// 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.
// (Threadsafe)
func (h *BasicHost) NewStream(ctx context.Context, p peer.ID, pids ...protocol.ID) (inet.Stream, error) {
pref, err := h.preferredProtocol(p, pids)
if err != nil {
return nil, err
}
if pref != "" {
return h.newStream(ctx, p, pref)
}
var protoStrs []string
for _, pid := range pids {
protoStrs = append(protoStrs, string(pid))
}
s, err := h.Network().NewStream(ctx, p)
if err != nil {
return nil, err
}
selected, err := msmux.SelectOneOf(protoStrs, s)
if err != nil {
s.Close()
return nil, err
}
selpid := protocol.ID(selected)
s.SetProtocol(selpid)
h.Peerstore().AddProtocols(p, selected)
return mstream.WrapStream(s, h.bwc), nil
}
func (t *transport) NewConn(nc net.Conn, isServer bool) (pst.Conn, error) {
var proto string
if isServer {
selected, _, err := t.mux.Negotiate(nc)
if err != nil {
return nil, err
}
proto = selected
} else {
// prefer yamux
selected, err := mss.SelectOneOf([]string{"/yamux", "/spdystream", "/multiplex"}, nc)
if err != nil {
return nil, err
}
proto = selected
}
tpt := t.tpts[proto]
return tpt.NewConn(nc, isServer)
}