WebSocket buffer utils
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README.md

bufferutil

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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.

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