feat(devops): separate public page server timing diagnostics

src/lib/public-page-performance.ts

@@ -0,0 +1,61 @@
+import { createStore, runWithStore } from "./foundation/request-context";
+import type { IpAddress } from "./foundation/types";
+import { collectPerformance } from "./performance-diagnostics";
+import { type PerformanceSample, recordPerformance } from "./performance-store";
+
+type PublicRoute =
+	| "/me"
+	| "/news"
+	| "/news/[slug]"
+	| "/u/[username]"
+	| "/events"
+	| "/search";
+/** Measures this server component invocation, not child rendering, streaming or browser load. */
+export function withPublicPagePerformance<Props, Result>(
+	route: PublicRoute,
+	render: (props: Props) => Promise<Result>,
+) {
+	return async (props: Props): Promise<Result> => {
+		if (
+			process.env.NEXT_PHASE === "phase-production-build" ||
+			process.env.NEXT_PHASE === "phase-production-compile"
+		)
+			return render(props);
+		const store = createStore("unknown" as IpAddress);
+		let outcome: PerformanceSample["outcome"] = "completed";
+		return runWithStore(store, async () => {
+			const result = await collectPerformance(
+				async () => {
+					try {
+						return await render(props);
+					} catch (error) {
+						const digest =
+							error && typeof error === "object" && "digest" in error
+								? String(error.digest)
+								: "";
+						outcome = digest.startsWith("NEXT_REDIRECT;")
+							? "redirect"
+							: digest === "NEXT_HTTP_ERROR_FALLBACK;404"
+								? "not-found"
+								: "failed";
+						throw error;
+					}
+				},
+				(metrics) =>
+					recordPerformance({
+						kind: "public-page",
+						outcome,
+						operationId: store.requestId,
+						route,
+						method: "PAGE",
+						status:
+							outcome === "failed" ? 500 : outcome === "not-found" ? 404 : 200,
+						at: Date.now(),
+						streaming: false,
+						metrics,
+					}),
+			);
+			return result.value;
+		});
+	};
+}