Struct WindowCloseMetrics 

pub struct WindowCloseMetrics { /* private fields */ }

Metrics for tracking window close behavior.

These counters track window lifecycle events and can be used for monitoring watermark lag and window throughput. Particularly useful for EmitStrategy::OnWindowClose where each window emits exactly once.

Implementations

impl WindowCloseMetrics

pub fn new() -> Self

Creates a new metrics tracker.

pub fn windows_closed_total(&self) -> u64

Returns the total number of windows that have emitted and closed.

pub fn avg_close_latency_ms(&self) -> i64

Returns the average window close latency in milliseconds.

Close latency measures the delay between window_end and the actual emission time (processing_time). This reflects watermark lag — how long after the window boundary the watermark advances enough to trigger emission.

Returns 0 if no windows have been closed.

pub fn max_close_latency_ms(&self) -> i64

Returns the maximum close latency observed (milliseconds).

pub fn record_close(&mut self, window_end: i64, processing_time: i64)

Records a window close event.

Arguments

• window_end - The exclusive upper bound of the closed window
• processing_time - The wall-clock time at which the window emitted

pub fn reset(&mut self)

Resets all counters to zero.

Trait Implementations

impl Clone for WindowCloseMetrics

fn clone(&self) -> WindowCloseMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WindowCloseMetrics

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

Formats the value using the given formatter.

impl Default for WindowCloseMetrics

fn default() -> WindowCloseMetrics

Returns the “default value” for a type.