simplify vls base access (#3465)

pkg/rtc/room.go

@@ -871,24 +871,24 @@ func (r *Room) IsClosed() bool {
 }
 
 // CloseIfEmpty closes the room if all participants had left, or it's still empty past timeout
-func (r *Room) CloseIfEmpty() string {
+func (r *Room) CloseIfEmpty() {
 	r.lock.Lock()
 
 	if r.IsClosed() || r.holds.Load() > 0 {
 		r.lock.Unlock()
-		return ""
+		return
 	}
 
 	for _, p := range r.participants {
 		if !p.IsDependent() {
 			r.lock.Unlock()
-			return ""
+			return
 		}
 	}
 
 	var timeout uint32
 	var elapsed int64
-	reason := ""
+	var reason string
 	if r.FirstJoinedAt() > 0 && r.LastLeftAt() > 0 {
 		elapsed = time.Now().Unix() - r.LastLeftAt()
 		// need to give time in case participant is reconnecting
@@ -903,10 +903,8 @@ func (r *Room) CloseIfEmpty() string {
 
 	if elapsed >= int64(timeout) {
 		r.Close(types.ParticipantCloseReasonRoomClosed)
-		return reason
+		r.Logger.Infow("closing idle room", "reason", reason)
 	}
-
-	return ""
 }
 
 func (r *Room) Close(reason types.ParticipantCloseReason) {

pkg/service/roommanager.go

@@ -197,10 +197,7 @@ func (r *RoomManager) CloseIdleRooms() {
 	r.lock.RUnlock()
 
 	for _, room := range rooms {
-		reason := room.CloseIfEmpty()
-		if reason != "" {
-			room.Logger.Infow("closing idle room", "reason", reason)
-		}
+		room.CloseIfEmpty()
 	}
 }
 

pkg/sfu/videolayerselector/base.go

@@ -50,6 +50,10 @@ func NewBase(logger logger.Logger) *Base {
 	}
 }
 
+func (b *Base) getBase() *Base {
+	return b
+}
+
 func (b *Base) IsOvershootOkay() bool {
 	return false
 }

pkg/sfu/videolayerselector/dependencydescriptor.go

@@ -51,30 +51,7 @@ func NewDependencyDescriptor(logger logger.Logger) *DependencyDescriptor {
 }
 
 func NewDependencyDescriptorFromOther(vls VideoLayerSelector) *DependencyDescriptor {
-	switch vls := vls.(type) {
-	case *Null:
-		return &DependencyDescriptor{
-			Base: vls.Base,
-		}
-
-	case *Simulcast:
-		return &DependencyDescriptor{
-			Base: vls.Base,
-		}
-
-	case *DependencyDescriptor:
-		return &DependencyDescriptor{
-			Base: vls.Base,
-		}
-
-	case *VP9:
-		return &DependencyDescriptor{
-			Base: vls.Base,
-		}
-
-	default:
-		return nil
-	}
+	return &DependencyDescriptor{Base: vls.getBase()}
 }
 
 func (d *DependencyDescriptor) IsOvershootOkay() bool {

pkg/sfu/videolayerselector/videolayerselector.go

@@ -29,6 +29,8 @@ type VideoLayerSelectorResult struct {
 }
 
 type VideoLayerSelector interface {
+	getBase() *Base
+
 	IsOvershootOkay() bool
 
 	SetTemporalLayerSelector(tls temporallayerselector.TemporalLayerSelector)

pkg/sfu/videolayerselector/vp9.go

@@ -15,9 +15,10 @@
 package videolayerselector
 
 import (
+	"github.com/pion/rtp/codecs"
+
 	"github.com/livekit/livekit-server/pkg/sfu/buffer"
 	"github.com/livekit/protocol/logger"
-	"github.com/pion/rtp/codecs"
 )
 
 type VP9 struct {
@@ -31,30 +32,7 @@ func NewVP9(logger logger.Logger) *VP9 {
 }
 
 func NewVP9FromOther(vls VideoLayerSelector) *VP9 {
-	switch vls := vls.(type) {
-	case *Null:
-		return &VP9{
-			Base: vls.Base,
-		}
-
-	case *Simulcast:
-		return &VP9{
-			Base: vls.Base,
-		}
-
-	case *DependencyDescriptor:
-		return &VP9{
-			Base: vls.Base,
-		}
-
-	case *VP9:
-		return &VP9{
-			Base: vls.Base,
-		}
-
-	default:
-		return nil
-	}
+	return &VP9{Base: vls.getBase()}
 }
 
 func (v *VP9) IsOvershootOkay() bool {