Struct Frontier 

pub struct Frontier<C> { /* private fields */ }

Active cursors of a query.

Exhausted lanes are retired lazily by retire_exhausted (also called by the methods that move cursors), so len() counts lanes that still have elements once that has run.

Implementations

impl<C: PostingCursor> Frontier<C>

pub fn new(lanes: impl IntoIterator<Item = Lane<C>>) -> Self

Build from lanes. Lanes with an exhausted cursor or a zero query weight are dropped right away.

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn lanes(&self) -> &[Lane<C>]

pub fn retire_exhausted(&mut self)

Drop lanes whose cursor is past the end.

pub fn min_id(&self) -> Option<RecordId>

Smallest current id across lanes: the next record that could be scored. None when every lane is exhausted.

pub fn max_last_id(&self) -> Option<RecordId>

Largest last id across lanes: no record beyond it exists in any lane.

pub fn best_possible(&self) -> f64

Upper bound on the score of any record no lane has consumed yet: the sum of every lane’s headroom. +inf when a lane is unbounded.

pub fn skip_below(&mut self, threshold: f32) -> Skip

Advance cursors past every id whose score cannot strictly exceed threshold.

Lanes are sorted by current id and their headrooms accumulated in that order. The pivot is the first lane at which the running total could beat the threshold. A record with an id below the pivot’s current id can only appear in lanes ordered before the pivot, whose combined headroom is below the threshold; those lanes are seeked to the pivot id. Without a pivot, nothing left can qualify.

pub fn score_window( &mut self, lo: RecordId, hi: RecordId, scores: &mut [f32], seen: &mut [bool], )

Consume every element with id in lo..=hi from every lane and add query_weight * weight into scores[id - lo], marking seen[id - lo]. Both buffers must be at least hi - lo + 1 long and scores must be zeroed for the slots that matter. Contributions are added in lane order, so a record’s score is the same f32 sum regardless of which window it lands in.

Trait Implementations

impl<C: Debug> Debug for Frontier<C>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.