Examples of org.apache.lucene.search.Weight

org.apache.lucene.search.Weight

Expert: Calculate query weights and build query scorers.

The purpose of {@link Weight} is to ensure searching does not modify a{@link Query}, so that a {@link Query} instance can be reused.
{@link IndexSearcher} dependent state of the query should reside in the{@link Weight}.
{@link AtomicReader} dependent state should reside in the {@link Scorer}.

Since {@link Weight} creates {@link Scorer} instances for a given{@link AtomicReaderContext} ({@link #scorer(AtomicReaderContext,boolean,boolean,Bits)}) callers must maintain the relationship between the searcher's top-level {@link IndexReaderContext} and the context used to create a {@link Scorer}.

A Weight is used in the following way:

A Weight is constructed by a top-level query, given a IndexSearcher ( {@link Query#createWeight(IndexSearcher)}).
The {@link #getValueForNormalization()} method is called on theWeight to compute the query normalization factor {@link Similarity#queryNorm(float)} of the query clauses contained in thequery.
The query normalization factor is passed to {@link #normalize(float,float)}. At this point the weighting is complete.
A Scorer is constructed by {@link #scorer(AtomicReaderContext,boolean,boolean,Bits)}.

@since 2.9

   * not a direct test of NearSpans, but a demonstration of how/when
   * this causes problems
   */
  public void testSpanNearScorerSkipTo1() throws Exception {
    SpanNearQuery q = makeQuery();
    Weight w = q.weight(searcher);
    Scorer s = w.scorer(searcher.getIndexReader(), true, false);
    assertEquals(1, s.advance(1));
  }

   * not a direct test of NearSpans, but a demonstration of how/when
   * this causes problems
   */
  public void testSpanNearScorerSkipTo1() throws Exception {
    SpanNearQuery q = makeQuery();
    Weight w = q.weight(searcher);
    Scorer s = w.scorer(searcher.getIndexReader(), true, false);
    assertEquals(1, s.advance(1));
  }

    iter = deletesFlushed.queries.entrySet().iterator();
    while(iter.hasNext()) {
      Entry entry = (Entry) iter.next();
      Query query = (Query) entry.getKey();
      int limit = ((Integer) entry.getValue()).intValue();
      Weight weight = query.weight(searcher);
      Scorer scorer = weight.scorer(reader, true, false);
      if (scorer != null) {
        while(true)  {
          int doc = scorer.nextDoc();
          if (((long) docIDStart) + doc >= limit)
            break;

Examples of org.apache.lucene.search.Weight

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