Method repartitioned

datafusion/datasource/src/memory.rs:150–177

If possible, redistribute batches across partitions according to their size. Returns `Ok(None)` if unable to repartition. Preserve output ordering if exists. Refer to [`DataSource::repartitioned`] for further details.

(
        &self,
        target_partitions: usize,
        _repartition_file_min_size: usize,
        output_ordering: Option<LexOrdering>,
    )

    /// Returns `Ok(None)` if unable to repartition. Preserve output ordering if exists.
    /// Refer to [`DataSource::repartitioned`] for further details.
    fn repartitioned(
        &self,
        target_partitions: usize,
        _repartition_file_min_size: usize,
        output_ordering: Option<LexOrdering>,
    ) -> Result<Option<Arc<dyn DataSource>>> {
        if self.partitions.is_empty() || self.partitions.len() >= target_partitions
        // if have no partitions, or already have more partitions than desired, do not repartition
        {
            return Ok(None);
        }

        let maybe_repartitioned = if let Some(output_ordering) = output_ordering {
            self.repartition_preserving_order(target_partitions, output_ordering)?
        } else {
            self.repartition_evenly_by_size(target_partitions)?
        };

        if let Some(repartitioned) = maybe_repartitioned {
            Ok(Some(Arc::new(Self::try_new(
                &repartitioned,
                self.original_schema(),
                self.projection.clone(),
            )?)))
        } else {
            Ok(None)
        }
    }

    fn output_partitioning(&self) -> Partitioning {
        Partitioning::UnknownPartitioning(self.partitions.len())