Do less useless intersections

milli/src/search/new/exact_attribute.rs

@@ -1,3 +1,4 @@
+use heed::types::Bytes;
 use roaring::{MultiOps, RoaringBitmap};
 
 use super::query_graph::QueryGraph;
@@ -5,7 +6,7 @@ use super::ranking_rules::{RankingRule, RankingRuleOutput};
 use crate::score_details::{self, ScoreDetails};
 use crate::search::new::query_graph::QueryNodeData;
 use crate::search::new::query_term::ExactTerm;
-use crate::{Result, SearchContext, SearchLogger};
+use crate::{CboRoaringBitmapCodec, Result, SearchContext, SearchLogger};
 
 /// A ranking rule that produces 3 disjoint buckets:
 ///
@@ -173,8 +174,7 @@ impl State {
                 let bucketed_position = crate::bucketed_position(position + offset);
                 let word_position_docids = ctx
                     .get_db_word_position_docids(Some(universe), *word, bucketed_position)?
-                    .unwrap_or_default()
-                    & universe;
+                    .unwrap_or_default();
                 candidates &= word_position_docids;
                 if candidates.is_empty() {
                     return Ok(State::Empty(query_graph.clone()));
@@ -205,16 +205,24 @@ impl State {
                             .unwrap_or_default())
                     }),
             )?;
+            // TODO Why not doing this intersection in the MultiOps above?
             intersection &= &candidates;
             if !intersection.is_empty() {
                 // Although not really worth it in terms of performance,
                 // if would be good to put this in cache for the sake of consistency
                 let candidates_with_exact_word_count = if count_all_positions < u8::MAX as usize {
-                    ctx.index
+                    let bitmap_bytes = ctx
+                        .index
                         .field_id_word_count_docids
-                        .get(ctx.txn, &(fid, count_all_positions as u8))?
-                        .unwrap_or_default()
-                        & universe
+                        .remap_data_type::<Bytes>()
+                        .get(ctx.txn, &(fid, count_all_positions as u8))?;
+
+                    match bitmap_bytes {
+                        Some(bytes) => {
+                            CboRoaringBitmapCodec::intersection_with_serialized(bytes, universe)?
+                        }
+                        None => RoaringBitmap::default(),
+                    }
                 } else {
                     RoaringBitmap::default()
                 };
@@ -237,6 +245,8 @@ impl State {
         let (state, output) = match state {
             State::Uninitialized => (state, None),
             State::ExactAttribute(query_graph, candidates_per_attribute) => {
+                // TODO it can be much faster to do the intersections before the unions...
+                //      or maybe the candidates_per_attribute are not containing anything outside universe
                 let mut candidates = MultiOps::union(candidates_per_attribute.iter().map(
                     |FieldCandidates { start_with_exact, exact_word_count }| {
                         start_with_exact & exact_word_count
@@ -255,6 +265,8 @@ impl State {
                 )
             }
             State::AttributeStarts(query_graph, candidates_per_attribute) => {
+                // TODO it can be much faster to do the intersections before the unions...
+                //      or maybe the candidates_per_attribute are not containing anything outside universe
                 let mut candidates = MultiOps::union(candidates_per_attribute.into_iter().map(
                     |FieldCandidates { mut start_with_exact, exact_word_count }| {
                         start_with_exact -= exact_word_count;

milli/src/search/new/ranking_rule_graph/fid/mod.rs

@@ -29,14 +29,12 @@ impl RankingRuleGraphTrait for FidGraph {
         let FidCondition { term, .. } = condition;
 
         let docids = if let Some(fid) = condition.fid {
-            // maybe compute_query_term_subset_docids_within_field_id should accept a universe as argument
-            let docids = compute_query_term_subset_docids_within_field_id(
+            compute_query_term_subset_docids_within_field_id(
                 ctx,
                 Some(universe),
                 &term.term_subset,
                 fid,
-            )?;
-            docids & universe
+            )?
         } else {
             RoaringBitmap::new()
         };

milli/src/search/new/ranking_rule_graph/position/mod.rs

@@ -28,15 +28,15 @@ impl RankingRuleGraphTrait for PositionGraph {
     ) -> Result<ComputedCondition> {
         let PositionCondition { term, positions } = condition;
         let mut docids = RoaringBitmap::new();
+        // TODO use MultiOps to do the big union
         for position in positions {
             // maybe compute_query_term_subset_docids_within_position should accept a universe as argument
-            docids |= universe
-                & compute_query_term_subset_docids_within_position(
-                    ctx,
-                    Some(universe),
-                    &term.term_subset,
-                    *position,
-                )?;
+            docids |= compute_query_term_subset_docids_within_position(
+                ctx,
+                Some(universe),
+                &term.term_subset,
+                *position,
+            )?;
         }
         Ok(ComputedCondition {
             docids,

milli/src/search/new/ranking_rule_graph/proximity/compute_docids.rs

@@ -143,7 +143,6 @@ fn compute_prefix_edges(
         right_prefix,
         forward_proximity,
     )? {
-        let new_docids = &universe & new_docids;
         if !new_docids.is_empty() {
             used_left_words.insert(left_word);
             used_right_prefix.insert(right_prefix);
@@ -153,13 +152,13 @@ fn compute_prefix_edges(
 
     // No swapping when computing the proximity between a phrase and a word
     if left_phrase.is_none() {
+        // TODO check that the fact that the universe always changes is not an issue, e.g. caching stuff.
         if let Some(new_docids) = ctx.get_db_prefix_word_pair_proximity_docids(
             Some(&universe),
             right_prefix,
             left_word,
             backward_proximity,
         )? {
-            let new_docids = &universe & new_docids;
             if !new_docids.is_empty() {
                 used_left_words.insert(left_word);
                 used_right_prefix.insert(right_prefix);
@@ -185,9 +184,7 @@ fn compute_non_prefix_edges(
     let mut universe = universe.clone();
 
     for phrase in left_phrase.iter().chain(right_phrase.iter()).copied() {
-        // TODO do the intersection in the method, again!
-        let phrase_docids = ctx.get_phrase_docids(Some(&universe), phrase)?;
-        universe &= phrase_docids;
+        universe &= ctx.get_phrase_docids(Some(&universe), phrase)?;
         if universe.is_empty() {
             return Ok(());
         }

milli/src/search/new/resolve_query_graph.rs

@@ -251,6 +251,7 @@ pub fn compute_phrase_docids(
         // We sort the bitmaps so that we perform the small intersections first, which is faster.
         bitmaps.sort_unstable_by_key(|a| a.len());
 
+        // TODO use MultiOps intersection which and remove the above sort
         for bitmap in bitmaps {
             candidates &= bitmap;