org.apache.lucene.search.ScoreMode Java Examples

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
    return new ConstantScoreWeight(this, boost) {
        @Override
        public boolean isCacheable(LeafReaderContext ctx) {
            return false;
        }

        @Override
        public Scorer scorer(LeafReaderContext context) {
            return new ConstantScoreScorer(
                this,
                0f,
                scoreMode,
                new NumTermsPerDocTwoPhaseIterator(context.reader(), numTermsPerDocFactory.apply(context), matches));
        }
    };
}
 

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  final Automaton originalAutomata;
  try (CompletionTokenStream stream = (CompletionTokenStream) analyzer.tokenStream(getField(), getTerm().text()) ) {
    originalAutomata = stream.toAutomaton(unicodeAware);
  }
  Set<IntsRef> refs = new HashSet<>();
  Automaton automaton = toLevenshteinAutomata(originalAutomata, refs);
  if (unicodeAware) {
    Automaton utf8automaton = new UTF32ToUTF8().convert(automaton);
    utf8automaton = Operations.determinize(utf8automaton, maxDeterminizedStates);
    automaton = utf8automaton;
  }
  // TODO Accumulating all refs is bad, because the resulting set may be very big.
  // TODO Better iterate over automaton again inside FuzzyCompletionWeight?
  return new FuzzyCompletionWeight(this, automaton, refs);
}
 

public void testSpanNearUnOrdered() throws Exception {
  //See http://www.gossamer-threads.com/lists/lucene/java-dev/52270 for discussion about this test
  SpanQuery senq = spanNearUnorderedQuery(field, 0, "u1", "u2");
  Spans spans = senq.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertNext(spans, 4, 1, 3);
  assertNext(spans, 5, 2, 4);
  assertNext(spans, 8, 2, 4);
  assertNext(spans, 9, 0, 2);
  assertNext(spans, 10, 0, 2);
  assertFinished(spans);

  senq = spanNearUnorderedQuery(1, senq, spanTermQuery(field, "u2")); 
  spans = senq.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertNext(spans, 4, 0, 3);
  assertNext(spans, 4, 1, 3); // unordered spans can be subsets
  assertNext(spans, 5, 0, 4);
  assertNext(spans, 5, 2, 4);
  assertNext(spans, 8, 0, 4);
  assertNext(spans, 8, 2, 4);
  assertNext(spans, 9, 0, 2);
  assertNext(spans, 9, 0, 4);
  assertNext(spans, 10, 0, 2);
  assertFinished(spans);
}
 

static CodecReader wrapReader(String recoverySourceField, CodecReader reader, Supplier<Query> retainSourceQuerySupplier)
    throws IOException {
    NumericDocValues recoverySource = reader.getNumericDocValues(recoverySourceField);
    if (recoverySource == null || recoverySource.nextDoc() == DocIdSetIterator.NO_MORE_DOCS) {
        return reader; // early terminate - nothing to do here since non of the docs has a recovery source anymore.
    }
    IndexSearcher s = new IndexSearcher(reader);
    s.setQueryCache(null);
    Weight weight = s.createWeight(s.rewrite(retainSourceQuerySupplier.get()), ScoreMode.COMPLETE_NO_SCORES, 1.0f);
    Scorer scorer = weight.scorer(reader.getContext());
    if (scorer != null) {
        BitSet recoverySourceToKeep = BitSet.of(scorer.iterator(), reader.maxDoc());
        // calculating the cardinality is significantly cheaper than skipping all bulk-merging we might do
        // if retentions are high we keep most of it
        if (recoverySourceToKeep.cardinality() == reader.maxDoc()) {
            return reader; // keep all source
        }
        return new SourcePruningFilterCodecReader(recoverySourceField, reader, recoverySourceToKeep);
    } else {
        return new SourcePruningFilterCodecReader(recoverySourceField, reader, null);
    }
}
 

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
    if (!scoreMode.needsScores()) {
        // If scores are not needed simply return a constant score on all docs
        return new ConstantScoreWeight(this.query, boost) {
            @Override
            public boolean isCacheable(LeafReaderContext ctx) {
                return true;
            }

            @Override
            public Scorer scorer(LeafReaderContext context) throws IOException {
                return new ConstantScoreScorer(this, score(),
                    scoreMode, DocIdSetIterator.all(context.reader().maxDoc()));
            }
        };
    }

    return new FVWeight(this);
}
 

public static final MatcherFactory<ScoringMatch> matchWithSimilarity(Similarity similarity) {
  return searcher -> {
    searcher.setSimilarity(similarity);
    return new CollectingMatcher<ScoringMatch>(searcher, ScoreMode.COMPLETE) {
      @Override
      protected ScoringMatch doMatch(String queryId, int doc, Scorable scorer) throws IOException {
        float score = scorer.score();
        if (score > 0)
          return new ScoringMatch(queryId, score);
        return null;
      }

      @Override
      public ScoringMatch resolve(ScoringMatch match1, ScoringMatch match2) {
        return new ScoringMatch(match1.getQueryId(), match1.getScore() + match2.getScore());
      }
    };
  };
}
 

public void testSpanNot() throws Exception {
  SpanQuery[] clauses = new SpanQuery[2];
  clauses[0] = new SpanTermQuery(new Term(PayloadHelper.FIELD, "one"));
  clauses[1] = new SpanTermQuery(new Term(PayloadHelper.FIELD, "three"));
  SpanQuery spq = new SpanNearQuery(clauses, 5, true);
  SpanNotQuery snq = new SpanNotQuery(spq, new SpanTermQuery(new Term(PayloadHelper.FIELD, "two")));



  Directory directory = newDirectory();
  RandomIndexWriter writer = new RandomIndexWriter(random(), directory,
                                                   newIndexWriterConfig(new PayloadAnalyzer()).setSimilarity(similarity));

  Document doc = new Document();
  doc.add(newTextField(PayloadHelper.FIELD, "one two three one four three", Field.Store.YES));
  writer.addDocument(doc);
  IndexReader reader = getOnlyLeafReader(writer.getReader());
  writer.close();

  checkSpans(snq.createWeight(newSearcher(reader, false), ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(reader.leaves().get(0), SpanWeight.Postings.PAYLOADS), 1, new int[]{2});
  reader.close();
  directory.close();
}
 

public void testSpans2() throws Exception {
  assumeTrue("Broken scoring: LUCENE-3723",
      searcher.getSimilarity() instanceof TFIDFSimilarity);
  SpanQuery qA1 = new SpanTermQuery(new Term("gender", "female"));
  SpanQuery qA2 = new SpanTermQuery(new Term("first",  "james"));
  SpanQuery qA  = new SpanOrQuery(qA1, new FieldMaskingSpanQuery(qA2, "gender"));
  SpanQuery qB  = new SpanTermQuery(new Term("last",   "jones"));
  SpanQuery q   = new SpanNearQuery(new SpanQuery[]
    { new FieldMaskingSpanQuery(qA, "id"),
      new FieldMaskingSpanQuery(qB, "id") }, -1, false );
  check(q, new int[] { 0, 1, 2, 3 });

  Spans span = q.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertNext(span, 0,0,1);
  assertNext(span, 1,1,2);
  assertNext(span, 2,0,1);
  assertNext(span, 2,2,3);
  assertNext(span, 3,0,1);
  assertFinished(span);
}
 

private LTRScoringQuery.ModelWeight performQuery(TopDocs hits,
    IndexSearcher searcher, int docid, LTRScoringQuery model) throws IOException,
    ModelException {
  final List<LeafReaderContext> leafContexts = searcher.getTopReaderContext()
      .leaves();
  final int n = ReaderUtil.subIndex(hits.scoreDocs[0].doc, leafContexts);
  final LeafReaderContext context = leafContexts.get(n);
  final int deBasedDoc = hits.scoreDocs[0].doc - context.docBase;

  final Weight weight = searcher.createWeight(searcher.rewrite(model), ScoreMode.COMPLETE, 1);
  final Scorer scorer = weight.scorer(context);

  // rerank using the field final-score
  scorer.iterator().advance(deBasedDoc);
  scorer.score();
  assertTrue(weight instanceof LTRScoringQuery.ModelWeight);
  final LTRScoringQuery.ModelWeight modelWeight = (LTRScoringQuery.ModelWeight) weight;
  return modelWeight;

}
 

private Bits searchForDocBits(Query query) throws IOException {
  FixedBitSet bitSet = new FixedBitSet(indexSearcher.getIndexReader().maxDoc());
  indexSearcher.search(query,
      new SimpleCollector() {
        int leafDocBase;
        @Override
        public void collect(int doc) throws IOException {
          bitSet.set(leafDocBase + doc);
        }

        @Override
        protected void doSetNextReader(LeafReaderContext context) throws IOException {
          leafDocBase = context.docBase;
        }

        @Override
        public ScoreMode scoreMode() {
          return ScoreMode.COMPLETE_NO_SCORES;
        }
      });
  return bitSet;
}
 

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  final Weight indexQueryWeight = indexQuery.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, boost);//scores aren't unsupported

  return new ConstantScoreWeight(this, boost) {

    @Override
    public Scorer scorer(LeafReaderContext context) throws IOException {

      final Scorer indexQueryScorer = indexQueryWeight.scorer(context);
      if (indexQueryScorer == null) {
        return null;
      }

      final TwoPhaseIterator predFuncValues = predicateValueSource.iterator(context, indexQueryScorer.iterator());
      return new ConstantScoreScorer(this, score(), scoreMode, predFuncValues);
    }

    @Override
    public boolean isCacheable(LeafReaderContext ctx) {
      return predicateValueSource.isCacheable(ctx);
    }

  };
}
 

public void testSpans1() throws Exception {
  SpanQuery q1 = new SpanTermQuery(new Term("first", "sally"));
  SpanQuery q2 = new SpanTermQuery(new Term("first", "james"));
  SpanQuery qA = new SpanOrQuery(q1, q2);
  SpanQuery qB = new FieldMaskingSpanQuery(qA, "id");
                                          
  check(qA, new int[] { 0, 1, 2, 4 });
  check(qB, new int[] { 0, 1, 2, 4 });

  Spans spanA = qA.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  Spans spanB = qB.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  
  while (spanA.nextDoc() != Spans.NO_MORE_DOCS) {
    assertNotSame("spanB not still going", Spans.NO_MORE_DOCS, spanB.nextDoc());
    while (spanA.nextStartPosition() != Spans.NO_MORE_POSITIONS) {
      assertEquals("spanB start position", spanA.startPosition(), spanB.nextStartPosition());
      assertEquals("spanB end position", spanA.endPosition(), spanB.endPosition());
    }
    assertEquals("spanB start position", Spans.NO_MORE_POSITIONS, spanB.nextStartPosition());
  }
  assertEquals("spanB end doc", Spans.NO_MORE_DOCS, spanB.nextDoc());
}
 

@Test
public void test_generic_function_query_cannot_be_cached_with_un_deterministic_functions_present() throws Exception {
    QueryTester.Builder builder = new QueryTester.Builder(
        createTempDir(),
        THREAD_POOL,
        clusterService,
        Version.CURRENT,
        "create table t (x int)"
    );
    builder.indexValues("x", 1, 2, 3);
    try (QueryTester tester = builder.build()) {
        var query = tester.toQuery("x = random()");
        var searcher = tester.searcher();
        var weight = query.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1.0f);
        assertThat(weight.isCacheable(searcher.getTopReaderContext().leaves().get(0)), is(false));
    }
}
 

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  return new ConstantScoreWeight(this, boost) {
    @Override
    public Scorer scorer(LeafReaderContext context) throws IOException {
      DocIdSet docSet = getDocIdSet(context);
      if (docSet == null) {
        return null;
      }
      DocIdSetIterator disi = docSet.iterator();
      if (disi == null) {
        return null;
      }
      return new ConstantScoreScorer(this, score(), scoreMode, disi);
    }

    @Override
    public boolean isCacheable(LeafReaderContext ctx) {
      return true;
    }
  };
}
 

public void test() throws IOException {
  SpanQuery query = new PayloadScoreQuery(new SpanTermQuery(new Term("field", "seventy")),
          new MaxPayloadFunction(), PayloadDecoder.FLOAT_DECODER);
  TopDocs hits = searcher.search(query, 100);
  assertTrue("hits is null and it shouldn't be", hits != null);
  assertTrue("hits Size: " + hits.totalHits.value + " is not: " + 100, hits.totalHits.value == 100);

  //they should all have the exact same score, because they all contain seventy once, and we set
  //all the other similarity factors to be 1

  for (int i = 0; i < hits.scoreDocs.length; i++) {
    ScoreDoc doc = hits.scoreDocs[i];
    assertTrue(doc.score + " does not equal: " + 1, doc.score == 1);
  }
  CheckHits.checkExplanations(query, PayloadHelper.FIELD, searcher, true);
  Spans spans = query.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertTrue("spans is null and it shouldn't be", spans != null);
  /*float score = hits.score(0);
  for (int i =1; i < hits.length(); i++)
  {
    assertTrue("scores are not equal and they should be", score == hits.score(i));
  }*/

}
 

private void assertInnerScoreMode(ScoreMode expectedScoreMode, ScoreMode inputScoreMode, DoubleValuesSource valueSource) throws IOException {
  final AtomicReference<ScoreMode> scoreModeInWeight = new AtomicReference<ScoreMode>();
  Query innerQ = new TermQuery(new Term(TEXT_FIELD, "a")) {
    
    @Override
    public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
      scoreModeInWeight.set(scoreMode);
      return super.createWeight(searcher, scoreMode, boost);
    }
  };
  
  FunctionScoreQuery fq = new FunctionScoreQuery(innerQ, valueSource);
  fq.createWeight(searcher, inputScoreMode, 1f);
  assertEquals(expectedScoreMode, scoreModeInWeight.get());
}
 

public void testOrderedSpanIterationSameTerms2() throws Exception {
  SpanNearQuery q = new SpanNearQuery(new SpanQuery[]{
      new SpanTermQuery(new Term(FIELD, "t2")), new SpanTermQuery(new Term(FIELD, "t1"))
  }, 1, true);
  Spans spans = q.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertNext(spans,4,1,4);
  assertNext(spans,4,2,4);
  assertFinished(spans);
}
 

public void testOrderedSpanIteration() throws Exception {
  SpanNearQuery q = new SpanNearQuery(new SpanQuery[]{
      new SpanOrQuery(new SpanTermQuery(new Term(FIELD, "w1")), new SpanTermQuery(new Term(FIELD, "w2"))),
      new SpanTermQuery(new Term(FIELD, "w4"))
  }, 10, true);
  Spans spans = q.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertNext(spans,0,0,4);
  assertNext(spans,0,1,4);
  assertFinished(spans);
}
 

public void testNearSpansAdvanceTo0() throws Exception {
  SpanNearQuery q = makeQuery();
  Spans span = q.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertEquals(0, span.advance(0));
  assertEquals(0, span.nextStartPosition());
  assertEquals(s(0,0,3), s(span));
}
 

@SuppressWarnings({"unchecked", "rawtypes"})
private static Iterable<Row> getRow(AtomicReference<Throwable> killed,
                                    Searcher searcher,
                                    Query query,
                                    List<DocValueAggregator> aggregators) throws IOException {
    IndexSearcher indexSearcher = searcher.searcher();
    Weight weight = indexSearcher.createWeight(indexSearcher.rewrite(query), ScoreMode.COMPLETE_NO_SCORES, 1f);
    List<LeafReaderContext> leaves = indexSearcher.getTopReaderContext().leaves();
    Object[] cells = new Object[aggregators.size()];
    for (int i = 0; i < aggregators.size(); i++) {
        cells[i] = aggregators.get(i).initialState();
    }
    for (var leaf : leaves) {
        Scorer scorer = weight.scorer(leaf);
        if (scorer == null) {
            continue;
        }
        for (int i = 0; i < aggregators.size(); i++) {
            aggregators.get(i).loadDocValues(leaf.reader());
        }
        DocIdSetIterator docs = scorer.iterator();
        Bits liveDocs = leaf.reader().getLiveDocs();
        for (int doc = docs.nextDoc(); doc != DocIdSetIterator.NO_MORE_DOCS; doc = docs.nextDoc()) {
            if (liveDocs != null && !liveDocs.get(doc)) {
                continue;
            }
            Throwable killCause = killed.get();
            if (killCause != null) {
                Exceptions.rethrowUnchecked(killCause);
            }
            for (int i = 0; i < aggregators.size(); i++) {
                aggregators.get(i).apply(cells[i], doc);
            }
        }
    }
    for (int i = 0; i < aggregators.size(); i++) {
        cells[i] = aggregators.get(i).partialResult(cells[i]);
    }
    return List.of(new RowN(cells));
}
 

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  final CompletionWeight innerWeight = ((CompletionWeight) innerQuery.createWeight(searcher, scoreMode, boost));
  final Automaton innerAutomaton = innerWeight.getAutomaton();

  // If the inner automaton matches nothing, then we return an empty weight to avoid
  // traversing all contexts during scoring.
  if (innerAutomaton.getNumStates() == 0) {
    return new CompletionWeight(this, innerAutomaton);
  }

  // if separators are preserved the fst contains a SEP_LABEL
  // behind each gap. To have a matching automaton, we need to
  // include the SEP_LABEL in the query as well
  Automaton optionalSepLabel = Operations.optional(Automata.makeChar(ConcatenateGraphFilter.SEP_LABEL));
  Automaton prefixAutomaton = Operations.concatenate(optionalSepLabel, innerAutomaton);
  Automaton contextsAutomaton = Operations.concatenate(toContextAutomaton(contexts, matchAllContexts), prefixAutomaton);
  contextsAutomaton = Operations.determinize(contextsAutomaton, Operations.DEFAULT_MAX_DETERMINIZED_STATES);

  final Map<IntsRef, Float> contextMap = new HashMap<>(contexts.size());
  final TreeSet<Integer> contextLengths = new TreeSet<>();
  for (Map.Entry<IntsRef, ContextMetaData> entry : contexts.entrySet()) {
    ContextMetaData contextMetaData = entry.getValue();
    contextMap.put(entry.getKey(), contextMetaData.boost);
    contextLengths.add(entry.getKey().length);
  }
  int[] contextLengthArray = new int[contextLengths.size()];
  final Iterator<Integer> iterator = contextLengths.descendingIterator();
  for (int i = 0; iterator.hasNext(); i++) {
    contextLengthArray[i] = iterator.next();
  }
  return new ContextCompletionWeight(this, contextsAutomaton, innerWeight, contextMap, contextLengthArray);
}
 

@Override
public Explanation explain(IndexSearcher searcher,
    Explanation firstPassExplanation, int docID) throws IOException {

  final List<LeafReaderContext> leafContexts = searcher.getTopReaderContext()
      .leaves();
  final int n = ReaderUtil.subIndex(docID, leafContexts);
  final LeafReaderContext context = leafContexts.get(n);
  final int deBasedDoc = docID - context.docBase;
  final Weight modelWeight = searcher.createWeight(searcher.rewrite(scoringQuery),
      ScoreMode.COMPLETE, 1);
  return modelWeight.explain(context, deBasedDoc);
}
 

@Override
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  final Weight in = this.in.createWeight(searcher, scoreMode, boost);
  return new FilterWeight(in) {
    @Override
    public Scorer scorer(LeafReaderContext context) throws IOException {
      used.set(true);
      return in.scorer(context);
    }
  };
}
 

@Override
public Weight createWeight(Query query, ScoreMode scoreMode, float boost) throws IOException {
    QueryProfileBreakdown profile = profiler.getQueryBreakdown(query);
    Timer timer = profile.getTimer(QueryTimingType.CREATE_WEIGHT);
    timer.start();
    final Weight weight;
    try {
        weight = super.createWeight(query, scoreMode, boost);
    } finally {
        timer.stop();
        profiler.pollLastElement();
    }
    return new ProfileWeight(query, weight, profile);
}
 

@Override
public DelegatingCollector getFilterCollector(IndexSearcher searcher) {
  @SuppressWarnings({"rawtypes"})
  Map fcontext = ValueSource.newContext(searcher);
  Weight weight = rangeFilt.createWeight(searcher, ScoreMode.COMPLETE, 1);
  return new FunctionRangeCollector(fcontext, weight);
}
 

@Override
public SpanWeight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  final TermStates context;
  final IndexReaderContext topContext = searcher.getTopReaderContext();
  if (termStates == null || termStates.wasBuiltFor(topContext) == false) {
    context = TermStates.build(topContext, term, scoreMode.needsScores());
  }
  else {
    context = termStates;
  }
  return new SpanTermWeight(context, searcher, scoreMode.needsScores() ? Collections.singletonMap(term, context) : null, boost);
}
 

public void testNearSpansNext() throws Exception {
  SpanNearQuery q = makeQuery();
  Spans span = q.createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f).getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
  assertNext(span,0,0,3);
  assertNext(span,1,0,4);
  assertFinished(span);
}
 

@Override
public SpanWeight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  SpanWeight bigWeight = big.createWeight(searcher, scoreMode, boost);
  SpanWeight littleWeight = little.createWeight(searcher, scoreMode, boost);
  return new SpanWithinWeight(searcher, scoreMode.needsScores() ? getTermStates(bigWeight, littleWeight) : null,
                                    bigWeight, littleWeight, boost);
}
 

protected Scorer getScorer(final LeafReader reader, final Weight weight, final float boost, final ScoreMode scoreMode) throws IOException {
  switch (query.getQueryRelation()) {
    case INTERSECTS: return getSparseScorer(reader, weight, boost, scoreMode);
    case WITHIN:
    case DISJOINT: return getDenseScorer(reader, weight, boost, scoreMode);
    case CONTAINS: return getContainsDenseScorer(reader, weight, boost, scoreMode);
    default: throw new IllegalArgumentException("Unsupported query type :[" + query.getQueryRelation() + "]");
  }
}
 

@Override
public final Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
  return new ConstantScoreWeight(this, boost) {
    Filter filter;

    @Override
    public Scorer scorer(LeafReaderContext context) throws IOException {
      if (filter == null) {
        DocSet set = getDocSet(searcher);
        filter = set.getTopFilter();
      }

      // Although this set only includes live docs, other filters can be pushed down to queries.
      DocIdSet readerSet = filter.getDocIdSet(context, null);
      if (readerSet == null) {
        return null;
      }
      DocIdSetIterator readerSetIterator = readerSet.iterator();
      if (readerSetIterator == null) {
        return null;
      }
      return new ConstantScoreScorer(this, score(), scoreMode, readerSetIterator);
    }

    @Override
    public boolean isCacheable(LeafReaderContext ctx) {
      return true;
    }
  };
}