low hanging fruit in optimization

src/query/phrase_prefix_query/phrase_prefix_scorer.rs

@@ -2,7 +2,7 @@ use crate::docset::{DocSet, TERMINATED};
 use crate::fieldnorm::FieldNormReader;
 use crate::postings::Postings;
 use crate::query::bm25::Bm25Weight;
-use crate::query::phrase_query::{intersection_count, PhraseScorer};
+use crate::query::phrase_query::{intersection_count, intersection_exists, PhraseScorer};
 use crate::query::Scorer;
 use crate::{DocId, Score};
 
@@ -92,14 +92,17 @@ impl<TPostings: Postings> Scorer for PhraseKind<TPostings> {
     }
 }
 
-pub struct PhrasePrefixScorer<TPostings: Postings> {
+pub struct PhrasePrefixScorer<TPostings: Postings, const SCORING_ENABLED: bool> {
     phrase_scorer: PhraseKind<TPostings>,
     suffixes: Vec<TPostings>,
     suffix_offset: u32,
     phrase_count: u32,
+    suffix_position_buffer: Vec<u32>,
 }
 
-impl<TPostings: Postings> PhrasePrefixScorer<TPostings> {
+impl<TPostings: Postings, const SCORING_ENABLED: bool>
+    PhrasePrefixScorer<TPostings, SCORING_ENABLED>
+{
     // If similarity_weight is None, then scoring is disabled.
     pub fn new(
         mut term_postings: Vec<(usize, TPostings)>,
@@ -107,7 +110,7 @@ impl<TPostings: Postings> PhrasePrefixScorer<TPostings> {
         fieldnorm_reader: FieldNormReader,
         suffixes: Vec<TPostings>,
         suffix_pos: usize,
-    ) -> PhrasePrefixScorer<TPostings> {
+    ) -> PhrasePrefixScorer<TPostings, SCORING_ENABLED> {
         // correct indices so we can merge with our suffix term the PhraseScorer doesn't know about
         let max_offset = term_postings
             .iter()
@@ -140,6 +143,7 @@ impl<TPostings: Postings> PhrasePrefixScorer<TPostings> {
             suffixes,
             suffix_offset: (max_offset - suffix_pos) as u32,
             phrase_count: 0,
+            suffix_position_buffer: Vec::with_capacity(100),
         };
         if phrase_prefix_scorer.doc() != TERMINATED && !phrase_prefix_scorer.matches_prefix() {
             phrase_prefix_scorer.advance();
@@ -153,7 +157,6 @@ impl<TPostings: Postings> PhrasePrefixScorer<TPostings> {
 
     fn matches_prefix(&mut self) -> bool {
         let mut count = 0;
-        let mut positions = Vec::new();
         let current_doc = self.doc();
         let pos_matching = self.phrase_scorer.get_intersection();
         for suffix in &mut self.suffixes {
@@ -162,16 +165,27 @@ impl<TPostings: Postings> PhrasePrefixScorer<TPostings> {
             }
             let doc = suffix.seek(current_doc);
             if doc == current_doc {
-                suffix.positions_with_offset(self.suffix_offset, &mut positions);
-                count += intersection_count(pos_matching, &positions);
+                suffix.positions_with_offset(self.suffix_offset, &mut self.suffix_position_buffer);
+                if SCORING_ENABLED {
+                    count += intersection_count(pos_matching, &self.suffix_position_buffer);
+                } else {
+                    if intersection_exists(pos_matching, &self.suffix_position_buffer) {
+                        return true;
+                    }
+                }
             }
         }
+        if !SCORING_ENABLED {
+            return false;
+        }
         self.phrase_count = count as u32;
         count != 0
     }
 }
 
-impl<TPostings: Postings> DocSet for PhrasePrefixScorer<TPostings> {
+impl<TPostings: Postings, const SCORING_ENABLED: bool> DocSet
+    for PhrasePrefixScorer<TPostings, SCORING_ENABLED>
+{
     fn advance(&mut self) -> DocId {
         loop {
             let doc = self.phrase_scorer.advance();
@@ -198,9 +212,15 @@ impl<TPostings: Postings> DocSet for PhrasePrefixScorer<TPostings> {
     }
 }
 
-impl<TPostings: Postings> Scorer for PhrasePrefixScorer<TPostings> {
+impl<TPostings: Postings, const SCORING_ENABLED: bool> Scorer
+    for PhrasePrefixScorer<TPostings, SCORING_ENABLED>
+{
     fn score(&mut self) -> Score {
+        if SCORING_ENABLED {
+            self.phrase_scorer.score()
+        } else {
+            1.0f32
+        }
         // TODO modify score??
-        self.phrase_scorer.score()
     }
 }

src/query/phrase_prefix_query/phrase_prefix_weight.rs

@@ -42,11 +42,11 @@ impl PhrasePrefixWeight {
         Ok(FieldNormReader::constant(reader.max_doc(), 1))
     }
 
-    pub(crate) fn phrase_scorer(
+    pub(crate) fn phrase_prefix_scorer<const SCORING_ENABLED: bool>(
         &self,
         reader: &SegmentReader,
         boost: Score,
-    ) -> crate::Result<Option<PhrasePrefixScorer<SegmentPostings>>> {
+    ) -> crate::Result<Option<PhrasePrefixScorer<SegmentPostings, SCORING_ENABLED>>> {
         let similarity_weight_opt = self
             .similarity_weight_opt
             .as_ref()
@@ -128,15 +128,20 @@ impl PhrasePrefixWeight {
 
 impl Weight for PhrasePrefixWeight {
     fn scorer(&self, reader: &SegmentReader, boost: Score) -> crate::Result<Box<dyn Scorer>> {
-        if let Some(scorer) = self.phrase_scorer(reader, boost)? {
-            Ok(Box::new(scorer))
+        if self.similarity_weight_opt.is_some() {
+            if let Some(scorer) = self.phrase_prefix_scorer::<true>(reader, boost)? {
+                return Ok(Box::new(scorer));
+            }
         } else {
-            Ok(Box::new(EmptyScorer))
+            if let Some(scorer) = self.phrase_prefix_scorer::<false>(reader, boost)? {
+                return Ok(Box::new(scorer));
+            }
         }
+        Ok(Box::new(EmptyScorer))
     }
 
     fn explain(&self, reader: &SegmentReader, doc: DocId) -> crate::Result<Explanation> {
-        let scorer_opt = self.phrase_scorer(reader, 1.0)?;
+        let scorer_opt = self.phrase_prefix_scorer::<true>(reader, 1.0)?;
         if scorer_opt.is_none() {
             return Err(does_not_match(doc));
         }
@@ -200,7 +205,7 @@ mod tests {
             .unwrap()
             .unwrap();
         let mut phrase_scorer = phrase_weight
-            .phrase_scorer(searcher.segment_reader(0u32), 1.0)?
+            .phrase_prefix_scorer::<true>(searcher.segment_reader(0u32), 1.0)?
             .unwrap();
         assert_eq!(phrase_scorer.doc(), 1);
         assert_eq!(phrase_scorer.phrase_count(), 2);
@@ -211,6 +216,38 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    pub fn test_phrase_no_count() -> crate::Result<()> {
+        let index = create_index(&[
+            "aa bb dd cc",
+            "aa aa bb c dd aa bb cc aa bb dc",
+            " aa bb cd",
+        ])?;
+        let schema = index.schema();
+        let text_field = schema.get_field("text").unwrap();
+        let searcher = index.reader()?.searcher();
+        let phrase_query = PhrasePrefixQuery::new(vec![
+            Term::from_field_text(text_field, "aa"),
+            Term::from_field_text(text_field, "bb"),
+            Term::from_field_text(text_field, "c"),
+        ]);
+        let enable_scoring = EnableScoring::enabled_from_searcher(&searcher);
+        let phrase_weight = phrase_query
+            .phrase_prefix_query_weight(enable_scoring)
+            .unwrap()
+            .unwrap();
+        let mut phrase_scorer = phrase_weight
+            .phrase_prefix_scorer::<false>(searcher.segment_reader(0u32), 1.0)?
+            .unwrap();
+        assert_eq!(phrase_scorer.doc(), 1);
+        assert_eq!(phrase_scorer.phrase_count(), 0);
+        assert_eq!(phrase_scorer.advance(), 2);
+        assert_eq!(phrase_scorer.doc(), 2);
+        assert_eq!(phrase_scorer.phrase_count(), 0);
+        assert_eq!(phrase_scorer.advance(), TERMINATED);
+        Ok(())
+    }
+
     #[test]
     pub fn test_phrase_count_mid() -> crate::Result<()> {
         let index = create_index(&["aa dd cc", "aa aa bb c dd aa bb cc aa dc", " aa bb cd"])?;
@@ -227,7 +264,7 @@ mod tests {
             .unwrap()
             .unwrap();
         let mut phrase_scorer = phrase_weight
-            .phrase_scorer(searcher.segment_reader(0u32), 1.0)?
+            .phrase_prefix_scorer::<true>(searcher.segment_reader(0u32), 1.0)?
             .unwrap();
         assert_eq!(phrase_scorer.doc(), 1);
         assert_eq!(phrase_scorer.phrase_count(), 2);

src/query/phrase_query/mod.rs

@@ -3,8 +3,8 @@ mod phrase_scorer;
 mod phrase_weight;
 
 pub use self::phrase_query::PhraseQuery;
-pub(crate) use self::phrase_scorer::intersection_count;
 pub use self::phrase_scorer::PhraseScorer;
+pub(crate) use self::phrase_scorer::{intersection_count, intersection_exists};
 pub use self::phrase_weight::PhraseWeight;
 
 #[cfg(test)]

src/query/phrase_query/phrase_scorer.rs

@@ -58,7 +58,7 @@ pub struct PhraseScorer<TPostings: Postings> {
 }
 
 /// Returns true if and only if the two sorted arrays contain a common element
-fn intersection_exists(left: &[u32], right: &[u32]) -> bool {
+pub(crate) fn intersection_exists(left: &[u32], right: &[u32]) -> bool {
     let mut left_index = 0;
     let mut right_index = 0;
     while left_index < left.len() && right_index < right.len() {