hcoa/play-ratelimiter

[Draft] Lock-free rate-limiter for Playframework (In-memory)

Play rate limiter

In-memory lock-free rate limiter for playframework. Backed by Caffeine for cache and Bucket4j-core for TokenBucket implementation.

To start using, just import

libraryDependencies ++= "org.hcoa" % "play-ratelimiter" % <version>

available two options:

1. RateLimiter as play action filter - RateLimitFilter, e.g. to create an Ip rate-limiter action filter for 10 requests per second would like:

import org.hcoa.playratelimiter.PlayRateLimiter

import scala.concurrent.duration._
import scala.concurrent.ExecutionContext

val capacity: Long = 10
val period: FiniteDuration = 1.second

val rateLimiterFilter = PlayRateLimiter.createFilter[String](capacity, period, req => req.remoteAddress)

Note: ensure that you have a client IP in a Request.remoteAddress, docs link here TODO

Usage

For example, simple IP rate limiter with no more than 10 requests per 100 milliseconds, and maximum elements to store in-memory:

val rateLimiter = new InMemoryRateLimiter[String](
  10, 
  100.milliseconds,
  10_000) // max amount of elements to store in the cache 

(of course the number might heavily differ for your use-cases, estimate size of elements by: max_amount * (keySize + valueSize))