Struct limitation::Limiter

pub struct Limiter { /* fields omitted */ }

A rate limiter using a fixed window counter, backed by Redis.

The per-period limit and the period duration are customizable when building an instance.

The count method is the primary unit of interaction which requires a key representing a user, a session, an interaction, etc. This method returns a Future which needs a runtime to drive the task to completion asynchronously.

Methods

impl Limiter

pub fn build(redis_url: &str) -> Builder

Returns a builder for a Limiter.

The finish method will build the final Limiter and perform a synchronous connection test to the Redis backend.

pub fn count<K: Into<String>>(
    &self,
    key: K
) -> impl Future<Item = Status, Error = Error>

Counts a request on a key over a period and returns a Status.

The Status type gives the caller a current state snapshot for the given key. If the limit is exceeded a Error::LimitExceeded will be returned which also contains a Status. Critically, the Status contains a time when the next period begins and the limit will reset. The time is a "unix timestamp" in UTC time.

Errors

Returns an Err if:

• The limit has been exceeded in the current period
• A client error has occurred
• A time computation failed

Trait Implementations

impl Clone for Limiter

fn clone(&self) -> Limiter

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Limiter

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

Formats the value using the given formatter.