Struct FanOut 

pub struct FanOut { /* private fields */ }

An Observer that forwards every event to several observers in turn.

The engine drives a single observer, so this composes many — e.g. one that updates a status surface and one that records metrics — without the engine knowing how many there are. Mirrors FanOutSink.

Implementations

impl FanOut

pub fn new(observers: Vec<Arc<dyn Observer>>) -> Self

Compose the given observers; each receives every event, in order.

Trait Implementations

impl Debug for FanOut

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

Formats the value using the given formatter.

impl Default for FanOut

fn default() -> FanOut

Returns the “default value” for a type.

impl Observer for FanOut

fn on_indexes_ensured(&self, count: usize)

The target indexes have been ensured at the sink (count of them), before any documents flow.

fn on_backfill_started(&self, indexes: &[IndexName])

Backfill is starting for indexes (those the sink reported unseeded).

fn on_index_seeded(&self, index: &IndexName)

index’s backfill is complete and it has been marked seeded.

fn on_backfill_completed(&self)

The backfill phase finished (all unseeded indexes seeded), or was skipped.

fn on_live_started(&self)

Live capture has started; the pipeline is now following ongoing changes.

fn on_change_captured(&self)

One change was pulled from the source into the queue.

fn on_batch_committed(&self, stats: BatchStats)

A batch was built, flushed, and acked. See BatchStats.

fn on_slot_lag(&self, bytes: u64)

The source’s capture lag, in bytes behind the latest position — e.g. a replication slot’s distance from the server’s current WAL. Reported by whoever polls ChangeCapture::lag, not by the engine loop itself.

fn on_document_quarantined(&self, index: &str, id: &str, reason: &str)

A document was quarantined: the sink rejected it at the item level and the engine’s failure policy is to skip and continue (see FailurePolicy::Skip). The document is not applied and the batch proceeds, so it is not redelivered — this is the signal to surface it (a metric, a log, a dead-letter record). index and id are the destination’s names for it; reason is why it was rejected.

fn on_error(&self, error: &str)

The pipeline stopped on an error (rendered to a string, since the engine’s error type is not part of this neutral surface).