Crate flux_limiter 

Flux Limiter

A high-performance rate limiter based on the Generic Cell Rate Algorithm (GCRA).

Quick Example

use flux_limiter::{FluxLimiter, FluxLimiterConfig, SystemClock};

let config = FluxLimiterConfig::new(10.0, 5.0);
let limiter = FluxLimiter::with_config(config, SystemClock).unwrap();

let decision = limiter.check_request("user_123").unwrap();
if decision.allowed {
    println!("Request allowed");
} else {
    println!("Rate limited - retry after {:.2}s",
             decision.retry_after_seconds.unwrap_or(0.0));
}

Structs

FluxLimiter

The main FluxLimiter model. T is the type used to identify clients (e.g., String, u64, etc.). C is the clock type, defaulting to SystemClock. We use Arc<DashMap> for thread-safe concurrent access to client state.

FluxLimiterConfig

Configuration for rate limiter behavior.

FluxLimiterDecision

Result of a rate limiting decision with metadata for HTTP responses

SystemClock

SystemClock implementation using the system time. Returns the current time in nanoseconds since the Unix epoch. Panics if the system clock is before the Unix epoch. This is the default clock used in the RateLimiter. Implements the Clock trait. Thread-safe and can be shared across threads.

Enums

ClockError

Clock error type

FluxLimiterError

Error type for FluxLimiter configuration issues.

Traits

Clock

Clock trait to abstract time retrieval. Implementors must be thread-safe (Send + Sync). The now method returns the current time in nanoseconds as a u64. This trait allows for different clock implementations, such as system time or a test clock. The Clock trait is used by the RateLimiter to get the current time.