Method poll_next

datafusion/physical-plan/src/recursive_query.rs:415–445

(
        mut self: std::pin::Pin<&mut Self>,
        cx: &mut Context<'_>,
    )

    type Item = Result<RecordBatch>;

    fn poll_next(
        mut self: std::pin::Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Poll<Option<Self::Item>> {
        if let Some(static_stream) = &mut self.static_stream {
            // While the static term's stream is available, we'll be forwarding the batches from it (also
            // saving them for the initial iteration of the recursive term).
            let batch_result = ready!(static_stream.poll_next_unpin(cx));
            match &batch_result {
                None => {
                    // Once this is done, we can start running the setup for the recursive term.
                    self.static_stream = None;
                    self.poll_next_iteration(cx)
                }
                Some(Ok(batch)) => self.push_batch(batch.clone()),
                _ => Poll::Ready(batch_result),
            }
        } else if let Some(recursive_stream) = &mut self.recursive_stream {
            let batch_result = ready!(recursive_stream.poll_next_unpin(cx));
            match batch_result {
                None => {
                    self.recursive_stream = None;
                    self.poll_next_iteration(cx)
                }
                Some(Ok(batch)) => self.push_batch(batch),
                _ => Poll::Ready(batch_result),
            }
        } else {
            Poll::Ready(None)
        }
    }
}

impl RecordBatchStream for RecursiveQueryStream {