Function evaluate_frame_bounds

nodedb-query/src/window/frame.rs:29–44

Resolve the frame for row at position `pos` in a partition of `len` rows. Returns `(start_idx, end_idx)` — both are inclusive indices into the sorted partition slice. Guaranteed: `start_idx <= end_idx`, both within `0..len`. Arguments: - `frame`: the `WindowFrame` from the spec. - `pos`: current row's position within the partition (0-based). - `len`: total number of rows in the partition. - `ord

(
    frame: &WindowFrame,
    pos: usize,
    len: usize,
    order_values: &[serde_json::Value],
    peer_groups: &[usize],
)

///   GROUPS mode). Computed once per partition by `build_peer_groups`.
///   Empty slice is fine when mode != "groups".
pub(super) fn evaluate_frame_bounds(
    frame: &WindowFrame,
    pos: usize,
    len: usize,
    order_values: &[serde_json::Value],
    peer_groups: &[usize],
) -> (usize, usize) {
    match frame.mode.as_str() {
        "rows" => rows_bounds(&frame.start, &frame.end, pos, len),
        "range" => range_bounds(&frame.start, &frame.end, pos, len, order_values),
        "groups" => groups_bounds(&frame.start, &frame.end, pos, len, peer_groups),
        // Unrecognised mode treated as full-partition — the planner must have
        // validated the mode; reaching here with an unknown value is a bug.
        _ => (0, len.saturating_sub(1)),
    }
}

/// Build a per-row peer-group index array for a partition.
///