Struct governor::Jitter

pub struct Jitter { /* private fields */ }

An interval specification for deviating from the nominal wait time.

Jitter can be added to wait time Durations to ensure that multiple tasks waiting on the same rate limit don’t wake up at the same time and attempt to measure at the same time.

Methods on rate limiters that work asynchronously like DirectRateLimiter.until_ready_with_jitter exist to automatically apply jitter to wait periods, thereby reducing the chance of a thundering herd problem.

Examples

Jitter can be added manually to a Duration:

let reference = Duration::from_secs(24);
let jitter = Jitter::new(Duration::from_secs(1), Duration::from_secs(1));
let result = jitter + reference;
assert!(result >= reference + Duration::from_secs(1));
assert!(result < reference + Duration::from_secs(2))

In a std build (the default), Jitter can also be added to an Instant:

let reference = Instant::now();
let jitter = Jitter::new(Duration::from_secs(1), Duration::from_secs(1));
let result = jitter + reference;
assert!(result >= reference + Duration::from_secs(1));
assert!(result < reference + Duration::from_secs(2))

Implementations

impl Jitter

pub fn up_to(max: Duration) -> Jitter

Constructs a new Jitter interval, waiting at most a duration of max.

let jitter = Jitter::up_to(Duration::from_secs(20));
let now = Duration::from_secs(0);
assert!(jitter + now <= Duration::from_secs(20)); // always.

pub fn new(min: Duration, interval: Duration) -> Jitter

Constructs a new Jitter interval, waiting at least min and at most min+interval.

Trait Implementations

impl Add<Duration> for Jitter

type Output = Duration

The resulting type after applying the + operator.

fn add(self, rhs: Duration) -> Duration

Performs the + operation.

impl Add<Instant> for Jitter

type Output = Instant

The resulting type after applying the + operator.

fn add(self, rhs: Instant) -> Instant

Performs the + operation.

impl Add<Nanos> for Jitter

type Output = Nanos

The resulting type after applying the + operator.

fn add(self, rhs: Nanos) -> Nanos

Performs the + operation.

impl Clone for Jitter

fn clone(&self) -> Jitter

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Jitter

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

Formats the value using the given formatter.

impl Default for Jitter

fn default() -> Jitter

Returns the “default value” for a type.

impl PartialEq for Jitter

fn eq(&self, other: &Jitter) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Jitter

impl Eq for Jitter

impl StructuralPartialEq for Jitter