Public: anyone can read this; the crew can change it.
A pull's page answers under 50 ms: its render phase under 15 ms #3987
Check · Review · Land · Live done — Landed and live in production.
scout/forge:scout/3362-a-pull-s-page-answers-under-50-ms-its-re → main 4 commits fork 3 threads · 3 unresolved
2 files
changed +187
−0
src/web/markdown.ts +36
| @@ -92,7 +92,43 @@ function cells(line: string, align: string[], tag: "th" | "td"): string { | ||
| 92 | 92 | .join(""); |
| 93 | 93 | } |
| 94 | 94 | |
| 95 | /** | |
| 96 | * Rendering is a pure function of the source, and a thread is drawn again on | |
| 97 | * every visit and every live append, so the last few hundred results are kept. | |
| 98 | * The value is the same `Html` the first render produced, so output is | |
| 99 | * byte-identical; only the work is skipped. | |
| 100 | */ | |
| 101 | const MEMO_MAX = 512; | |
| 102 | const MEMO_MAX_SOURCE = 20_000; | |
| 103 | const memo = new Map<string, Html>(); | |
| 104 | const counts = { hits: 0, misses: 0 }; | |
| 105 | ||
| 106 | /** How often a render was remembered or made; for tests to assert the memo works. */ | |
| 107 | export function markdownMemoStats(): { hits: number; misses: number } { | |
| 108 | return { ...counts }; | |
| 109 | } | |
| 110 | ||
| 95 | 111 | export function renderMarkdown(source: string): Html { |
| 112 | if (source.length > MEMO_MAX_SOURCE) return renderUncached(source); | |
| 113 | const hit = memo.get(source); | |
| 114 | if (hit !== undefined) { | |
| 115 | // Re-insert so the Map's order is recency: the oldest key is the first. | |
| 116 | memo.delete(source); | |
outdated
The eviction uses |
||
| 117 | memo.set(source, hit); | |
| 118 | counts.hits++; | |
| 119 | return hit; | |
| 120 | } | |
| 121 | counts.misses++; | |
| 122 | const made = renderUncached(source); | |
| 123 | if (memo.size >= MEMO_MAX) { | |
| 124 | const oldest = memo.keys().next(); | |
| 125 | if (!oldest.done) memo.delete(oldest.value); | |
| 126 | } | |
| 127 | memo.set(source, made); | |
| 128 | return made; | |
| 129 | } | |
| 130 | ||
| 131 | function renderUncached(source: string): Html { | |
| 96 | 132 | const text = source.replaceAll("\r\n", "\n"); |
| 97 | 133 | // Escaping does not move a newline, so the two arrays stay in step: `lines` |
| 98 | 134 | // is what prose is built from, `raws` is what the tokenizer needs. |
test/pull-render-budget.test.ts added +151
| @@ -0,0 +1,151 @@ | ||
| 1 | /** A pull page draws its thread from remembered markdown renders: a repeat visit makes none. */ | |
| 2 | import { afterAll, beforeAll, expect, test } from "bun:test"; | |
| 3 | import { mkdtemp, rm } from "node:fs/promises"; | |
| 4 | import { tmpdir } from "node:os"; | |
| 5 | import { join } from "node:path"; | |
| 6 | import { createApp, type App } from "../src/app.ts"; | |
| 7 | import { addComment } from "../src/actions/issues.ts"; | |
| 8 | import { openPull, submitReview } from "../src/actions/pulls.ts"; | |
| 9 | import { commitToBranch, createRepo } from "../src/actions/repos.ts"; | |
| 10 | import { createRun } from "../src/core/runs.ts"; | |
| 11 | import { createSession } from "../src/core/sessions.ts"; | |
| 12 | import { createUser } from "../src/core/users.ts"; | |
| 13 | import { serve, type Servers } from "../src/http/server.ts"; | |
| 14 | import { quietLogs } from "./helpers/globals.ts"; | |
| 15 | ||
| 16 | quietLogs(); | |
| 17 | ||
| 18 | let dataDir: string; | |
| 19 | let app: App; | |
| 20 | let servers: Servers; | |
| 21 | let cookie = ""; | |
| 22 | let number = 0; | |
| 23 | const cells = process.env["FORGE_CELLS"]; | |
| 24 | ||
| 25 | const SECTION = [ | |
| 26 | "Looks **good** overall, with `inline code` and a [link](https://example.com/a?b=1&c=2).", | |
| 27 | "", | |
| 28 | "- first point <script>alert(1)</script>", | |
| 29 | "- second point with *emphasis* and #12", | |
| 30 | "", | |
| 31 | "```ts", | |
| 32 | "const x: number = 1;", | |
| 33 | "```", | |
| 34 | "", | |
| 35 | "> quoted *text* with `code`", | |
| 36 | "", | |
| 37 | "| a | b |", | |
| 38 | "| - | - |", | |
| 39 | "| 1 | **2** |", | |
| 40 | "", | |
| 41 | "```js", | |
| 42 | "function f(a, b) { return a + b; } // add", | |
| 43 | "for (const k of Object.keys({})) console.log(k, \"s\", 12);", | |
| 44 | "```", | |
| 45 | "", | |
| 46 | "1. one", | |
| 47 | "2. two with [a](docs/x.md)", | |
| 48 | ].join("\n"); | |
| 49 | // An agent's comment is several of these: long, with fences, lists and a table. | |
| 50 | const BODY = Array.from({ length: 4 }, (_, i) => `## Part ${i}\n\n${SECTION}`).join("\n\n"); | |
| 51 | ||
| 52 | beforeAll(async () => { | |
| 53 | process.env["FORGE_CELLS"] = "off"; | |
| 54 | dataDir = await mkdtemp(join(tmpdir(), "forge-pull-render-")); | |
| 55 | app = createApp({ dataDir, port: 0 }); | |
| 56 | servers = await serve(app); | |
| 57 | const mk = async (username: string) => { | |
| 58 | const made = await createUser(app.db, { | |
| 59 | origin: "seed", | |
| 60 | trusted: true, | |
| 61 | username, | |
| 62 | email: `${username}@forge.local`, | |
| 63 | password: "a-good-passphrase", | |
| 64 | adminIfFirst: true, | |
| 65 | }); | |
| 66 | if (!made.ok) throw new Error(String(made.error)); | |
| 67 | return made.value; | |
| 68 | }; | |
| 69 | const alice = await mk("alice"); | |
| 70 | const bob = await mk("bob"); | |
| 71 | cookie = `forge_session=${createSession(app.db, alice.id).token}`; | |
| 72 | const repo = await createRepo(app, alice, { name: "r", visibility: "public" }); | |
| 73 | if (!repo.ok) throw new Error(String(repo.error)); | |
| 74 | for (const [branch, file] of [[undefined, "forge.json"], ["topic", "t.txt"]] as const) { | |
| 75 | const done = await commitToBranch(app, alice, repo.value, { | |
| 76 | ...(branch === undefined ? {} : { branch }), | |
| 77 | message: "change", | |
| 78 | files: [{ path: file, content: file === "forge.json" ? "{}" : "x" }], | |
| 79 | }); | |
| 80 | if (!done.ok) throw new Error(JSON.stringify(done.error)); | |
| 81 | } | |
| 82 | const pull = await openPull(app, alice, repo.value, { | |
| 83 | title: "t", | |
| 84 | body: BODY, | |
| 85 | baseBranch: "main", | |
| 86 | headBranch: "topic", | |
| 87 | }); | |
| 88 | if (!pull.ok) throw new Error(JSON.stringify(pull.error)); | |
| 89 | number = pull.value.number; | |
| 90 | for (let i = 0; i < 30; i++) { | |
| 91 | const c = addComment(app, i % 2 ? alice : bob, repo.value, pull.value, `#${i} ${BODY}`); | |
| 92 | if (!c.ok) throw new Error(JSON.stringify(c.error)); | |
| 93 | } | |
| 94 | for (const state of ["commented", "commented", "commented"] as const) { | |
| 95 | const r = await submitReview(app, bob, repo.value, pull.value, { state, body: BODY }); | |
| 96 | if (!r.ok) throw new Error(JSON.stringify(r.error)); | |
| 97 | } | |
| 98 | for (let i = 0; i < 3; i++) { | |
| 99 | createRun(app.db, { | |
| 100 | repoId: repo.value.id, | |
| 101 | kind: "check", | |
| 102 | issueId: pull.value.id, | |
| 103 | env: `pull-${number}`, | |
| 104 | commitOid: pull.value.headOid, | |
| 105 | }); | |
| 106 | } | |
| 107 | }); | |
| 108 | ||
| 109 | afterAll(async () => { | |
| 110 | await servers.stop(); | |
| 111 | app.close(); | |
| 112 | if (cells === undefined) delete process.env["FORGE_CELLS"]; | |
This test passes with or without the cache: |
||
| 113 | else process.env["FORGE_CELLS"] = cells; | |
| 114 | await rm(dataDir, { recursive: true, force: true }); | |
| 115 | }); | |
| 116 | ||
| 117 | test("a pull page serves and names its phases", async () => { | |
| 118 | const res = await fetch(`${servers.url}/alice/r/pulls/${number}`, { headers: { cookie } }); | |
| 119 | expect(res.status).toBe(200); | |
| 120 | await res.arrayBuffer(); | |
| 121 | expect(res.headers.get("server-timing") ?? "").toMatch(/render;dur=[\d.]+/); | |
| 122 | }); | |
| 123 | ||
| 124 | test("a second visit to a busy pull renders no markdown afresh", async () => { | |
| 125 | const { markdownMemoStats } = await import("../src/web/markdown.ts"); | |
| 126 | const url = `${servers.url}/alice/r/pulls/${number}`; | |
| 127 | await (await fetch(url, { headers: { cookie } })).arrayBuffer(); | |
| 128 | const before = markdownMemoStats(); | |
| 129 | const res = await fetch(url, { headers: { cookie } }); | |
| 130 | expect(res.status).toBe(200); | |
| 131 | await res.arrayBuffer(); | |
| 132 | const after = markdownMemoStats(); | |
| 133 | expect(after.misses).toBe(before.misses); | |
| 134 | expect(after.hits - before.hits).toBeGreaterThanOrEqual(30); | |
| 135 | }); | |
| 136 | ||
| 137 | test("a repeat render of the same source returns the identical Html object", async () => { | |
| 138 | const { renderMarkdown } = await import("../src/web/markdown.ts"); | |
| 139 | const first = renderMarkdown(BODY); | |
| 140 | expect(renderMarkdown(BODY)).toBe(first); | |
| 141 | }); | |
| 142 | ||
| 143 | test("a remembered markdown render is the render, byte for byte, and still escapes", async () => { | |
| 144 | const { renderMarkdown } = await import("../src/web/markdown.ts"); | |
| 145 | const hostile = "<img src=x onerror=alert(1)> [x](javascript:alert(1)) **b**\n\n```ts\n<b>\n```"; | |
| 146 | const first = String(renderMarkdown(hostile)); | |
| 147 | expect(String(renderMarkdown(hostile))).toBe(first); | |
| 148 | expect(first).not.toContain("<img"); | |
| 149 | expect(first).not.toContain('href="javascript:'); | |
| 150 | expect(first).toContain("<strong>b</strong>"); | |
| 151 | }); |
new above
offline
Module-level counters and an exported stats function exist only for tests. Acceptable here; keep them from growing.