optimize streaming

Overlord-Client/cmd/agent/capture/flowcontrol.go

@@ -0,0 +1,49 @@
+package capture
+
+import (
+	"sync/atomic"
+	"time"
+)
+
+const maxInFlightFrames int64 = 2
+
+var (
+	inFlightFrames atomic.Int64
+	frameAckSeen   atomic.Bool
+	lastAckNano    atomic.Int64
+)
+
+func AcquireFrameSlot() bool {
+	if !frameAckSeen.Load() {
+		return true
+	}
+
+	for {
+		cur := inFlightFrames.Load()
+		if cur >= maxInFlightFrames {
+			lastAck := lastAckNano.Load()
+			if lastAck > 0 && time.Since(time.Unix(0, lastAck)) > time.Second {
+				inFlightFrames.Store(0)
+				continue
+			}
+			return false
+		}
+		if inFlightFrames.CompareAndSwap(cur, cur+1) {
+			return true
+		}
+	}
+}
+
+func ReleaseFrameSlot() {
+	frameAckSeen.Store(true)
+	lastAckNano.Store(time.Now().UnixNano())
+	if inFlightFrames.Add(-1) < 0 {
+		inFlightFrames.Store(0)
+	}
+}
+
+func ResetFrameSlots() {
+	inFlightFrames.Store(0)
+	frameAckSeen.Store(false)
+	lastAckNano.Store(0)
+}