Move connections to their own package.

client.go

 package main
 
+import (
+	"sfu/conn"
+)
+
 type clientCredentials struct {
 	Username string `json:"username,omitempty"`
 	Password string `json:"password,omitempty"`
@@ -16,7 +20,7 @@ type client interface {
 	Id() string
 	Credentials() clientCredentials
 	SetPermissions(clientPermissions)
-	pushConn(id string, conn upConnection, tracks []upTrack, label string) error
+	pushConn(id string, conn conn.Up, tracks []conn.UpTrack, label string) error
 	pushClient(id, username string, add bool) error
 }
 

conn.go → conn/conn.go

@@ -3,7 +3,8 @@
 // This is not open source software.  Copy it, and I'll break into your
 // house and tell your three year-old that Santa doesn't exist.
 
-package main
+// Package conn defines interfaces for connections and tracks.
+package conn
 
 import (
 	"errors"
@@ -15,29 +16,33 @@ import (
 var ErrConnectionClosed = errors.New("connection is closed")
 var ErrKeyframeNeeded = errors.New("keyframe needed")
 
-type upConnection interface {
-	addLocal(downConnection) error
-	delLocal(downConnection) bool
+// Type Up represents a connection in the client to server direction.
+type Up interface {
+	AddLocal(Down) error
+	DelLocal(Down) bool
 	Id() string
 	Label() string
 }
 
-type upTrack interface {
-	addLocal(downTrack) error
-	delLocal(downTrack) bool
+// Type UpTrack represents a track in the client to server direction.
+type UpTrack interface {
+	AddLocal(DownTrack) error
+	DelLocal(DownTrack) bool
 	Label() string
 	Codec() *webrtc.RTPCodec
 	// get a recent packet.  Returns 0 if the packet is not in cache.
-	getRTP(seqno uint16, result []byte) uint16
+	GetRTP(seqno uint16, result []byte) uint16
 }
 
-type downConnection interface {
+// Type Down represents a connection in the server to client direction.
+type Down interface {
 	GetMaxBitrate(now uint64) uint64
 }
 
-type downTrack interface {
+// Type DownTrack represents a track in the server to client direction.
+type DownTrack interface {
 	WriteRTP(packat *rtp.Packet) error
 	Accumulate(bytes uint32)
-	setTimeOffset(ntp uint64, rtp uint32)
-	setCname(string)
+	SetTimeOffset(ntp uint64, rtp uint32)
+	SetCname(string)
 }

disk.go

@@ -14,6 +14,8 @@ import (
 	"github.com/pion/rtp/codecs"
 	"github.com/pion/webrtc/v3"
 	"github.com/pion/webrtc/v3/pkg/media/samplebuilder"
+
+	"sfu/conn"
 )
 
 type diskClient struct {
@@ -81,7 +83,7 @@ func (client *diskClient) kick(message string) error {
 	return err
 }
 
-func (client *diskClient) pushConn(id string, conn upConnection, tracks []upTrack, label string) error {
+func (client *diskClient) pushConn(id string, up conn.Up, tracks []conn.UpTrack, label string) error {
 	client.mu.Lock()
 	defer client.mu.Unlock()
 
@@ -95,7 +97,7 @@ func (client *diskClient) pushConn(id string, conn upConnection, tracks []upTrac
 		delete(client.down, id)
 	}
 
-	if conn == nil {
+	if up == nil {
 		return nil
 	}
 
@@ -109,12 +111,12 @@ func (client *diskClient) pushConn(id string, conn upConnection, tracks []upTrac
 		client.down = make(map[string]*diskConn)
 	}
 
-	down, err := newDiskConn(directory, label, conn, tracks)
+	down, err := newDiskConn(directory, label, up, tracks)
 	if err != nil {
 		return err
 	}
 
-	client.down[conn.Id()] = down
+	client.down[up.Id()] = down
 	return nil
 }
 
@@ -125,7 +127,7 @@ type diskConn struct {
 
 	mu            sync.Mutex
 	file          *os.File
-	remote        upConnection
+	remote        conn.Up
 	tracks        []*diskTrack
 	width, height uint32
 }
@@ -150,7 +152,7 @@ func (conn *diskConn) reopen() error {
 }
 
 func (conn *diskConn) Close() error {
-	conn.remote.delLocal(conn)
+	conn.remote.DelLocal(conn)
 
 	conn.mu.Lock()
 	tracks := make([]*diskTrack, 0, len(conn.tracks))
@@ -164,7 +166,7 @@ func (conn *diskConn) Close() error {
 	conn.mu.Unlock()
 
 	for _, t := range tracks {
-		t.remote.delLocal(t)
+		t.remote.DelLocal(t)
 	}
 	return nil
 }
@@ -196,7 +198,7 @@ func openDiskFile(directory, label string) (*os.File, error) {
 }
 
 type diskTrack struct {
-	remote upTrack
+	remote conn.UpTrack
 	conn   *diskConn
 
 	writer  webm.BlockWriteCloser
@@ -206,7 +208,7 @@ type diskTrack struct {
 	origin uint64
 }
 
-func newDiskConn(directory, label string, up upConnection, remoteTracks []upTrack) (*diskConn, error) {
+func newDiskConn(directory, label string, up conn.Up, remoteTracks []conn.UpTrack) (*diskConn, error) {
 	conn := diskConn{
 		directory: directory,
 		label:     label,
@@ -231,10 +233,10 @@ func newDiskConn(directory, label string, up upConnection, remoteTracks []upTrac
 			conn:    &conn,
 		}
 		conn.tracks = append(conn.tracks, track)
-		remote.addLocal(track)
+		remote.AddLocal(track)
 	}
 
-	err := up.addLocal(&conn)
+	err := up.AddLocal(&conn)
 	if err != nil {
 		return nil, err
 	}
@@ -242,10 +244,10 @@ func newDiskConn(directory, label string, up upConnection, remoteTracks []upTrac
 	return &conn, nil
 }
 
-func (t *diskTrack) setTimeOffset(ntp uint64, rtp uint32) {
+func (t *diskTrack) SetTimeOffset(ntp uint64, rtp uint32) {
 }
 
-func (t *diskTrack) setCname(string) {
+func (t *diskTrack) SetCname(string) {
 }
 
 func clonePacket(packet *rtp.Packet) *rtp.Packet {
@@ -310,7 +312,7 @@ func (t *diskTrack) WriteRTP(packet *rtp.Packet) error {
 
 		if t.writer == nil {
 			if !keyframe {
-				return ErrKeyframeNeeded
+				return conn.ErrKeyframeNeeded
 			}
 			return nil
 		}

rtpconn.go

@@ -14,14 +14,15 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/pion/rtcp"
+	"github.com/pion/rtp"
+	"github.com/pion/webrtc/v3"
+
+	"sfu/conn"
 	"sfu/estimator"
 	"sfu/jitter"
 	"sfu/packetcache"
 	"sfu/rtptime"
-
-	"github.com/pion/rtcp"
-	"github.com/pion/rtp"
-	"github.com/pion/webrtc/v3"
 )
 
 type bitrate struct {
@@ -71,7 +72,7 @@ type iceConnection interface {
 
 type rtpDownTrack struct {
 	track         *webrtc.Track
-	remote        upTrack
+	remote        conn.UpTrack
 	maxBitrate    *bitrate
 	rate          *estimator.Estimator
 	stats         *receiverStats
@@ -91,25 +92,25 @@ func (down *rtpDownTrack) Accumulate(bytes uint32) {
 	down.rate.Accumulate(bytes)
 }
 
-func (down *rtpDownTrack) setTimeOffset(ntp uint64, rtp uint32) {
+func (down *rtpDownTrack) SetTimeOffset(ntp uint64, rtp uint32) {
 	atomic.StoreUint64(&down.remoteNTPTime, ntp)
 	atomic.StoreUint32(&down.remoteRTPTime, rtp)
 }
 
-func (down *rtpDownTrack) setCname(cname string) {
+func (down *rtpDownTrack) SetCname(cname string) {
 	down.cname.Store(cname)
 }
 
 type rtpDownConnection struct {
 	id             string
 	pc             *webrtc.PeerConnection
-	remote         upConnection
+	remote         conn.Up
 	tracks         []*rtpDownTrack
 	maxREMBBitrate *bitrate
 	iceCandidates  []*webrtc.ICECandidateInit
 }
 
-func newDownConn(c client, id string, remote upConnection) (*rtpDownConnection, error) {
+func newDownConn(c client, id string, remote conn.Up) (*rtpDownConnection, error) {
 	pc, err := c.Group().API().NewPeerConnection(iceConfiguration())
 	if err != nil {
 		return nil, err
@@ -193,7 +194,7 @@ type rtpUpTrack struct {
 
 	mu        sync.Mutex
 	cname     string
-	local     []downTrack
+	local     []conn.DownTrack
 	srTime    uint64
 	srNTPTime uint64
 	srRTPTime uint32
@@ -201,17 +202,17 @@ type rtpUpTrack struct {
 
 type localTrackAction struct {
 	add   bool
-	track downTrack
+	track conn.DownTrack
 }
 
-func (up *rtpUpTrack) notifyLocal(add bool, track downTrack) {
+func (up *rtpUpTrack) notifyLocal(add bool, track conn.DownTrack) {
 	select {
 	case up.localCh <- localTrackAction{add, track}:
 	case <-up.readerDone:
 	}
 }
 
-func (up *rtpUpTrack) addLocal(local downTrack) error {
+func (up *rtpUpTrack) AddLocal(local conn.DownTrack) error {
 	up.mu.Lock()
 	for _, t := range up.local {
 		if t == local {
@@ -226,7 +227,7 @@ func (up *rtpUpTrack) addLocal(local downTrack) error {
 	return nil
 }
 
-func (up *rtpUpTrack) delLocal(local downTrack) bool {
+func (up *rtpUpTrack) DelLocal(local conn.DownTrack) bool {
 	up.mu.Lock()
 	for i, l := range up.local {
 		if l == local {
@@ -240,15 +241,15 @@ func (up *rtpUpTrack) delLocal(local downTrack) bool {
 	return false
 }
 
-func (up *rtpUpTrack) getLocal() []downTrack {
+func (up *rtpUpTrack) getLocal() []conn.DownTrack {
 	up.mu.Lock()
 	defer up.mu.Unlock()
-	local := make([]downTrack, len(up.local))
+	local := make([]conn.DownTrack, len(up.local))
 	copy(local, up.local)
 	return local
 }
 
-func (up *rtpUpTrack) getRTP(seqno uint16, result []byte) uint16 {
+func (up *rtpUpTrack) GetRTP(seqno uint16, result []byte) uint16 {
 	return up.cache.Get(seqno, result)
 }
 
@@ -278,7 +279,7 @@ type rtpUpConnection struct {
 
 	mu     sync.Mutex
 	tracks []*rtpUpTrack
-	local  []downConnection
+	local  []conn.Down
 }
 
 func (up *rtpUpConnection) getTracks() []*rtpUpTrack {
@@ -297,7 +298,7 @@ func (up *rtpUpConnection) Label() string {
 	return up.label
 }
 
-func (up *rtpUpConnection) addLocal(local downConnection) error {
+func (up *rtpUpConnection) AddLocal(local conn.Down) error {
 	up.mu.Lock()
 	defer up.mu.Unlock()
 	for _, t := range up.local {
@@ -309,7 +310,7 @@ func (up *rtpUpConnection) addLocal(local downConnection) error {
 	return nil
 }
 
-func (up *rtpUpConnection) delLocal(local downConnection) bool {
+func (up *rtpUpConnection) DelLocal(local conn.Down) bool {
 	up.mu.Lock()
 	defer up.mu.Unlock()
 	for i, l := range up.local {
@@ -321,10 +322,10 @@ func (up *rtpUpConnection) delLocal(local downConnection) bool {
 	return false
 }
 
-func (up *rtpUpConnection) getLocal() []downConnection {
+func (up *rtpUpConnection) getLocal() []conn.Down {
 	up.mu.Lock()
 	defer up.mu.Unlock()
-	local := make([]downConnection, len(up.local))
+	local := make([]conn.Down, len(up.local))
 	copy(local, up.local)
 	return local
 }
@@ -396,10 +397,10 @@ func newUpConn(c client, id string) (*rtpUpConnection, error) {
 		return nil, err
 	}
 
-	conn := &rtpUpConnection{id: id, pc: pc}
+	up := &rtpUpConnection{id: id, pc: pc}
 
 	pc.OnTrack(func(remote *webrtc.Track, receiver *webrtc.RTPReceiver) {
-		conn.mu.Lock()
+		up.mu.Lock()
 
 		mid := getTrackMid(pc, remote)
 		if mid == "" {
@@ -407,7 +408,7 @@ func newUpConn(c client, id string) (*rtpUpConnection, error) {
 			return
 		}
 
-		label, ok := conn.labels[mid]
+		label, ok := up.labels[mid]
 		if !ok {
 			log.Printf("Couldn't get track's label")
 			isvideo := remote.Kind() == webrtc.RTPCodecTypeVideo
@@ -428,34 +429,34 @@ func newUpConn(c client, id string) (*rtpUpConnection, error) {
 			readerDone: make(chan struct{}),
 		}
 
-		conn.tracks = append(conn.tracks, track)
+		up.tracks = append(up.tracks, track)
 
-		go readLoop(conn, track)
+		go readLoop(up, track)
 
-		go rtcpUpListener(conn, track, receiver)
+		go rtcpUpListener(up, track, receiver)
 
-		complete := conn.complete()
-		var tracks []upTrack
-		if(complete) {
-			tracks = make([]upTrack, len(conn.tracks))
-			for i, t := range conn.tracks {
+		complete := up.complete()
+		var tracks []conn.UpTrack
+		if complete {
+			tracks = make([]conn.UpTrack, len(up.tracks))
+			for i, t := range up.tracks {
 				tracks[i] = t
 			}
 		}
 
 		// pushConn might need to take the lock
-		conn.mu.Unlock()
+		up.mu.Unlock()
 
 		if complete {
 			clients := c.Group().getClients(c)
 			for _, cc := range clients {
-				cc.pushConn(conn.id, conn, tracks, conn.label)
+				cc.pushConn(up.id, up, tracks, up.label)
 			}
-			go rtcpUpSender(conn)
+			go rtcpUpSender(up)
 		}
 	})
 
-	return conn, nil
+	return up, nil
 }
 
 func readLoop(conn *rtpUpConnection, track *rtpUpTrack) {
@@ -606,7 +607,7 @@ func sendRecovery(p *rtcp.TransportLayerNack, track *rtpDownTrack) {
 	buf := make([]byte, packetcache.BufSize)
 	for _, nack := range p.Nacks {
 		for _, seqno := range nack.PacketList() {
-			l := track.remote.getRTP(seqno, buf)
+			l := track.remote.GetRTP(seqno, buf)
 			if l == 0 {
 				continue
 			}
@@ -650,7 +651,7 @@ func rtcpUpListener(conn *rtpUpConnection, track *rtpUpTrack, r *webrtc.RTPRecei
 				track.srRTPTime = p.RTPTime
 				track.mu.Unlock()
 				for _, l := range local {
-					l.setTimeOffset(p.NTPTime, p.RTPTime)
+					l.SetTimeOffset(p.NTPTime, p.RTPTime)
 				}
 			case *rtcp.SourceDescription:
 				for _, c := range p.Chunks {
@@ -665,7 +666,7 @@ func rtcpUpListener(conn *rtpUpConnection, track *rtpUpTrack, r *webrtc.RTPRecei
 						track.cname = i.Text
 						track.mu.Unlock()
 						for _, l := range local {
-							l.setCname(i.Text)
+							l.SetCname(i.Text)
 						}
 					}
 				}

rtpwriter.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/pion/rtp"
 
+	"sfu/conn"
 	"sfu/packetcache"
 	"sfu/rtptime"
 )
@@ -43,7 +44,7 @@ func sqrt(n int) int {
 }
 
 // add adds or removes a track from a writer pool
-func (wp *rtpWriterPool) add(track downTrack, add bool) error {
+func (wp *rtpWriterPool) add(track conn.DownTrack, add bool) error {
 	n := 4
 	if wp.count > 16 {
 		n = sqrt(wp.count)
@@ -166,7 +167,7 @@ var ErrUnknownTrack = errors.New("unknown track")
 
 type writerAction struct {
 	add       bool
-	track     downTrack
+	track     conn.DownTrack
 	maxTracks int
 	ch        chan error
 }
@@ -192,7 +193,7 @@ func newRtpWriter(conn *rtpUpConnection, track *rtpUpTrack) *rtpWriter {
 }
 
 // add adds or removes a track from a writer.
-func (writer *rtpWriter) add(track downTrack, add bool, max int) error {
+func (writer *rtpWriter) add(track conn.DownTrack, add bool, max int) error {
 	ch := make(chan error, 1)
 	select {
 	case writer.action <- writerAction{add, track, max, ch}:
@@ -208,13 +209,13 @@ func (writer *rtpWriter) add(track downTrack, add bool, max int) error {
 }
 
 // rtpWriterLoop is the main loop of an rtpWriter.
-func rtpWriterLoop(writer *rtpWriter, conn *rtpUpConnection, track *rtpUpTrack) {
+func rtpWriterLoop(writer *rtpWriter, up *rtpUpConnection, track *rtpUpTrack) {
 	defer close(writer.done)
 
 	buf := make([]byte, packetcache.BufSize)
 	var packet rtp.Packet
 
-	local := make([]downTrack, 0)
+	local := make([]conn.DownTrack, 0)
 
 	// reset whenever a new track is inserted
 	firSent := false
@@ -239,10 +240,10 @@ func rtpWriterLoop(writer *rtpWriter, conn *rtpUpConnection, track *rtpUpTrack)
 				cname := track.cname
 				track.mu.Unlock()
 				if ntp != 0 {
-					action.track.setTimeOffset(ntp, rtp)
+					action.track.SetTimeOffset(ntp, rtp)
 				}
 				if cname != "" {
-					action.track.setCname(cname)
+					action.track.SetCname(cname)
 				}
 			} else {
 				found := false
@@ -283,7 +284,7 @@ func rtpWriterLoop(writer *rtpWriter, conn *rtpUpConnection, track *rtpUpTrack)
 			for _, l := range local {
 				err := l.WriteRTP(&packet)
 				if err != nil {
-					if err == ErrKeyframeNeeded {
+					if err == conn.ErrKeyframeNeeded {
 						kfNeeded = true
 					}
 					continue
@@ -292,9 +293,9 @@ func rtpWriterLoop(writer *rtpWriter, conn *rtpUpConnection, track *rtpUpTrack)
 			}
 
 			if kfNeeded {
-				err := conn.sendFIR(track, !firSent)
+				err := up.sendFIR(track, !firSent)
 				if err == ErrUnsupportedFeedback {
-					conn.sendPLI(track)
+					up.sendPLI(track)
 				}
 				firSent = true
 			}

webclient.go

@@ -14,10 +14,11 @@ import (
 	"sync"
 	"time"
 
-	"sfu/estimator"
-
 	"github.com/gorilla/websocket"
 	"github.com/pion/webrtc/v3"
+
+	"sfu/conn"
+	"sfu/estimator"
 )
 
 var iceConf webrtc.Configuration
@@ -300,7 +301,7 @@ func getConn(c *webClient, id string) iceConnection {
 	return nil
 }
 
-func addDownConn(c *webClient, id string, remote upConnection) (*rtpDownConnection, error) {
+func addDownConn(c *webClient, id string, remote conn.Up) (*rtpDownConnection, error) {
 	conn, err := newDownConn(c, id, remote)
 	if err != nil {
 		return nil, err
@@ -333,7 +334,7 @@ func addDownConn(c *webClient, id string, remote upConnection) (*rtpDownConnecti
 		}
 	})
 
-	err = remote.addLocal(conn)
+	err = remote.AddLocal(conn)
 	if err != nil {
 		conn.pc.Close()
 		return nil, err
@@ -355,18 +356,18 @@ func delDownConn(c *webClient, id string) bool {
 		return false
 	}
 
-	conn.remote.delLocal(conn)
+	conn.remote.DelLocal(conn)
 	for _, track := range conn.tracks {
 		// we only insert the track after we get an answer, so
 		// ignore errors here.
-		track.remote.delLocal(track)
+		track.remote.DelLocal(track)
 	}
 	conn.pc.Close()
 	delete(c.down, id)
 	return true
 }
 
-func addDownTrack(c *webClient, conn *rtpDownConnection, remoteTrack upTrack, remoteConn upConnection) (*webrtc.RTPSender, error) {
+func addDownTrack(c *webClient, conn *rtpDownConnection, remoteTrack conn.UpTrack, remoteConn conn.Up) (*webrtc.RTPSender, error) {
 	var pt uint8
 	var ssrc uint32
 	var id, label string
@@ -524,7 +525,7 @@ func gotAnswer(c *webClient, id string, answer webrtc.SessionDescription) error
 	}
 
 	for _, t := range down.tracks {
-		t.remote.addLocal(t)
+		t.remote.AddLocal(t)
 	}
 	return nil
 }
@@ -568,7 +569,7 @@ func (c *webClient) isRequested(label string) bool {
 	return c.requested[label] != 0
 }
 
-func addDownConnTracks(c *webClient, remote upConnection, tracks []upTrack) (*rtpDownConnection, error) {
+func addDownConnTracks(c *webClient, remote conn.Up, tracks []conn.UpTrack) (*rtpDownConnection, error) {
 	requested := false
 	for _, t := range tracks {
 		if c.isRequested(t.Label()) {
@@ -601,13 +602,13 @@ func addDownConnTracks(c *webClient, remote upConnection, tracks []upTrack) (*rt
 	return down, nil
 }
 
-func (c *webClient) pushConn(id string, conn upConnection, tracks []upTrack, label string) error {
-	err := c.action(pushConnAction{id, conn, tracks})
+func (c *webClient) pushConn(id string, up conn.Up, tracks []conn.UpTrack, label string) error {
+	err := c.action(pushConnAction{id, up, tracks})
 	if err != nil {
 		return err
 	}
-	if conn != nil && label != "" {
-		err := c.action(addLabelAction{conn.Id(), conn.Label()})
+	if up != nil && label != "" {
+		err := c.action(addLabelAction{up.Id(), up.Label()})
 		if err != nil {
 			return err
 		}
@@ -726,8 +727,8 @@ func startClient(conn *websocket.Conn) (err error) {
 
 type pushConnAction struct {
 	id     string
-	conn   upConnection
-	tracks []upTrack
+	conn   conn.Up
+	tracks []conn.UpTrack
 }
 
 type addLabelAction struct {
@@ -749,9 +750,9 @@ type kickAction struct {
 	message string
 }
 
-func clientLoop(c *webClient, conn *websocket.Conn) error {
+func clientLoop(c *webClient, ws *websocket.Conn) error {
 	read := make(chan interface{}, 1)
-	go clientReader(conn, read, c.done)
+	go clientReader(ws, read, c.done)
 
 	defer func() {
 		c.setRequested(map[string]uint32{})
@@ -848,7 +849,7 @@ func clientLoop(c *webClient, conn *websocket.Conn) error {
 			case pushConnsAction:
 				for _, u := range c.up {
 					tracks := u.getTracks()
-					ts := make([]upTrack, len(tracks))
+					ts := make([]conn.UpTrack, len(tracks))
 					for i, t := range tracks {
 						ts[i] = t
 					}
@@ -861,7 +862,7 @@ func clientLoop(c *webClient, conn *websocket.Conn) error {
 						return err
 					}
 					tracks := make(
-						[]upTrack, len(down.tracks),
+						[]conn.UpTrack, len(down.tracks),
 					)
 					for i, t := range down.tracks {
 						tracks[i] = t.remote