From 53b52a67cad04a84b6a822d37da801d9c2617d6d Mon Sep 17 00:00:00 2001
From: David Zhao <david@davidzhao.com>
Date: Tue, 13 Jul 2021 22:28:34 -0700
Subject: [PATCH] use protobuf for clients with protocol > 1 (#52)

---
 pkg/rtc/types/protocol_version.go |  4 ++++
 pkg/service/rtcservice.go         |  4 ++++
 pkg/service/wsprotocol.go         | 10 ++++++----
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/pkg/rtc/types/protocol_version.go b/pkg/rtc/types/protocol_version.go
index 6611a4c55..9113ddb69 100644
--- a/pkg/rtc/types/protocol_version.go
+++ b/pkg/rtc/types/protocol_version.go
@@ -8,6 +8,10 @@ func (v ProtocolVersion) SupportsPackedStreamId() bool {
 	return v > 0
 }
 
+func (v ProtocolVersion) SupportsProtobuf() bool {
+	return v > 0
+}
+
 func (v ProtocolVersion) HandlesDataPackets() bool {
 	return v > 1
 }
diff --git a/pkg/service/rtcservice.go b/pkg/service/rtcservice.go
index 2063dc440..5f5fc217f 100644
--- a/pkg/service/rtcservice.go
+++ b/pkg/service/rtcservice.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/gorilla/websocket"
+	"github.com/livekit/livekit-server/pkg/rtc/types"
 
 	"github.com/livekit/livekit-server/pkg/config"
 	"github.com/livekit/livekit-server/pkg/logger"
@@ -126,6 +127,9 @@ func (s *RTCService) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	sigConn := NewWSSignalConnection(conn)
+	if types.ProtocolVersion(pi.ProtocolVersion).SupportsProtobuf() {
+		sigConn.useJSON = false
+	}
 
 	logger.Infow("new client WS connected",
 		"connectionId", connId,
diff --git a/pkg/service/wsprotocol.go b/pkg/service/wsprotocol.go
index 97abc7ab9..8f6ae3af1 100644
--- a/pkg/service/wsprotocol.go
+++ b/pkg/service/wsprotocol.go
@@ -45,10 +45,12 @@ func (c *WSSignalConnection) ReadRequest() (*livekit.SignalRequest, error) {
 		msg := &livekit.SignalRequest{}
 		switch messageType {
 		case websocket.BinaryMessage:
-			c.mu.Lock()
-			// switch to protobuf if client supports it
-			c.useJSON = false
-			c.mu.Unlock()
+			if c.useJSON {
+				c.mu.Lock()
+				// switch to protobuf if client supports it
+				c.useJSON = false
+				c.mu.Unlock()
+			}
 			// protobuf encoded
 			err := proto.Unmarshal(payload, msg)
 			return msg, err