Struct CompositeAccumulator 

pub struct CompositeAccumulator { /* private fields */ }

Composite accumulator holding multiple DynAccumulator instances.

Fans out each event to all sub-accumulators and collects results as a multi-column [RecordBatch].

Implementations

impl CompositeAccumulator

pub fn add_event(&mut self, event: &Event)

Adds an event to all sub-accumulators.

pub fn merge(&mut self, other: &Self) -> Result<(), &'static str>

Merges another composite accumulator into this one.

Errors

Returns an error if the accumulators have different numbers of sub-accumulators (mismatched window definitions).

pub fn results(&self) -> Vec<ScalarResult>

Returns all results as ScalarResult values.

pub fn is_empty(&self) -> bool

Returns true if all sub-accumulators are empty.

pub fn serialize(&self) -> Vec<u8>

Serializes all sub-accumulators for checkpointing.

pub fn to_record_batch( &self, window_id: &WindowId, schema: &SchemaRef, ) -> Option<RecordBatch>

Creates a multi-column [RecordBatch] from the results.

The batch has columns: window_start, window_end, [aggregate results].

Errors

Returns None if the batch cannot be created.

pub fn num_accumulators(&self) -> usize

Returns the number of sub-accumulators.

Trait Implementations

impl Clone for CompositeAccumulator

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CompositeAccumulator

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

Formats the value using the given formatter.