Merge pull request #131 from libp2p/simplify-handle-reserve

simplify generation of reservations

v2/relay/relay.go

@@ -120,7 +120,7 @@ func (r *Relay) handleStream(s network.Stream) {
 
 	switch msg.GetType() {
 	case pbv2.HopMessage_RESERVE:
-		r.handleReserve(s, &msg)
+		r.handleReserve(s)
 
 	case pbv2.HopMessage_CONNECT:
 		r.handleConnect(s, &msg)
@@ -130,7 +130,7 @@ func (r *Relay) handleStream(s network.Stream) {
 	}
 }
 
-func (r *Relay) handleReserve(s network.Stream, msg *pbv2.HopMessage) {
+func (r *Relay) handleReserve(s network.Stream) {
 	defer s.Close()
 
 	p := s.Conn().RemotePeer()
@@ -175,15 +175,12 @@ func (r *Relay) handleReserve(s network.Stream, msg *pbv2.HopMessage) {
 
 	log.Debugf("reserving relay slot for %s", p)
 
-	err := r.writeResponse(s, pbv2.Status_OK, r.makeReservationMsg(p, expire), r.makeLimitMsg(p))
-	if err != nil {
-		s.Reset()
+	// Delivery of the reservation might fail for a number of reasons.
+	// For example, the stream might be reset or the connection might be closed before the reservation is received.
+	// In that case, the reservation will just be garbage collected later.
+	if err := r.writeResponse(s, pbv2.Status_OK, r.makeReservationMsg(p, expire), r.makeLimitMsg(p)); err != nil {
 		log.Debugf("error writing reservation response; retracting reservation for %s", p)
-		r.mx.Lock()
-		delete(r.rsvp, p)
-		r.ipcs.RemoveReservation(p)
-		r.host.ConnManager().UntagPeer(p, "relay-reservation")
-		r.mx.Unlock()
+		s.Reset()
 	}
 }