Enum BackoffStrategy 

pub enum BackoffStrategy {
    Fixed(Duration),
    Exponential {
        initial: Duration,
        max: Duration,
    },
    Linear {
        initial: Duration,
        increment: Duration,
        max: Duration,
    },
    Fibonacci {
        initial: Duration,
        max: Duration,
    },
    Custom(Arc<dyn Fn(usize) -> Duration + Send + Sync>),
}

Defines the delay between restart attempts

Variants

Fixed(Duration)

Fixed delay between restarts

Example: Always wait 5 seconds

Exponential

Exponential backoff: initial * 2^(attempt-1), capped at max

Example: 2s -> 4s -> 8s -> 16s -> … -> 60s (max)

Best for: Network failures, external service issues

Fields

initial: Duration

max: Duration

Linear

Linear backoff: initial + (increment * attempt)

Example: 5s -> 10s -> 15s -> 20s -> … -> 60s (max)

Best for: Predictable delay patterns

Fields

initial: Duration

increment: Duration

max: Duration

Fibonacci

Fibonacci backoff: delays follow Fibonacci sequence

Example: 1s -> 1s -> 2s -> 3s -> 5s -> 8s -> … -> max

Best for: Graceful degradation scenarios

Fields

initial: Duration

max: Duration

Custom(Arc<dyn Fn(usize) -> Duration + Send + Sync>)

Custom backoff with user-defined delay calculation

Receives attempt number, returns delay duration. Wrapped in Arc for correct cloning behavior.

Implementations

impl BackoffStrategy

pub fn calculate_delay(&self, attempt: usize) -> Duration

Calculate the delay for a given attempt number (1-indexed)

pub fn fixed(duration: Duration) -> Self

Create a fixed delay strategy

pub fn exponential() -> Self

Create exponential backoff with defaults (2s -> 60s)

pub fn exponential_custom(initial: Duration, max: Duration) -> Self

Create exponential backoff with custom parameters

pub fn linear() -> Self

Create linear backoff with defaults (5s increments, max 60s)

pub fn linear_custom( initial: Duration, increment: Duration, max: Duration, ) -> Self

Create linear backoff with custom parameters

pub fn fibonacci_with_default() -> Self

Create Fibonacci backoff with defaults (1s -> 60s)

pub fn custom<F>(func: F) -> Self

where F: Fn(usize) -> Duration + Send + Sync + 'static,

Create custom backoff with user-defined function

Trait Implementations

impl Clone for BackoffStrategy

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BackoffStrategy

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

Formats the value using the given formatter.

impl Default for BackoffStrategy

fn default() -> Self

Returns the “default value” for a type.