statStream 是 /v1/stat/stream 的 SSE 处理器（无需认证）。 连接时立即推送 event:init（完整 stat 数据），之后每 2s 推送 event:metrics（实时网速）， 每 60s 重推 event:init（刷新 uptime bars 等慢变数据）。
(w http.ResponseWriter, r *http.Request)
| 369 | // 连接时立即推送 event:init（完整 stat 数据），之后每 2s 推送 event:metrics（实时网速）， |
| 370 | // 每 60s 重推 event:init（刷新 uptime bars 等慢变数据）。 |
| 371 | func (h *Handler) statStream(w http.ResponseWriter, r *http.Request) { |
| 372 | flusher, ok := w.(http.Flusher) |
| 373 | if !ok { |
| 374 | http.Error(w, "streaming not supported", http.StatusInternalServerError) |
| 375 | return |
| 376 | } |
| 377 | w.Header().Set("Content-Type", "text/event-stream") |
| 378 | w.Header().Set("Cache-Control", "no-cache") |
| 379 | w.Header().Set("Connection", "keep-alive") |
| 380 | |
| 381 | sendInit := func() { |
| 382 | payload, err := h.buildStatPayload() |
| 383 | if err != nil { |
| 384 | return |
| 385 | } |
| 386 | data, err := json.Marshal(payload) |
| 387 | if err != nil { |
| 388 | return |
| 389 | } |
| 390 | fmt.Fprintf(w, "event: init\ndata: %s\n\n", data) |
| 391 | flusher.Flush() |
| 392 | } |
| 393 | |
| 394 | type nodeMetric struct { |
| 395 | NodeID string `json:"node_id"` |
| 396 | UploadSpeed int64 `json:"upload_speed"` |
| 397 | DownloadSpeed int64 `json:"download_speed"` |
| 398 | Connections int `json:"connections"` |
| 399 | Running bool `json:"running"` |
| 400 | } |
| 401 | |
| 402 | sendMetrics := func() { |
| 403 | nodeList, err := h.nodeStore.List() |
| 404 | if err != nil { |
| 405 | return |
| 406 | } |
| 407 | results := make([]nodeMetric, 0, len(nodeList)) |
| 408 | var mu sync.Mutex |
| 409 | var wg sync.WaitGroup |
| 410 | for _, n := range nodeList { |
| 411 | wg.Add(1) |
| 412 | go func(n nodes.Node) { |
| 413 | defer wg.Done() |
| 414 | client, err := h.dial(n.ID) |
| 415 | if err != nil { |
| 416 | return |
| 417 | } |
| 418 | ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second) |
| 419 | defer cancel() |
| 420 | stats, err := client.Usage(ctx, false) |
| 421 | if err != nil { |
| 422 | return |
| 423 | } |
| 424 | mu.Lock() |
| 425 | results = append(results, nodeMetric{ |
| 426 | NodeID: n.ID, |
| 427 | UploadSpeed: stats.UploadSpeed, |
| 428 | DownloadSpeed: stats.DownloadSpeed, |