Profiles Bench

1import { bench, describe } from "vitest";
2import { query } from "./clickhouse.js";
3import { type Reader, Cursor } from "../src/readers/core.js";
4import {
5  type ProfileRow,
6  readProfileRow,
7  readProfileRowFast,
8} from "../src/examples/profiles.js";
9
10/**
11 * Benchmark: API-combinator `readProfileRow` vs monomorphized
12 * `readProfileRowFast` over the same large buffer. This is the first case where
13 * the API version allocates a combinator closure per row (`readArray(readString)`
14 * and `readNullable(readInt32)`), so the inlined version should pull ahead.
15 */
16const N = 20_000;
17const BUF = await query(
18  `SELECT toUInt32(number) AS id, ` +
19    `arrayMap(x -> concat('t', toString(x)), range(number % 4)) AS tags, ` +
20    `CAST(if(number % 3 = 0, NULL, toInt32(number) - 50) AS Nullable(Int32)) AS score ` +
21    `FROM numbers(${N}) FORMAT RowBinary`,
22);
23
24function decodeAll(read: Reader<ProfileRow>): ProfileRow[] {
25  const s = new Cursor(BUF);
26  const out: ProfileRow[] = [];
27  while (s.pos < s.buf.length) out.push(read(s));
28  return out;
29}
30
31const norm = (rows: ProfileRow[]): string => JSON.stringify(rows);
32{
33  const a = decodeAll(readProfileRow);
34  const b = decodeAll(readProfileRowFast);
35  if (a.length !== N)
36    throw new Error(`profiles: decoded ${a.length} rows, expected ${N}`);
37  if (norm(a) !== norm(b)) throw new Error("profiles: API vs fast mismatch");
38}
39
40describe("example profiles: API vs optimized", () => {
41  bench("API (combinators)", () => {
42    decodeAll(readProfileRow);
43  });
44  bench("optimized (monomorphized)", () => {
45    decodeAll(readProfileRowFast);
46  });
47});