Events Bench

1import { bench, describe } from "vitest";
2import { query } from "./clickhouse.js";
3import { type Reader, Cursor } from "../src/readers/core.js";
4import {
5  type EventRow,
6  readEventRow,
7  readEventRowFast,
8} from "../src/examples/events.js";
9
10/**
11 * Benchmark: the API-combinator `readEventRow` vs the inlined `readEventRowFast`,
12 * both decoding the SAME large `FORMAT RowBinary` buffer (N rows from numbers()).
13 * Each `bench` op decodes the whole buffer, so the number is rows/iteration; the
14 * ratio between the two contenders is the takeaway. Equivalence is checked once
15 * before timing — a faster wrong answer is worthless.
16 */
17const N = 20_000;
18const BUF = await query(
19  `SELECT toUInt64(number) AS id, concat('name', toString(number)) AS name, ` +
20    `toDateTime('2021-01-01 00:00:00', 'UTC') + number AS ts ` +
21    `FROM numbers(${N}) FORMAT RowBinary`,
22);
23
24function decodeAll(read: Reader<EventRow>): EventRow[] {
25  const s = new Cursor(BUF);
26  const out: EventRow[] = [];
27  while (s.pos < s.buf.length) out.push(read(s));
28  return out;
29}
30
31const norm = (rows: EventRow[]): string =>
32  JSON.stringify(rows, (_k, v) => (typeof v === "bigint" ? `${v}n` : v));
33{
34  const a = decodeAll(readEventRow);
35  const b = decodeAll(readEventRowFast);
36  if (a.length !== N)
37    throw new Error(`events: decoded ${a.length} rows, expected ${N}`);
38  if (norm(a) !== norm(b)) throw new Error("events: API vs fast mismatch");
39}
40
41describe("example events: API vs optimized", () => {
42  bench("API (combinators)", () => {
43    decodeAll(readEventRow);
44  });
45  bench("optimized (inlined)", () => {
46    decodeAll(readEventRowFast);
47  });
48});