Struct FixedWindowRateLimiter 

pub struct FixedWindowRateLimiter { /* private fields */ }

Fixed window rate limiter

Divides time into fixed-size windows; each key has an independent counter within each window. Requests are rejected when the counter exceeds max_requests.

Boundary burst

The fixed window algorithm has the boundary burst problem: if max_requests requests pass in the last 1 second before the window ends, and another max_requests requests pass in the first 1 second of the new window, then 2 * max_requests requests pass within 2 seconds. For smoother rate limiting, use SlidingWindowRateLimiter or TokenBucketRateLimiter.

Implementations

impl FixedWindowRateLimiter

pub fn new(max_requests: u64, window_size: Duration) -> Self

Creates a fixed window rate limiter

• max_requests: maximum number of requests allowed within each window
• window_size: window size (e.g., 60 seconds)

pub fn with_max_keys(self, max_keys: usize) -> Self

Configures the maximum number of keys (OOM protection)

pub fn max_requests(&self) -> u64

pub fn window_size(&self) -> Duration

pub fn max_keys(&self) -> usize

pub fn key_count(&self) -> usize

Trait Implementations

impl RateLimiter for FixedWindowRateLimiter

fn acquire(&self, key: &str) -> Result<RateLimitResult, RateLimitError>

fn try_acquire(&self, key: &str) -> Result<RateLimitResult, RateLimitError>

fn reset(&self, key: &str) -> Result<(), RateLimitError>