Struct KeyWatermarkState 

pub struct KeyWatermarkState {
    pub max_event_time: i64,
    pub watermark: i64,
    pub last_activity: Instant,
    pub is_idle: bool,
}

Per-key watermark state.

Tracks the maximum event time seen for a key and computes its watermark using bounded out-of-orderness.

Fields

max_event_time: i64

Maximum event time seen for this key

watermark: i64

Current watermark (max_event_time - bounded_delay)

last_activity: Instant

Last activity time (wall clock)

is_idle: bool

Whether this key is marked idle

Implementations

impl KeyWatermarkState

pub fn new() -> Self

Creates a new key watermark state.

pub fn update( &mut self, event_time: i64, bounded_delay: i64, now: Instant, ) -> bool

Updates state with a new event timestamp.

Returns true if the watermark advanced.

The now parameter should be the current processing time, cached once per batch or poll iteration to avoid per-key Instant::now() syscalls.

pub fn is_late(&self, event_time: i64) -> bool

Checks if an event is late relative to this key’s watermark.

Trait Implementations

impl Clone for KeyWatermarkState

fn clone(&self) -> KeyWatermarkState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KeyWatermarkState

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

Formats the value using the given formatter.

impl Default for KeyWatermarkState

fn default() -> Self

Returns the “default value” for a type.