Struct ExponentialBackoff 

pub struct ExponentialBackoff { /* private fields */ }

Implementations

impl ExponentialBackoff

An exponential backoff mechanism with optional jitter and immediate-first behavior.

The backoff starts at an initial delay, multiplies that delay by a factor after each call, and caps it at the configured maximum. Each result includes bounded random jitter. When immediate_first is true, the first call to Self::next_duration returns zero. Calling Self::reset restores both the initial delay and the original immediate-first setting.

pub fn new( delay_initial: Duration, delay_max: Duration, factor: f64, jitter_ms: u64, immediate_first: bool, ) -> Result<Self>

Creates a new [ExponentialBackoff] instance.

Errors

Returns an error if:

• delay_initial is zero.
• delay_max is less than delay_initial.
• delay_max exceeds Duration::from_nanos(u64::MAX) (≈584 years).
• factor is not in the range [1.0, 100.0] (to prevent reconnect spam).

pub fn next_duration(&mut self) -> Duration

Returns the next backoff delay with jitter and updates the internal state.

If the immediate_first flag is set and this is the first call (i.e. the current delay equals the initial delay), it returns Duration::ZERO to trigger an immediate reconnect and disables the immediate behavior for subsequent calls.

Near the cap the jittered base is lowered to delay_max - jitter so the spread survives saturation; the result is clamped into [min(delay_initial, delay_max), delay_max].

pub const fn reset(&mut self)

Resets the backoff to its initial state.

pub const fn current_delay(&self) -> Duration

Returns the current base delay without jitter. This represents the delay that would be used as the base for the next call to next(), before any jitter is applied.

Trait Implementations

impl Clone for ExponentialBackoff

fn clone(&self) -> ExponentialBackoff

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExponentialBackoff

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

Formats the value using the given formatter.