chore: rebuild slowdown code

component/proxydialer/slowdown.go

@@ -0,0 +1,34 @@
+package proxydialer
+
+import (
+	"context"
+	"net"
+	"net/netip"
+
+	"github.com/metacubex/mihomo/component/slowdown"
+	C "github.com/metacubex/mihomo/constant"
+)
+
+type SlowDownDialer struct {
+	C.Dialer
+	Slowdown *slowdown.SlowDown
+}
+
+func (d SlowDownDialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	return slowdown.Do(d.Slowdown, ctx, func() (net.Conn, error) {
+		return d.Dialer.DialContext(ctx, network, address)
+	})
+}
+
+func (d SlowDownDialer) ListenPacket(ctx context.Context, network, address string, rAddrPort netip.AddrPort) (net.PacketConn, error) {
+	return slowdown.Do(d.Slowdown, ctx, func() (net.PacketConn, error) {
+		return d.Dialer.ListenPacket(ctx, network, address, rAddrPort)
+	})
+}
+
+func NewSlowDownDialer(d C.Dialer, sd *slowdown.SlowDown) SlowDownDialer {
+	return SlowDownDialer{
+		Dialer:   d,
+		Slowdown: sd,
+	}
+}

component/proxydialer/slowdown_sing.go

@@ -0,0 +1,33 @@
+package proxydialer
+
+import (
+	"context"
+	"net"
+
+	"github.com/metacubex/mihomo/component/slowdown"
+	M "github.com/sagernet/sing/common/metadata"
+)
+
+type SlowDownSingDialer struct {
+	SingDialer
+	Slowdown *slowdown.SlowDown
+}
+
+func (d SlowDownSingDialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
+	return slowdown.Do(d.Slowdown, ctx, func() (net.Conn, error) {
+		return d.SingDialer.DialContext(ctx, network, destination)
+	})
+}
+
+func (d SlowDownSingDialer) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	return slowdown.Do(d.Slowdown, ctx, func() (net.PacketConn, error) {
+		return d.SingDialer.ListenPacket(ctx, destination)
+	})
+}
+
+func NewSlowDownSingDialer(d SingDialer, sd *slowdown.SlowDown) SlowDownSingDialer {
+	return SlowDownSingDialer{
+		SingDialer: d,
+		Slowdown:   sd,
+	}
+}

component/slowdown/backoff.go

@@ -0,0 +1,101 @@
+// modify from https://github.com/jpillora/backoff/blob/v1.0.0/backoff.go
+
+package slowdown
+
+import (
+	"math"
+	"math/rand"
+	"sync/atomic"
+	"time"
+)
+
+// Backoff is a time.Duration counter, starting at Min. After every call to
+// the Duration method the current timing is multiplied by Factor, but it
+// never exceeds Max.
+//
+// Backoff is not generally concurrent-safe, but the ForAttempt method can
+// be used concurrently.
+type Backoff struct {
+	attempt atomic.Uint64
+	// Factor is the multiplying factor for each increment step
+	Factor float64
+	// Jitter eases contention by randomizing backoff steps
+	Jitter bool
+	// Min and Max are the minimum and maximum values of the counter
+	Min, Max time.Duration
+}
+
+// Duration returns the duration for the current attempt before incrementing
+// the attempt counter. See ForAttempt.
+func (b *Backoff) Duration() time.Duration {
+	d := b.ForAttempt(float64(b.attempt.Add(1) - 1))
+	return d
+}
+
+const maxInt64 = float64(math.MaxInt64 - 512)
+
+// ForAttempt returns the duration for a specific attempt. This is useful if
+// you have a large number of independent Backoffs, but don't want use
+// unnecessary memory storing the Backoff parameters per Backoff. The first
+// attempt should be 0.
+//
+// ForAttempt is concurrent-safe.
+func (b *Backoff) ForAttempt(attempt float64) time.Duration {
+	// Zero-values are nonsensical, so we use
+	// them to apply defaults
+	min := b.Min
+	if min <= 0 {
+		min = 100 * time.Millisecond
+	}
+	max := b.Max
+	if max <= 0 {
+		max = 10 * time.Second
+	}
+	if min >= max {
+		// short-circuit
+		return max
+	}
+	factor := b.Factor
+	if factor <= 0 {
+		factor = 2
+	}
+	//calculate this duration
+	minf := float64(min)
+	durf := minf * math.Pow(factor, attempt)
+	if b.Jitter {
+		durf = rand.Float64()*(durf-minf) + minf
+	}
+	//ensure float64 wont overflow int64
+	if durf > maxInt64 {
+		return max
+	}
+	dur := time.Duration(durf)
+	//keep within bounds
+	if dur < min {
+		return min
+	}
+	if dur > max {
+		return max
+	}
+	return dur
+}
+
+// Reset restarts the current attempt counter at zero.
+func (b *Backoff) Reset() {
+	b.attempt.Store(0)
+}
+
+// Attempt returns the current attempt counter value.
+func (b *Backoff) Attempt() float64 {
+	return float64(b.attempt.Load())
+}
+
+// Copy returns a backoff with equals constraints as the original
+func (b *Backoff) Copy() *Backoff {
+	return &Backoff{
+		Factor: b.Factor,
+		Jitter: b.Jitter,
+		Min:    b.Min,
+		Max:    b.Max,
+	}
+}

component/slowdown/slowdown.go

@@ -0,0 +1,49 @@
+package slowdown
+
+import (
+	"context"
+	"sync/atomic"
+	"time"
+)
+
+type SlowDown struct {
+	errTimes atomic.Int64
+	backoff  Backoff
+}
+
+func (s *SlowDown) Wait(ctx context.Context) (err error) {
+	select {
+	case <-time.After(s.backoff.Duration()):
+	case <-ctx.Done():
+		err = ctx.Err()
+	}
+	return
+}
+
+func New() *SlowDown {
+	return &SlowDown{
+		backoff: Backoff{
+			Min:    10 * time.Millisecond,
+			Max:    1 * time.Second,
+			Factor: 2,
+			Jitter: true,
+		},
+	}
+}
+
+func Do[T any](s *SlowDown, ctx context.Context, fn func() (T, error)) (t T, err error) {
+	if s.errTimes.Load() > 10 {
+		err = s.Wait(ctx)
+		if err != nil {
+			return
+		}
+	}
+	t, err = fn()
+	if err != nil {
+		s.errTimes.Add(1)
+		return
+	}
+	s.errTimes.Store(0)
+	s.backoff.Reset()
+	return
+}