PLT-5750 Add sequence number to websocket connections and events (#5907)

* Add sequence number to websocket connections and events

* Copy pointer instead of pass by value and use int64 over uint64

* Add more logging to missed events

7 files changed, 41 insertions, 46 deletions

diff --git a/app/web_conn.go b/app/web_conn.go
index da6330f5c..11290b67d 100644
--- a/app/web_conn.go
+++ b/app/web_conn.go
@@ -35,6 +35,7 @@ type WebConn struct {
 	Locale                    string
 	AllChannelMembers         map[string]string
 	LastAllChannelMembersTime int64
+	Sequence                  int64
 }
 
 func NewWebConn(ws *websocket.Conn, session model.Session, t goi18n.TranslateFunc, locale string) *WebConn {
@@ -104,8 +105,19 @@ func (c *WebConn) WritePump() {
 				return
 			}
 
+			var msgBytes []byte
+			if evt, ok := msg.(*model.WebSocketEvent); ok {
+				cpyEvt := &model.WebSocketEvent{}
+				*cpyEvt = *evt
+				cpyEvt.Sequence = c.Sequence
+				msgBytes = []byte(cpyEvt.ToJson())
+				c.Sequence++
+			} else {
+				msgBytes = []byte(msg.ToJson())
+			}
+
 			c.WebSocket.SetWriteDeadline(time.Now().Add(WRITE_WAIT))
-			if err := c.WebSocket.WriteMessage(websocket.TextMessage, msg.GetPreComputeJson()); err != nil {
+			if err := c.WebSocket.WriteMessage(websocket.TextMessage, msgBytes); err != nil {
 				// browsers will appear as CloseNoStatusReceived
 				if websocket.IsCloseError(err, websocket.CloseNormalClosure, websocket.CloseNoStatusReceived) {
 					l4g.Debug(fmt.Sprintf("websocket.send: client side closed socket userId=%v", c.UserId))
@@ -179,7 +191,6 @@ func (webCon *WebConn) IsAuthenticated() bool {
 func (webCon *WebConn) SendHello() {
 	msg := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_HELLO, "", "", webCon.UserId, nil)
 	msg.Add("server_version", fmt.Sprintf("%v.%v.%v.%v", model.CurrentVersion, model.BuildNumber, utils.CfgHash, utils.IsLicensed))
-	msg.DoPreComputeJson()
 	webCon.Send <- msg
 }
 
diff --git a/app/web_hub.go b/app/web_hub.go
index 65d18481f..a0663459a 100644
--- a/app/web_hub.go
+++ b/app/web_hub.go
@@ -94,7 +94,6 @@ func Publish(message *model.WebSocketEvent) {
 		metrics.IncrementWebsocketEvent(message.Event)
 	}
 
-	message.DoPreComputeJson()
 	for _, hub := range hubs {
 		hub.Broadcast(message)
 	}
@@ -105,7 +104,6 @@ func Publish(message *model.WebSocketEvent) {
 }
 
 func PublishSkipClusterSend(message *model.WebSocketEvent) {
-	message.DoPreComputeJson()
 	for _, hub := range hubs {
 		hub.Broadcast(message)
 	}
diff --git a/app/websocket_router.go b/app/websocket_router.go
index 30714a447..4569134b0 100644
--- a/app/websocket_router.go
+++ b/app/websocket_router.go
@@ -61,7 +61,6 @@ func (wr *WebSocketRouter) ServeWebSocket(conn *WebConn, r *model.WebSocketReque
 			HubRegister(conn)
 
 			resp := model.NewWebSocketResponse(model.STATUS_OK, r.Seq, nil)
-			resp.DoPreComputeJson()
 			conn.Send <- resp
 		}
 
@@ -91,7 +90,6 @@ func ReturnWebSocketError(conn *WebConn, r *model.WebSocketRequest, err *model.A
 
 	err.DetailedError = ""
 	errorResp := model.NewWebSocketError(r.Seq, err)
-	errorResp.DoPreComputeJson()
 
 	conn.Send <- errorResp
 }
diff --git a/model/websocket_message.go b/model/websocket_message.go
index 23820470b..6c47eb948 100644
--- a/model/websocket_message.go
+++ b/model/websocket_message.go
@@ -36,8 +36,6 @@ const (
 type WebSocketMessage interface {
 	ToJson() string
 	IsValid() bool
-	DoPreComputeJson()
-	GetPreComputeJson() []byte
 	EventType() string
 }
 
@@ -49,10 +47,10 @@ type WebsocketBroadcast struct {
 }
 
 type WebSocketEvent struct {
-	Event          string                 `json:"event"`
-	Data           map[string]interface{} `json:"data"`
-	Broadcast      *WebsocketBroadcast    `json:"broadcast"`
-	PreComputeJson []byte                 `json:"-"`
+	Event     string                 `json:"event"`
+	Data      map[string]interface{} `json:"data"`
+	Broadcast *WebsocketBroadcast    `json:"broadcast"`
+	Sequence  int64                  `json:"seq"`
 }
 
 func (m *WebSocketEvent) Add(key string, value interface{}) {
@@ -72,19 +70,6 @@ func (o *WebSocketEvent) EventType() string {
 	return o.Event
 }
 
-func (o *WebSocketEvent) DoPreComputeJson() {
-	b, err := json.Marshal(o)
-	if err != nil {
-		o.PreComputeJson = []byte("")
-	} else {
-		o.PreComputeJson = b
-	}
-}
-
-func (o *WebSocketEvent) GetPreComputeJson() []byte {
-	return o.PreComputeJson
-}
-
 func (o *WebSocketEvent) ToJson() string {
 	b, err := json.Marshal(o)
 	if err != nil {
@@ -106,11 +91,10 @@ func WebSocketEventFromJson(data io.Reader) *WebSocketEvent {
 }
 
 type WebSocketResponse struct {
-	Status         string                 `json:"status"`
-	SeqReply       int64                  `json:"seq_reply,omitempty"`
-	Data           map[string]interface{} `json:"data,omitempty"`
-	Error          *AppError              `json:"error,omitempty"`
-	PreComputeJson []byte                 `json:"-"`
+	Status   string                 `json:"status"`
+	SeqReply int64                  `json:"seq_reply,omitempty"`
+	Data     map[string]interface{} `json:"data,omitempty"`
+	Error    *AppError              `json:"error,omitempty"`
 }
 
 func (m *WebSocketResponse) Add(key string, value interface{}) {
@@ -142,19 +126,6 @@ func (o *WebSocketResponse) ToJson() string {
 	}
 }
 
-func (o *WebSocketResponse) DoPreComputeJson() {
-	b, err := json.Marshal(o)
-	if err != nil {
-		o.PreComputeJson = []byte("")
-	} else {
-		o.PreComputeJson = b
-	}
-}
-
-func (o *WebSocketResponse) GetPreComputeJson() []byte {
-	return o.PreComputeJson
-}
-
 func WebSocketResponseFromJson(data io.Reader) *WebSocketResponse {
 	decoder := json.NewDecoder(data)
 	var o WebSocketResponse
diff --git a/webapp/actions/websocket_actions.jsx b/webapp/actions/websocket_actions.jsx
index e36d11fde..e07e3e217 100644
--- a/webapp/actions/websocket_actions.jsx
+++ b/webapp/actions/websocket_actions.jsx
@@ -61,6 +61,13 @@ export function initialize() {
 
     WebSocketClient.setEventCallback(handleEvent);
     WebSocketClient.setFirstConnectCallback(handleFirstConnect);
+    WebSocketClient.setReconnectCallback(() => reconnect(false));
+    WebSocketClient.setMissedEventCallback(() => {
+        if (global.window.mm_config.EnableDeveloper === 'true') {
+            Client.logClientError('missed websocket event seq=' + WebSocketClient.eventSequence);
+        }
+        reconnect(false);
+    });
     WebSocketClient.setCloseCallback(handleClose);
     WebSocketClient.initialize(connUrl);
 }
diff --git a/webapp/client/websocket_client.jsx b/webapp/client/websocket_client.jsx
index 35be5c3df..1cf97b788 100644
--- a/webapp/client/websocket_client.jsx
+++ b/webapp/client/websocket_client.jsx
@@ -10,11 +10,13 @@ export default class WebSocketClient {
         this.conn = null;
         this.connectionUrl = null;
         this.sequence = 1;
+        this.eventSequence = 0;
         this.connectFailCount = 0;
         this.eventCallback = null;
         this.responseCallbacks = {};
         this.firstConnectCallback = null;
         this.reconnectCallback = null;
+        this.missedEventCallback = null;
         this.errorCallback = null;
         this.closeCallback = null;
     }
@@ -37,6 +39,8 @@ export default class WebSocketClient {
         this.connectionUrl = connectionUrl;
 
         this.conn.onopen = () => {
+            this.eventSequence = 0;
+
             if (token) {
                 this.sendMessage('authentication_challenge', {token});
             }
@@ -108,6 +112,11 @@ export default class WebSocketClient {
                     Reflect.deleteProperty(this.responseCallbacks, msg.seq_reply);
                 }
             } else if (this.eventCallback) {
+                if (msg.seq !== this.eventSequence && this.missedEventCallback) {
+                    console.log('missed websocket event, act_seq=' + msg.seq + ' exp_seq=' + this.eventSequence); //eslint-disable-line no-console
+                    this.missedEventCallback();
+                }
+                this.eventSequence = msg.seq + 1;
                 this.eventCallback(msg);
             }
         };
@@ -125,6 +134,10 @@ export default class WebSocketClient {
         this.reconnectCallback = callback;
     }
 
+    setMissedEventCallback(callback) {
+        this.missedEventCallback = callback;
+    }
+
     setErrorCallback(callback) {
         this.errorCallback = callback;
     }
diff --git a/wsapi/websocket_handler.go b/wsapi/websocket_handler.go
index 193539242..8d78ece04 100644
--- a/wsapi/websocket_handler.go
+++ b/wsapi/websocket_handler.go
@@ -27,7 +27,6 @@ func (wh webSocketHandler) ServeWebSocket(conn *app.WebConn, r *model.WebSocketR
 		l4g.Error(utils.T("api.web_socket_handler.log.error"), "/api/v3/users/websocket", r.Action, r.Seq, conn.UserId, sessionErr.SystemMessage(utils.T), sessionErr.Error())
 		sessionErr.DetailedError = ""
 		errResp := model.NewWebSocketError(r.Seq, sessionErr)
-		errResp.DoPreComputeJson()
 
 		conn.Send <- errResp
 		return
@@ -44,14 +43,12 @@ func (wh webSocketHandler) ServeWebSocket(conn *app.WebConn, r *model.WebSocketR
 		l4g.Error(utils.T("api.web_socket_handler.log.error"), "/api/v3/users/websocket", r.Action, r.Seq, r.Session.UserId, err.SystemMessage(utils.T), err.DetailedError)
 		err.DetailedError = ""
 		errResp := model.NewWebSocketError(r.Seq, err)
-		errResp.DoPreComputeJson()
 
 		conn.Send <- errResp
 		return
 	}
 
 	resp := model.NewWebSocketResponse(model.STATUS_OK, r.Seq, data)
-	resp.DoPreComputeJson()
 
 	conn.Send <- resp
 }