Struct WindowOperatorConfig 

pub struct WindowOperatorConfig {
    pub window_type: WindowType,
    pub time_column: String,
    pub size: Duration,
    pub slide: Option<Duration>,
    pub gap: Option<Duration>,
    pub offset_ms: i64,
    pub allowed_lateness: Duration,
    pub emit_strategy: EmitStrategy,
    pub late_data_side_output: Option<String>,
}

Complete configuration for instantiating a window operator.

This structure holds all the information needed to create and configure a window operator in Ring 0.

EMIT ON WINDOW CLOSE

When emit_strategy is OnWindowClose or FinalOnly, use validate() to ensure the configuration is valid. These strategies require:

• A watermark definition on the source (timers are driven by watermark)
• A windowed aggregation context (non-windowed queries cannot use EOWC)

Fields

window_type: WindowType

The type of window (tumbling, sliding, session)

time_column: String

The time column name used for windowing

size: Duration

Window size (for tumbling and sliding)

slide: Option<Duration>

Slide interval for sliding windows

gap: Option<Duration>

Gap interval for session windows

offset_ms: i64

Window offset in milliseconds for timezone-aligned windows

allowed_lateness: Duration

Maximum allowed lateness for late events

emit_strategy: EmitStrategy

Emit strategy (when to output results)

late_data_side_output: Option<String>

Side output name for late data (if configured)

Implementations

impl WindowOperatorConfig

pub fn tumbling(time_column: String, size: Duration) -> Self

Create a new tumbling window configuration.

pub fn sliding(time_column: String, size: Duration, slide: Duration) -> Self

Create a new sliding window configuration.

pub fn session(time_column: String, gap: Duration) -> Self

Create a new session window configuration.

pub fn cumulate(time_column: String, step: Duration, max_size: Duration) -> Self

Create a new cumulate window configuration.

step is the window growth increment and max_size is the epoch size. The slide field is reused to store the step interval.

pub fn with_offset_ms(self, offset_ms: i64) -> Self

Set window offset in milliseconds.

pub fn from_window_function(window: &WindowFunction) -> Result<Self, ParseError>

Build configuration from a parsed WindowFunction.

Errors

Returns ParseError::WindowError if:

• Time column cannot be extracted
• Interval cannot be parsed

pub fn with_emit_clause( self, emit_clause: &EmitClause, ) -> Result<Self, ParseError>

Apply EMIT clause configuration.

Errors

Returns ParseError::WindowError if the emit clause cannot be converted.

pub fn with_late_data_clause( self, late_data_clause: &LateDataClause, ) -> Result<Self, ParseError>

Apply late data clause configuration.

Errors

Returns ParseError::WindowError if the allowed lateness cannot be parsed.

pub fn with_allowed_lateness(self, lateness: Duration) -> Self

Set allowed lateness duration.

pub fn with_emit_strategy(self, strategy: EmitStrategy) -> Self

Set emit strategy.

pub fn with_late_data_side_output(self, name: String) -> Self

Set late data side output.

pub fn validate( &self, has_watermark: bool, has_window: bool, ) -> Result<(), ParseError>

Validates that the window operator configuration is used in a valid context.

Checks:

• EMIT ON WINDOW CLOSE and EMIT FINAL require a watermark on the source
• EMIT ON WINDOW CLOSE and EMIT FINAL require a windowed aggregation

Arguments

• has_watermark - Whether the source has a watermark definition
• has_window - Whether the query contains a windowed aggregation

Errors

Returns ParseError::WindowError if validation fails.

pub fn is_append_only_compatible(&self) -> bool

Check if this configuration supports append-only output.

Append-only sinks (Kafka, S3, Delta Lake) require emit strategies that don’t produce retractions.

pub fn has_late_data_handling(&self) -> bool

Check if late data handling is configured.

Trait Implementations

impl Clone for WindowOperatorConfig

fn clone(&self) -> WindowOperatorConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WindowOperatorConfig

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

Formats the value using the given formatter.

impl Display for WindowOperatorConfig

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

Formats the value using the given formatter.