gzip chunkSize and readable/writableHighWatermark

README.md

Not much difference...

default: chunkSize 16KB, hwm: 16KB x 20.80 ops/sec ±1.65% (51 runs sampled)
chunkSize 128KB, hwm: 16KB x 22.86 ops/sec ±1.07% (55 runs sampled)
chunkSize 128KB, hwm: 128KB x 21.54 ops/sec ±8.46% (52 runs sampled)
chunkSize 16KB, hwm: 128KB x 21.48 ops/sec ±1.87% (52 runs sampled)
Fastest is [ 'chunkSize 128KB, hwm: 16KB', 'chunkSize 128KB, hwm: 128KB' ]

benchmark.js

const { once } = require("events");
const { Suite } = require("benchmark");
const { HttpsAgent } = require('agentkeepalive');
const url = require("url");
const http = require("http");
const https = require("https");
const zlib = require("zlib");

const agent = new HttpsAgent();

async function makeRequest({
  chunkSize,
  hwm,
} = {}) {
  const targetUrl = "https://jsonplaceholder.typicode.com/photos";
  const req = https.request({
    ...url.parse(targetUrl),
    agent,
    headers: {
      "Accept-Encoding": "gzip"
    }
  });
  req.end();

  const [res] = await once(req, "response");
  res.writableHighwatermark = hwm;
  res.readableHighWatermark = hwm;
  const unzipped = res.pipe(
    zlib.createGunzip({
      chunkSize
    })
  );
  let chunkCount = 0;

  for await (const chunk of unzipped) {
    chunkCount++;
  }

  // console.log("done", { chunkCount, chunkSize, hwm });
}

function createTest(options) {
  return {
    defer: true,
    async fn(deferred) {
      await makeRequest(options);
      deferred.resolve();
    }
  };
}

(async () => {
  // Warm up
  for (let i = 0; i < 10; i++) {
    await makeRequest();
  }

  const suite = new Suite();
  suite
    .add('default: chunkSize 16KB, hwm: 16KB', createTest())
    .add('chunkSize 128KB, hwm: 16KB', createTest({
      chunkSize: 128 * 1024,
      hwm: 16 * 1024,
    }))
    .add('chunkSize 128KB, hwm: 128KB', createTest({
      chunkSize: 128 * 1024,
      hwm: 128 * 1024,
    }))
    .add('chunkSize 16KB, hwm: 128KB', createTest({
      chunkSize: 16 * 1024,
      hwm: 128 * 1024,
    }))
    .on('cycle', (event) => {
      console.log(String(event.target));
    })
    .on('complete', () => {
      console.log('Fastest is', suite.filter('fastest').map('name'));
    })
    .run();
})();