Method calculate_range

datafusion/expr/src/window_state.rs:156–188

This function calculates beginning/ending indices for the frame of the current row.

(
        &mut self,
        range_columns: &[ArrayRef],
        last_range: &Range<usize>,
        length: usize,
        idx: usize,
    )

    /// This function calculates beginning/ending indices for the frame of the current row.
    pub fn calculate_range(
        &mut self,
        range_columns: &[ArrayRef],
        last_range: &Range<usize>,
        length: usize,
        idx: usize,
    ) -> Result<Range<usize>> {
        match self {
            WindowFrameContext::Rows(window_frame) => {
                Self::calculate_range_rows(window_frame, length, idx)
            }
            // Sort options is used in RANGE mode calculations because the
            // ordering or position of NULLs impact range calculations and
            // comparison of rows.
            WindowFrameContext::Range {
                window_frame,
                state,
            } => state.calculate_range(
                window_frame,
                last_range,
                range_columns,
                length,
                idx,
            ),
            // Sort options is not used in GROUPS mode calculations as the
            // inequality of two rows indicates a group change, and ordering
            // or position of NULLs do not impact inequality.
            WindowFrameContext::Groups {
                window_frame,
                state,
            } => state.calculate_range(window_frame, range_columns, length, idx),
        }
    }

    /// This function calculates beginning/ending indices for the frame of the current row.
    fn calculate_range_rows(