|
func probePersistent(serverAddr, token string, opts chunkClientOptions) bool {
|
|
sid, err := randomSessionID()
|
|
if err != nil {
|
|
return false
|
|
}
|
|
timeout := opts.txnTimeout
|
|
if timeout <= 0 || timeout > 2500*time.Millisecond {
|
|
timeout = 2500 * time.Millisecond
|
|
}
|
|
lane := newRequestLane(serverAddr, opts.tcpBuffer, 0, timeout, opts.headerMask, opts.coverProfile)
|
|
defer lane.Close()
|
|
for i := 0; i < 8; i++ {
|
|
seq := probeSeq.Add(1)
|
|
payload := makeProbePayload(wire.ProbeKeepalive, i, 32+len(token), token)
|
|
status, _, err := lane.single(wire.ModeProbe, sid, seq, payload)
|
|
if err != nil || status != wire.StatusOK {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func probeCandidates(minSize, maxSize int) []int {
|
|
base := []int{32, 64, 128, 256, 512, 1024, 1200, 1280, 1320, 1350, 1360, 1380, 1400, 1450, 1600, 2048, 3205, 4096, 8192, 16384, 32768, 65536, 98304, 131072, 262144, 524288, 786432, 1048576}
|
|
seen := map[int]bool{}
|
|
out := make([]int, 0, len(base)+2)
|
|
for _, n := range base {
|
|
if n >= minSize && n <= maxSize && !seen[n] {
|
|
out = append(out, n)
|
|
seen[n] = true
|
|
}
|
|
}
|
|
if !seen[minSize] {
|
|
out = append(out, minSize)
|
|
}
|
|
if !seen[maxSize] {
|
|
out = append(out, maxSize)
|
|
}
|
|
sort.Ints(out)
|
|
return out
|
|
}
|
|
|
|
func probeMaximum(serverAddr, token string, opts chunkClientOptions, kind byte) int {
|
|
candidates := probeCandidates(opts.minSize, opts.maxSize)
|
|
lo, hi := 0, len(candidates)-1
|
|
best := opts.minSize
|
|
for lo <= hi {
|
|
mid := lo + (hi-lo)/2
|
|
candidate := candidates[mid]
|
|
if probeOne(serverAddr, token, opts, kind, candidate) {
|
|
best = candidate
|
|
lo = mid + 1
|
|
} else {
|
|
hi = mid - 1
|
|
}
|
|
}
|
|
if best < opts.minSize {
|
|
best = opts.minSize
|
|
}
|
|
return best
|
|
}
|
|
|
|
func getPathProfile(serverAddr, token string, opts chunkClientOptions) pathProfile {
|
|
key := fmt.Sprintf("%s|%s|%d|%d|%02x|%t|%04x|%d|%t", serverAddr, token, opts.minSize, opts.maxSize, opts.headerMask, opts.coverProfile.Enabled, opts.coverProfile.ID, opts.coverProfile.Padding, opts.coverProfile.Clear)
|
|
profileState.Lock()
|
|
if profileState.key == key && time.Since(profileState.p.at) < 30*time.Minute {
|
|
p := profileState.p
|
|
profileState.Unlock()
|
|
return p
|
|
}
|
|
profileState.Unlock()
|
|
|
|
fallbackUp := minInt(opts.maxSize, maxInt(opts.minSize, 32768))
|
|
fallbackDown := minInt(opts.maxSize, maxInt(opts.minSize, 1350))
|
|
|
|
upCh := make(chan int, 1)
|
|
downCh := make(chan int, 1)
|
|
go func() { upCh <- probeMaximum(serverAddr, token, opts, wire.ProbeUpload) }()
|
|
go func() { downCh <- probeMaximum(serverAddr, token, opts, wire.ProbeDownload) }()
|
|
|
|
p := pathProfile{upload: fallbackUp, download: fallbackDown, persistent: false, at: time.Now()}
|
|
select {
|
|
case p.upload = <-upCh:
|
|
case <-time.After(20 * time.Second):
|
|
}
|
|
select {
|
|
case p.download = <-downCh:
|
|
case <-time.After(20 * time.Second):
|
|
}
|
|
p.persistent = probePersistent(serverAddr, token, opts)
|
|
|
|
fmt.Printf("path probe: upload=%d download=%d persistent=%t\n", p.upload, p.download, p.persistent)
|
|
|
|
profileState.Lock()
|
|
profileState.key = key
|
|
profileState.p = p
|
|
profileState.Unlock()
|
|
return p
|
|
}
|
|
|
|
func encodeOpen(token, host string, port int) ([]byte, error) {
|
|
if len(token) > 65535 || len(host) > 65535 {
|
|
return nil, fmt.Errorf("token or hostname too long")
|
|
}
|
|
out := make([]byte, 6+len(token)+len(host))
|
|
binary.BigEndian.PutUint16(out[0:2], uint16(len(token)))
|
|
binary.BigEndian.PutUint16(out[2:4], uint16(len(host)))
|
|
binary.BigEndian.PutUint16(out[4:6], uint16(port))
|
|
copy(out[6:6+len(token)], token)
|
|
copy(out[6+len(token):], host)
|
|
return out, nil
|
|
}
|
|
|
|
type chunkConn struct {
|
|
sid wire.SessionID
|
|
opts chunkClientOptions
|
|
uploadLane *requestLane
|
|
downloadLane *requestLane
|
|
serverMax int
|
|
upSizer *adaptiveSizer
|
|
downSizer *adaptiveSizer
|
|
|
|
writeMu sync.Mutex
|
|
upOffset uint64
|
|
|
|
readMu sync.Mutex
|
|
readBuf []byte
|
|
downloadOffset uint64
|
|
consumedOffset uint64
|
|
eof bool
|
|
pipeline int
|
|
minPipeline int
|
|
maxPipeline int
|
|
|
|
closeOnce sync.Once
|
|
dead atomic.Bool
|
|
}
|
|
|
|
// appendChunkParts keeps the single-response fast path zero-copy. For a batch,
|
|
// it reserves the complete size once rather than repeatedly growing and copying
|
|
// the aggregate read buffer.
|
|
func appendChunkParts(dst []byte, parts [][]byte) []byte {
|
|
if len(parts) == 0 {
|
|
return dst
|
|
}
|
|
if len(dst) == 0 && len(parts) == 1 {
|
|
return parts[0]
|
|
}
|
|
total := len(dst)
|
|
for _, part := range parts {
|
|
total += len(part)
|
|
}
|
|
if cap(dst) < total {
|
|
grown := make([]byte, len(dst), total)
|
|
copy(grown, dst)
|
|
dst = grown
|
|
}
|
|
for _, part := range parts {
|
|
dst = append(dst, part...)
|
|
}
|
|
return dst
|
|
}
|
|
|
|
func openChunkTunnel(serverAddr, token, targetHost string, targetPort int, opts chunkClientOptions) (net.Conn, error) {
|
|
if opts.minSize < 32 {
|
|
opts.minSize = 32
|
|
}
|
|
if opts.maxSize < opts.minSize {
|
|
opts.maxSize = opts.minSize
|
|
}
|
|
if opts.maxSize > 1024*1024 {
|
|
opts.maxSize = 1024 * 1024
|
|
}
|
|
if opts.txnTimeout <= 0 {
|
|
opts.txnTimeout = 5 * time.Second
|
|
}
|
|
if opts.adaptSuccesses < 1 {
|
|
opts.adaptSuccesses = 64
|
|
}
|
|
if opts.reconnectEvery < 0 {
|
|
opts.reconnectEvery = 0
|
|
}
|
|
if opts.maxPipeline < 1 {
|
|
opts.maxPipeline = 1
|
|
}
|
|
if opts.maxPipeline > 256 {
|
|
opts.maxPipeline = 256
|
|
}
|
|
if opts.minPipeline < 1 {
|
|
opts.minPipeline = 1
|
|
}
|
|
if opts.minPipeline > opts.maxPipeline {
|
|
opts.minPipeline = opts.maxPipeline
|
|
}
|
|
|
|
profile := pathProfile{
|
|
upload: opts.minSize,
|
|
download: opts.minSize,
|
|
persistent: false,
|
|
at: time.Now(),
|
|
}
|
|
if !opts.skipPathProbe {
|
|
profile = getPathProfile(serverAddr, token, opts)
|
|
}
|
|
reconnect := opts.reconnectEvery
|
|
// Compatibility-friendly reconnect modes:
|
|
// 0 = persistent (CLI explicit)
|
|
// 1 = auto: start persistent, then learn one request/connection only if
|
|
// reuse fails during real traffic
|
|
// N>=2 = force connection rotation after N logical requests
|
|
|
|
sid, err := randomSessionID()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// OPEN rides the upload lane instead of a throwaway connection. A dedicated
|
|
// control connection cost one extra dial per proxied flow, which shows up on
|
|
// the server as connection churn on top of the steady-state count.
|
|
uploadLane := newRequestLane(serverAddr, opts.tcpBuffer, reconnect, opts.txnTimeout, opts.headerMask, opts.coverProfile)
|
|
payload, err := encodeOpen(token, targetHost, targetPort)
|
|
if err != nil {
|
|
uploadLane.Close()
|
|
return nil, err
|
|
}
|
|
status, body, err := uploadLane.single(wire.ModeOpen, sid, 0, payload)
|
|
if err != nil {
|
|
uploadLane.Close()
|
|
return nil, err
|
|
}
|
|
if status == wire.StatusError {
|
|
uploadLane.Close()
|
|
return nil, fmt.Errorf("%s", string(body))
|
|
}
|
|
if status != wire.StatusOK || len(body) != 4 {
|
|
uploadLane.Close()
|
|
return nil, fmt.Errorf("bad OPEN response")
|
|
}
|
|
serverMax := int(binary.BigEndian.Uint32(body))
|
|
if serverMax < opts.minSize {
|
|
uploadLane.Close()
|
|
return nil, fmt.Errorf("server maximum chunk %d is below client minimum %d", serverMax, opts.minSize)
|
|
}
|
|
if opts.maxSize > serverMax {
|
|
opts.maxSize = serverMax
|
|
}
|
|
upStart := minInt(profile.upload, opts.maxSize)
|
|
downStart := minInt(profile.download, opts.maxSize)
|
|
if upStart < opts.minSize {
|
|
upStart = opts.minSize
|
|
}
|
|
if downStart < opts.minSize {
|
|
downStart = opts.minSize
|
|
}
|
|
|
|
c := &chunkConn{
|
|
sid: sid,
|
|
opts: opts,
|
|
serverMax: serverMax,
|
|
uploadLane: uploadLane,
|
|
downloadLane: newRequestLane(serverAddr, opts.tcpBuffer, reconnect, opts.txnTimeout, opts.headerMask, opts.coverProfile),
|
|
// Start at the configured ceiling. On transport failure the batch is
|
|
// halved but never below minPipeline; successful data grows it back by
|
|
// one. When min == max the depth is pinned and never adapts, which is
|
|
// what paths that only work at one specific batch size need.
|
|
pipeline: opts.maxPipeline,
|
|
minPipeline: opts.minPipeline,
|
|
maxPipeline: opts.maxPipeline,
|
|
}
|
|
c.upSizer = newAdaptiveSizer("upload", upStart, opts)
|
|
c.downSizer = newAdaptiveSizer("download", downStart, opts)
|
|
return c, nil
|
|
}
|
|
|
|
func (c *chunkConn) fillReadBuffer() error {
|
|
if c.eof {
|
|
return io.EOF
|
|
}
|
|
minFailures := 0
|
|
for len(c.readBuf) == 0 && !c.eof {
|
|
chunk := c.downSizer.Current()
|
|
count := c.pipeline
|
|
if count < c.minPipeline {
|
|
count = c.minPipeline
|
|
}
|
|
if count > c.maxPipeline {
|
|
count = c.maxPipeline
|
|
}
|
|
// Bound each batch to roughly 1 MiB of useful data, but never below the
|
|
// configured floor: a pinned depth is a path requirement, not a hint.
|
|
if maxCount := (1024 * 1024) / maxInt(chunk, 1); maxCount < count {
|
|
count = maxInt(maxCount, c.minPipeline)
|
|
}
|
|
|
|
data, status, err := c.downloadLane.download(c.sid, c.downloadOffset, c.consumedOffset, chunk, count)
|
|
c.readBuf = appendChunkParts(c.readBuf, data)
|
|
for _, part := range data {
|
|
c.downloadOffset += uint64(len(part))
|
|
}
|
|
if len(data) > 0 {
|
|
c.downSizer.Success(chunk)
|
|
if c.pipeline < c.maxPipeline {
|
|
c.pipeline++
|
|
}
|
|
minFailures = 0
|
|
}
|
|
if err != nil {
|
|
if isTransportTimeout(err) {
|
|
c.dead.Store(true)
|
|
return err
|
|
}
|
|
if c.pipeline > c.minPipeline {
|
|
old := c.pipeline
|
|
c.pipeline /= 2
|
|
if c.pipeline < c.minPipeline {
|
|
c.pipeline = c.minPipeline
|
|
}
|
|
if c.opts.adaptLog && old != c.pipeline {
|
|
fmt.Printf("adaptive download pipeline: %d -> %d after transport failure: %v\n", old, c.pipeline, err)
|
|
}
|
|
} else {
|
|
old, next := c.downSizer.FailureReason(chunk, err)
|
|
if old == next && next == c.opts.minSize {
|
|
minFailures++
|
|
if minFailures >= 8 {
|
|
return fmt.Errorf("download failed at minimum chunk %d: %w", next, err)
|
|
}
|
|
}
|
|
}
|
|
time.Sleep(30 * time.Millisecond)
|
|
if len(c.readBuf) > 0 {
|
|
return nil
|
|
}
|
|
continue
|
|
}
|
|
switch status {
|
|
case wire.StatusEOF:
|
|
c.eof = true
|
|
case wire.StatusWait:
|
|
if c.opts.pollDelay > 0 {
|
|
time.Sleep(c.opts.pollDelay)
|
|
} else {
|
|
time.Sleep(5 * time.Millisecond)
|
|
}
|
|
}
|
|
if len(c.readBuf) > 0 {
|
|
return nil
|
|
}
|
|
}
|
|
if c.eof && len(c.readBuf) == 0 {
|
|
return io.EOF
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *chunkConn) Read(p []byte) (int, error) {
|
|
c.readMu.Lock()
|
|
defer c.readMu.Unlock()
|
|
if len(p) == 0 {
|
|
return 0, nil
|
|
}
|
|
if len(c.readBuf) == 0 {
|
|
if err := c.fillReadBuffer(); err != nil {
|
|
return 0, err
|
|
}
|
|
}
|
|
n := copy(p, c.readBuf)
|
|
c.readBuf = c.readBuf[n:]
|
|
c.consumedOffset += uint64(n)
|
|
return n, nil
|
|
}
|
|
|
|
func (c *chunkConn) Write(p []byte) (int, error) {
|
|
c.writeMu.Lock()
|
|
defer c.writeMu.Unlock()
|
|
if len(p) == 0 {
|
|
return 0, nil
|
|
}
|
|
total := 0
|
|
minFailures := 0
|
|
for len(p) > 0 {
|
|
size := c.upSizer.Current()
|
|
n := minInt(size, len(p))
|
|
status, body, err := c.uploadLane.single(wire.ModeUpload, c.sid, c.upOffset, p[:n])
|
|
if err != nil {
|
|
if isTransportTimeout(err) {
|
|
c.dead.Store(true)
|
|
return total, err
|
|
}
|
|
old, next := c.upSizer.FailureReason(size, err)
|
|
if old == next && next == c.opts.minSize {
|
|
minFailures++
|
|
if minFailures >= 8 {
|
|
return total, fmt.Errorf("upload failed at minimum chunk %d: %w", next, err)
|
|
}
|
|
} else {
|
|
minFailures = 0
|
|
}
|
|
time.Sleep(30 * time.Millisecond)
|
|
continue
|
|
}
|
|
if status == wire.StatusError {
|
|
return total, fmt.Errorf("%s", string(body))
|
|
}
|
|
if status != wire.StatusOK {
|
|
return total, fmt.Errorf("unexpected upload status %d", status)
|
|
}
|
|
c.upOffset += uint64(n)
|
|
total += n
|
|
p = p[n:]
|
|
c.upSizer.Success(size)
|
|
minFailures = 0
|
|
}
|
|
return total, nil
|
|
}
|
|
|
|
func (c *chunkConn) Close() error {
|
|
c.closeOnce.Do(func() {
|
|
// A timed-out tunnel is already dead. Do not redial merely to send a
|
|
// graceful CLOSE for a session that the caller is abandoning.
|
|
if !c.dead.Load() {
|
|
// Reuse the upload lane rather than dialling a connection just to say
|
|
// goodbye; that was a second wasted dial per flow.
|
|
_, _, _ = c.uploadLane.single(wire.ModeClose, c.sid, 0, nil)
|
|
}
|
|
c.uploadLane.Close()
|
|
c.downloadLane.Close()
|
|
})
|
|
return nil
|
|
}
|
|
|
|
func (c *chunkConn) LocalAddr() net.Addr { return dummyAddr("dragontcp-binary-local") }
|
|
func (c *chunkConn) RemoteAddr() net.Addr { return dummyAddr("dragontcp-binary-remote") }
|
|
func (c *chunkConn) SetDeadline(time.Time) error { return nil }
|
|
func (c *chunkConn) SetReadDeadline(time.Time) error { return nil }
|
|
func (c *chunkConn) SetWriteDeadline(time.Time) error { return nil }
|
|
|
|
type dummyAddr string
|
|
|
|
func (d dummyAddr) Network() string { return "dragontcp-binary" }
|
|
func (d dummyAddr) String() string { return string(d) }
|
|
|
|
func minInt(a, b int) int {
|
|
if a < b {
|
|
return a
|
|
}
|
|
return b
|
|
}
|
|
func maxInt(a, b int) int {
|
|
if a > b {
|
|
return a
|
|
}
|
|
return b
|
|
}
|