torrent/webrtc.go

86 lines
2.3 KiB
Go

package torrent
import (
"net"
"strconv"
"time"
"github.com/pion/datachannel"
"github.com/pion/webrtc/v3"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
"github.com/anacrolix/torrent/webtorrent"
)
const webrtcNetwork = "webrtc"
type webrtcNetConn struct {
datachannel.ReadWriteCloser
webtorrent.DataChannelContext
}
type webrtcNetAddr struct {
*webrtc.ICECandidate
}
var _ net.Addr = webrtcNetAddr{}
func (webrtcNetAddr) Network() string {
// Now that we have the ICE candidate, we can tell if it's over udp or tcp. But should we use
// that for the network?
return webrtcNetwork
}
func (me webrtcNetAddr) String() string {
return net.JoinHostPort(me.Address, strconv.FormatUint(uint64(me.Port), 10))
}
func (me webrtcNetConn) LocalAddr() net.Addr {
// I'm not sure if this evolves over time. It might also be unavailable if the PeerConnection is
// closed or closes itself. The same concern applies to RemoteAddr.
pair, err := me.DataChannelContext.GetSelectedIceCandidatePair()
if err != nil {
panic(err)
}
return webrtcNetAddr{pair.Local}
}
func (me webrtcNetConn) RemoteAddr() net.Addr {
// See comments on LocalAddr.
pair, err := me.DataChannelContext.GetSelectedIceCandidatePair()
if err != nil {
panic(err)
}
return webrtcNetAddr{pair.Remote}
}
// Do we need these for WebRTC connections exposed as net.Conns? Can we set them somewhere inside
// PeerConnection or on the channel or some transport?
func (w webrtcNetConn) SetDeadline(t time.Time) error {
w.Span.AddEvent("SetDeadline", trace.WithAttributes(attribute.String("time", t.String())))
return nil
}
func (w webrtcNetConn) SetReadDeadline(t time.Time) error {
w.Span.AddEvent("SetReadDeadline", trace.WithAttributes(attribute.String("time", t.String())))
return nil
}
func (w webrtcNetConn) SetWriteDeadline(t time.Time) error {
w.Span.AddEvent("SetWriteDeadline", trace.WithAttributes(attribute.String("time", t.String())))
return nil
}
func (w webrtcNetConn) Read(b []byte) (n int, err error) {
_, span := otel.Tracer(tracerName).Start(w.Context, "Read")
defer span.End()
span.SetAttributes(attribute.Int("buf_len", len(b)))
n, err = w.ReadWriteCloser.Read(b)
span.RecordError(err)
span.SetAttributes(attribute.Int("bytes_read", n))
return
}