Add ranking_score_threshold to milli

milli/src/search/hybrid.rs

@@ -169,6 +169,7 @@ impl<'a> Search<'a> {
             index: self.index,
             semantic: self.semantic.clone(),
             time_budget: self.time_budget.clone(),
+            ranking_score_threshold: self.ranking_score_threshold,
         };
 
         let semantic = search.semantic.take();

milli/src/search/mod.rs

@@ -50,6 +50,7 @@ pub struct Search<'a> {
     index: &'a Index,
     semantic: Option<SemanticSearch>,
     time_budget: TimeBudget,
+    ranking_score_threshold: Option<f64>,
 }
 
 impl<'a> Search<'a> {
@@ -70,6 +71,7 @@ impl<'a> Search<'a> {
             index,
             semantic: None,
             time_budget: TimeBudget::max(),
+            ranking_score_threshold: None,
         }
     }
 
@@ -146,6 +148,14 @@ impl<'a> Search<'a> {
         self
     }
 
+    pub fn ranking_score_threshold(
+        &mut self,
+        ranking_score_threshold: Option<f64>,
+    ) -> &mut Search<'a> {
+        self.ranking_score_threshold = ranking_score_threshold;
+        self
+    }
+
     pub fn execute_for_candidates(&self, has_vector_search: bool) -> Result<RoaringBitmap> {
         if has_vector_search {
             let ctx = SearchContext::new(self.index, self.rtxn)?;
@@ -184,6 +194,7 @@ impl<'a> Search<'a> {
                     embedder_name,
                     embedder,
                     self.time_budget.clone(),
+                    self.ranking_score_threshold,
                 )?
             }
             _ => execute_search(
@@ -201,6 +212,7 @@ impl<'a> Search<'a> {
                 &mut DefaultSearchLogger,
                 &mut DefaultSearchLogger,
                 self.time_budget.clone(),
+                self.ranking_score_threshold,
             )?,
         };
 
@@ -239,6 +251,7 @@ impl fmt::Debug for Search<'_> {
             index: _,
             semantic,
             time_budget,
+            ranking_score_threshold,
         } = self;
         f.debug_struct("Search")
             .field("query", query)
@@ -257,6 +270,7 @@ impl fmt::Debug for Search<'_> {
                 &semantic.as_ref().map(|semantic| &semantic.embedder_name),
             )
             .field("time_budget", time_budget)
+            .field("ranking_score_threshold", ranking_score_threshold)
             .finish()
     }
 }

milli/src/search/new/bucket_sort.rs

@@ -28,6 +28,7 @@ pub fn bucket_sort<'ctx, Q: RankingRuleQueryTrait>(
     scoring_strategy: ScoringStrategy,
     logger: &mut dyn SearchLogger<Q>,
     time_budget: TimeBudget,
+    ranking_score_threshold: Option<f64>,
 ) -> Result<BucketSortOutput> {
     logger.initial_query(query);
     logger.ranking_rules(&ranking_rules);
@@ -144,6 +145,7 @@ pub fn bucket_sort<'ctx, Q: RankingRuleQueryTrait>(
                 ctx,
                 from,
                 length,
+                ranking_score_threshold,
                 logger,
                 &mut valid_docids,
                 &mut valid_scores,
@@ -164,7 +166,9 @@ pub fn bucket_sort<'ctx, Q: RankingRuleQueryTrait>(
             loop {
                 let bucket = std::mem::take(&mut ranking_rule_universes[cur_ranking_rule_index]);
                 ranking_rule_scores.push(ScoreDetails::Skipped);
+
                 maybe_add_to_results!(bucket);
+
                 ranking_rule_scores.pop();
 
                 if cur_ranking_rule_index == 0 {
@@ -220,6 +224,17 @@ pub fn bucket_sort<'ctx, Q: RankingRuleQueryTrait>(
         debug_assert!(
             ranking_rule_universes[cur_ranking_rule_index].is_superset(&next_bucket.candidates)
         );
+
+        if let Some(ranking_score_threshold) = ranking_score_threshold {
+            let current_score = ScoreDetails::global_score(ranking_rule_scores.iter());
+            if current_score < ranking_score_threshold {
+                all_candidates -=
+                    next_bucket.candidates | &ranking_rule_universes[cur_ranking_rule_index];
+                back!();
+                continue;
+            }
+        }
+
         ranking_rule_universes[cur_ranking_rule_index] -= &next_bucket.candidates;
 
         if cur_ranking_rule_index == ranking_rules_len - 1
@@ -262,6 +277,7 @@ fn maybe_add_to_results<'ctx, Q: RankingRuleQueryTrait>(
     ctx: &mut SearchContext<'ctx>,
     from: usize,
     length: usize,
+    ranking_score_threshold: Option<f64>,
     logger: &mut dyn SearchLogger<Q>,
 
     valid_docids: &mut Vec<u32>,
@@ -279,6 +295,15 @@ fn maybe_add_to_results<'ctx, Q: RankingRuleQueryTrait>(
     ranking_rule_scores: &[ScoreDetails],
     candidates: RoaringBitmap,
 ) -> Result<()> {
+    // remove candidates from the universe without adding them to result if their score is below the threshold
+    if let Some(ranking_score_threshold) = ranking_score_threshold {
+        let score = ScoreDetails::global_score(ranking_rule_scores.iter());
+        if score < ranking_score_threshold {
+            *all_candidates -= candidates | &ranking_rule_universes[cur_ranking_rule_index];
+            return Ok(());
+        }
+    }
+
     // First apply the distinct rule on the candidates, reducing the universes if necessary
     let candidates = if let Some(distinct_fid) = distinct_fid {
         let DistinctOutput { remaining, excluded } =

milli/src/search/new/matches/mod.rs

@@ -523,6 +523,7 @@ mod tests {
                 &mut crate::DefaultSearchLogger,
                 &mut crate::DefaultSearchLogger,
                 TimeBudget::max(),
+                None,
             )
             .unwrap();
 

milli/src/search/new/mod.rs

@@ -568,6 +568,7 @@ pub fn execute_vector_search(
     embedder_name: &str,
     embedder: &Embedder,
     time_budget: TimeBudget,
+    ranking_score_threshold: Option<f64>,
 ) -> Result<PartialSearchResult> {
     check_sort_criteria(ctx, sort_criteria.as_ref())?;
 
@@ -597,6 +598,7 @@ pub fn execute_vector_search(
         scoring_strategy,
         placeholder_search_logger,
         time_budget,
+        ranking_score_threshold,
     )?;
 
     Ok(PartialSearchResult {
@@ -626,6 +628,7 @@ pub fn execute_search(
     placeholder_search_logger: &mut dyn SearchLogger<PlaceholderQuery>,
     query_graph_logger: &mut dyn SearchLogger<QueryGraph>,
     time_budget: TimeBudget,
+    ranking_score_threshold: Option<f64>,
 ) -> Result<PartialSearchResult> {
     check_sort_criteria(ctx, sort_criteria.as_ref())?;
 
@@ -714,6 +717,7 @@ pub fn execute_search(
             scoring_strategy,
             query_graph_logger,
             time_budget,
+            ranking_score_threshold,
         )?
     } else {
         let ranking_rules =
@@ -728,6 +732,7 @@ pub fn execute_search(
             scoring_strategy,
             placeholder_search_logger,
             time_budget,
+            ranking_score_threshold,
         )?
     };