Struct InMemoryDistributedBackend 

pub struct InMemoryDistributedBackend { /* private fields */ }

In-process distributed rate-limit backend.

Uses a single tokio::sync::Mutex guarding a HashMap so that the entire acquire/refill cycle for any key is one atomic critical section. This makes it correct for concurrent in-process workers and a faithful local stand-in for a Redis backend during tests.

Although it shares one mutex across all keys (simple and contention-safe for tests and single-process deployments), the public contract only promises per-key atomicity, so a future sharded implementation remains compatible.

Implementations

impl InMemoryDistributedBackend

pub fn new() -> Self

Create a new empty in-memory backend.

pub async fn key_count(&self) -> usize

Number of keys currently tracked (primarily for tests/diagnostics).

Trait Implementations

impl Debug for InMemoryDistributedBackend

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

Formats the value using the given formatter.

impl Default for InMemoryDistributedBackend

fn default() -> Self

Returns the “default value” for a type.

impl DistributedRateLimitBackend for InMemoryDistributedBackend

fn acquire<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, cost: f64, params: RateLimitParams, ) -> Pin<Box<dyn Future<Output = Result<AcquireOutcome>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Atomically attempt to acquire cost permits for key.

fn available<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, params: RateLimitParams, ) -> Pin<Box<dyn Future<Output = Result<f64>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Report the currently available permits for key (after refill).

fn time_until_available<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, cost: f64, params: RateLimitParams, ) -> Pin<Box<dyn Future<Output = Result<Duration>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Estimate the time until at least cost permits are available for key.

fn reset<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Clear all stored state for key.

fn backend_name(&self) -> &str

Backend name, for diagnostics.