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* Licensed to Elasticsearch under one or more contributor
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* 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.fetch.subphase.highlight;
import org.apache.lucene.search.highlight.DefaultEncoder;
import org.apache.lucene.search.highlight.Encoder;
import org.apache.lucene.search.highlight.SimpleHTMLEncoder;
import org.elasticsearch.index.fieldvisitor.CustomFieldsVisitor;
import org.elasticsearch.index.mapper.FieldMapper;
import org.elasticsearch.search.fetch.FetchSubPhase;
import org.elasticsearch.search.internal.SearchContext;
import org.elasticsearch.search.lookup.SourceLookup;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
import static java.util.Collections.singleton;
public final class HighlightUtils {
//U+2029 PARAGRAPH SEPARATOR (PS): each value holds a discrete passage for highlighting (postings highlighter)
public static final char PARAGRAPH_SEPARATOR = 8233;
public static final char NULL_SEPARATOR = '\u0000';
private HighlightUtils() {
}
/**
* Load field values for highlighting.
*/
public static List<Object> loadFieldValues(SearchContextHighlight.Field field, FieldMapper mapper, SearchContext searchContext,
FetchSubPhase.HitContext hitContext) throws IOException {
//percolator needs to always load from source, thus it sets the global force source to true
boolean forceSource = searchContext.highlight().forceSource(field);
List<Object> textsToHighlight;
if (!forceSource && mapper.fieldType().stored()) {
CustomFieldsVisitor fieldVisitor = new CustomFieldsVisitor(singleton(mapper.fieldType().name()), false);
hitContext.reader().document(hitContext.docId(), fieldVisitor);
textsToHighlight = fieldVisitor.fields().get(mapper.fieldType().name());
if (textsToHighlight == null) {
// Can happen if the document doesn't have the field to highlight
textsToHighlight = Collections.emptyList();
}
} else {
SourceLookup sourceLookup = searchContext.lookup().source();
sourceLookup.setSegmentAndDocument(hitContext.readerContext(), hitContext.docId());
textsToHighlight = sourceLookup.extractRawValues(mapper.fieldType().name());
}
assert textsToHighlight != null;
return textsToHighlight;
}
static class Encoders {
static final Encoder DEFAULT = new DefaultEncoder();
static final Encoder HTML = new SimpleHTMLEncoder();
}
}