Struct CrossJoinStream 

struct CrossJoinStream<T> {
    schema: Arc<Schema>,
    left_fut: OnceFut<JoinLeftData>,
    right: SendableRecordBatchStream,
    left_index: usize,
    join_metrics: BuildProbeJoinMetrics,
    state: CrossJoinStreamState,
    left_data: RecordBatch,
    batch_transformer: T,
}

A stream that issues [RecordBatch]es as they arrive from the right of the join.

Fields

schema: Arc<Schema>

Input schema

left_fut: OnceFut<JoinLeftData>

Future for data from left side

right: SendableRecordBatchStream

Right side stream

left_index: usize

Current value on the left

join_metrics: BuildProbeJoinMetrics

Join execution metrics

state: CrossJoinStreamState

State of the stream

left_data: RecordBatch

Left data (copy of the entire buffered left side)

batch_transformer: T

Batch transformer

Implementations

impl<T: BatchTransformer> CrossJoinStream<T>

fn poll_next_impl( &mut self, cx: &mut Context<'_>, ) -> Poll<Option<Result<RecordBatch>>>

Separate implementation function that unpins the CrossJoinStream so that partial borrows work correctly

fn collect_build_side( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<StatefulStreamResult<Option<RecordBatch>>>>

Collects build (left) side of the join into the state. In case of an empty build batch, the execution terminates. Otherwise, the state is updated to fetch probe (right) batch.

fn fetch_probe_batch( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<StatefulStreamResult<Option<RecordBatch>>>>

Fetches the probe (right) batch, updates the metrics, and save the batch in the state. Then, the state is updated to build result batches.

fn build_batches(&mut self) -> Result<StatefulStreamResult<Option<RecordBatch>>>

Joins the indexed row of left data with the current probe batch. If all the results are produced, the state is set to fetch new probe batch.

Trait Implementations

impl<T: BatchTransformer + Unpin + Send> RecordBatchStream for CrossJoinStream<T>

fn schema(&self) -> SchemaRef

Returns the schema of this RecordBatchStream.

impl<T: BatchTransformer + Unpin + Send> Stream for CrossJoinStream<T>

type Item = Result<RecordBatch, DataFusionError>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.