| /* |
| * 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 java.util.Set; |
| |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.Term; |
| 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 <code>query</code> with an <code>automaton</code>, |
| * using the <code>reader</code> 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 void extractTerms(Set<Term> terms) { |
| // no-op |
| } |
| |
| @Override |
| public Explanation explain(LeafReaderContext context, int doc) throws IOException { |
| //TODO |
| return null; |
| } |
| |
| } |