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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.analysis.common;
import org.apache.lucene.analysis.CharArraySet;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter;
import org.apache.lucene.analysis.miscellaneous.WordDelimiterIterator;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.env.Environment;
import org.elasticsearch.index.IndexSettings;
import org.elasticsearch.index.analysis.AbstractTokenFilterFactory;
import org.elasticsearch.index.analysis.Analysis;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.CATENATE_ALL;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.CATENATE_NUMBERS;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.CATENATE_WORDS;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.GENERATE_NUMBER_PARTS;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.GENERATE_WORD_PARTS;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.PRESERVE_ORIGINAL;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.SPLIT_ON_CASE_CHANGE;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.SPLIT_ON_NUMERICS;
import static org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter.STEM_ENGLISH_POSSESSIVE;
public class WordDelimiterTokenFilterFactory extends AbstractTokenFilterFactory {
private final byte[] charTypeTable;
private final int flags;
private final CharArraySet protoWords;
public WordDelimiterTokenFilterFactory(IndexSettings indexSettings, Environment env,
String name, Settings settings) {
super(indexSettings, name, settings);
// Sample Format for the type table:
// $ => DIGIT
// % => DIGIT
// . => DIGIT
// \u002C => DIGIT
// \u200D => ALPHANUM
List<String> charTypeTableValues = Analysis.getWordList(env, settings, "type_table");
if (charTypeTableValues == null) {
this.charTypeTable = WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE;
} else {
this.charTypeTable = parseTypes(charTypeTableValues);
}
int flags = 0;
// If set, causes parts of words to be generated: "PowerShot" => "Power" "Shot"
flags |= getFlag(GENERATE_WORD_PARTS, settings, "generate_word_parts", true);
// If set, causes number subwords to be generated: "500-42" => "500" "42"
flags |= getFlag(GENERATE_NUMBER_PARTS, settings, "generate_number_parts", true);
// 1, causes maximum runs of word parts to be catenated: "wi-fi" => "wifi"
flags |= getFlag(CATENATE_WORDS, settings, "catenate_words", false);
// If set, causes maximum runs of number parts to be catenated: "500-42" => "50042"
flags |= getFlag(CATENATE_NUMBERS, settings, "catenate_numbers", false);
// If set, causes all subword parts to be catenated: "wi-fi-4000" => "wifi4000"
flags |= getFlag(CATENATE_ALL, settings, "catenate_all", false);
// 1, causes "PowerShot" to be two tokens; ("Power-Shot" remains two parts regards)
flags |= getFlag(SPLIT_ON_CASE_CHANGE, settings, "split_on_case_change", true);
// If set, includes original words in subwords: "500-42" => "500" "42" "500-42"
flags |= getFlag(PRESERVE_ORIGINAL, settings, "preserve_original", false);
// 1, causes "j2se" to be three tokens; "j" "2" "se"
flags |= getFlag(SPLIT_ON_NUMERICS, settings, "split_on_numerics", true);
// If set, causes trailing "'s" to be removed for each subword: "O'Neil's" => "O", "Neil"
flags |= getFlag(STEM_ENGLISH_POSSESSIVE, settings, "stem_english_possessive", true);
// If not null is the set of tokens to protect from being delimited
Set<?> protectedWords = Analysis.getWordSet(env, indexSettings.getIndexVersionCreated(),
settings, "protected_words");
this.protoWords = protectedWords == null ? null : CharArraySet.copy(protectedWords);
this.flags = flags;
}
@Override
public TokenStream create(TokenStream tokenStream) {
return new WordDelimiterFilter(tokenStream,
charTypeTable,
flags,
protoWords);
}
public int getFlag(int flag, Settings settings, String key, boolean defaultValue) {
if (settings.getAsBooleanLenientForPreEs6Indices(indexSettings.getIndexVersionCreated(),
key, defaultValue, deprecationLogger)) {
return flag;
}
return 0;
}
// source => type
private static Pattern typePattern = Pattern.compile("(.*)\\s*=>\\s*(.*)\\s*$");
/**
* parses a list of MappingCharFilter style rules into a custom byte[] type table
*/
static byte[] parseTypes(Collection<String> rules) {
SortedMap<Character, Byte> typeMap = new TreeMap<>();
for (String rule : rules) {
Matcher m = typePattern.matcher(rule);
if (!m.find())
throw new RuntimeException("Invalid Mapping Rule : [" + rule + "]");
String lhs = parseString(m.group(1).trim());
Byte rhs = parseType(m.group(2).trim());
if (lhs.length() != 1)
throw new RuntimeException("Invalid Mapping Rule : ["
+ rule + "]. Only a single character is allowed.");
if (rhs == null)
throw new RuntimeException("Invalid Mapping Rule : [" + rule + "]. Illegal type.");
typeMap.put(lhs.charAt(0), rhs);
}
// ensure the table is always at least as big as DEFAULT_WORD_DELIM_TABLE for performance
byte types[] = new byte[Math.max(
typeMap.lastKey() + 1, WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE.length)];
for (int i = 0; i < types.length; i++)
types[i] = WordDelimiterIterator.getType(i);
for (Map.Entry<Character, Byte> mapping : typeMap.entrySet())
types[mapping.getKey()] = mapping.getValue();
return types;
}
private static Byte parseType(String s) {
if (s.equals("LOWER"))
return WordDelimiterFilter.LOWER;
else if (s.equals("UPPER"))
return WordDelimiterFilter.UPPER;
else if (s.equals("ALPHA"))
return WordDelimiterFilter.ALPHA;
else if (s.equals("DIGIT"))
return WordDelimiterFilter.DIGIT;
else if (s.equals("ALPHANUM"))
return WordDelimiterFilter.ALPHANUM;
else if (s.equals("SUBWORD_DELIM"))
return WordDelimiterFilter.SUBWORD_DELIM;
else
return null;
}
private static String parseString(String s) {
char[] out = new char[256];
int readPos = 0;
int len = s.length();
int writePos = 0;
while (readPos < len) {
char c = s.charAt(readPos++);
if (c == '\\') {
if (readPos >= len)
throw new RuntimeException("Invalid escaped char in [" + s + "]");
c = s.charAt(readPos++);
switch (c) {
case '\\':
c = '\\';
break;
case 'n':
c = '\n';
break;
case 't':
c = '\t';
break;
case 'r':
c = '\r';
break;
case 'b':
c = '\b';
break;
case 'f':
c = '\f';
break;
case 'u':
if (readPos + 3 >= len)
throw new RuntimeException("Invalid escaped char in [" + s + "]");
c = (char) Integer.parseInt(s.substring(readPos, readPos + 4), 16);
readPos += 4;
break;
}
}
out[writePos++] = c;
}
return new String(out, 0, writePos);
}
@Override
public boolean breaksFastVectorHighlighter() {
return true;
}
}