Analysis: 'truncate' token filter, closes #1165.

This commit is contained in:
Shay Banon 2011-07-29 23:36:02 +03:00
parent f4889dd846
commit 06bcd4253b
5 changed files with 190 additions and 0 deletions

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@ -0,0 +1,55 @@
/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.analysis.miscellaneous;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import java.io.IOException;
/**
* A token filter that truncates tokens.
*/
public class TruncateTokenFilter extends TokenFilter {
private final CharTermAttribute termAttribute = addAttribute(CharTermAttribute.class);
private final int size;
public TruncateTokenFilter(TokenStream in, int size) {
super(in);
this.size = size;
}
@Override public final boolean incrementToken() throws IOException {
if (input.incrementToken()) {
final int length = termAttribute.length();
if (length > size) {
termAttribute.setLength(size);
}
return true;
} else {
return false;
}
}
}

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@ -338,6 +338,7 @@ public class AnalysisModule extends AbstractModule {
tokenFiltersBindings.processTokenFilter("edge_ngram", EdgeNGramTokenFilterFactory.class);
tokenFiltersBindings.processTokenFilter("shingle", ShingleTokenFilterFactory.class);
tokenFiltersBindings.processTokenFilter("unique", UniqueTokenFilterFactory.class);
tokenFiltersBindings.processTokenFilter("truncate", TruncateTokenFilterFactory.class);
}
@Override public void processTokenizers(TokenizersBindings tokenizersBindings) {

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@ -0,0 +1,51 @@
/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.TokenStream;
import org.apache.lucene.analysis.miscellaneous.TruncateTokenFilter;
import org.elasticsearch.ElasticSearchIllegalArgumentException;
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.IndexSettings;
/**
*
*/
@AnalysisSettingsRequired
public class TruncateTokenFilterFactory extends AbstractTokenFilterFactory {
private final int length;
@Inject public TruncateTokenFilterFactory(Index index, @IndexSettings Settings indexSettings,
@Assisted String name, @Assisted Settings settings) {
super(index, indexSettings, name, settings);
this.length = settings.getAsInt("length", -1);
if (length <= 0) {
throw new ElasticSearchIllegalArgumentException("length parameter must be provided");
}
}
@Override public TokenStream create(TokenStream tokenStream) {
return new TruncateTokenFilter(tokenStream, length);
}
}

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@ -49,6 +49,7 @@ import org.apache.lucene.analysis.hy.ArmenianAnalyzer;
import org.apache.lucene.analysis.id.IndonesianAnalyzer;
import org.apache.lucene.analysis.it.ItalianAnalyzer;
import org.apache.lucene.analysis.miscellaneous.PatternAnalyzer;
import org.apache.lucene.analysis.miscellaneous.TruncateTokenFilter;
import org.apache.lucene.analysis.miscellaneous.UniqueTokenFilter;
import org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter;
import org.apache.lucene.analysis.miscellaneous.WordDelimiterIterator;
@ -433,6 +434,16 @@ public class IndicesAnalysisService extends AbstractComponent {
}
}));
tokenFilterFactories.put("truncate", new PreBuiltTokenFilterFactoryFactory(new TokenFilterFactory() {
@Override public String name() {
return "truncate";
}
@Override public TokenStream create(TokenStream tokenStream) {
return new TruncateTokenFilter(tokenStream, 10);
}
}));
// Extended Token Filters
tokenFilterFactories.put("snowball", new PreBuiltTokenFilterFactoryFactory(new TokenFilterFactory() {
@Override public String name() {

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@ -0,0 +1,72 @@
/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.analysis.miscellaneous;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.ReusableAnalyzerBase;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.WhitespaceTokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.elasticsearch.common.lucene.Lucene;
import org.testng.annotations.Test;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import static org.hamcrest.MatcherAssert.*;
import static org.hamcrest.Matchers.*;
/**
*/
@Test
public class TruncateTokenFilterTests {
@Test public void simpleTest() throws IOException {
Analyzer analyzer = new ReusableAnalyzerBase() {
@Override
protected TokenStreamComponents createComponents(String fieldName,
Reader reader) {
Tokenizer t = new WhitespaceTokenizer(Lucene.VERSION, reader);
return new TokenStreamComponents(t, new TruncateTokenFilter(t, 3));
}
};
TokenStream test = analyzer.reusableTokenStream("test", new StringReader("a bb ccc dddd eeeee"));
CharTermAttribute termAttribute = test.addAttribute(CharTermAttribute.class);
assertThat(test.incrementToken(), equalTo(true));
assertThat(termAttribute.toString(), equalTo("a"));
assertThat(test.incrementToken(), equalTo(true));
assertThat(termAttribute.toString(), equalTo("bb"));
assertThat(test.incrementToken(), equalTo(true));
assertThat(termAttribute.toString(), equalTo("ccc"));
assertThat(test.incrementToken(), equalTo(true));
assertThat(termAttribute.toString(), equalTo("ddd"));
assertThat(test.incrementToken(), equalTo(true));
assertThat(termAttribute.toString(), equalTo("eee"));
assertThat(test.incrementToken(), equalTo(false));
}
}