'use strict';

const fs = require('node:fs');

const readable = fs.createReadStream('./data.tmp', { highWaterMark: 12345 });

const writable = fs.createWriteStream('./copy.tmp', { highWaterMark: 54321 });

readable.on('data', (chunk) => {

console.log(`Write: ${chunk.length} bytes`);

const canWrite = writable.write(chunk);

if (!canWrite) {

console.log('Pause reabable due to backpressure');

readable.pause();

}

});

writable.on('drain', () => {

console.log('Event drain: resume readable');

readable.resume();

});

readable.on('end', () => {

writable.end();

});

writable.on('finish', () => {

console.log('Done');

});