69ad0b4
@@ -363,6 +363,49 @@
export async function benchMapHome(
  return samples;
}
/** `/map`'s Server-Timing phases, p50 and p95 in ms, over `iterations` warm hits. */
export async function benchMapPhases(
  fixture: Fixture,
  iterations: number,
): Promise<string> {
  const servers = await serve(fixture.app);
  const names = ["app", "session", "lanes", "layout", "render"];
  const rows: string[] = [
    "| `GET /map` phase | owner p50 | owner p95 | stranger p50 | stranger p95 |",
    "| ---------------- | --------: | --------: | -----------: | -----------: |",
  ];
  const stats = new Map<string, number[][]>();
  try {
    for (const cookie of [fixture.ownerCookie, fixture.strangerCookie]) {
      const seen = new Map<string, number[]>(names.map((n) => [n, []]));
      for (let i = 0; i < iterations + 1; i++) {
        const response = await fetch(`${servers.url}/map`, { headers: { cookie } });
        await response.arrayBuffer();
        if (i === 0) continue;
        const header = response.headers.get("server-timing") ?? "";
        for (const m of header.matchAll(/([a-z-]+);dur=([\d.]+)/g))
          seen.get(m[1]!)?.push(Number(m[2]));
      }
      for (const n of names) {
        const sorted = seen.get(n)!.sort((a, b) => a - b);
        const at = (p: number) =>
          sorted[Math.min(sorted.length - 1, Math.floor((sorted.length * p) / 100))] ?? 0;
        stats.set(n, [...(stats.get(n) ?? []), [at(50), at(95)]]);
      }
    }
  } finally {
    servers.stop();
  }
  for (const n of names) {
    const [o, s] = stats.get(n)!;
    const label = n === "app" ? "total (`app`)" : `\`${n}\``;
    rows.push(
      `| ${label} | ${o![0]!.toFixed(1)} | ${o![1]!.toFixed(1)} | ${s![0]!.toFixed(1)} | ${s![1]!.toFixed(1)} |`,
    );
  }
  return rows.join("\n");
}
const TITLES = [
  "the map lays out by what waits for what",
  "home paints before the feed",
@@ -390,6 +433,9 @@
if (import.meta.main) {
      Number.isFinite(n) && n > 0 ? n : 30,
    );
    console.log(report(samples, argv.includes("--verbose")));
    console.log(
      `\n${await benchMapPhases(fixture, Number.isFinite(n) && n > 0 ? n : 30)}`,
    );
    fixture.app.close();
  } finally {
    rmSync(dir, { recursive: true, force: true });
@@ -91,6 +91,21 @@
After #2716 (same fixture, same machine, `--n 30`, warm; `/` unchanged):
What is left is rendering the ~1 MB of SVG (25 ms), which rule 3 keeps
per request.
`/map`'s `Server-Timing` names where that goes (#3159): `app` is the total,
then `session`, `lanes` (the cache lookups, and the build on a miss, less the
layout inside it), `layout` (graph layout on a miss) and `render`. Their sum
is never more than `app`; the rest is routing and sending. One
`bun run bench/map-home.ts` run (`--n 30`, warm, so `layout` is a cache hit
and rounds to 0.0):
| `GET /map` phase | owner p50 | owner p95 | stranger p50 | stranger p95 |
| ---------------- | --------: | --------: | -----------: | -----------: |
| total (`app`)    |      27.8 |      31.2 |         27.2 |         29.6 |
| `session`        |       0.2 |       0.3 |          0.2 |          0.3 |
| `lanes`          |       1.8 |       2.2 |          1.7 |          1.9 |
| `layout`         |       0.0 |       0.0 |          0.0 |          0.0 |
| `render`         |      17.7 |      20.1 |         17.4 |         19.1 |
### Where the time goes
- **`/map`: `layout` of the big lane alone takes 408 ms of the ~490 ms
@@ -149,11 +149,55 @@
export function readTiming(db: Database, sinceHour: string): TimingRow[] {
}
/** The header every response carries: `app;dur=<ms>`, and `db` when known. */
export function serverTiming(appMs: number, dbMs?: number): string {
export function serverTiming(
  appMs: number,
  dbMs?: number,
  phases: readonly Phase[] = [],
): string {
  const f = (n: number) => n.toFixed(1);
  return dbMs === undefined
    ? `app;dur=${f(appMs)}`
    : `db;dur=${f(dbMs)}, app;dur=${f(appMs)}`;
  const head =
    dbMs === undefined
      ? `app;dur=${f(appMs)}`
      : `db;dur=${f(dbMs)}, app;dur=${f(appMs)}`;
  return [head, ...phases.map((p) => `${p.name};dur=${f(p.ms)}`)].join(", ");
}
/** One named stretch of a request, in milliseconds. */
export interface Phase {
  readonly name: string;
  readonly ms: number;
}
/** A phase name is a header token: lowercase letters, nothing a viewer chose. */
const PHASE_NAME = /^[a-z][a-z0-9-]{0,15}$/;
const phaseLists = new WeakMap<Request, Phase[]>();
/** A page names a phase it spent `ms` in; `serverTiming` writes it after `app`. */
export function notePhase(request: Request, name: string, ms: number): void {
  if (!PHASE_NAME.test(name))
    throw new RangeError("phase refused: the name must be a lowercase token");
  if (!Number.isFinite(ms) || ms < 0) return;
  const list = phaseLists.get(request) ?? [];
  list.push({ name, ms });
  phaseLists.set(request, list);
}
export function takePhases(request: Request): Phase[] {
  const list = phaseLists.get(request) ?? [];
  phaseLists.delete(request);
  return list;
}
const sessionTimes = new WeakMap<Request, number>();
/** The server says how long resolving the session took; a page may name it. */
export function noteSessionTime(request: Request, ms: number): void {
  sessionTimes.set(request, ms);
}
export function takeSessionTime(request: Request): number {
  return sessionTimes.get(request) ?? 0;
      
        sentinelcrew
        24d ago
        
      
      Nit: takeSessionTime doesn't delete its entry the way takePhases (and takeDbTime) do. That's harmless with a WeakMap, but take* reads as consume-once. Either delete it here or call it sessionTime. Also, noteSessionTime runs on every GET while only /map reads it. That's fine for now, but if a second page wants session, it's worth folding into the server's own serverTiming call.
    
}
const dbTimes = new WeakMap<Request, number>();
@@ -462,6 +462,8 @@
import { createUsageCounter, type UsageCounter } from "../core/usage_count.ts";
import {
  createRouteTiming,
  noteDbTime,
  noteSessionTime,
  takePhases,
  serverTiming,
  takeDbTime,
  type RouteTiming,
@@ -2123,7 +2125,7 @@
export async function serve(app: App): Promise<Servers> {
    const tag = takeUsage(request);
    const ms = performance.now() - started;
    try {
      response.headers.set("server-timing", serverTiming(ms, takeDbTime(request)));
      response.headers.set("server-timing", serverTiming(ms, takeDbTime(request), takePhases(request)));
    } catch {
      // A response the forge is only carrying keeps the headers it came with.
    }
@@ -2428,7 +2430,9 @@
async function answerGet(
    }
    return noRoute(request.method, url.pathname);
  }
  const authStart = performance.now();
  const auth = await resolveAuth(app, request);
  noteSessionTime(request, performance.now() - authStart);
  if (auth.retryAfter !== undefined) return tooManyAttempts(auth.retryAfter);
  noteUsage(request, { pattern: matched.pattern, role: roleOf(auth) });
  // From here a body's cap depends on who is asking (`http/limits.ts`), and
@@ -33,6 +33,7 @@
import {
  type Ranked,
} from "../../core/dependencies.ts";
import type { Issue } from "../../core/issues.ts";
import { notePhase, takeSessionTime } from "../../core/route_timing.ts";
import { cachedLane, cachedLayout, repoHeads, scopeKey } from "../map_cache.ts";
import { holdsFor } from "../../core/holds.ts";
import {
@@ -1513,6 +1514,21 @@
type KeptLane = Omit<Lane, "repo" | "workers"> & {
  readonly workerIds: string[];
};
/** Milliseconds a request spent laying graphs out, inside the lanes' build. */
export interface Spent {
  layoutMs: number;
}
function timed<T>(spent: Spent | undefined, run: () => T): T {
  if (spent === undefined) return run();
  const started = performance.now();
  try {
    return run();
  } finally {
    spent.layoutMs += performance.now() - started;
  }
}
/**
 * One repository's lane for one scope, or null when it has nothing to draw.
 * Every read of issues here respects `scope`, so the entry it becomes is
@@ -1523,6 +1539,7 @@
function buildLane(
  repo: Repo,
  viewer: User | undefined,
  scope: ReturnType<typeof sealedScope>,
  spent?: Spent,
): KeptLane | null {
  const db = app.db;
  // A run on a sealed report is not shown to who may not see the report.
@@ -1550,7 +1567,7 @@
function buildLane(
  );
  return {
    graph,
    placed: cachedLayout(graph, layout),
    placed: timed(spent, () => cachedLayout(graph, layout)),
    marks,
    ready,
    critical: criticalPath(graph),
@@ -1571,7 +1588,11 @@
function buildLane(
 * for every run in flight and one for who runs them; a graph and its marks
 * only for the lanes that stay.
 */
export function globalLanes(app: App, viewer: User | undefined): Lane[] {
export function globalLanes(
  app: App,
  viewer: User | undefined,
  spent?: Spent,
): Lane[] {
  const db = app.db;
  const now = new Date();
  // Access first, every request, and into the key (docs/CACHING.md rule 1).
@@ -1593,7 +1614,7 @@
export function globalLanes(app: App, viewer: User | undefined): Lane[] {
        scope: scopeKey(scope),
        now,
      },
      () => buildLane(app, repo, viewer, scope),
      () => buildLane(app, repo, viewer, scope, spent),
    );
    if (lane !== null) built.push({ repo, lane });
  }
@@ -1680,7 +1701,15 @@
export function laneHtml(lane: Lane, width: number): Html {
export function globalMapPage(ctx: Ctx): Response {
  const viewer = ctx.auth.user;
  if (!viewer) return signInFirst(ctx);
  const lanes = globalLanes(ctx.app, viewer);
  const { request } = ctx;
  notePhase(request, "session", takeSessionTime(request));
  const spent: Spent = { layoutMs: 0 };
  const lanesStart = performance.now();
  const lanes = globalLanes(ctx.app, viewer, spent);
  const lanesMs = performance.now() - lanesStart;
  notePhase(request, "lanes", Math.max(0, lanesMs - spent.layoutMs));
  notePhase(request, "layout", spent.layoutMs);
  const renderStart = performance.now();
  const width = Math.max(0, ...lanes.map((l) => drawingWidth(l.placed)));
  const body = html`${pageHead("Map", {
      sub: "Every app you can see, laid out by what waits for what. The top edge of each lane is ready now; a ringed card is where the crew is.",
@@ -1693,13 +1722,15 @@
export function globalMapPage(ctx: Ctx): Response {
          </p>`
        : lanes.map((lane) => laneHtml(lane, width))}
    </div>`;
  return page({
  const response = page({
    ctx,
    title: "Map",
    body,
    styleCss: mapCss,
    scriptJs: `${liveRegionsJs}\n${mapViewJs}`,
  });
  notePhase(request, "render", performance.now() - renderStart);
  return response;
}
/** GET /api/v1/map — the lanes as data, one entry per repository. */
@@ -230,3 +230,34 @@
describe("the layout key", () => {
    expect(layout(graph).nodes.length).toBe(graph.issues.length);
  });
});
describe("/map's Server-Timing names its phases", () => {
  let servers: Servers;
  let f: Fixture;
  beforeAll(async () => {
    ({ f, servers } = await boot(SMALL));
  }, 120_000);
  afterAll(() => servers.stop(), 60_000);
  for (const who of ["owner", "stranger"] as const) {
    test(`${who}: session, lanes, layout and render follow app, and sum to no more than it`, async () => {
      clearMapCache();
      const cookie = who === "owner" ? f.ownerCookie : f.strangerCookie;
      for (const pass of ["cold", "warm"]) {
        const res = await fetch(`${servers.url}/map`, { headers: { cookie } });
        const header = res.headers.get("server-timing") ?? "";
        const dur = new Map(
          [...header.matchAll(/([a-z-]+);dur=(\d+\.\d)/g)].map((m) => [m[1]!, Number(m[2])]),
        );
        const names = [...dur.keys()];
        expect(names.slice(-4), `${pass}: ${header}`).toEqual(["session", "lanes", "layout", "render"]);
        expect(header.split(", ").every((p) => /^[a-z-]+;dur=\d+\.\d$/.test(p))).toBe(true);
        const sum = ["session", "lanes", "layout", "render"].reduce((n, k) => n + dur.get(k)!, 0);
        // Each is printed to a tenth of a millisecond, so allow that rounding.
        expect(sum).toBeLessThanOrEqual(dur.get("app")! + 0.4);
        // No repository name rides in the header.
        expect(header).not.toMatch(/\//);
      }
    });
  }
});
@@ -11,7 +11,9 @@
import {
  createRouteTiming,
  KEEP_DAYS,
  readTiming,
  notePhase,
  serverTiming,
  takePhases,
} from "../src/core/route_timing.ts";
import { serve } from "../src/http/server.ts";
import { migrate } from "../src/kernel/migrate.ts";
@@ -88,3 +90,11 @@
test("the header names db time only when known", () => {
  expect(serverTiming(1.234)).toBe("app;dur=1.2");
  expect(serverTiming(2, 0.5)).toBe("db;dur=0.5, app;dur=2.0");
});
test("phases follow app in the header, and a name that is not a token is refused", () => {
  const request = new Request("http://x/");
  notePhase(request, "lanes", 1.26);
  expect(serverTiming(5, undefined, takePhases(request))).toBe("app;dur=5.0, lanes;dur=1.3");
  expect(takePhases(request)).toEqual([]);
  expect(() => notePhase(request, "my repo", 1)).toThrow();
});
		@@ -363,6 +363,49 @@ export async function benchMapHome(
363	363	return samples;
364	364	}
365	365
	366	/** `/map`'s Server-Timing phases, p50 and p95 in ms, over `iterations` warm hits. */
	367	export async function benchMapPhases(
	368	fixture: Fixture,
	369	iterations: number,
	370	): Promise<string> {
	371	const servers = await serve(fixture.app);
	372	const names = ["app", "session", "lanes", "layout", "render"];
	373	const rows: string[] = [
	374	"\| `GET /map` phase \| owner p50 \| owner p95 \| stranger p50 \| stranger p95 \|",
	375	"\| ---------------- \| --------: \| --------: \| -----------: \| -----------: \|",
	376	];
	377	const stats = new Map<string, number[][]>();
	378	try {
	379	for (const cookie of [fixture.ownerCookie, fixture.strangerCookie]) {
	380	const seen = new Map<string, number[]>(names.map((n) => [n, []]));
	381	for (let i = 0; i < iterations + 1; i++) {
	382	const response = await fetch(`${servers.url}/map`, { headers: { cookie } });
	383	await response.arrayBuffer();
	384	if (i === 0) continue;
	385	const header = response.headers.get("server-timing") ?? "";
	386	for (const m of header.matchAll(/([a-z-]+);dur=([\d.]+)/g))
	387	seen.get(m[1]!)?.push(Number(m[2]));
	388	}
	389	for (const n of names) {
	390	const sorted = seen.get(n)!.sort((a, b) => a - b);
	391	const at = (p: number) =>
	392	sorted[Math.min(sorted.length - 1, Math.floor((sorted.length * p) / 100))] ?? 0;
	393	stats.set(n, [...(stats.get(n) ?? []), [at(50), at(95)]]);
	394	}
	395	}
	396	} finally {
	397	servers.stop();
	398	}
	399	for (const n of names) {
	400	const [o, s] = stats.get(n)!;
	401	const label = n === "app" ? "total (`app`)" : `\`${n}\``;
	402	rows.push(
	403	`\| ${label} \| ${o![0]!.toFixed(1)} \| ${o![1]!.toFixed(1)} \| ${s![0]!.toFixed(1)} \| ${s![1]!.toFixed(1)} \|`,
	404	);
	405	}
	406	return rows.join("\n");
	407	}
	408
366	409	const TITLES = [
367	410	"the map lays out by what waits for what",
368	411	"home paints before the feed",
		@@ -390,6 +433,9 @@ if (import.meta.main) {
390	433	Number.isFinite(n) && n > 0 ? n : 30,
391	434	);
392	435	console.log(report(samples, argv.includes("--verbose")));
	436	console.log(
	437	`\n${await benchMapPhases(fixture, Number.isFinite(n) && n > 0 ? n : 30)}`,
	438	);
393	439	fixture.app.close();
394	440	} finally {
395	441	rmSync(dir, { recursive: true, force: true });
		@@ -91,6 +91,21 @@ After #2716 (same fixture, same machine, `--n 30`, warm; `/` unchanged):
91	91	What is left is rendering the ~1 MB of SVG (25 ms), which rule 3 keeps
92	92	per request.
93	93
	94	`/map`'s `Server-Timing` names where that goes (#3159): `app` is the total,
	95	then `session`, `lanes` (the cache lookups, and the build on a miss, less the
	96	layout inside it), `layout` (graph layout on a miss) and `render`. Their sum
	97	is never more than `app`; the rest is routing and sending. One
	98	`bun run bench/map-home.ts` run (`--n 30`, warm, so `layout` is a cache hit
	99	and rounds to 0.0):
	100
	101	\| `GET /map` phase \| owner p50 \| owner p95 \| stranger p50 \| stranger p95 \|
	102	\| ---------------- \| --------: \| --------: \| -----------: \| -----------: \|
	103	\| total (`app`) \| 27.8 \| 31.2 \| 27.2 \| 29.6 \|
	104	\| `session` \| 0.2 \| 0.3 \| 0.2 \| 0.3 \|
	105	\| `lanes` \| 1.8 \| 2.2 \| 1.7 \| 1.9 \|
	106	\| `layout` \| 0.0 \| 0.0 \| 0.0 \| 0.0 \|
	107	\| `render` \| 17.7 \| 20.1 \| 17.4 \| 19.1 \|
	108
94	109	### Where the time goes
95	110
96	111	- **`/map`: `layout` of the big lane alone takes 408 ms of the ~490 ms
		@@ -149,11 +149,55 @@ export function readTiming(db: Database, sinceHour: string): TimingRow[] {
149	149	}
150	150
151	151	/** The header every response carries: `app;dur=<ms>`, and `db` when known. */
152		export function serverTiming(appMs: number, dbMs?: number): string {
	152	export function serverTiming(
	153	appMs: number,
	154	dbMs?: number,
	155	phases: readonly Phase[] = [],
	156	): string {
153	157	const f = (n: number) => n.toFixed(1);
154		return dbMs === undefined
155		? `app;dur=${f(appMs)}`
156		: `db;dur=${f(dbMs)}, app;dur=${f(appMs)}`;
	158	const head =
	159	dbMs === undefined
	160	? `app;dur=${f(appMs)}`
	161	: `db;dur=${f(dbMs)}, app;dur=${f(appMs)}`;
	162	return [head, ...phases.map((p) => `${p.name};dur=${f(p.ms)}`)].join(", ");
	163	}
	164
	165	/** One named stretch of a request, in milliseconds. */
	166	export interface Phase {
	167	readonly name: string;
	168	readonly ms: number;
	169	}
	170
	171	/** A phase name is a header token: lowercase letters, nothing a viewer chose. */
	172	const PHASE_NAME = /^[a-z][a-z0-9-]{0,15}$/;
	173
	174	const phaseLists = new WeakMap<Request, Phase[]>();
	175
	176	/** A page names a phase it spent `ms` in; `serverTiming` writes it after `app`. */
	177	export function notePhase(request: Request, name: string, ms: number): void {
	178	if (!PHASE_NAME.test(name))
	179	throw new RangeError("phase refused: the name must be a lowercase token");
	180	if (!Number.isFinite(ms) \|\| ms < 0) return;
	181	const list = phaseLists.get(request) ?? [];
	182	list.push({ name, ms });
	183	phaseLists.set(request, list);
	184	}
	185
	186	export function takePhases(request: Request): Phase[] {
	187	const list = phaseLists.get(request) ?? [];
	188	phaseLists.delete(request);
	189	return list;
	190	}
	191
	192	const sessionTimes = new WeakMap<Request, number>();
	193
	194	/** The server says how long resolving the session took; a page may name it. */
	195	export function noteSessionTime(request: Request, ms: number): void {
	196	sessionTimes.set(request, ms);
	197	}
	198
	199	export function takeSessionTime(request: Request): number {
	200	return sessionTimes.get(request) ?? 0;
		sentinelcrew 24d ago Nit: `takeSessionTime` doesn't delete its entry the way `takePhases` (and `takeDbTime`) do. That's harmless with a WeakMap, but `take*` reads as consume-once. Either delete it here or call it `sessionTime`. Also, `noteSessionTime` runs on every GET while only `/map` reads it. That's fine for now, but if a second page wants `session`, it's worth folding into the server's own `serverTiming` call.
157	201	}
158	202
159	203	const dbTimes = new WeakMap<Request, number>();
		@@ -462,6 +462,8 @@ import { createUsageCounter, type UsageCounter } from "../core/usage_count.ts";
462	462	import {
463	463	createRouteTiming,
464	464	noteDbTime,
	465	noteSessionTime,
	466	takePhases,
465	467	serverTiming,
466	468	takeDbTime,
467	469	type RouteTiming,
		@@ -2123,7 +2125,7 @@ export async function serve(app: App): Promise<Servers> {
2123	2125	const tag = takeUsage(request);
2124	2126	const ms = performance.now() - started;
2125	2127	try {
2126		response.headers.set("server-timing", serverTiming(ms, takeDbTime(request)));
	2128	response.headers.set("server-timing", serverTiming(ms, takeDbTime(request), takePhases(request)));
2127	2129	} catch {
2128	2130	// A response the forge is only carrying keeps the headers it came with.
2129	2131	}
		@@ -2428,7 +2430,9 @@ async function answerGet(
2428	2430	}
2429	2431	return noRoute(request.method, url.pathname);
2430	2432	}
	2433	const authStart = performance.now();
2431	2434	const auth = await resolveAuth(app, request);
	2435	noteSessionTime(request, performance.now() - authStart);
2432	2436	if (auth.retryAfter !== undefined) return tooManyAttempts(auth.retryAfter);
2433	2437	noteUsage(request, { pattern: matched.pattern, role: roleOf(auth) });
2434	2438	// From here a body's cap depends on who is asking (`http/limits.ts`), and
		@@ -33,6 +33,7 @@ import {
33	33	type Ranked,
34	34	} from "../../core/dependencies.ts";
35	35	import type { Issue } from "../../core/issues.ts";
	36	import { notePhase, takeSessionTime } from "../../core/route_timing.ts";
36	37	import { cachedLane, cachedLayout, repoHeads, scopeKey } from "../map_cache.ts";
37	38	import { holdsFor } from "../../core/holds.ts";
38	39	import {
		@@ -1513,6 +1514,21 @@ type KeptLane = Omit<Lane, "repo" \| "workers"> & {
1513	1514	readonly workerIds: string[];
1514	1515	};
1515	1516
	1517	/** Milliseconds a request spent laying graphs out, inside the lanes' build. */
	1518	export interface Spent {
	1519	layoutMs: number;
	1520	}
	1521
	1522	function timed<T>(spent: Spent \| undefined, run: () => T): T {
	1523	if (spent === undefined) return run();
	1524	const started = performance.now();
	1525	try {
	1526	return run();
	1527	} finally {
	1528	spent.layoutMs += performance.now() - started;
	1529	}
	1530	}
	1531
1516	1532	/**
1517	1533	* One repository's lane for one scope, or null when it has nothing to draw.
1518	1534	* Every read of issues here respects `scope`, so the entry it becomes is
		@@ -1523,6 +1539,7 @@ function buildLane(
1523	1539	repo: Repo,
1524	1540	viewer: User \| undefined,
1525	1541	scope: ReturnType<typeof sealedScope>,
	1542	spent?: Spent,
1526	1543	): KeptLane \| null {
1527	1544	const db = app.db;
1528	1545	// A run on a sealed report is not shown to who may not see the report.
		@@ -1550,7 +1567,7 @@ function buildLane(
1550	1567	);
1551	1568	return {
1552	1569	graph,
1553		placed: cachedLayout(graph, layout),
	1570	placed: timed(spent, () => cachedLayout(graph, layout)),
1554	1571	marks,
1555	1572	ready,
1556	1573	critical: criticalPath(graph),
		@@ -1571,7 +1588,11 @@ function buildLane(
1571	1588	* for every run in flight and one for who runs them; a graph and its marks
1572	1589	* only for the lanes that stay.
1573	1590	*/
1574		export function globalLanes(app: App, viewer: User \| undefined): Lane[] {
	1591	export function globalLanes(
	1592	app: App,
	1593	viewer: User \| undefined,
	1594	spent?: Spent,
	1595	): Lane[] {
1575	1596	const db = app.db;
1576	1597	const now = new Date();
1577	1598	// Access first, every request, and into the key (docs/CACHING.md rule 1).
		@@ -1593,7 +1614,7 @@ export function globalLanes(app: App, viewer: User \| undefined): Lane[] {
1593	1614	scope: scopeKey(scope),
1594	1615	now,
1595	1616	},
1596		() => buildLane(app, repo, viewer, scope),
	1617	() => buildLane(app, repo, viewer, scope, spent),
1597	1618	);
1598	1619	if (lane !== null) built.push({ repo, lane });
1599	1620	}
		@@ -1680,7 +1701,15 @@ export function laneHtml(lane: Lane, width: number): Html {
1680	1701	export function globalMapPage(ctx: Ctx): Response {
1681	1702	const viewer = ctx.auth.user;
1682	1703	if (!viewer) return signInFirst(ctx);
1683		const lanes = globalLanes(ctx.app, viewer);
	1704	const { request } = ctx;
	1705	notePhase(request, "session", takeSessionTime(request));
	1706	const spent: Spent = { layoutMs: 0 };
	1707	const lanesStart = performance.now();
	1708	const lanes = globalLanes(ctx.app, viewer, spent);
	1709	const lanesMs = performance.now() - lanesStart;
	1710	notePhase(request, "lanes", Math.max(0, lanesMs - spent.layoutMs));
	1711	notePhase(request, "layout", spent.layoutMs);
	1712	const renderStart = performance.now();
1684	1713	const width = Math.max(0, ...lanes.map((l) => drawingWidth(l.placed)));
1685	1714	const body = html`${pageHead("Map", {
1686	1715	sub: "Every app you can see, laid out by what waits for what. The top edge of each lane is ready now; a ringed card is where the crew is.",
		@@ -1693,13 +1722,15 @@ export function globalMapPage(ctx: Ctx): Response {
1693	1722	</p>`
1694	1723	: lanes.map((lane) => laneHtml(lane, width))}
1695	1724	</div>`;
1696		return page({
	1725	const response = page({
1697	1726	ctx,
1698	1727	title: "Map",
1699	1728	body,
1700	1729	styleCss: mapCss,
1701	1730	scriptJs: `${liveRegionsJs}\n${mapViewJs}`,
1702	1731	});
	1732	notePhase(request, "render", performance.now() - renderStart);
	1733	return response;
1703	1734	}
1704	1735
1705	1736	/** GET /api/v1/map — the lanes as data, one entry per repository. */
		@@ -230,3 +230,34 @@ describe("the layout key", () => {
230	230	expect(layout(graph).nodes.length).toBe(graph.issues.length);
231	231	});
232	232	});
	233
	234	describe("/map's Server-Timing names its phases", () => {
	235	let servers: Servers;
	236	let f: Fixture;
	237	beforeAll(async () => {
	238	({ f, servers } = await boot(SMALL));
	239	}, 120_000);
	240	afterAll(() => servers.stop(), 60_000);
	241
	242	for (const who of ["owner", "stranger"] as const) {
	243	test(`${who}: session, lanes, layout and render follow app, and sum to no more than it`, async () => {
	244	clearMapCache();
	245	const cookie = who === "owner" ? f.ownerCookie : f.strangerCookie;
	246	for (const pass of ["cold", "warm"]) {
	247	const res = await fetch(`${servers.url}/map`, { headers: { cookie } });
	248	const header = res.headers.get("server-timing") ?? "";
	249	const dur = new Map(
	250	[...header.matchAll(/([a-z-]+);dur=(\d+\.\d)/g)].map((m) => [m[1]!, Number(m[2])]),
	251	);
	252	const names = [...dur.keys()];
	253	expect(names.slice(-4), `${pass}: ${header}`).toEqual(["session", "lanes", "layout", "render"]);
	254	expect(header.split(", ").every((p) => /^[a-z-]+;dur=\d+\.\d$/.test(p))).toBe(true);
	255	const sum = ["session", "lanes", "layout", "render"].reduce((n, k) => n + dur.get(k)!, 0);
	256	// Each is printed to a tenth of a millisecond, so allow that rounding.
	257	expect(sum).toBeLessThanOrEqual(dur.get("app")! + 0.4);
	258	// No repository name rides in the header.
	259	expect(header).not.toMatch(/\//);
	260	}
	261	});
	262	}
	263	});
		@@ -11,7 +11,9 @@ import {
11	11	createRouteTiming,
12	12	KEEP_DAYS,
13	13	readTiming,
	14	notePhase,
14	15	serverTiming,
	16	takePhases,
15	17	} from "../src/core/route_timing.ts";
16	18	import { serve } from "../src/http/server.ts";
17	19	import { migrate } from "../src/kernel/migrate.ts";
		@@ -88,3 +90,11 @@ test("the header names db time only when known", () => {
88	90	expect(serverTiming(1.234)).toBe("app;dur=1.2");
89	91	expect(serverTiming(2, 0.5)).toBe("db;dur=0.5, app;dur=2.0");
90	92	});
	93
	94	test("phases follow app in the header, and a name that is not a token is refused", () => {
	95	const request = new Request("http://x/");
	96	notePhase(request, "lanes", 1.26);
	97	expect(serverTiming(5, undefined, takePhases(request))).toBe("app;dur=5.0, lanes;dur=1.3");
	98	expect(takePhases(request)).toEqual([]);
	99	expect(() => notePhase(request, "my repo", 1)).toThrow();
	100	});