Enum RetryDelay

Source

pub enum RetryDelay {
    None,
    Fixed(Duration),
    Random {
        min: Duration,
        max: Duration,
    },
    Exponential {
        initial: Duration,
        max: Duration,
        multiplier: f64,
    },
}

Expand description

Base delay strategy before jitter is applied.

RetryDelay strategies are value types that can be reused across executors. Random and exponential strategies are validated separately by RetryDelay::validate, which is called when building crate::RetryOptions.

Variants§

§

None

Retry immediately.

§

Fixed(Duration)

Wait for a constant delay after every failed attempt.

§

Random

Pick a delay uniformly from the inclusive range.

Fields

§min: Duration

Lower bound for the delay.

§max: Duration

Upper bound for the delay.

§

Exponential

Exponential backoff capped by max.

Fields

§initial: Duration

RetryDelay used for the first retry.

§max: Duration

Maximum delay.

§multiplier: f64

Multiplicative factor applied per failed attempt.

Implementations§

Source §

impl RetryDelay

Source

pub fn none() -> RetryDelay

Creates a no-delay strategy.

§Parameters

This function has no parameters.

§Returns

A RetryDelay::None strategy.

§Errors

This function does not return errors.

Source

pub fn fixed(delay: Duration) -> RetryDelay

Creates a fixed-delay strategy.

§Parameters

delay: Duration slept after each failed attempt.

§Returns

A RetryDelay::Fixed strategy.

§Errors

This constructor does not validate delay; use RetryDelay::validate to reject a zero duration.

Source

pub fn random(min: Duration, max: Duration) -> RetryDelay

Creates a random-delay strategy.

§Parameters

min: Inclusive lower bound for generated delays.
max: Inclusive upper bound for generated delays.

§Returns

A RetryDelay::Random strategy.

§Errors

This constructor does not validate the range; use RetryDelay::validate to reject a zero minimum or a minimum greater than the maximum.

Source

pub fn exponential( initial: Duration, max: Duration, multiplier: f64, ) -> RetryDelay

Creates an exponential-backoff strategy.

§Parameters

initial: RetryDelay used for the first retry.
max: Upper bound applied to every calculated delay.
multiplier: Factor applied for each subsequent failed attempt.

§Returns

A RetryDelay::Exponential strategy.

§Errors

This constructor does not validate the parameters; use RetryDelay::validate to reject a zero initial delay, max < initial, or a multiplier that is non-finite or less than or equal to 1.0.

Source

pub fn base_delay(&self, attempt: u32) -> Duration

Calculates the base delay for an attempt number starting at 1.

Attempt 1 means the first failed attempt, so exponential backoff returns initial for attempts 0 and 1. Random delays use a fresh random value for every call.

§Parameters

attempt: Failed attempt number. Values 0 and 1 are treated as the first exponential-backoff step.

§Returns

The base delay before jitter is applied.

§Errors

This function does not return errors. Invalid strategies should be rejected with RetryDelay::validate before they are used in an executor.

Source

pub fn validate(&self) -> Result<(), String>

Validates strategy parameters.

Returns a human-readable message describing the invalid field when the strategy cannot be used safely by an executor.

§Returns

Ok(()) when all parameters are usable; otherwise an error message that can be wrapped by crate::RetryConfigError.

§Parameters

This method has no parameters.

§Errors

Returns an error when a fixed delay is zero, a random range is invalid, or exponential backoff parameters are zero, inverted, non-finite, or too small.