Struct BufferedSink 

pub struct BufferedSink { /* private fields */ }

A sink that buffers writes and only makes them durable on flush — modelling a real buffered sink whose output is committed at flush time (a Parquet footer, an S3 multipart completion). Used to exercise assert_cancellation_flushes: the pipeline must flush at the cancellation page boundary or the staged rows are lost.

Construct with BufferedSink::new for a faithful sink (flush commits the staging buffer) or BufferedSink::broken for one whose flush silently drops the buffer (used to prove the check fails when a cancel does not yield durable output).

Implementations

impl BufferedSink

pub fn new() -> Self

A buffered sink whose flush durably commits everything staged so far.

pub fn broken() -> Self

A broken buffered sink whose flush is a silent no-op — staged rows never become durable, so any output buffered when the run ends is lost.

pub fn durable_len(&self) -> usize

Number of rows that are durable (committed via a flush).

pub fn staged_len(&self) -> usize

Number of rows currently staged but not yet flushed.

Trait Implementations

impl Clone for BufferedSink

fn clone(&self) -> BufferedSink

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for BufferedSink

fn default() -> Self

Returns the “default value” for a type.

impl Sink for BufferedSink

fn write_batch<'life0, 'life1, 'async_trait>( &'life0 self, records: &'life1 [Value], ) -> Pin<Box<dyn Future<Output = Result<usize, FaucetError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Write a batch of records to the destination.

fn flush<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<(), FaucetError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Flush any buffered data to the destination.

fn connector_name(&self) -> &'static str

Stable identifier used as the connector label on metrics and the connector attribute on spans. See Source::connector_name.

fn write_batch_partial<'life0, 'life1, 'async_trait>( &'life0 self, records: &'life1 [Value], ) -> Pin<Box<dyn Future<Output = Result<Vec<Result<(), FaucetError>>, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Write a batch and report per-row outcomes.

fn supports_idempotent_writes(&self) -> bool

Whether this sink can durably commit a page’s rows and a commit token in a single atomic transaction. Default: false (at-least-once only).

fn sink_guarantee(&self) -> SinkGuarantee

The strongest delivery guarantee this sink can uphold — see SinkGuarantee.

fn dedups_by_key(&self) -> bool

Whether this sink instance is configured to dedup by key — i.e. write_mode: upsert (or delete) with a non-empty key, so re-applying a record with the same key converges instead of duplicating. Default: false.

fn supported_write_modes(&self) -> &'static [WriteMode]

Write modes this sink can apply. Default: append-only. Sinks that implement key-based merge override this to include WriteMode::Upsert / WriteMode::Delete. The CLI rejects a configured mode that is not in this set at config-load time.

fn current_schema<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Option<Value>, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, Self: 'async_trait,

The sink’s live destination schema as an infer_schema-shaped object ({"type":"object","properties":{ <col>: <type-fragment>, … }}), or None for a schemaless sink or a target that does not exist yet.

fn supports_schema_evolution(&self) -> bool

Whether this sink can apply additive/widening DDL via evolve_schema. Default: false. The CLI rejects on_drift: evolve against a sink that returns false at config-load.

fn evolve_schema<'life0, 'life1, 'async_trait>( &'life0 self, evolution: &'life1 SchemaEvolution, ) -> Pin<Box<dyn Future<Output = Result<(), FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Apply an additive schema evolution (new columns, lossless widenings, nullability relaxations) to the destination. MUST be idempotent (ADD COLUMN IF NOT EXISTS semantics) so concurrent runs converge.

fn supports_cleanup(&self) -> bool

Whether this sink can delete a scoped set of rows for scoped cleanup (#478). Default false; the upsert-capable sinks override it.

fn cleanup_scope<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, scope: &'life1 BTreeMap<String, Value>, seen: &'life2 SeenKeys, ) -> Pin<Box<dyn Future<Output = Result<u64, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, Self: 'async_trait,

Delete rows matching scope whose key is not in seen.

fn write_batch_idempotent<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, records: &'life1 [Value], scope: &'life2 str, token: &'life3 str, ) -> Pin<Box<dyn Future<Output = Result<usize, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait, Self: 'async_trait,

Write records AND durably record token for scope, atomically.

fn last_committed_token<'life0, 'life1, 'async_trait>( &'life0 self, scope: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Option<String>, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

The last token durably committed for scope, or None if this sink has never committed under that scope. Default: None.

fn config_schema(&self) -> Value

Return a JSON Schema describing the configuration this sink accepts.

fn dataset_uri(&self) -> String

Logical dataset identity for lineage emission, following OpenLineage naming conventions (https://openlineage.io/docs/spec/naming).

fn check<'life0, 'life1, 'async_trait>( &'life0 self, _ctx: &'life1 CheckContext, ) -> Pin<Box<dyn Future<Output = Result<CheckReport, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Run a fast, non-mutating preflight probe (used by faucet doctor).