Struct RateLimiter 

pub struct RateLimiter { /* private fields */ }

Per-IP rate limiter using sliding window algorithm.

Uses DashMap for lock-free concurrent access, critical for high-RPS WAF scenarios. Bounded to [MAX_ENTRIES] to prevent memory exhaustion under DDoS.

Implementations

impl RateLimiter

pub fn new(limit_per_minute: u32) -> Self

Creates a new rate limiter with the specified limit per minute.

pub fn with_window(limit: u32, window: Duration) -> Self

Creates a new rate limiter with custom window duration.

pub fn check_and_increment(&self, ip: &str) -> bool

Checks if the IP is within rate limit and increments counter.

Returns true if the request is allowed, false if rate-limited. Enforces [MAX_ENTRIES] capacity bound, evicting expired entries when full.

pub fn check(&self, ip: &str) -> bool

Checks if the IP would be allowed without incrementing.

pub fn get_count(&self, ip: &str) -> u32

Gets the current count for an IP.

pub fn cleanup(&self)

Cleans up stale entries older than 2x the window duration.

Call this periodically from a background task to prevent unbounded memory growth.

pub fn len(&self) -> usize

Returns the number of tracked IPs.

pub fn is_empty(&self) -> bool

Returns true if no IPs are being tracked.

pub fn stats(&self) -> RateLimiterStats

Returns statistics about the rate limiter.

pub fn max_entries(&self) -> usize

Returns the maximum number of tracked IPs.

pub fn reset(&self)

Resets all statistics and clears tracked IPs.