Add proxy Scheduler

proxy/proxy.go

@@ -184,7 +184,7 @@ func NewTrafficState(userUUID []byte, flow string) *TrafficState {
 	return &state
 }
 
-// VisionReader is used to read xtls vision protocol
+// VisionReader is used to read seed protocol
 // Note Vision probably only make sense as the inner most layer of reader, since it need assess traffic state from origin proxy traffic
 type VisionReader struct {
 	buf.Reader
@@ -304,7 +304,7 @@ func (w *VisionReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	return buffer, err
 }
 
-// VisionWriter is used to write xtls vision protocol
+// VisionWriter is used to write seed protocol
 // Note Vision probably only make sense as the inner most layer of writer, since it need assess traffic state from origin proxy traffic
 type VisionWriter struct {
 	buf.Writer
@@ -318,6 +318,7 @@ type VisionWriter struct {
 	// internal
 	writeOnceUserUUID  []byte
 	directWriteCounter stats.Counter
+	scheduler          *Scheduler
 }
 
 func NewVisionWriter(writer buf.Writer, addon *Addons, trafficState *TrafficState, isUplink bool, ctx context.Context, conn net.Conn, ob *session.Outbound) *VisionWriter {
@@ -332,6 +333,7 @@ func NewVisionWriter(writer buf.Writer, addon *Addons, trafficState *TrafficStat
 		isUplink:          isUplink,
 		conn:              conn,
 		ob:                ob,
+		scheduler:         NewScheduler(writer, addon, trafficState, ctx),
 	}
 }
 
@@ -413,7 +415,14 @@ func (w *VisionWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	if w.trafficState.StartTime.IsZero() {
 		w.trafficState.StartTime = time.Now()
 	}
-	return w.Writer.WriteMultiBuffer(mb)
+	w.scheduler.Buffer <- mb
+	if w.addons.Scheduler == nil {
+		w.scheduler.Trigger <- -1 // send all buffers
+	}
+	if len(w.scheduler.Error) > 0 {
+		return <-w.scheduler.Error
+	}
+	return nil
 }
 
 // ReshapeMultiBuffer prepare multi buffer for padding structure (max 21 bytes)

proxy/scheduler.go

@@ -0,0 +1,74 @@
+package proxy
+
+import (
+	"context"
+	"crypto/rand"
+	"math/big"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/buf"
+	"github.com/xtls/xray-core/common/errors"
+)
+
+type Scheduler struct {
+	Buffer         chan buf.MultiBuffer
+	Trigger        chan int
+	Error          chan error
+	bufferReadLock *sync.Mutex
+	writer         buf.Writer
+	addons         *Addons
+	trafficState   *TrafficState
+	ctx            context.Context
+}
+
+func NewScheduler(w buf.Writer, addon *Addons, state *TrafficState, context context.Context) *Scheduler {
+	var s = Scheduler{
+		Buffer: make(chan buf.MultiBuffer, 100),
+		Trigger: make(chan int),
+		Error: make(chan error, 100),
+		bufferReadLock: new(sync.Mutex),
+		writer: w,
+		addons: addon,
+		trafficState: state,
+		ctx: context,
+	}
+	go s.mainLoop()
+	if s.addons.Scheduler != nil {
+		go s.exampleIndependentScheduler()
+	}
+	return &s
+}
+
+func(s *Scheduler) mainLoop() {
+	for trigger := range s.Trigger {
+		go func() { // each trigger has independent delay, trigger does not block
+			var d = 0 * time.Millisecond
+			if s.addons.Delay != nil {
+				l, err := rand.Int(rand.Reader, big.NewInt(int64(s.addons.Delay.MaxMillis - s.addons.Delay.MinMillis)))
+				if err != nil {
+					errors.LogWarningInner(s.ctx, err, "failed to generate delay", trigger)
+				}
+				d = time.Duration(uint32(l.Int64()) + s.addons.Delay.MinMillis) 
+				time.Sleep(d * time.Millisecond)
+			}
+
+			s.bufferReadLock.Lock() // guard against multiple trigger threads
+			var sending = len(s.Buffer)
+			if sending > 0 {
+				errors.LogDebug(s.ctx, "Scheduler Trigger for ", sending, " buffer(s) with ", d, " ", trigger)
+			}
+			for i := 0; i<sending; i++ {
+				s.Error <- s.writer.WriteMultiBuffer(<-s.Buffer)
+			}
+			s.bufferReadLock.Unlock()
+		}()
+	}
+}
+
+func(s *Scheduler) exampleIndependentScheduler() {
+	for {
+		time.Sleep(500 * time.Millisecond)
+		s.Trigger <- -1 // send all buffers
+	}
+}