wip(cloud-function): clean up server-timing logic

mdn · Jul 30, 2024 · 3f264cf · 3f264cf
1 parent db9360e
commit 3f264cf
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Showing 2 changed files with 12 additions and 14 deletions.
diff --git a/cloud-function/src/handlers/render-html.ts b/cloud-function/src/handlers/render-html.ts
@@ -18,6 +18,7 @@ export async function renderIndexHTML(
   next: NextFunction
 ) {
   if (req.url.endsWith("/index.html")) {
+    req.startServerTiming("totalSSR");
     const html = await renderHTMLForContext(
       req,
       res,
@@ -55,9 +56,7 @@ export async function renderHTMLForContext(
   }
 
   try {
-    req.startServerTiming("addHeaders");
     withRenderedContentResponseHeaders(req, res);
-    req.endServerTiming("addHeaders");
     req.startServerTiming("renderHTML");
     const html = renderHTML(context);
     req.endServerTiming("renderHTML");

diff --git a/cloud-function/src/middlewares/server-timing.ts b/cloud-function/src/middlewares/server-timing.ts
@@ -8,28 +8,27 @@ export async function addServerTimingHeaders(
   res: Response,
   next: NextFunction
 ) {
-  const timers = new Map<
-    string,
-    { finished: boolean; hrtime: [number, number] }
-  >();
+  const timers = new Map<string, { start: bigint; diff?: bigint }>();
 
   req.startServerTiming = (id: string) => {
-    timers.set(id, { finished: false, hrtime: hrtime() });
+    timers.set(id, { start: hrtime.bigint() });
   };
+
   req.endServerTiming = (id: string) => {
-    timers.set(id, { finished: true, hrtime: hrtime(timers.get(id)?.hrtime) });
+    const start = timers.get(id)?.start;
+    if (start !== undefined) {
+      timers.set(id, { start, diff: hrtime.bigint() - start });
+    }
   };
 
   req.startServerTiming("total");
 
   onHeaders(res, () => {
-    req.endServerTiming("total");
     const header = [...timers]
-      .filter(([, { finished }]) => finished)
-      .map(
-        ([id, { hrtime }]) =>
-          `${id};dur=${((hrtime[0] * 1e9 + hrtime[1]) / 1e6).toFixed(0)}`
-      )
+      .map(([id, { start, diff }]) => {
+        const time = diff !== undefined ? diff : hrtime.bigint() - start;
+        return `${id};dur=${time / BigInt(1e6)}`;
+      })
       .join(", ");
     res.setHeader("Server-Timing", header);
   });