All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.lucene.search.suggest.document.CompletionWeight Maven / Gradle / Ivy

There is a newer version: 10.0.0
Show newest version
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.lucene.search.suggest.document;

import java.io.IOException;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.Terms;
import org.apache.lucene.search.BulkScorer;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Weight;
import org.apache.lucene.search.suggest.BitsProducer;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.IntsRef;
import org.apache.lucene.util.automaton.Automaton;

/**
 * Expert: the Weight for CompletionQuery, used to score and explain these queries.
 *
 * 

Subclasses can override {@link #setNextMatch(IntsRef)}, {@link #boost()} and {@link * #context()} to calculate the boost and extract the context of a matched path prefix. * * @lucene.experimental */ public class CompletionWeight extends Weight { private final CompletionQuery completionQuery; private final Automaton automaton; /** * Creates a weight for query with an automaton, using the reader * for index stats */ public CompletionWeight(final CompletionQuery query, final Automaton automaton) throws IOException { super(query); this.completionQuery = query; this.automaton = automaton; } /** * Returns the automaton specified by the {@link CompletionQuery} * * @return query automaton */ public Automaton getAutomaton() { return automaton; } @Override public BulkScorer bulkScorer(final LeafReaderContext context) throws IOException { final LeafReader reader = context.reader(); final Terms terms; final NRTSuggester suggester; if ((terms = reader.terms(completionQuery.getField())) == null) { return null; } if (terms instanceof CompletionTerms) { CompletionTerms completionTerms = (CompletionTerms) terms; if ((suggester = completionTerms.suggester()) == null) { // a segment can have a null suggester // i.e. no FST was built return null; } } else { throw new IllegalArgumentException(completionQuery.getField() + " is not a SuggestField"); } BitsProducer filter = completionQuery.getFilter(); Bits filteredDocs = null; if (filter != null) { filteredDocs = filter.getBits(context); if (filteredDocs.getClass() == Bits.MatchNoBits.class) { return null; } } return new CompletionScorer(this, suggester, reader, filteredDocs, filter != null, automaton); } /** * Set for every partial path in the index that matched the query automaton. * *

Subclasses should override {@link #boost()} and {@link #context()} to return an appropriate * value with respect to the current pathPrefix. * * @param pathPrefix the prefix of a matched path */ protected void setNextMatch(IntsRef pathPrefix) {} /** * Returns the boost of the partial path set by {@link #setNextMatch(IntsRef)} * * @return suggestion query-time boost */ protected float boost() { return 0; } /** * Returns the context of the partial path set by {@link #setNextMatch(IntsRef)} * * @return suggestion context */ protected CharSequence context() { return null; } @Override public Scorer scorer(LeafReaderContext context) throws IOException { throw new UnsupportedOperationException(); } /** * This object can be cached * * @see org.apache.lucene.search.SegmentCacheable#isCacheable(LeafReaderContext) */ @Override public boolean isCacheable(LeafReaderContext ctx) { return true; } @Override public Explanation explain(LeafReaderContext context, int doc) throws IOException { // TODO return null; } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy