Struct StreamingTopKOperator 

pub struct StreamingTopKOperator { /* private fields */ }

Streaming top-K operator for ORDER BY ... LIMIT N.

Maintains a sorted buffer of at most K entries. Each incoming event is checked against the current worst entry. If better, it replaces the worst and changelog records are emitted.

Implementations

impl StreamingTopKOperator

pub fn new( operator_id: String, k: usize, sort_columns: Vec<TopKSortColumn>, emit_strategy: TopKEmitStrategy, ) -> Self

Creates a new streaming top-K operator.

pub fn len(&self) -> usize

Returns the current number of entries in the top-K buffer.

pub fn is_empty(&self) -> bool

Returns true if the top-K buffer is empty.

pub fn entries(&self) -> Vec<&Event>

Returns the current entries as events (best first).

pub fn current_watermark(&self) -> i64

Returns the current watermark value.

pub fn pending_changes_count(&self) -> usize

Returns the number of pending changelog records.

Trait Implementations

impl Operator for StreamingTopKOperator

fn process( &mut self, event: &Event, _ctx: &mut OperatorContext<'_>, ) -> OutputVec

Process an incoming event

fn on_timer( &mut self, _timer: Timer, _ctx: &mut OperatorContext<'_>, ) -> OutputVec

Handle timer expiration

fn checkpoint(&self) -> OperatorState

Checkpoint the operator’s state

fn restore(&mut self, state: OperatorState) -> Result<(), OperatorError>

Restore from a checkpoint