Enum StreamMessage 

pub enum StreamMessage<T> {
    Event(T),
    Watermark(i64),
    Barrier(CheckpointBarrier),
}

A message that flows through streaming channels.

Wraps user events with control messages (watermarks and barriers) in a single enum. Operators pattern-match on this to handle data vs. control flow.

Generic Parameter

T is the event payload type — typically RecordBatch or a domain-specific event struct.

Variants

Event(T)

A user data event.

Watermark(i64)

A watermark indicating event-time progress (millis since epoch).

Barrier(CheckpointBarrier)

A checkpoint barrier for consistent snapshots.

Implementations

impl<T> StreamMessage<T>

pub const fn is_barrier(&self) -> bool

Returns true if this is a barrier message.

pub const fn is_watermark(&self) -> bool

Returns true if this is a watermark message.

pub const fn is_event(&self) -> bool

Returns true if this is a data event.

pub const fn as_barrier(&self) -> Option<&CheckpointBarrier>

Extracts the barrier if this is a StreamMessage::Barrier.

Trait Implementations

impl<T: Clone> Clone for StreamMessage<T>

fn clone(&self) -> StreamMessage<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for StreamMessage<T>

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

Formats the value using the given formatter.

impl<T: PartialEq> PartialEq for StreamMessage<T>

fn eq(&self, other: &StreamMessage<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> StructuralPartialEq for StreamMessage<T>