Trait RetryPolicyExt

pub trait RetryPolicyExt: RetryPolicy + Sized {
    // Provided methods
    fn with_time_limit(
        self,
        maximum_duration: Duration,
    ) -> LimitedElapsedTime<Self> { ... }
    fn with_attempt_limit(
        self,
        maximum_attempts: u32,
    ) -> LimitedAttemptCount<Self> { ... }
}

Extension trait for RetryPolicy

Provided Methods

fn with_time_limit(self, maximum_duration: Duration) -> LimitedElapsedTime<Self>

Decorate a RetryPolicy to limit the total elapsed time in the retry loop.

While the time spent in the retry loop (including time in backoff) is less than the prescribed duration the on_error() method returns the results of the inner policy. After that time it returns Exhausted if the inner policy returns Continue.

The remaining_time() function returns the remaining time. This is always Duration::ZERO once or after the policy’s expiration time is reached.

Example

let d = std::time::Duration::from_secs(10);
let policy = Aip194Strict.with_time_limit(d);
assert!(policy.remaining_time(std::time::Instant::now(), 0) <= Some(d));

fn with_attempt_limit(self, maximum_attempts: u32) -> LimitedAttemptCount<Self>

Decorate a RetryPolicy to limit the number of retry attempts.

This policy decorates an inner policy and limits the total number of attempts. Note that on_error() is not called before the initial (non-retry) attempt. Therefore, setting the maximum number of attempts to 0 or 1 results in no retry attempts.

The policy passes through the results from the inner policy as long as attempt_count < maximum_attempts. Once the maximum number of attempts is reached, the policy returns Exhausted if the inner policy returns Continue.

Example

use std::time::Instant;
let policy = Aip194Strict.with_attempt_limit(3);
assert_eq!(policy.remaining_time(Instant::now(), 0), None);
assert!(policy.on_error(Instant::now(), 0, true, Error::authentication(format!("transient"))).is_continue());
assert!(policy.on_error(Instant::now(), 1, true, Error::authentication(format!("transient"))).is_continue());
assert!(policy.on_error(Instant::now(), 2, true, Error::authentication(format!("transient"))).is_continue());
assert!(policy.on_error(Instant::now(), 3, true, Error::authentication(format!("transient"))).is_exhausted());

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T: RetryPolicy> RetryPolicyExt for T