Node.js Stream readable.resume() Method

The readable.resume() method in a Readable Stream is used to paused data that can be resumed again and data starts flowing again.

Syntax:

readable.resume()

Parameters: This method doesn’t accept any parameters.

Return Value: If this method is used then the data that was paused, starts flowing again.

Below examples illustrate the use of readable.resume() method in Node.js:

Example 1:

// Node.js program to demonstrate the
// readable.resume() method

// Including fs module
const fs = require('fs');

// Constructing readable stream
const readable = fs.createReadStream("input.text");
readable.on('data', (chunk) => {
  console.log(`${chunk}`);
});

// Calling pause method
readable.pause();

// Calling resume method
readable.resume();

console.log("Data starts flowing again!!");

Output:

Data starts flowing again!!
Hello!!!

Example 2:

// Node.js program to demonstrate the
// readable.resume() method

// Include fs module
const fs = require('fs');

// Create readable stream
const readable = fs.createReadStream("input.text");

// Handling data event
readable.on('data', (chunk) => {
  console.log(`${chunk}`);

  // Calling pause method
  readable.pause();

  // After this any data will be displayed
  // after 3 sec.
  console.log('No additional data will be '
             + 'displayed for 3 seconds.');

  // Using setTimeout function
  setTimeout(() => {
    console.log('Now data starts flowing again.');

    // Calling resume method
    readable.resume();
  }, 3000);
});

// Displays that program
// is ended
console.log("Program ends!!");

Output:

Program ends!!
Hello!!!
No additional data will be displayed for 3 seconds.
Now data starts flowing again.

However, you can see while running, that after the execution of pause() method, no further data will be displayed for 3 seconds.

Reference: https://nodejs.org/api/stream.html#stream_readable_resume