Package org.apache.lucene.search

Class ConstantScoreQuery.ConstantBulkScorer

java.lang.Object

org.apache.lucene.search.BulkScorer

org.apache.lucene.search.ConstantScoreQuery.ConstantBulkScorer

Enclosing class:

ConstantScoreQuery

protected static class ConstantScoreQuery.ConstantBulkScorer
extends BulkScorer

We return this as our BulkScorer so that if the CSQ wraps a query with its own optimized top-level scorer (e.g. BooleanScorer) we can use that top-level scorer.

Constructor Summary

Constructors

Constructor	Description
ConstantBulkScorer(BulkScorer bulkScorer, Weight weight, float theScore)

Method Summary

Modifier and Type	Method	Description
long	cost()	Same as DocIdSetIterator.cost() for bulk scorers.
int	score(LeafCollector collector, Bits acceptDocs, int min, int max)	Collects matching documents in a range and return an estimation of the next matching document which is on or after max.

Methods inherited from class org.apache.lucene.search.BulkScorer

score

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ConstantBulkScorer

public ConstantBulkScorer(BulkScorer bulkScorer,
 Weight weight,
 float theScore)

Method Details

score

public int score(LeafCollector collector,
 Bits acceptDocs,
 int min,
 int max)
          throws IOException

Description copied from class: BulkScorer

Collects matching documents in a range and return an estimation of the next matching document which is on or after max.

The return value must be:

• >= max,
• DocIdSetIterator.NO_MORE_DOCS if there are no more matches,
• <= the first matching document that is >= max otherwise.

min is the minimum document to be considered for matching. All documents strictly before this value must be ignored.

Although max would be a legal return value for this method, higher values might help callers skip more efficiently over non-matching portions of the docID space.

For instance, a Scorer-based implementation could look like below:

 private final Scorer scorer; // set via constructor

 public int score(LeafCollector collector, Bits acceptDocs, int min, int max) throws IOException {
   collector.setScorer(scorer);
   int doc = scorer.docID();
   if (doc < min) {
     doc = scorer.advance(min);
   }
   while (doc < max) {
     if (acceptDocs == null || acceptDocs.get(doc)) {
       collector.collect(doc);
     }
     doc = scorer.nextDoc();
   }
   return doc;
 }
 

Specified by:

score in class BulkScorer

Parameters:

collector - The collector to which all matching documents are passed.

acceptDocs - Bits that represents the allowed documents to match, or null if they are all allowed to match.

min - Score starting at, including, this document

max - Score up to, but not including, this doc

Returns:

an under-estimation of the next matching doc after max

Throws:

IOException

cost

public long cost()

Description copied from class: BulkScorer

Same as DocIdSetIterator.cost() for bulk scorers.

Specified by:

cost in class BulkScorer