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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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
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package org.elasticsearch.search.suggest.term;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.spell.DirectSpellChecker;
import org.apache.lucene.search.spell.SuggestWord;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.BytesRefBuilder;
import org.apache.lucene.util.CharsRefBuilder;
import org.elasticsearch.common.bytes.BytesArray;
import org.elasticsearch.common.text.BytesText;
import org.elasticsearch.common.text.StringText;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.search.suggest.SuggestContextParser;
import org.elasticsearch.search.suggest.SuggestUtils;
import org.elasticsearch.search.suggest.Suggester;
import org.elasticsearch.search.suggest.SuggestionSearchContext.SuggestionContext;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public final class TermSuggester extends Suggester<TermSuggestionContext> {
@Override
public TermSuggestion innerExecute(String name, TermSuggestionContext suggestion, IndexReader indexReader, CharsRefBuilder spare) throws IOException {
DirectSpellChecker directSpellChecker = SuggestUtils.getDirectSpellChecker(suggestion.getDirectSpellCheckerSettings());
TermSuggestion response = new TermSuggestion(
name, suggestion.getSize(), suggestion.getDirectSpellCheckerSettings().sort()
);
List<Token> tokens = queryTerms(suggestion, spare);
for (Token token : tokens) {
// TODO: Extend DirectSpellChecker in 4.1, to get the raw suggested words as BytesRef
SuggestWord[] suggestedWords = directSpellChecker.suggestSimilar(
token.term, suggestion.getShardSize(), indexReader, suggestion.getDirectSpellCheckerSettings().suggestMode()
);
Text key = new BytesText(new BytesArray(token.term.bytes()));
TermSuggestion.Entry resultEntry = new TermSuggestion.Entry(key, token.startOffset, token.endOffset - token.startOffset);
for (SuggestWord suggestWord : suggestedWords) {
Text word = new StringText(suggestWord.string);
resultEntry.addOption(new TermSuggestion.Entry.Option(word, suggestWord.freq, suggestWord.score));
}
response.addTerm(resultEntry);
}
return response;
}
@Override
public String[] names() {
return new String[] {"term"};
}
@Override
public SuggestContextParser getContextParser() {
return new TermSuggestParser(this);
}
private List<Token> queryTerms(SuggestionContext suggestion, CharsRefBuilder spare) throws IOException {
final List<Token> result = new ArrayList<>();
final String field = suggestion.getField();
SuggestUtils.analyze(suggestion.getAnalyzer(), suggestion.getText(), field, new SuggestUtils.TokenConsumer() {
@Override
public void nextToken() {
Term term = new Term(field, BytesRef.deepCopyOf(fillBytesRef(new BytesRefBuilder())));
result.add(new Token(term, offsetAttr.startOffset(), offsetAttr.endOffset()));
}
}, spare);
return result;
}
private static class Token {
public final Term term;
public final int startOffset;
public final int endOffset;
private Token(Term term, int startOffset, int endOffset) {
this.term = term;
this.startOffset = startOffset;
this.endOffset = endOffset;
}
}
}