org.elasticsearch.index.mapper.CustomTermFreqField Maven / Gradle / Ivy
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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.index.mapper;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.TermFrequencyAttribute;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FieldType;
import org.apache.lucene.index.IndexOptions;
/**
* Custom field that allows storing an integer value as a term frequency in lucene.
*/
public final class CustomTermFreqField extends Field {
private static final FieldType FIELD_TYPE = new FieldType();
static {
FIELD_TYPE.setTokenized(false);
FIELD_TYPE.setOmitNorms(true);
FIELD_TYPE.setIndexOptions(IndexOptions.DOCS_AND_FREQS);
}
private final int fieldValue;
public CustomTermFreqField(String fieldName, CharSequence term, int fieldValue) {
super(fieldName, term, FIELD_TYPE);
this.fieldValue = fieldValue;
}
@Override
public TokenStream tokenStream(Analyzer analyzer, TokenStream reuse) {
CustomTermFreqTokenStream stream;
if (reuse instanceof CustomTermFreqTokenStream) {
stream = (CustomTermFreqTokenStream) reuse;
} else {
stream = new CustomTermFreqTokenStream();
}
stream.setValues((String) fieldsData, fieldValue);
return stream;
}
private static final class CustomTermFreqTokenStream extends TokenStream {
private final CharTermAttribute termAttribute = addAttribute(CharTermAttribute.class);
private final TermFrequencyAttribute freqAttribute = addAttribute(TermFrequencyAttribute.class);
private boolean used = true;
private String value = null;
private int freq = 0;
private CustomTermFreqTokenStream() {}
/** Sets the values */
void setValues(String value, int freq) {
this.value = value;
this.freq = freq;
}
@Override
public boolean incrementToken() {
if (used) {
return false;
}
clearAttributes();
termAttribute.append(value);
freqAttribute.setTermFrequency(freq);
used = true;
return true;
}
@Override
public void reset() {
used = false;
}
@Override
public void close() {
value = null;
}
}
}