Package org.apache.lucene.search.suggest.document

Class CompletionScorer

java.lang.Object

org.apache.lucene.search.BulkScorer

org.apache.lucene.search.suggest.document.CompletionScorer

public class CompletionScorer
extends BulkScorer

Expert: Responsible for executing the query against an appropriate suggester and collecting the results via a collector. score(LeafCollector, Bits, int, int) is called for each leaf reader. accept(int,Bits) and score(float, float) is called for every matched completion (i.e. document)

Field Summary

Fields

Modifier and Type	Field	Description
protected CompletionWeight	weight	weight that created this scorer

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CompletionScorer(CompletionWeight weight, NRTSuggester suggester, LeafReader reader, Bits filterDocs, boolean filtered, Automaton automaton)	Creates a scorer for a field-specific suggester scoped by acceptDocs

Method Summary

Modifier and Type	Method	Description
boolean	accept(int docID, Bits liveDocs)	Returns true if a document with docID is accepted, false if the docID maps to a deleted document or has been filtered out
long	cost()	Same as DocIdSetIterator.cost() for bulk scorers.
float	score(float weight, float boost)	Returns the score for a matched completion based on the query time boost and the index time weight.
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

Field Detail

weight

protected final CompletionWeight weight

weight that created this scorer

Constructor Detail

CompletionScorer

protected CompletionScorer(CompletionWeight weight,
                           NRTSuggester suggester,
                           LeafReader reader,
                           Bits filterDocs,
                           boolean filtered,
                           Automaton automaton)
                    throws IOException

Creates a scorer for a field-specific suggester scoped by acceptDocs

Throws:

IOException

Method Detail

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

accept

public final boolean accept(int docID,
                            Bits liveDocs)

Returns true if a document with docID is accepted, false if the docID maps to a deleted document or has been filtered out

Parameters:

liveDocs - the Bits representing live docs, or possibly null if all docs are live

score

public float score(float weight,
                   float boost)

Returns the score for a matched completion based on the query time boost and the index time weight.