初始化2

bj_power_mes/internal/sse/sse.go

@@ -0,0 +1,81 @@
+package sse
+
+import (
+	"fmt"
+	"net/http"
+	"sync"
+)
+
+// SseMsg SSE 事件消息
+type SseMsg struct {
+	Type string // 事件名，如表单名 dashboard.*
+	Data string // JSON 字符串
+}
+
+// Hub SSE 推送中心（支持看板局部刷新）
+type Hub struct {
+	mu      sync.Mutex
+	clients map[chan SseMsg]struct{}
+	closed  map[chan SseMsg]bool
+}
+
+func NewHub() *Hub {
+	return &Hub{clients: make(map[chan SseMsg]struct{})}
+}
+
+// Add 新增客户端
+func (h *Hub) Add() chan SseMsg {
+	ch := make(chan SseMsg, 16)
+	h.mu.Lock()
+	h.clients[ch] = struct{}{}
+	h.mu.Unlock()
+	return ch
+}
+
+func (h *Hub) Remove(ch chan SseMsg) {
+	h.mu.Lock()
+	if _, ok := h.clients[ch]; ok {
+		delete(h.clients, ch)
+		close(ch)
+	}
+	h.mu.Unlock()
+}
+
+// Publish 广播事件
+func (h *Hub) Publish(typ string, data string) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	for ch := range h.clients {
+		select {
+		case ch <- SseMsg{Type: typ, Data: data}:
+		default:
+		}
+	}
+}
+
+// Handler SSE 长连接端点
+func (h *Hub) Handler(w http.ResponseWriter, r *http.Request) {
+	fl, ok := w.(http.Flusher)
+	if !ok {
+		http.Error(w, "streaming unsupported", http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+	ch := h.Add()
+	defer h.Remove(ch)
+
+	h.Publish("dashboard.hello", "{}")
+	for {
+		select {
+		case m := <-ch:
+			if _, err := fmt.Fprintf(w, "event: %s\ndata: %s\n\n", m.Type, m.Data); err != nil {
+				return
+			}
+			fl.Flush()
+		case <-r.Context().Done():
+			return
+		}
+	}
+}