ws-rate-limit

Rate limiting utility for ws

This rate limits the 'message' event on ws objects. Also triggers an additional 'limited' event for handling.

// Initialize module at 100 requests per 10 seconds:
var rateLimit = require('ws-rate-limit')(100, '10s')
 
// Handle connections on WS server
wss.on('connection', function (ws) {
  // Apply rate limiting to client
  rateLimit(ws)
 
  // Listen for messages normally
  ws.on('message', data => ...)
 
  // Triggered instead of 'message' when requests maxed in time frame.
  ws.on('limited', data => ...)
})

This can also be used with uws because they are compatible.

Installation

npm install --save ws-rate-limit

Usage

rateLimit(rate, max) -> limiter

Creates a limiter function with your specified rate limiting options. Used to easily reapply same settings on multiple connections.

Parameters

• rate (String): A css-duration string of the rate. (i.e. 10m, 0.5d, 1w, etc.)
• max (Number): Maximum amount of requests that can be made during the rate.

Example

// 100 requests per 10 seconds:
var limiter = rateLimit('10s', 100)
 
// 5000 requests every half a day:
var limiter = rateLimit('.5d', 5000)

limiter(client)

Apply rate limiting options on a ws client.

Note: This will unset your 'message' event handlers in order to create a new rate limited one wrapping it. Try using 'newListener' event to cache for unsetting yourself.

Parameters

• client (WebSocket): A ws websocket client to apply rate limits.

Example

var limiter = rateLimit('10s', 100)
 
wss.on('connection', function (client) {
  limiter(client)
})

Event 'limited'

Event is triggered instead of 'message' when the rate limiting has capped in the time frame.

Example

wss.on('connection', function (client) {
  // Apply limiting
  limiter(client)
 
  client.on('limited', function (data) {
    // Respond with rate limit error.
    client.send('No!')
  })
})

License

MIT © Jamen Marz