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ReadableEventStore

aion_store::store

Trait ReadableEventStore 

Source 
pub trait ReadableEventStore:
    Send
    + Sync
    + 'static {
    // Required methods
    fn read_history<'life0, 'life1, 'async_trait>(
        &'life0 self,
        workflow_id: &'life1 WorkflowId,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<Event>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
    fn read_history_from<'life0, 'life1, 'async_trait>(
        &'life0 self,
        workflow_id: &'life1 WorkflowId,
        from_seq: u64,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<Event>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
    fn read_run_chain<'life0, 'life1, 'async_trait>(
        &'life0 self,
        workflow_id: &'life1 WorkflowId,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<RunSummary>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
    fn list_workflow_ids<'life0, 'async_trait>(
        &'life0 self,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<WorkflowId>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait;
    fn list_active<'life0, 'async_trait>(
        &'life0 self,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<WorkflowId>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait;
    fn query<'life0, 'life1, 'async_trait>(
        &'life0 self,
        filter: &'life1 WorkflowFilter,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<WorkflowSummary>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
    fn schedule_timer<'life0, 'life1, 'life2, 'async_trait>(
        &'life0 self,
        workflow_id: &'life1 WorkflowId,
        timer_id: &'life2 TimerId,
        fire_at: DateTime<Utc>,
    ) -> Pin<Box<dyn Future<Output = Result<(), StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait,
             'life2: 'async_trait;
    fn expired_timers<'life0, 'async_trait>(
        &'life0 self,
        as_of: DateTime<Utc>,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<TimerEntry>, StoreError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait;
}
Expand description

Read and durable-timer contract for Aion event stores.

Required Methods§

Source

fn read_history<'life0, 'life1, 'async_trait>( &'life0 self, workflow_id: &'life1 WorkflowId, ) -> Pin<Box<dyn Future<Output = Result<Vec<Event>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Reads the complete event history for workflow_id in ascending sequence order.

A workflow with no recorded events is observed as an empty history. This includes unknown workflow identifiers: because the first append with expected_seq == 0 creates a workflow implicitly, “unknown workflow” and “empty history” are the same observable state for reads. This method must not return StoreError::NotFound for absent workflows.

Source

fn read_history_from<'life0, 'life1, 'async_trait>( &'life0 self, workflow_id: &'life1 WorkflowId, from_seq: u64, ) -> Pin<Box<dyn Future<Output = Result<Vec<Event>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Reads the event history for workflow_id restricted to events with sequence number greater than or equal to from_seq, in ascending sequence order.

This is the range-read primitive behind O(delta) WS resume: callers replaying from a cursor must not pay for the full history. Semantics:

  • from_seq <= 1 is equivalent to Self::read_history: sequence numbers start at 1, so every recorded event satisfies the bound.
  • from_seq beyond the current head returns an empty vector, never an error. Whether a beyond-head cursor is valid is protocol judgment, not store judgment: the WS resume protocol rejects resume_from_seq > head + 1 as an invalid cursor (ResumeCursorAheadOfHistory), but it makes that call by comparing the cursor against the head it observes — the store only answers which events exist at or after the requested sequence.
  • Unknown workflows behave exactly like Self::read_history for unknown workflows: empty history, never StoreError::NotFound, because “unknown workflow” and “empty history” are the same observable state for reads.

There is deliberately no default implementation: a read-all-then-filter fallback would silently reintroduce O(history) behavior. Every backend must implement this as a real range read (for SQL backends, an indexed seq >= ? range scan).

Source

fn read_run_chain<'life0, 'life1, 'async_trait>( &'life0 self, workflow_id: &'life1 WorkflowId, ) -> Pin<Box<dyn Future<Output = Result<Vec<RunSummary>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Reads the concrete run chain for workflow_id in continuation order.

Source

fn list_workflow_ids<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Vec<WorkflowId>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait,

Lists every workflow identifier that has at least one event in history.

Unlike Self::list_active, this includes terminal workflows and exists to let projection repair jobs reconcile derived indexes against the authoritative event history.

Source

fn list_active<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Vec<WorkflowId>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait,

Lists workflow identifiers whose projected status is non-terminal.

Source

fn query<'life0, 'life1, 'async_trait>( &'life0 self, filter: &'life1 WorkflowFilter, ) -> Pin<Box<dyn Future<Output = Result<Vec<WorkflowSummary>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Returns workflow summaries matching filter.

Source

fn schedule_timer<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, workflow_id: &'life1 WorkflowId, timer_id: &'life2 TimerId, fire_at: DateTime<Utc>, ) -> Pin<Box<dyn Future<Output = Result<(), StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Persists a durable timer for workflow_id that is due at fire_at.

Timer scheduling remains on the public store surface because timers are not workflow-history appends and are used by the timer subsystem after the recorder has written TimerStarted.

Source

fn expired_timers<'life0, 'async_trait>( &'life0 self, as_of: DateTime<Utc>, ) -> Pin<Box<dyn Future<Output = Result<Vec<TimerEntry>, StoreError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait,

Returns durable timers whose fire_at is less than or equal to as_of.

Dyn Compatibility§

This trait is dyn compatible.

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

Implementors§