retransmit lost packets, send StopWaiting frames

ackhandler/packet.go

@@ -15,3 +15,30 @@ type Packet struct {
 	MissingReports uint8
 	Retransmitted  bool // has this Packet ever been retransmitted
 }
+
+func (p *Packet) GetStreamFramesForRetransmission() []*frames.StreamFrame {
+	streamFrames := make([]*frames.StreamFrame, 0)
+	for _, frame := range p.Frames {
+		if streamFrame, isStreamFrame := frame.(*frames.StreamFrame); isStreamFrame {
+			streamFrames = append(streamFrames, streamFrame)
+		}
+	}
+	return streamFrames
+}
+
+func (p *Packet) GetControlFramesForRetransmission() []frames.Frame {
+	controlFrames := make([]frames.Frame, 0)
+	for _, frame := range p.Frames {
+		// omit ACKs
+		if _, isStreamFrame := frame.(*frames.StreamFrame); isStreamFrame {
+			continue
+		}
+
+		_, isAck := frame.(*frames.AckFrame)
+		_, isStopWaiting := frame.(*frames.StopWaitingFrame)
+		if !isAck && !isStopWaiting {
+			controlFrames = append(controlFrames, frame)
+		}
+	}
+	return controlFrames
+}