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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
* under the License.
*/
package org.elasticsearch.index.analysis;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.ngram.EdgeNGramTokenizer;
import org.apache.lucene.analysis.ngram.Lucene43EdgeNGramTokenizer;
import org.apache.lucene.analysis.ngram.NGramTokenizer;
import org.apache.lucene.util.Version;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.inject.assistedinject.Assisted;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.settings.IndexSettingsService;
import static org.elasticsearch.index.analysis.NGramTokenizerFactory.parseTokenChars;
/**
*
*/
@SuppressWarnings("deprecation")
public class EdgeNGramTokenizerFactory extends AbstractTokenizerFactory {
private final int minGram;
private final int maxGram;
private final Lucene43EdgeNGramTokenizer.Side side;
private final CharMatcher matcher;
protected org.elasticsearch.Version esVersion;
@Inject
public EdgeNGramTokenizerFactory(Index index, IndexSettingsService indexSettingsService, @Assisted String name, @Assisted Settings settings) {
this(index, indexSettingsService.getSettings(), name, settings);
}
//package private for testing
public EdgeNGramTokenizerFactory(Index index, Settings indexSettings, String name, Settings settings) {
super(index, indexSettings, name, settings);
this.minGram = settings.getAsInt("min_gram", NGramTokenizer.DEFAULT_MIN_NGRAM_SIZE);
this.maxGram = settings.getAsInt("max_gram", NGramTokenizer.DEFAULT_MAX_NGRAM_SIZE);
this.side = Lucene43EdgeNGramTokenizer.Side.getSide(settings.get("side", Lucene43EdgeNGramTokenizer.DEFAULT_SIDE.getLabel()));
this.matcher = parseTokenChars(settings.getAsArray("token_chars"));
this.esVersion = org.elasticsearch.Version.indexCreated(indexSettings);
}
@Override
public Tokenizer create() {
if (version.onOrAfter(Version.LUCENE_4_3) && esVersion.onOrAfter(org.elasticsearch.Version.V_0_90_2)) {
/*
* We added this in 0.90.2 but 0.90.1 used LUCENE_43 already so we can not rely on the lucene version.
* Yet if somebody uses 0.90.2 or higher with a prev. lucene version we should also use the deprecated version.
*/
if (side == Lucene43EdgeNGramTokenizer.Side.BACK) {
throw new IllegalArgumentException("side=back is not supported anymore. Please fix your analysis chain or use"
+ " an older compatibility version (<=4.2) but beware that it might cause highlighting bugs."
+ " To obtain the same behavior as the previous version please use \"edgeNGram\" filter which still supports side=back"
+ " in combination with a \"keyword\" tokenizer");
}
final Version version = this.version == Version.LUCENE_4_3 ? Version.LUCENE_4_4 : this.version; // always use 4.4 or higher
if (matcher == null) {
return new EdgeNGramTokenizer(minGram, maxGram);
} else {
return new EdgeNGramTokenizer(minGram, maxGram) {
@Override
protected boolean isTokenChar(int chr) {
return matcher.isTokenChar(chr);
}
};
}
} else {
return new Lucene43EdgeNGramTokenizer(side, minGram, maxGram);
}
}
}