Files
olcrtc/internal/telemost/peer.go

418 lines
8.7 KiB
Go

package telemost
import (
"context"
"fmt"
"log"
"strings"
"time"
"github.com/google/uuid"
"github.com/gorilla/websocket"
"github.com/pion/webrtc/v4"
)
type Peer struct {
roomURL string
name string
conn *ConnectionInfo
ws *websocket.Conn
pcSub *webrtc.PeerConnection
pcPub *webrtc.PeerConnection
dc *webrtc.DataChannel
onData func([]byte)
reconnectCh chan struct{}
closeCh chan struct{}
}
func NewPeer(roomURL, name string, onData func([]byte)) (*Peer, error) {
conn, err := GetConnectionInfo(roomURL, name)
if err != nil {
return nil, err
}
return &Peer{
roomURL: roomURL,
name: name,
conn: conn,
onData: onData,
reconnectCh: make(chan struct{}, 1),
closeCh: make(chan struct{}),
}, nil
}
func (p *Peer) Connect(ctx context.Context) error {
config := webrtc.Configuration{
ICEServers: []webrtc.ICEServer{
{URLs: []string{"stun:stun.rtc.yandex.net:3478"}},
},
SDPSemantics: webrtc.SDPSemanticsUnifiedPlan,
}
settingEngine := webrtc.SettingEngine{}
api := webrtc.NewAPI(webrtc.WithSettingEngine(settingEngine))
var err error
p.pcSub, err = api.NewPeerConnection(config)
if err != nil {
return err
}
p.pcPub, err = api.NewPeerConnection(config)
if err != nil {
return err
}
p.dc, err = p.pcPub.CreateDataChannel("olcrtc", nil)
if err != nil {
return err
}
dcReady := make(chan struct{})
p.dc.OnOpen(func() {
close(dcReady)
})
p.dc.OnMessage(func(msg webrtc.DataChannelMessage) {
if p.onData != nil && len(msg.Data) > 0 {
p.onData(msg.Data)
}
})
p.pcSub.OnDataChannel(func(dc *webrtc.DataChannel) {
log.Printf("Received datachannel: %s", dc.Label())
dc.OnMessage(func(msg webrtc.DataChannelMessage) {
if p.onData != nil && len(msg.Data) > 0 {
p.onData(msg.Data)
}
})
})
ws, _, err := websocket.DefaultDialer.Dial(p.conn.ClientConfig.MediaServerURL, nil)
if err != nil {
return err
}
p.ws = ws
ws.SetPongHandler(func(string) error {
ws.SetReadDeadline(time.Now().Add(60 * time.Second))
return nil
})
go p.keepAlive()
if err := p.sendHello(); err != nil {
return err
}
p.setupICEHandlers()
go p.handleSignaling()
select {
case <-dcReady:
return nil
case <-time.After(15 * time.Second):
return fmt.Errorf("datachannel timeout")
case <-ctx.Done():
return ctx.Err()
}
}
func (p *Peer) Send(data []byte) error {
return p.dc.Send(data)
}
func (p *Peer) sendHello() error {
hello := map[string]interface{}{
"uid": uuid.New().String(),
"hello": map[string]interface{}{
"participantMeta": map[string]interface{}{
"name": p.name,
"role": "SPEAKER",
"sendAudio": false,
"sendVideo": false,
},
"participantAttributes": map[string]interface{}{
"name": p.name,
"role": "SPEAKER",
},
"sendAudio": false,
"sendVideo": false,
"sendSharing": false,
"participantId": p.conn.PeerID,
"roomId": p.conn.RoomID,
"serviceName": "telemost",
"credentials": p.conn.Credentials,
"capabilitiesOffer": map[string]interface{}{
"offerAnswerMode": []string{"SEPARATE"},
"initialSubscriberOffer": []string{"ON_HELLO"},
"slotsMode": []string{"FROM_CONTROLLER"},
"simulcastMode": []string{"DISABLED"},
"selfVadStatus": []string{"FROM_SERVER"},
"dataChannelSharing": []string{"TO_RTP"},
},
"sdkInfo": map[string]interface{}{
"implementation": "go",
"version": "1.0.0",
"userAgent": "OlcRTC-" + p.name,
},
"sdkInitializationId": uuid.New().String(),
"disablePublisher": false,
"disableSubscriber": false,
},
}
return p.ws.WriteJSON(hello)
}
func (p *Peer) handleSignaling() {
pubSent := false
for {
var msg map[string]interface{}
if err := p.ws.ReadJSON(&msg); err != nil {
log.Printf("WS read error: %v", err)
select {
case p.reconnectCh <- struct{}{}:
default:
}
return
}
uid, _ := msg["uid"].(string)
if _, ok := msg["serverHello"]; ok {
p.sendAck(uid)
}
if offer, ok := msg["subscriberSdpOffer"].(map[string]interface{}); ok && !pubSent {
sdp, _ := offer["sdp"].(string)
pcSeq, _ := offer["pcSeq"].(float64)
if err := p.pcSub.SetRemoteDescription(webrtc.SessionDescription{
Type: webrtc.SDPTypeOffer,
SDP: sdp,
}); err != nil {
log.Printf("SetRemoteDescription error: %v", err)
continue
}
answer, err := p.pcSub.CreateAnswer(nil)
if err != nil {
log.Printf("CreateAnswer error: %v", err)
continue
}
if err := p.pcSub.SetLocalDescription(answer); err != nil {
log.Printf("SetLocalDescription error: %v", err)
continue
}
p.ws.WriteJSON(map[string]interface{}{
"uid": uuid.New().String(),
"subscriberSdpAnswer": map[string]interface{}{
"pcSeq": int(pcSeq),
"sdp": answer.SDP,
},
})
p.sendAck(uid)
time.Sleep(300 * time.Millisecond)
pubOffer, err := p.pcPub.CreateOffer(nil)
if err != nil {
log.Printf("CreateOffer error: %v", err)
continue
}
if err := p.pcPub.SetLocalDescription(pubOffer); err != nil {
log.Printf("SetLocalDescription error: %v", err)
continue
}
p.ws.WriteJSON(map[string]interface{}{
"uid": uuid.New().String(),
"publisherSdpOffer": map[string]interface{}{
"pcSeq": 1,
"sdp": pubOffer.SDP,
},
})
pubSent = true
}
if answer, ok := msg["publisherSdpAnswer"].(map[string]interface{}); ok {
sdp, _ := answer["sdp"].(string)
if err := p.pcPub.SetRemoteDescription(webrtc.SessionDescription{
Type: webrtc.SDPTypeAnswer,
SDP: sdp,
}); err != nil {
log.Printf("SetRemoteDescription error: %v", err)
}
p.sendAck(uid)
}
if cand, ok := msg["webrtcIceCandidate"].(map[string]interface{}); ok {
p.handleICE(cand)
}
}
}
func (p *Peer) handleICE(cand map[string]interface{}) {
candStr, _ := cand["candidate"].(string)
target, _ := cand["target"].(string)
sdpMid, _ := cand["sdpMid"].(string)
sdpMLineIndex, _ := cand["sdpMlineIndex"].(float64)
parts := strings.Fields(candStr)
if len(parts) < 8 {
return
}
init := webrtc.ICECandidateInit{
Candidate: candStr,
SDPMid: &sdpMid,
SDPMLineIndex: func() *uint16 { v := uint16(sdpMLineIndex); return &v }(),
}
if target == "SUBSCRIBER" {
p.pcSub.AddICECandidate(init)
} else if target == "PUBLISHER" {
p.pcPub.AddICECandidate(init)
}
}
func (p *Peer) sendAck(uid string) {
p.ws.WriteJSON(map[string]interface{}{
"uid": uid,
"ack": map[string]interface{}{
"status": map[string]interface{}{
"code": "OK",
},
},
})
}
func (p *Peer) setupICEHandlers() {
p.pcSub.OnICECandidate(func(c *webrtc.ICECandidate) {
if c == nil {
return
}
init := c.ToJSON()
p.ws.WriteJSON(map[string]interface{}{
"uid": uuid.New().String(),
"webrtcIceCandidate": map[string]interface{}{
"candidate": init.Candidate,
"sdpMid": init.SDPMid,
"sdpMlineIndex": init.SDPMLineIndex,
"target": "SUBSCRIBER",
"pcSeq": 1,
},
})
})
p.pcPub.OnICECandidate(func(c *webrtc.ICECandidate) {
if c == nil {
return
}
init := c.ToJSON()
p.ws.WriteJSON(map[string]interface{}{
"uid": uuid.New().String(),
"webrtcIceCandidate": map[string]interface{}{
"candidate": init.Candidate,
"sdpMid": init.SDPMid,
"sdpMlineIndex": init.SDPMLineIndex,
"target": "PUBLISHER",
"pcSeq": 1,
},
})
})
}
func (p *Peer) Close() error {
close(p.closeCh)
if p.ws != nil {
p.ws.Close()
}
if p.pcSub != nil {
p.pcSub.Close()
}
if p.pcPub != nil {
p.pcPub.Close()
}
return nil
}
func (p *Peer) keepAlive() {
ticker := time.NewTicker(30 * time.Second)
defer ticker.Stop()
for {
select {
case <-ticker.C:
if p.ws != nil {
if err := p.ws.WriteControl(websocket.PingMessage, []byte{}, time.Now().Add(10*time.Second)); err != nil {
log.Printf("Ping error: %v", err)
select {
case p.reconnectCh <- struct{}{}:
default:
}
return
}
}
case <-p.closeCh:
return
}
}
}
func (p *Peer) reconnect(ctx context.Context) error {
log.Println("Reconnecting...")
if p.ws != nil {
p.ws.Close()
}
if p.pcSub != nil {
p.pcSub.Close()
}
if p.pcPub != nil {
p.pcPub.Close()
}
time.Sleep(2 * time.Second)
conn, err := GetConnectionInfo(p.roomURL, p.name)
if err != nil {
return err
}
p.conn = conn
return p.Connect(ctx)
}
func (p *Peer) WatchConnection(ctx context.Context) {
for {
select {
case <-p.reconnectCh:
for {
if err := p.reconnect(ctx); err != nil {
log.Printf("Reconnect failed: %v, retrying in 5s...", err)
time.Sleep(5 * time.Second)
continue
}
log.Println("Reconnected successfully")
break
}
case <-p.closeCh:
return
case <-ctx.Done():
return
}
}
}