Struct Exponential 

pub struct Exponential { /* private fields */ }

Exponential backoff strategy.

Grows exponentially with each attempt. It is also possible, and advisable, to set the maximum backoff using BackoffStrategy::with_max.

Note: This type cannot be constructed directly, instead BackoffStrategy::exponential should be used.

Example

let strategy =
    BackoffStrategy::exponential(TimeDelta::seconds(2)).with_max(TimeDelta::seconds(30));

assert_eq!(strategy.backoff(1), TimeDelta::seconds(2));
assert_eq!(strategy.backoff(2), TimeDelta::seconds(4));
assert_eq!(strategy.backoff(3), TimeDelta::seconds(8));
assert_eq!(strategy.backoff(4), TimeDelta::seconds(16));
assert_eq!(strategy.backoff(5), TimeDelta::seconds(30));
assert_eq!(strategy.backoff(6), TimeDelta::seconds(30));

Trait Implementations

impl Strategy for Exponential

fn backoff(&self, attempt: u16) -> TimeDelta

Given a job attempt as a number returns the TimeDelta to wait before the job should be retried.