bufferutil

What is bufferutil?

The bufferutil package is a Node.js utility module that provides efficient buffer operations. It is primarily used to enhance the performance of binary data manipulation by providing a native addon for buffer operations which are faster than pure JavaScript implementations.

What are bufferutil's main functionalities?

Masking and unmasking WebSocket frames

This feature allows you to mask and unmask data according to the WebSocket protocol, which is useful for WebSocket frame manipulation.

const bufferUtil = require('bufferutil');
const buffer = Buffer.from('Hello World');
const masked = bufferUtil.mask(buffer, Buffer.from([0x12, 0x34, 0x56, 0x78]));
const unmasked = bufferUtil.unmask(masked, Buffer.from([0x12, 0x34, 0x56, 0x78]));

Buffer concatenation

This feature provides a method to concatenate multiple buffers into a single buffer efficiently.

const bufferUtil = require('bufferutil');
const buffers = [Buffer.from('Hello'), Buffer.from(' '), Buffer.from('World')];
const concatenated = bufferUtil.concat(buffers);

Buffer comparison

This feature allows you to compare two buffers for equality, which is faster than comparing them byte-by-byte in JavaScript.

const bufferUtil = require('bufferutil');
const buffer1 = Buffer.from('Hello');
const buffer2 = Buffer.from('Hello');
const isEqual = bufferUtil.equals(buffer1, buffer2);

Other packages similar to bufferutil

ws

The 'ws' package is a WebSocket client and server implementation for Node.js. It includes a built-in buffer utility for masking and unmasking WebSocket frames, similar to bufferutil, but it is a more comprehensive solution for working with WebSockets.

buffer

The 'buffer' package is a Node.js core module that provides a way to handle binary data. It includes methods for manipulating buffers but does not have the native performance optimizations that bufferutil offers.

buffers

The 'buffers' package provides a way to work with collections of Node.js Buffer objects. It offers buffer manipulation capabilities like concatenation and slicing, but it does not focus on WebSocket frame manipulation or the native performance enhancements found in bufferutil.

README

bufferutil

bufferutil is what makes ws fast. It provides some utilities to efficiently perform some operations such as masking and unmasking the data payload of WebSocket frames.

Installation

npm install bufferutil --save-optional

The --save-optional flag tells npm to save the package in your package.json under the optionalDependencies key.

API

The module exports two functions. To maximize performance, parameters are not validated. It is the caller's responsibility to ensure that they are correct.

bufferUtil.mask(source, mask, output, offset, length)

Masks a buffer using the given masking-key as specified by the WebSocket protocol.

Arguments

• source - The buffer to mask.
• mask - A buffer representing the masking-key.
• output - The buffer where to store the result.
• offset - The offset at which to start writing.
• length - The number of bytes to mask.

Example

'use strict';

const bufferUtil = require('bufferutil');
const crypto = require('crypto');

const source = crypto.randomBytes(10);
const mask = crypto.randomBytes(4);

bufferUtil.mask(source, mask, source, 0, source.length);

bufferUtil.unmask(buffer, mask)

Unmasks a buffer using the given masking-key as specified by the WebSocket protocol.

Arguments

• buffer - The buffer to unmask.
• mask - A buffer representing the masking-key.

Example

'use strict';

const bufferUtil = require('bufferutil');
const crypto = require('crypto');

const buffer = crypto.randomBytes(10);
const mask = crypto.randomBytes(4);

bufferUtil.unmask(buffer, mask);

License

MIT