Speed up TermQuery

lucene/core/src/java/org/apache/lucene/search/ImpactsDISI.java

@@ -98,6 +98,15 @@ private int advanceTarget(int target) throws IOException {
     }
   }
 
+  /** If current doc is not competitive, move to a competitive one. */
+  void ensureCompetitive() throws IOException {
+    int doc = docID();
+    int advanceTarget = advanceTarget(doc);
+    if (advanceTarget != doc) {
+      in.advance(advanceTarget);
+    }
+  }
+
   @Override
   public int advance(int target) throws IOException {
     return in.advance(advanceTarget(target));

lucene/core/src/java/org/apache/lucene/search/TermQuery.java

@@ -173,7 +173,7 @@ public BulkScorer bulkScorer() throws IOException {
             return ConstantScoreScorerSupplier.fromIterator(iterator, 0f, scoreMode, maxDoc)
                 .bulkScorer();
           }
-          return super.bulkScorer();
+          return new DefaultBulkScorer(get(Long.MAX_VALUE), scoreMode);
         }
 
         @Override

lucene/core/src/java/org/apache/lucene/search/TermScorer.java

@@ -134,6 +134,10 @@ public void nextDocsAndScores(int upTo, Bits liveDocs, DocAndScoreBuffer buffer)
       docAndFreqBuffer = new DocAndFreqBuffer();
     }
 
+    if (impactsDisi != null) {
+      impactsDisi.ensureCompetitive();
+    }
+
     for (; ; ) {
       postingsEnum.nextPostings(upTo, docAndFreqBuffer);
       if (liveDocs != null && docAndFreqBuffer.size != 0) {

lucene/core/src/java/org/apache/lucene/search/Weight.java

@@ -231,16 +231,25 @@ protected static class DefaultBulkScorer extends BulkScorer {
     private final Scorer scorer;
     private final DocIdSetIterator iterator;
     private final TwoPhaseIterator twoPhase;
+    private final ScoreMode scoreMode;
+    private DocAndScoreBuffer buffer;
+    private SimpleScorable scorable;
 
     /** Sole constructor. */
     public DefaultBulkScorer(Scorer scorer) {
+      this(scorer, null);
+    }
+
+    /** Sole constructor. */
+    public DefaultBulkScorer(Scorer scorer, ScoreMode scoreMode) {
       this.scorer = Objects.requireNonNull(scorer);
       this.twoPhase = scorer.twoPhaseIterator();
       if (twoPhase == null) {
         this.iterator = scorer.iterator();
       } else {
         this.iterator = twoPhase.approximation();
       }
+      this.scoreMode = scoreMode;
     }
 
     @Override
@@ -251,9 +260,14 @@ public long cost() {
     @Override
     public int score(LeafCollector collector, Bits acceptDocs, int min, int max)
         throws IOException {
-      collector.setScorer(scorer);
       DocIdSetIterator competitiveIterator = collector.competitiveIterator();
 
+      if (scoreMode != null && scoreMode.needsScores() && competitiveIterator == null) {
+        return batchScore(collector, acceptDocs, min, max);
+      }
+
+      collector.setScorer(scorer);
+
       if (competitiveIterator != null) {
         if (competitiveIterator.docID() > min) {
           min = competitiveIterator.docID();
@@ -290,6 +304,37 @@ public int score(LeafCollector collector, Bits acceptDocs, int min, int max)
       return iterator.docID();
     }
 
+    private int batchScore(LeafCollector collector, Bits acceptDocs, int min, int max)
+        throws IOException {
+      if (buffer == null) {
+        buffer = new DocAndScoreBuffer();
+      }
+      if (scorable == null) {
+        scorable = new SimpleScorable();
+      }
+
+      collector.setScorer(scorable);
+      scorer.setMinCompetitiveScore(scorable.minCompetitiveScore);
+
+      if (scorer.docID() < min) {
+        scorer.iterator().advance(min);
+      }
+
+      for (scorer.nextDocsAndScores(max, acceptDocs, buffer);
+          buffer.size > 0;
+          scorer.nextDocsAndScores(max, acceptDocs, buffer)) {
+        for (int i = 0, size = buffer.size; i < size; i++) {
+          float score = scorable.score = buffer.scores[i];
+          if (score >= scorable.minCompetitiveScore) {
+            collector.collect(buffer.docs[i]);
+          }
+        }
+        scorer.setMinCompetitiveScore(scorable.minCompetitiveScore);
+      }
+
+      return scorer.docID();
+    }
+
     private static void scoreIterator(
         LeafCollector collector, Bits acceptDocs, DocIdSetIterator iterator, int max)
         throws IOException {