node-pull.js

import { ReadableStream, WritableStream } from 'stream/web';

async function measure(name, func) {
  for (let i = 0; i < 5; i++) {
    const start = Date.now();
    await func();
    console.log(`${name}: ${Date.now() - start}ms`);
  }
}

const count = 100000;

await measure('stream', async () => {
  let i = 0;
  let sum = 0;
  await new ReadableStream({
    pull(controller) {
      if (i < count) {
        controller.enqueue(i);
        i++;
      } else {
        controller.close();
      }
    }
  }, { highWaterMark: 1 }).pipeTo(new WritableStream({
    write(chunk) {
      sum += chunk;
    },
  }, { highWaterMark: 10000 }))
  console.log(sum);
});

await measure('call', () => {
  let sum = 0;
  function write(chunk) {
    sum += chunk;
  }

  for (let i = 0; i < count; i++) {
    write(i);
  }
  console.log(sum);
});

polyfill-push.js

const script = document.createElement('script');
script.src = 'https://unpkg.com/web-streams-polyfill/dist/polyfill.min.js';

script.onload = async () => {
    console.log(ReadableStream);
    
    async function measure(name, func) {
        const start = Date.now();
        await func();
        console.log(`${name}: ${Date.now() - start}ms`);
    }

    const count = 100000;

    await measure('stream', async () => {
        let sum = 0;
        await new ReadableStream({
            start(controller) {
                for (let i = 0; i < count; i++) {
                    controller.enqueue(i);
                }
                controller.close();
            }
        }).pipeTo(new WritableStream({
            write(chunk) {
                sum += chunk;
            },
        }))
        console.log(sum);
    });

    await measure('call', () => {
        let sum = 0;
        function write(chunk) {
            sum += chunk;
        }

        for (let i = 0; i < count; i++) {
            write(i);
        }
        console.log(sum);
    });
}

document.head.appendChild(script);