Struct TimerWheel 

pub struct TimerWheel<T> { /* private fields */ }

A hierarchical timing wheel holding payloads of type T. Time is in ticks; the owner decides what a tick is. See the module docs.

Implementations

impl<T> TimerWheel<T>

pub fn new(now: u64) -> TimerWheel<T>

An empty wheel whose clock reads now.

pub fn now(&self) -> u64

The wheel’s current tick.

pub fn len(&self) -> usize

Scheduled timers.

pub fn is_empty(&self) -> bool

Whether no timer is scheduled.

pub fn insert(&mut self, deadline: u64, payload: T) -> TimerId

Schedules payload to expire at tick deadline (a deadline in the past expires at the next TimerWheel::advance).

pub fn is_pending(&self, id: TimerId) -> bool

Whether a timer is still scheduled (not expired and popped, not cancelled).

pub fn cancel(&mut self, id: TimerId) -> Option<T>

Cancels a timer and returns its payload, or None if it already expired or was cancelled.

pub fn next_deadline(&self) -> Option<u64>

The earliest tick at which something may need doing: a deadline, or the start of a slot whose timers must be re-filed. None when the wheel is empty.

pub fn advance(&mut self, now: u64, out: &mut Vec<T>)

Moves the clock to now and appends every expired payload to out, in deadline order.

pub fn collect(&mut self, now: u64)

Moves the clock to now and sets every expired timer aside, in deadline order, for TimerWheel::pop_ready. Until popped they can still be cancelled, so a callback that cancels a timer due in the same batch stops it from firing.

pub fn pop_ready(&mut self) -> Option<T>

Takes the next expired timer set aside by TimerWheel::collect. Timers inserted after the collect, even ones already due, wait for the next collect.

Trait Implementations

impl<T> Debug for TimerWheel<T>

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

Formats the value using the given formatter.

impl<T> Default for TimerWheel<T>

fn default() -> Self

Returns the “default value” for a type.