Struct DurableEventJournal 

pub struct DurableEventJournal { /* private fields */ }

Append-only segmented journal with fsync-before-acknowledgement.

Implementations

impl DurableEventJournal

pub fn open( root: &Path, config: JournalConfig, clock: Arc<dyn BrokerClock>, ) -> Result<Self, JournalError>

Open (or create) the journal under root, recovering existing segments. Recovery ignores only an incomplete final record of the newest segment and fails loudly on any malformed completed record (066 FR-009).

Errors

Returns JournalError::InvalidConfig for zero limits, JournalError::Io on filesystem failures, and JournalError::Corrupt when a completed record is malformed.

pub fn append(&mut self, event: &TraverseEvent) -> Result<String, JournalError>

Append an event, fsync it, and return its cursor (066 FR-006: the record is durable before this returns). Rolls the active segment over at the configured size or age bound, whichever occurs first (067 FR-001).

Errors

Returns JournalError::Io when the durable write fails; the event is not acknowledged in that case.

pub fn append_revocation( &mut self, revoked_cursor: &str, ) -> Result<String, JournalError>

Durably record that the event at revoked_cursor was rejected and must never be delivered through replay (067 FR-004). Used when a caller abandoned a write that later completed, or when a durably written event could not be delivered.

Errors

Returns JournalError::InvalidCursor for unparseable cursors and JournalError::Io when the durable write fails.

pub fn replay_from( &self, cursor: &str, max_events: usize, ) -> Result<Vec<(String, TraverseEvent)>, JournalError>

Replay up to max_events events strictly after cursor.

"0" replays from the start of retained history. Cursors are opaque monotonic sequence identifiers independent of segment layout (066 FR-007).

Errors

Returns JournalError::InvalidCursor for unparseable cursors, JournalError::CursorExpired with the oldest available cursor when the requested history was reclaimed (066 FR-008), and JournalError::Io / JournalError::Corrupt on read failures.

pub fn oldest_available_cursor(&self) -> String

The cursor from which the oldest retained event replays; callers that receive JournalError::CursorExpired resume from here.

pub fn prune(&mut self) -> Result<Vec<PathBuf>, JournalError>

Reclaim expired history by deleting whole sealed segments only — never rewriting or truncating in place (067 FR-002). A segment is deleted only once every event in it falls outside the retention window; the active segment is never deleted, bounding the overhang to one rollover period.

Errors

Returns JournalError::Io when a reclaimable segment cannot be deleted.

Trait Implementations

impl JournalSink for DurableEventJournal

fn append_event( &mut self, event: &TraverseEvent, ) -> Result<String, JournalError>

Durably append an event, returning its cursor.

fn append_revocation( &mut self, revoked_cursor: &str, ) -> Result<String, JournalError>

Durably suppress a previously written cursor from replay.