Merge pull request 'Cleaning up websocket comms for efficiency.' (#2) from ws-refactor into master

Reviewed-on: #2

main.go

@@ -44,6 +44,7 @@ type Config struct {
 
 type Client struct {
 	conn *websocket.Conn
+	mu   sync.Mutex
 }
 
 type Server struct {
@@ -110,7 +111,7 @@ func (s *Server) addClient(client *Client) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.clients[client] = true
-	broadcastAllRecordsToClient(client)
+	sendAllRecordsToClient(client)
 }
 
 func (s *Server) removeClient(client *Client) {
@@ -154,77 +155,69 @@ func (s *Server) handleConnections(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func sendMessageToClient(client *Client, message Message) {
+	var msgJSON, err = json.Marshal(message)
+	if err != nil {
+		log.Println("Error marshalling json:", err)
+		return
+	}
+	sendToClient(client, msgJSON)
+}
+
+func sendToClient(client *Client, msgJSON []byte) {
+	client.mu.Lock()
+	defer client.mu.Unlock()
+	if err := client.conn.WriteMessage(websocket.TextMessage, msgJSON); err != nil {
+		log.Println("Failed to send message to client:", err)
+	}
+}
+
 func broadcastAllRecords(s *Server) {
 	allRecords, err := fetchAllRecords()
 	if err != nil {
 		log.Println("Error fetching all records:", err)
 	}
 	if len(allRecords) > 0 {
-		var message Message
 		for _, msgContent := range allRecords {
-			err = json.Unmarshal([]byte(msgContent), &message)
+			fmt.Printf("Broadcasting %s to %d clients\n", msgContent, len(s.clients))
-			if err != nil {
-				log.Println("Unable to marshal JSON due to: ", err)
-			}
-			fmt.Printf("Broadcasting %s,%s,%s,%s to %d clients\n", message.Id, message.Status, message.Name, message.Timestamp, len(s.clients))
-
 			for client := range s.clients {
-				if err := client.conn.WriteMessage(websocket.TextMessage, []byte(msgContent)); err != nil {
+				sendToClient(client, []byte(msgContent))
-					log.Println("Failed to broadcast update:", err)
-				}
 			}
 		}
 	}
 }
 
 func broadcastRemovedRecords(s *Server, message Message) {
-	var msgJSON, err = json.Marshal(message)
-	if err != nil {
-		log.Println("Error marshalling json:", err)
-		return
-	}
 	fmt.Printf("Broadcasting removal: %s,%s,%s,%s to %d clients\n", message.Id, message.Status, message.Name, message.Timestamp, len(s.clients))
-
 	for client := range s.clients {
-		if err := client.conn.WriteMessage(websocket.TextMessage, msgJSON); err != nil {
+		sendMessageToClient(client, message)
-			log.Println("Failed to broadcast update:", err)
-			return
-		}
 	}
 }
 
 func broadcastExpiredRecords(s *Server, removed string) {
 	var message = Message{Id: removed, Name: "", Image: "", Status: "removed", Timestamp: ""}
-	var msgJSON, err = json.Marshal(message)
+	fmt.Printf("Broadcasting expiration: %s to %d clients\n", message, len(s.clients))
-	if err != nil {
-		log.Println("Error marshalling json:", err)
-		return
-	}
-	fmt.Printf("Broadcasting expiration: %s to %d clients\n", string(msgJSON), len(s.clients))
 	for client := range s.clients {
-		if err := client.conn.WriteMessage(websocket.TextMessage, msgJSON); err != nil {
+		sendMessageToClient(client, message)
-			log.Println("Failed to broadcast update:", err)
-			return
-		}
 	}
 }
 
-func broadcastAllRecordsToClient(c *Client) {
+func sendAllRecordsToClient(client *Client) {
 	allRecords, err := fetchAllRecords()
 	if err != nil {
 		log.Println("Error fetching all records:", err)
 	}
 	fmt.Printf("Broadcasting %d records to client\n", len(allRecords))
 	var message Message
+	client.mu.Lock()
+	defer client.mu.Unlock()
 	for _, msgContent := range allRecords {
 		err = json.Unmarshal([]byte(msgContent), &message)
 		if err != nil {
 			log.Println("Unable to marshal JSON due to: ", err)
 		}
 		fmt.Printf("Broadcasting %s,%s,%s,%s\n", message.Id, message.Status, message.Name, message.Timestamp)
-		if err := c.conn.WriteMessage(websocket.TextMessage, []byte(msgContent)); err != nil {
+		sendToClient(client, []byte(msgContent))
-			log.Println("Failed to broadcast update:", err)
-		}
 	}
 }