refactor common code into unlockAndInvokeFECRecovery

pkg/sfu/buffer/buffer.go

@@ -103,6 +103,14 @@ type Buffer struct {
 	warnedPendingOverflow bool
 }
 
+func (b *Buffer) unlockAndInvokeFECRecovery(
+	delta fecRecoveryDelta,
+	callback func(received int, recovered int, discarded int, bytesReceived int),
+) {
+	b.Unlock()
+	delta.invoke(callback)
+}
+
 // StreamInfoProbe identifies a stream from the mid/rid/rsid header extensions of its
 // packets. It runs on the write path, i. e. as SRTP pushes into this buffer, because
 // nothing reads remote streams through pion's interceptor chain.
@@ -287,8 +295,7 @@ func (b *Buffer) Write(pkt []byte) (n int, err error) {
 		// previously unrecoverable FEC window
 		fecDelta, onFECRecovery = b.feedFECLocked(&rtpPacket, now)
 	}
-	b.Unlock()
-	fecDelta.invoke(onFECRecovery)
+	b.unlockAndInvokeFECRecovery(fecDelta, onFECRecovery)
 
 	if len(rtcpPackets) != 0 {
 		if cb := b.getOnRtcpFeedback(); cb != nil {
@@ -418,8 +425,7 @@ func (b *Buffer) writeRTX(rtxPkt *rtp.Packet, arrivalTime int64) {
 	if b.fecDecoder != nil {
 		fecDelta, onFECRecovery = b.feedFECLocked(&repairedPkt, arrivalTime)
 	}
-	b.Unlock()
-	fecDelta.invoke(onFECRecovery)
+	b.unlockAndInvokeFECRecovery(fecDelta, onFECRecovery)
 }
 
 func (b *Buffer) SetPrimaryBufferForFEC(primaryBuffer *Buffer) {
@@ -565,8 +571,7 @@ func (b *Buffer) writeFEC(fecPkt *rtp.Packet, arrivalTime int64) {
 	}
 
 	fecDelta, onFECRecovery := b.feedFECLocked(fecPkt, arrivalTime)
-	b.Unlock()
-	fecDelta.invoke(onFECRecovery)
+	b.unlockAndInvokeFECRecovery(fecDelta, onFECRecovery)
 }
 
 // feedFECLocked runs a media or FEC packet through the FEC decoder and