Rate Limit Middleware

The RateLimit function in the middlewares package provides rate limiting functionality for your Twix router. This middleware helps control the number of requests a client can make to your server within a specified time window.

RateLimitConfig

The RateLimitConfig struct holds the configuration for the rate limit middleware.

type RateLimitConfig struct {
    RequestLimit int
    WindowSize   time.Duration
}

• RequestLimit: The maximum number of requests allowed within the WindowSize.
• WindowSize: The duration within which the RequestLimit applies.

RateLimit

The RateLimit function creates a middleware handler that enforces rate limiting based on the specified configuration.

func RateLimit(config RateLimitConfig) func(http.Handler) http.Handler

Example

package main

import (
    "net/http"
    "time"
    "github.com/farhanmobashir/twix"
    "github.com/farhanmobashir/twix/middlewares"
)

func main() {
    router := twix.New()

    // Define rate limit configuration
    rateLimitConfig := middlewares.RateLimitConfig{
        RequestLimit: 100,
        WindowSize:   1 * time.Minute,
    }

    // Apply rate limit middleware to the router
    router.Use(middlewares.RateLimit(rateLimitConfig))

    router.Get("/", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte("Hello, World!"))
    })

    http.ListenAndServe(":8080", router)
}

In this example, the RateLimit middleware is configured to allow up to 100 requests per minute per IP address. Requests exceeding this limit will receive a 429 Too Many Requests response.

Rate Limiting Behavior

The rate limiting middleware works as follows:

1. Extract IP Address: It extracts the client's IP address from the request.
2. Check Rate Limit Data: It checks if the IP address has existing rate limit data.
3. Update or Set Data:
   • If the data is within the specified WindowSize and the request count exceeds the limit, it responds with 429 Too Many Requests.
   • If the data is within the WindowSize but the request count is below the limit, it increments the count.
   • If the WindowSize has passed, it resets the count and updates the timestamp.
4. Store Data: It stores the updated rate limit data for the IP address.

Usage

You can apply the RateLimit middleware to your Twix router by calling the Use method with the rate limit configuration:

router.Use(middlewares.RateLimit(rateLimitConfig))

This will enforce the rate limit rules for incoming requests based on the client's IP address.

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