allow removal of stream handlers

host/basic/basic_host.go

@@ -118,6 +118,10 @@ func (h *BasicHost) SetStreamHandler(pid protocol.ID, handler inet.StreamHandler
 	h.Mux().SetHandler(pid, handler)
 }
 
+func (h *BasicHost) RemoveStreamHandler(pid protocol.ID) {
+	h.Mux().RemoveHandler(pid)
+}
+
 // NewStream opens a new stream to given peer p, and writes a p2p/protocol
 // header with given protocol.ID. If there is no connection to p, attempts
 // to create one. If ProtocolID is "", writes no header.

host/host.go

@@ -46,6 +46,10 @@ type Host interface {
 	// (Threadsafe)
 	SetStreamHandler(pid protocol.ID, handler inet.StreamHandler)
 
+	// RemoveStreamHandler removes a handler on the mux that was set by
+	// SetStreamHandler
+	RemoveStreamHandler(pid protocol.ID)
+
 	// NewStream opens a new stream to given peer p, and writes a p2p/protocol
 	// header with given protocol.ID. If there is no connection to p, attempts
 	// to create one. If ProtocolID is "", writes no header.

host/routed/routed.go

@@ -84,21 +84,31 @@ func logRoutingErrDifferentPeers(ctx context.Context, wanted, got peer.ID, err e
 func (rh *RoutedHost) ID() peer.ID {
 	return rh.host.ID()
 }
+
 func (rh *RoutedHost) Peerstore() peer.Peerstore {
 	return rh.host.Peerstore()
 }
+
 func (rh *RoutedHost) Addrs() []ma.Multiaddr {
 	return rh.host.Addrs()
 }
+
 func (rh *RoutedHost) Network() inet.Network {
 	return rh.host.Network()
 }
+
 func (rh *RoutedHost) Mux() *protocol.Mux {
 	return rh.host.Mux()
 }
+
 func (rh *RoutedHost) SetStreamHandler(pid protocol.ID, handler inet.StreamHandler) {
 	rh.host.SetStreamHandler(pid, handler)
 }
+
+func (rh *RoutedHost) RemoveStreamHandler(pid protocol.ID) {
+	rh.host.RemoveStreamHandler(pid)
+}
+
 func (rh *RoutedHost) NewStream(pid protocol.ID, p peer.ID) (inet.Stream, error) {
 	return rh.host.NewStream(pid, p)
 }

protocol/mux.go

@@ -90,6 +90,15 @@ func (m *Mux) SetHandler(p ID, h inet.StreamHandler) {
 	m.lock.Unlock()
 }
 
+// RemoveHandler removes the protocol handler on the Network's Muxer.
+// This operation is threadsafe.
+func (m *Mux) RemoveHandler(p ID) {
+	log.Debugf("%s removing handler for protocol: %s (%d)", m, p, len(p))
+	m.lock.Lock()
+	delete(m.handlers, p)
+	m.lock.Unlock()
+}
+
 // Handle reads the next name off the Stream, and calls a handler function
 // This is done in its own goroutine, to avoid blocking the caller.
 func (m *Mux) Handle(s inet.Stream) {