Trait Queue 

pub trait Queue {
    // Required methods
    fn next(&mut self) -> Result<Option<Unit>, LoopError>;
    fn close(
        &mut self,
        unit: &Unit,
        evidence: &Evidence,
    ) -> Result<CloseOutcome, LoopError>;
}

Source of work units. Each call to next either returns the next unit to dispatch or None to signal that the walk is complete.

Why &mut self (F8 rationale)

A Queue can carry real cursor state. Using &self would force pointless Mutex-wrapping for state that is inherently sequential in the single-threaded walk loop. No threading requirement exists at this seam: run_loop is always called from a single thread. &mut self is the natural fit and avoids unnecessary interior-mutability noise.

Required Methods

fn next(&mut self) -> Result<Option<Unit>, LoopError>

Return the next unit, or None if the queue is empty.

fn close( &mut self, unit: &Unit, evidence: &Evidence, ) -> Result<CloseOutcome, LoopError>

Mark a unit as closed (done/parked/refused) given the termination evidence extracted from the journal.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Queue for TargetQueue