feat: 完成网关服务代码实现，支持 WebSocket 长连接与健康检查

backend/gateway/main.go

@@ -0,0 +1,155 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/gorilla/websocket"
+)
+
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+type Hub struct {
+	clients    map[*Client]bool
+	broadcast  chan []byte
+	register   chan *Client
+	unregister chan *Client
+}
+
+type Client struct {
+	hub  *Hub
+	conn *websocket.Conn
+	send chan []byte
+}
+
+type Message struct {
+	Type    string `json:"type"`
+	Content string `json:"content"`
+	Sender  string `json:"sender"`
+}
+
+func newHub() *Hub {
+	return &Hub{
+		broadcast:  make(chan []byte),
+		register:   make(chan *Client),
+		unregister: make(chan *Client),
+		clients:    make(map[*Client]bool),
+	}
+}
+
+func (h *Hub) run() {
+	for {
+		select {
+		case client := <-h.register:
+			h.clients[client] = true
+		case client := <-h.unregister:
+			if _, ok := h.clients[client]; ok {
+				delete(h.clients, client)
+				close(client.send)
+			}
+		case message := <-h.broadcast:
+			for client := range h.clients {
+				select {
+				case client.send <- message:
+				default:
+					close(client.send)
+					delete(h.clients, client)
+				}
+			}
+		}
+	}
+}
+
+func (c *Client) readPump() {
+	defer func() {
+		c.hub.unregister <- c
+		c.conn.Close()
+	}()
+
+	for {
+		_, message, err := c.conn.ReadMessage()
+		if err != nil {
+			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
+				log.Printf("error: %v", err)
+			}
+			break
+		}
+		c.hub.broadcast <- message
+	}
+}
+
+func (c *Client) writePump() {
+	defer func() {
+		c.conn.Close()
+	}()
+
+	for {
+		message, ok := <-c.send
+		if !ok {
+			c.conn.WriteMessage(websocket.CloseMessage, []byte{})
+			return
+		}
+
+		w, err := c.conn.NextWriter(websocket.TextMessage)
+		if err != nil {
+			return
+		}
+		w.Write(message)
+
+		n := len(c.send)
+		for i := 0; i < n; i++ {
+			w.Write([]byte("\n"))
+			w.Write(<-c.send)
+		}
+
+		if err := w.Close(); err != nil {
+			return
+		}
+	}
+}
+
+func handleWebSocket(hub *Hub) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		client := &Client{
+			hub:  hub,
+			conn: conn,
+			send: make(chan []byte, 256),
+		}
+		client.hub.register <- client
+
+		go client.writePump()
+		go client.readPump()
+	}
+}
+
+func main() {
+	hub := newHub()
+	go hub.run()
+
+	r := gin.Default()
+
+	r.GET("/ws", handleWebSocket(hub))
+	r.GET("/health", func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{
+			"status": "ok",
+		})
+	})
+
+	log.Println("Gateway server starting on port 8080...")
+	if err := r.Run(":8080"); err != nil {
+		log.Fatalf("Failed to start server: %v", err)
+	}
+}