Struct ConcurrencyLimit 

pub struct ConcurrencyLimit { /* private fields */ }

Bounds execution and waiting, returning 503 with Retry-After on overload.

Defaults to one queue slot per execution slot and a five-second queue deadline. Permits normally end at response production. hold_body(true) retains them until body completion, error or drop. Upgraded connections require their own lifecycle budget. Clones share admission and counters.

Implementations

impl ConcurrencyLimit

pub fn new(max: usize) -> Self

Configure execution capacity, treating zero as one for compatibility.

Args: max: Maximum active requests, at most Semaphore::MAX_PERMITS.

Returns: Bounded limit; invalid oversized configuration fails requests.

pub fn try_new(max: usize) -> Result<Self, ConcurrencyLimitError>

Validate a strictly positive execution capacity immediately.

Args: max: Maximum active requests.

Returns: Configured limit or invalid-capacity error.

pub fn queue(self, max: usize, timeout: Duration) -> Self

Set bounded queue capacity and deadline, including a zero-slot queue.

Args: max: Maximum waiting requests, at most Semaphore::MAX_PERMITS. timeout: Maximum admission wait; zero means immediate admission.

Returns: Fresh admission state; existing clones keep their previous state.

pub fn hold_body(self, enabled: bool) -> Self

Include response-body consumption in the execution limit.

Args: enabled: Retain permits until body completion, error or drop.

Returns: Layer sharing its original admission state.

pub fn close(&self)

Close admission and wake waiters; already active work can complete.

Returns: No value; all clones observe the closed state.

pub fn stats(&self) -> ConcurrencyStats

Read an approximate concurrent snapshot without locking.

Returns: Current capacities and cumulative admission counters.

Trait Implementations

impl Clone for ConcurrencyLimit

fn clone(&self) -> ConcurrencyLimit

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ConcurrencyLimit

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

Formats the value using the given formatter.

impl Layer<BoxCloneSyncService<Request<Body>, Response<Body>, Infallible>> for ConcurrencyLimit

type Service = BoxCloneSyncService<Request<Body>, Response<Body>, Infallible>

The wrapped service

fn layer(&self, inner: BoxService) -> Self::Service

Wrap the given service with the middleware, returning a new service that has been decorated with the middleware.