Struct ChannelStreamSource 

pub struct ChannelStreamSource { /* private fields */ }

Bridges LaminarDB’s push-based Reactor and DataFusion’s pull-based query execution. The sender is take-once (not cloned) so dropping it closes the channel and lets the query terminate.

Implementations

impl ChannelStreamSource

pub fn new(schema: SchemaRef) -> Self

Creates a new channel stream source with default capacity.

pub fn with_capacity(schema: SchemaRef, capacity: usize) -> Self

Creates a new channel stream source with the given channel capacity.

pub fn with_ordering(self, ordering: Vec<SortColumn>) -> Self

Declares that this source produces data in the given sort order. When set, DataFusion can elide SortExec for ORDER BY queries that match the declared ordering.

pub fn take_sender(&self) -> Option<BridgeSender>

Takes the sender for pushing batches into this source.

This method can only be called once. The sender is moved out of the source to ensure the caller has full ownership and can close the channel by dropping the sender.

The returned sender can be cloned to allow multiple producers.

Returns None if the sender was already taken.

pub fn sender(&self) -> Option<BridgeSender>

Returns a clone of the sender if it hasn’t been taken yet.

Warning: Using this method can lead to channel leak issues if the original sender is never dropped. Prefer take_sender() for proper channel lifecycle management.

pub fn reset(&self) -> BridgeSender

Resets the source with a new bridge and sender.

This is useful when you need to reuse the source after the previous stream has been consumed. Any data sent before the reset but not yet consumed will be lost.

Returns the new sender.

Trait Implementations

impl Debug for ChannelStreamSource

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

Formats the value using the given formatter.

impl StreamSource for ChannelStreamSource

fn schema(&self) -> SchemaRef

Returns the schema of records produced by this source.

fn output_ordering(&self) -> Option<Vec<SortColumn>>

Returns the output ordering of this source, if any.

fn stream( &self, projection: Option<Vec<usize>>, _filters: Vec<Expr>, ) -> Result<SendableRecordBatchStream, DataFusionError>

Creates a stream of RecordBatch instances.

fn supports_filters(&self, filters: &[Expr]) -> Vec<bool>

Returns which filters this source can apply.