Struct RateLimiter 

pub struct RateLimiter { /* private fields */ }

Thread-safe rate limiter.

Implementations

impl RateLimiter

pub fn new(config: RateLimitConfig) -> Self

Create a new rate limiter.

pub fn disabled() -> Self

Create a disabled rate limiter.

pub fn is_enabled(&self) -> bool

Check if rate limiting is enabled.

pub fn check(&self, ip: IpAddr) -> RateLimitDecision

Check if a request from the given IP should be allowed.

pub fn refund(&self, ip: IpAddr, charge: RateLimitCharge)

Give back the exact slot charge took.

For a request whose legitimacy is only established after the limiter has already had to decide. A device proves its enrolment token in the first WebSocket frame, long after the middleware ran on the upgrade request, so the choice is between not limiting those routes at all — which is where an enrolment token could be guessed at line speed — and charging every attempt and refunding the ones that turn out to be authenticated. This is the second: what accumulates in the bucket is failed and abandoned attempts, which is exactly what the limit is for.

Removing the slot by identity rather than dropping the newest one is what keeps this from handing out credit. The two differ whenever the charge being refunded has already aged out of the window — a device may take seconds to send its first frame — and dropping the newest would then free a live slot belonging to whoever else is calling from that address. A charge that is already gone refunds nothing, which is right: the window has released it once already.

pub fn stats(&self) -> RateLimitStats

Get current stats.

Trait Implementations

impl Debug for RateLimiter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for RateLimiter

fn default() -> Self

Returns the “default value” for a type.