Module window 

Window Operators

Implementation of various window types for stream processing.

Window Types

• Tumbling: Fixed-size, non-overlapping windows (implemented)
• Sliding: Fixed-size, overlapping windows (future)
• Session: Dynamic windows based on activity gaps (future)

Emit Strategies

Windows support different emission strategies via EmitStrategy:

• OnWatermark (default): Emit results when watermark passes window end
• Periodic: Emit intermediate results at fixed intervals
• OnUpdate: Emit after every state change (most expensive)

Example

use laminar_core::operator::window::{
    TumblingWindowAssigner, TumblingWindowOperator, CountAggregator, EmitStrategy,
};
use std::time::Duration;

// Create a 1-minute tumbling window with count aggregation
let assigner = TumblingWindowAssigner::new(Duration::from_secs(60));
let mut operator = TumblingWindowOperator::new(
    assigner,
    CountAggregator::new(),
    Duration::from_secs(5), // 5 second grace period
);

// Emit intermediate results every 10 seconds
operator.set_emit_strategy(EmitStrategy::Periodic(Duration::from_secs(10)));

Structs

ArchivedAvgAccumulator

An archived AvgAccumulator

ArchivedCountAccumulator

An archived CountAccumulator

ArchivedFirstValueAccumulator

An archived FirstValueAccumulator

ArchivedFirstValueF64Accumulator

An archived FirstValueF64Accumulator

ArchivedLastValueAccumulator

An archived LastValueAccumulator

ArchivedLastValueF64Accumulator

An archived LastValueF64Accumulator

ArchivedMaxAccumulator

An archived MaxAccumulator

ArchivedMinAccumulator

An archived MinAccumulator

ArchivedSumAccumulator

An archived SumAccumulator

ArchivedWindowId

An archived WindowId

AvgAccumulator

Accumulator for average aggregation.

AvgAccumulatorResolver

The resolver for an archived AvgAccumulator

AvgAggregator

Average aggregator - computes average of i64 values.

AvgF64Factory

Avg aggregator for f64 columns.

AvgF64IndexedAccumulator

f64 avg accumulator with embedded column index.

ChangelogRecord

A changelog record with Z-set weight for CDC pipelines.

CompositeAccumulator

Composite accumulator holding multiple DynAccumulator instances.

CompositeAggregator

Composite aggregator combining multiple DynAggregatorFactory instances.

CountAccumulator

Accumulator for count aggregation.

CountAccumulatorResolver

The resolver for an archived CountAccumulator

CountAggregator

Count aggregator - counts the number of events in a window.

CountDynAccumulator

Count accumulator implementing DynAccumulator.

CountDynFactory

Count factory for DynAccumulator.

FirstValueAccumulator

Accumulator for FIRST_VALUE aggregation.

FirstValueAccumulatorResolver

The resolver for an archived FirstValueAccumulator

FirstValueAggregator

FIRST_VALUE aggregator - returns the first value seen in a window.

FirstValueF64Accumulator

Accumulator for FIRST_VALUE aggregation on f64 values.

FirstValueF64AccumulatorResolver

The resolver for an archived FirstValueF64Accumulator

FirstValueF64Aggregator

FIRST_VALUE aggregator for f64 columns.

FirstValueF64DynAccumulator

FIRST_VALUE accumulator for f64 columns via DynAccumulator.

FirstValueF64DynFactory

FIRST_VALUE factory for f64 columns via DynAccumulator.

LastValueAccumulator

Accumulator for LAST_VALUE aggregation.

LastValueAccumulatorResolver

The resolver for an archived LastValueAccumulator

LastValueAggregator

LAST_VALUE aggregator - returns the last value seen in a window.

LastValueF64Accumulator

Accumulator for LAST_VALUE aggregation on f64 values.

LastValueF64AccumulatorResolver

The resolver for an archived LastValueF64Accumulator

LastValueF64Aggregator

LAST_VALUE aggregator for f64 columns.

LastValueF64DynAccumulator

LAST_VALUE accumulator for f64 columns via DynAccumulator.

LastValueF64DynFactory

LAST_VALUE factory for f64 columns via DynAccumulator.

LateDataConfig

Configuration for late data handling.

LateDataMetrics

Metrics for tracking late data.

MaxAccumulator

Accumulator for max aggregation.

MaxAccumulatorResolver

The resolver for an archived MaxAccumulator

MaxAggregator

Max aggregator - tracks maximum i64 value.

MaxF64Factory

Max aggregator for f64 columns.

MaxF64IndexedAccumulator

f64 max accumulator with embedded column index.

MinAccumulator

Accumulator for min aggregation.

MinAccumulatorResolver

The resolver for an archived MinAccumulator

MinAggregator

Min aggregator - tracks minimum i64 value.

MinF64Factory

Min aggregator for f64 columns.

MinF64IndexedAccumulator

f64 min accumulator with embedded column index.

SumAccumulator

Accumulator for sum aggregation.

SumAccumulatorResolver

The resolver for an archived SumAccumulator

SumAggregator

Sum aggregator - sums i64 values from events.

SumF64Accumulator

Accumulator for f64 sum aggregation.

SumF64Aggregator

Sum aggregator for f64 columns.

SumF64Factory

Factory for SumF64Accumulator.

SumF64IndexedAccumulator

f64 sum accumulator with embedded column index.

TumblingWindowAssigner

Tumbling window assigner.

TumblingWindowOperator

Tumbling window operator.

WindowCloseMetrics

Metrics for tracking window close behavior.

WindowId

Unique identifier for a window.

WindowIdResolver

The resolver for an archived WindowId

Enums

ArchivedCdcOperation

An archived CdcOperation

CdcOperation

CDC operation type for changelog records.

CdcOperationResolver

The resolver for an archived CdcOperation

EmitStrategy

Strategy for when window results should be emitted.

ScalarResult

Scalar result type supporting multiple numeric types.

Traits

Accumulator

Accumulator state for aggregations.

Aggregator

Trait for window aggregation functions.

DynAccumulator

Dynamic accumulator trait for composite aggregation.

DynAggregatorFactory

Factory trait for creating DynAccumulator instances.

ResultToArrow

Trait for converting aggregation results to Arrow arrays.

ResultToI64

Trait for converting aggregation results to i64 for output.

WindowAssigner

Trait for assigning events to windows.

Type Aliases

WindowIdVec

Collection type for window assignments.