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use std::time::Duration;
use super::super::RetryStrategy;
#[derive(Clone)]
pub struct ExponentialBackoff {
current: u64,
base: u64
}
impl ExponentialBackoff {
pub fn from_millis(base: u64) -> ExponentialBackoff {
ExponentialBackoff{current: base, base: base}
}
}
impl RetryStrategy for ExponentialBackoff {
fn delay(&mut self) -> Option<Duration> {
let duration = Duration::from_millis(self.current);
self.current = self.current * self.base;
return Some(duration);
}
}
#[test]
fn returns_some_exponential_base_10() {
let mut s = ExponentialBackoff::from_millis(10);
assert_eq!(s.delay(), Some(Duration::from_millis(10)));
assert_eq!(s.delay(), Some(Duration::from_millis(100)));
assert_eq!(s.delay(), Some(Duration::from_millis(1000)));
}
#[test]
fn returns_some_exponential_base_2() {
let mut s = ExponentialBackoff::from_millis(2);
assert_eq!(s.delay(), Some(Duration::from_millis(2)));
assert_eq!(s.delay(), Some(Duration::from_millis(4)));
assert_eq!(s.delay(), Some(Duration::from_millis(8)));
}