Struct SharedThreshold 

pub struct SharedThreshold { /* private fields */ }

Cross-segment top-k score floor, shared across the parallel/concurrent per-segment searches of a single query.

Stores an f32 as raw bits in an atomic so it can be read and monotonically raised from many threads without a lock. Each segment reads the current floor as its initial pruning threshold (ScorerOptions::initial_threshold) and, once it has collected a full top-k of its own, raises the floor to its k-th score.

Safety of seeding: a segment only raises the floor after filling its own heap, so a floor value v is always backed by at least k real documents scoring >= v. The final merged k-th score is therefore >= v, and seeding any other segment with v can never drop a document that belongs in the final top-k. Completion order is arbitrary, so the floor is best-effort — it only changes how aggressively later segments prune, never correctness.

The floor carries the query’s result-window depth k (for_limit). Publishing from a heap shallower than k is invalid — a segment with fewer documents than the window fills its clamped heap early, and its heap threshold says nothing about the query-global k-th score. Executors must check SharedThreshold::covers before raising the floor with a full-heap threshold.

Implementations

impl SharedThreshold

pub fn new() -> Self

A fresh floor of 0.0 (no pruning seed) with an unknown window depth. Executors can read and manually raise it, but never publish their own full-heap thresholds into it.

pub fn for_limit(limit: usize) -> Self

A fresh floor valid for a query fetching limit results.

pub fn with_deadline(self, deadline: Option<Instant>) -> Self

Attach a wall-clock budget (None = unbounded).

pub fn deadline(&self) -> Option<Instant>

The query’s deadline, if any.

pub fn expired(&self) -> bool

Whether the deadline has passed.

pub fn mark_truncated(&self)

Record that an executor stopped early because the deadline passed.

pub fn truncated(&self) -> bool

Whether any executor of this query stopped early.

pub fn get(&self) -> f32

Current floor.

pub fn raise(&self, score: f32)

Raise the floor to score if it is strictly higher. Monotonic; a lower or non-positive score is ignored. Scores here are BM25/sparse and thus non-negative, but the comparison is done on f32 values (not raw bits) so it stays correct regardless.

Trait Implementations

impl Clone for SharedThreshold

fn clone(&self) -> SharedThreshold

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SharedThreshold

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

Formats the value using the given formatter.

impl Default for SharedThreshold

fn default() -> Self

Returns the “default value” for a type.