Struct SpentKeys 

pub struct SpentKeys {
    capacity: usize,
    seen: HashMap<String, OffsetDateTime>,
    last_swept: OffsetDateTime,
}

Keys already spent, each until its own expiry, bounded at a capacity.

Not itself synchronised: a caller holds it behind whatever lock its own read and write paths need.

Fields

capacity: usize

seen: HashMap<String, OffsetDateTime>

last_swept: OffsetDateTime

Implementations

impl SpentKeys

pub fn new(capacity: usize, swept_at: OffsetDateTime) -> Self

An empty window holding at most capacity keys, counting sweep_if_due’s interval from swept_at.

pub fn holds(&self, key: &str) -> bool

Whether key is held.

Held, not live: an elapsed entry reads as spent until a sweep drops it, which is the safe direction – refusing a key twice costs a caller one retry, admitting one twice is the replay.

pub fn sweep(&mut self, now: OffsetDateTime)

Drops every entry that has elapsed by now.

pub fn sweep_if_due(&mut self, now: OffsetDateTime, interval: Duration)

sweep, if it has been at least interval since the last one.

pub fn spend( &mut self, key: String, until: OffsetDateTime, now: OffsetDateTime, ) -> Result<(), Spent>

Spends key until until.

A full window sweeps once at now before refusing, so a window full of elapsed keys is not a refusal.

pub fn held(&self) -> impl Iterator<Item = (&str, OffsetDateTime)>

Every key held, with the moment it stops mattering.

Held, not live, for the reason holds gives: a caller writing these down sweeps first if it wants only the live ones.

pub fn len(&self) -> usize

How many keys are held.

pub fn is_empty(&self) -> bool

Whether nothing is held.

Trait Implementations

impl Debug for SpentKeys

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

Formats the value using the given formatter.