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Fast pages, required checks on the branch, self-hosted runners, honest incidents1import { AsyncLocalStorage } from "node:async_hooks";
2
3import type { ServiceBinding } from "@g1t/contracts";
4
5import {
6 type Bookmarks,
7 type ServiceTiming,
8 PRIMARY_WINDOW_SECONDS,
9 bookmarkCookie,
10 coveredMs,
11 mayWrite,
Public pages cacheable again: a signed-out GET never sets g1t_d1; stars, about and public_links are reads12 setsBookmark,
Fast pages, required checks on the branch, self-hosted runners, honest incidents13 readBookmarks,
14 rpcMethodOf,
15 serverTiming,
16 serviceDuration,
Git storage hardened, pages in tens of milliseconds, honest security alerts, and costs reconciled daily17 databaseTime,
Fast pages, required checks on the branch, self-hosted runners, honest incidents18 sessionFor,
19 SESSION_SERVICES,
20} from "./perf";
21
22/**
23 * What one request to the site did: when it started, each service call
24 * and how long it took, each loader, and the D1 bookmarks it read with and
25 * got back. Kept per request with AsyncLocalStorage, so the service
26 * clients, which are shared by every request in the isolate, can record
27 * into the right one.
28 */
29type RequestPerf = {
30 started: number;
31 /** Not GET or HEAD: an action, a form post. */
32 writing: boolean;
33 /** A service call that may have written (lib/perf.ts `mayWrite`). */
34 wrote: boolean;
35 bookmarks: Bookmarks;
36 returned: Record<string, string>;
37 intervals: [number, number][];
38 services: Record<string, ServiceTiming>;
39 loaders: { id: string; ms: number; kind: "loader" | "action" }[];
40 /** How each session-capable service was asked to read, for the header. */
41 sessions: Map<string, string>;
42};
43
44const scope = new AsyncLocalStorage<RequestPerf>();
45
46/** Runs `handle` with a fresh record for `request`. */
47export function withRequestPerf<T>(request: Request, handle: () => Promise<T>): Promise<T> {
48 const writing = request.method !== "GET" && request.method !== "HEAD";
49 return scope.run(
50 {
51 started: Date.now(),
52 writing,
53 wrote: false,
54 bookmarks: readBookmarks(request.headers.get("cookie")),
55 returned: {},
56 intervals: [],
57 services: {},
58 loaders: [],
59 sessions: new Map(),
60 },
61 handle,
62 );
63}
64
65/**
66 * `binding` with its calls timed, and, for a service that reads D1 with
67 * sessions, the `x-d1-bookmark` each call should carry (lib/perf.ts
68 * `sessionFor`). Only `fetch` is wrapped: the clients use nothing else.
69 */
70export function instrumented(name: string, binding: ServiceBinding): ServiceBinding {
71 return {
72 async fetch(input: string, init?: RequestInit) {
73 const perf = scope.getStore();
74 if (!perf) return binding.fetch(input, init);
75 const session = sessionFor(name, perf.bookmarks, perf.writing, Math.floor(Date.now() / 1000));
76 let sent = init;
77 if (session) {
78 const headers = new Headers(init?.headers);
79 headers.set("x-d1-bookmark", session);
80 sent = { ...init, headers };
81 perf.sessions.set(name, session.startsWith("first-") ? session.slice(6) : "bookmark");
82 }
83 if (SESSION_SERVICES.has(name) && mayWrite(rpcMethodOf(input))) perf.wrote = true;
84 const from = Date.now();
85 const response = await binding.fetch(input, sent);
86 const to = Date.now();
87 perf.intervals.push([from, to]);
88 const timing = (perf.services[name] ??= { calls: 0, wallMs: 0, serviceMs: 0 });
89 timing.calls += 1;
90 timing.wallMs += to - from;
Git storage hardened, pages in tens of milliseconds, honest security alerts, and costs reconciled daily91 const reported = response.headers.get("server-timing");
92 timing.serviceMs += serviceDuration(reported) ?? 0;
93 const database = databaseTime(reported);
94 if (database) {
95 timing.dbMs = (timing.dbMs ?? 0) + database.ms;
96 timing.dbTrips = (timing.dbTrips ?? 0) + database.trips;
97 }
Fast pages, required checks on the branch, self-hosted runners, honest incidents98 const bookmark = response.headers.get("x-d1-bookmark");
99 if (bookmark && SESSION_SERVICES.has(name)) perf.returned[name] = bookmark;
100 return response;
101 },
102 };
103}
104
105/**
106 * Whether this request must read current data: it writes, or the person
107 * wrote moments ago (lib/perf.ts `PRIMARY_WINDOW_SECONDS`). Caches step
108 * aside then (lib/cache.server.ts).
109 */
110export function mustReadFresh(): boolean {
111 const perf = scope.getStore();
112 if (!perf) return true;
113 if (perf.writing) return true;
114 const at = perf.bookmarks.at;
115 return at != null && Math.floor(Date.now() / 1000) - at < PRIMARY_WINDOW_SECONDS;
116}
117
118/** Records a loader's or action's time, from the route instrumentation. */
119export function recordHandler(id: string, kind: "loader" | "action", ms: number) {
120 scope.getStore()?.loaders.push({ id, kind, ms });
121}
122
123/**
124 * `response` with the request's `Server-Timing`, and, after a request
125 * that may have written, the bookmarks its services returned, so the
126 * person's next pages read at least what they just did.
127 */
128export function finishResponse(request: Request, response: Response): Response {
129 const perf = scope.getStore();
130 if (!perf) return response;
Chat and workspace agents: channels, DMs and named agents you talk to131 // A WebSocket handed over (chat's live socket) goes back as it is: a
132 // copy would lose the socket.
133 if (response.status === 101 || (response as Response & { webSocket?: unknown }).webSocket) return response;
Fast pages, required checks on the branch, self-hosted runners, honest incidents134 // A redirect's headers cannot be changed; a copy's can.
135 const answered = new Response(response.body, response);
136 const sessions = [...perf.sessions].map(([service, how]) => `${service}=${how}`).join(" ");
137 answered.headers.append(
138 "server-timing",
139 serverTiming({
140 totalMs: Date.now() - perf.started,
141 loaders: perf.loaders,
142 rpcMs: coveredMs(perf.intervals),
143 services: perf.services,
144 sessions,
145 }),
146 );
147 // Signing in with GitHub writes on a GET; the session it starts says so.
148 const signedIn = answered.headers.getSetCookie().some((cookie) => cookie.startsWith("g1t_session="));
Public pages cacheable again: a signed-out GET never sets g1t_d1; stars, about and public_links are reads149 const hasSession = /(?:^|;\s*)g1t_session=/.test(request.headers.get("cookie") ?? "");
150 if (setsBookmark({ writing: perf.writing, wrote: perf.wrote, hasSession, signedIn })) {
Fast pages, required checks on the branch, self-hosted runners, honest incidents151 const next: Bookmarks = {
152 at: Math.floor(Date.now() / 1000),
153 services: { ...perf.bookmarks.services, ...perf.returned },
154 };
155 answered.headers.append("set-cookie", bookmarkCookie(next, new URL(request.url).protocol === "https:"));
156 }
157 return answered;
158}