Struct InvocationLedger 

pub struct InvocationLedger<T> { /* private fields */ }

The idempotency ledger behind ActionHost::invoke.

Maps each admitted InvocationId to the caller and request that admitted it and to the host’s own handle for the running job. A retry with the same caller and request returns the existing handle without starting anything; any other reuse of the id is a conflict. Only admitted invocations are remembered — a refused one ran nothing, so retrying it may be admitted later. The oldest entries are forgotten past capacity.

Implementations

impl<T> InvocationLedger<T>

pub fn with_capacity(capacity: usize) -> InvocationLedger<T>

A ledger remembering at most capacity invocations (at least one).

pub fn admit( &mut self, caller: &Caller, request: &InvokeRequest, start: impl FnOnce() -> Result<T, ActionHostError>, ) -> Result<(&T, Admission), ActionHostError>

Admit request for caller, calling start only if the id is new.

Errors

Returns ActionHostError::InvocationConflict when the id was admitted for another caller or request, or whatever start returns.

pub fn reserve( &mut self, caller: &Caller, request: &InvokeRequest, ) -> Result<Reservation, ActionHostError>

First half of an admission whose start completes later (for example across an asynchronous resolution): claim the id for caller and request, then complete or abandon it.

Errors

Returns ActionHostError::InvocationConflict when the id belongs to another caller or request, and ActionHostError::Unavailable while an earlier start of the same invocation is still in flight.

pub fn complete(&mut self, id: &InvocationId, handle: T)

Record the host’s handle for a reserved invocation.

pub fn abandon(&mut self, id: &InvocationId)

Release a reservation whose start failed: nothing ran, so the id may be admitted later.

pub fn get(&self, caller: &Caller, id: &InvocationId) -> Option<&T>

The handle for an invocation caller admitted.

pub fn get_mut(&mut self, caller: &Caller, id: &InvocationId) -> Option<&mut T>

Mutable access to the handle for an invocation caller admitted.

Trait Implementations

impl<T> Default for InvocationLedger<T>

fn default() -> InvocationLedger<T>

Returns the “default value” for a type.