fix(workbench): flush sse and report open latency (#1986)

Co-authored-by: root <root@lyon.remote>

internal/cloud/server-workbench-http.ts

@@ -106,6 +106,7 @@ export async function handleWorkbenchRealtimeHttp(request, response, url, option
     "x-accel-buffering": "no",
     "x-content-type-options": "nosniff"
   });
+  if (typeof response.flushHeaders === "function") response.flushHeaders();
 
   const writeEvent = (name, payload = {}) => {
     if (closed || response.destroyed) return;
@@ -146,7 +147,7 @@ export async function handleWorkbenchRealtimeHttp(request, response, url, option
     await (perf ? perf.measure("workbench_initial_trace", () => writeTraceRealtimeSnapshotSafe({ writeEvent, options, actor: auth.actor, traceId: activeTraceId, reason: "initial" })) : writeTraceRealtimeSnapshotSafe({ writeEvent, options, actor: auth.actor, traceId: activeTraceId, reason: "initial" }));
   }
   const runtimeStore = options.runtimeStore ?? null;
-  const outboxPollMs = parsePositiveInteger(options.env?.HWLAB_WORKBENCH_SSE_OUTBOX_POLL_MS, 2000);
+  const outboxPollMs = parsePositiveInteger(options.env?.HWLAB_WORKBENCH_SSE_OUTBOX_POLL_MS, 500);
   let outboxCursor = 0;
   const outboxTraceSnapshots = new Set(activeTraceId ? [activeTraceId] : []);
   if (typeof runtimeStore?.readWorkbenchProjectionOutbox === "function" && (streamSessionId || activeTraceId)) {

web/hwlab-cloud-web/src/api/workbench-events.ts

@@ -65,10 +65,12 @@ export function connectWorkbenchEvents(options: WorkbenchEventStreamOptions): Wo
   appendParam(params, "sessionId", options.sessionId);
   appendParam(params, "traceId", options.traceId);
   const eventRoute = `/v1/workbench/events?${params.toString()}`;
+  const connectStartedAt = typeof performance === "undefined" ? Date.now() : performance.now();
   recordWorkbenchSseLifecycle({ state: "connect", route: eventRoute, sessionId: options.sessionId, traceId: options.traceId });
   const source = new EventSource(eventRoute, { withCredentials: true });
   source.onopen = () => {
-    recordWorkbenchSseLifecycle({ state: "open", route: eventRoute, sessionId: options.sessionId, traceId: options.traceId });
+    const openedAt = typeof performance === "undefined" ? Date.now() : performance.now();
+    recordWorkbenchSseLifecycle({ state: "open", route: eventRoute, sessionId: options.sessionId, traceId: options.traceId, valueMs: Math.max(0, Math.round(openedAt - connectStartedAt)) });
     options.onOpen?.();
   };
   source.onerror = (event) => {

web/hwlab-cloud-web/src/utils/workbench-performance.ts

@@ -299,18 +299,20 @@ function serverTimingSummary(entries: readonly PerformanceServerTiming[] | undef
   return summary.slice(0, 240) || undefined;
 }
 
-export function recordWorkbenchSseLifecycle(input: { state: "connect" | "open" | "error" | "close"; route: string; sessionId?: string | null; traceId?: string | null; errorName?: string | null }): void {
+export function recordWorkbenchSseLifecycle(input: { state: "connect" | "open" | "error" | "close"; route: string; sessionId?: string | null; traceId?: string | null; errorName?: string | null; valueMs?: number | null }): void {
   ensureInstalled();
   const state = input.state;
+  const endedAt = wallNow();
+  const valueMs = roundedNonNegative(Number(input.valueMs ?? 0)) ?? 0;
   enqueueWorkbenchUiEvent({
     eventType: "sse_lifecycle",
     loadingScope: "sse",
     state,
     reason: state === "connect" ? "sse_connect" : state === "open" ? "sse_open" : state === "close" ? "sse_close" : "sse_error",
     route: input.route,
-    valueMs: 0,
-    startedAtEpochMs: wallNow(),
-    endedAtEpochMs: wallNow(),
+    valueMs,
+    startedAtEpochMs: Math.max(0, endedAt - valueMs),
+    endedAtEpochMs: endedAt,
     sessionHash: hashIdentifier(input.sessionId, "ses"),
     traceHash: hashIdentifier(input.traceId, "trc"),
     outcome: state === "error" ? "network" : "ok",