Method AcquirePermitAsync

AcquirePermitAsync(IShortLivedStore, string, string, int, TimeSpan, TimeProvider, CancellationToken)

Acquires a permit from a fixed window count, unless permitLimit permits were already acquired in the current window. Windows start at fixed times on the clock (a one-hour window starts at every full hour), so every server that shares the store counts the same window.

Declaration

public static ValueTask<FixedWindowPermit> AcquirePermitAsync(this IShortLivedStore store, string keyPrefix, string key, int permitLimit, TimeSpan window, TimeProvider timeProvider, CancellationToken cancellationToken = default)

Parameters

Type	Name	Description
IShortLivedStore	store	The store.
string	keyPrefix	The start of the key, which keeps the counts of one limit apart from all others, for example "myapp:setup-emails:".
string	key	What the limit applies to, such as an email address. The store is given a hash of it rather than the value itself, so keys are compared exactly: [email protected] and [email protected] are counted apart.
int	permitLimit	The number of permits that can be acquired in each window. Must be positive.
TimeSpan	window	The length of a window. Must be positive.
TimeProvider	timeProvider	The clock that windows are measured by, such as the registered TimeProvider.
CancellationToken	cancellationToken	A token to cancel the operation.

Returns

Type	Description
ValueTask<FixedWindowPermit>

Remarks

Every attempt is counted, including attempts that acquire no permit.