feat(api): 实现 WebSocket 服务器的订阅功能

- 将 clients map 的值从 bool 改为 string，用于存储订阅的主题
- 在 handleWebSocket 函数中实现客户端注册逻辑
- 在 handleClient 函数中处理订阅请求，并保存订阅的主题
- 修改 handleDataChange 函数，仅向订阅了相应主题的客户端广播事件
- 在 DataPointID 结构中添加 MetricHash 方法，用于生成主题哈希值

pkg/api/websocket.go

@@ -20,7 +20,7 @@ type WebSocketServer struct {
 	dataManager *manager.DataManager
 	router      *gin.Engine
 	server      *http.Server
-	clients     map[*websocket.Conn]bool
+	clients     map[*websocket.Conn]string
 	clientsLock sync.RWMutex
 	upgrader    websocket.Upgrader
 }
@@ -48,7 +48,7 @@ func NewWebSocketServer(dataManager *manager.DataManager) *WebSocketServer {
 	server := &WebSocketServer{
 		dataManager: dataManager,
 		router:      router,
-		clients:     make(map[*websocket.Conn]bool),
+		clients:     make(map[*websocket.Conn]string),
 		upgrader: websocket.Upgrader{
 			CheckOrigin: func(r *http.Request) bool {
 				return true // 允许所有来源的WebSocket连接
@@ -81,7 +81,7 @@ func (s *WebSocketServer) handleWebSocket(c *gin.Context) {
 
 	// 注册客户端
 	s.clientsLock.Lock()
-	s.clients[conn] = true
+	s.clients[conn] = ""
 	s.clientsLock.Unlock()
 
 	// 处理客户端消息
@@ -116,9 +116,12 @@ func (s *WebSocketServer) handleClient(conn *websocket.Conn) {
 			log.Printf("Failed to parse subscription request: %v", err)
 			continue
 		}
+		id := model.DataPointID{
+			DeviceID:   req.DeviceID,
+			MetricCode: req.MetricCode,
+		}
+		s.clients[conn] = id.MetricHash()
 
-		// 处理订阅请求
-		// TODO: 实现订阅逻辑
 	}
 }
 
@@ -133,6 +136,7 @@ func (s *WebSocketServer) handleDataChange(id model.DataPointID, value model.Dat
 		Value:      value.Value,
 	}
 
+	metricHash := id.MetricHash()
 	// 序列化事件
 	data, err := json.Marshal(event)
 	if err != nil {
@@ -142,7 +146,10 @@ func (s *WebSocketServer) handleDataChange(id model.DataPointID, value model.Dat
 
 	// 广播事件
 	s.clientsLock.RLock()
-	for client := range s.clients {
+	for client, subject := range s.clients {
+		if subject != metricHash {
+			continue // 忽略非匹配的订阅
+		}
 		if err := client.WriteMessage(websocket.TextMessage, data); err != nil {
 			log.Printf("Failed to send data change event: %v", err)
 			client.Close()

pkg/model/datapoint.go

@@ -19,6 +19,10 @@ func (id DataPointID) String() string {
 	return id.Hash()
 }
 
+func (id DataPointID) MetricHash() string {
+	return fmt.Sprintf("%s:%s", id.DeviceID, id.MetricCode)
+}
+
 // Equal 判断两个数据点标识是否相等
 func (id DataPointID) Equal(other DataPointID) bool {
 	if id.DeviceID != other.DeviceID || id.MetricCode != other.MetricCode {