Method merge_batch

datafusion/functions-aggregate/src/first_last.rs:670–707

(
        &mut self,
        values: &[ArrayRef],
        group_indices: &[usize],
        opt_filter: Option<&BooleanArray>,
        total_num_groups: usize,
    )

    }

    fn merge_batch(
        &mut self,
        values: &[ArrayRef],
        group_indices: &[usize],
        opt_filter: Option<&BooleanArray>,
        total_num_groups: usize,
    ) -> Result<()> {
        self.resize_states(total_num_groups);

        let mut ordering_buf = Vec::with_capacity(self.ordering_req.len());

        let (is_set_arr, val_and_order_cols) = match values.split_last() {
            Some(result) => result,
            None => return internal_err!("Empty row in FIRST_VALUE"),
        };

        let is_set_arr = as_boolean_array(is_set_arr)?;

        let vals = &values[0];
        // The overhead of calling `extract_row_at_idx_to_buf` is somewhat high, so we need to minimize its calls as much as possible.
        let groups = self.get_filtered_extreme_of_each_group(
            &val_and_order_cols[1..],
            group_indices,
            opt_filter,
            vals,
            Some(is_set_arr),
        )?;

        for (group_idx, idx) in groups.into_iter() {
            extract_row_at_idx_to_buf(&val_and_order_cols[1..], idx, &mut ordering_buf)?;

            if self.should_update_state(group_idx, &ordering_buf)? {
                self.update_state(group_idx, &ordering_buf, vals, idx)?;
            }
        }

        Ok(())
    }

    fn size(&self) -> usize {
        self.state.size()