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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.search.fetch.subphase.highlight;
import org.apache.lucene.search.Query;
import org.elasticsearch.common.regex.Regex;
import org.elasticsearch.index.mapper.KeywordFieldMapper;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.mapper.SourceFieldMapper;
import org.elasticsearch.index.mapper.TextFieldMapper;
import org.elasticsearch.search.fetch.FetchSubPhase;
import org.elasticsearch.search.internal.SearchContext;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
public class HighlightPhase implements FetchSubPhase {
private final Map highlighters;
public HighlightPhase(Map highlighters) {
this.highlighters = highlighters;
}
@Override
public void hitExecute(SearchContext context, HitContext hitContext) {
if (context.highlight() == null) {
return;
}
Map highlightFields = new HashMap<>();
for (SearchContextHighlight.Field field : context.highlight().fields()) {
Collection fieldNamesToHighlight;
if (Regex.isSimpleMatchPattern(field.field())) {
fieldNamesToHighlight = context.mapperService().simpleMatchToFullName(field.field());
} else {
fieldNamesToHighlight = Collections.singletonList(field.field());
}
if (context.highlight().forceSource(field)) {
SourceFieldMapper sourceFieldMapper = context.mapperService().documentMapper(hitContext.hit().getType()).sourceMapper();
if (!sourceFieldMapper.enabled()) {
throw new IllegalArgumentException("source is forced for fields " + fieldNamesToHighlight
+ " but type [" + hitContext.hit().getType() + "] has disabled _source");
}
}
boolean fieldNameContainsWildcards = field.field().contains("*");
for (String fieldName : fieldNamesToHighlight) {
MappedFieldType fieldType = context.mapperService().fullName(fieldName);
if (fieldType == null) {
continue;
}
// We should prevent highlighting if a field is anything but a text or keyword field.
// However, someone might implement a custom field type that has text and still want to
// highlight on that. We cannot know in advance if the highlighter will be able to
// highlight such a field and so we do the following:
// If the field is only highlighted because the field matches a wildcard we assume
// it was a mistake and do not process it.
// If the field was explicitly given we assume that whoever issued the query knew
// what they were doing and try to highlight anyway.
if (fieldNameContainsWildcards) {
if (fieldType.typeName().equals(TextFieldMapper.CONTENT_TYPE) == false &&
fieldType.typeName().equals(KeywordFieldMapper.CONTENT_TYPE) == false) {
continue;
}
}
String highlighterType = field.fieldOptions().highlighterType();
if (highlighterType == null) {
highlighterType = "unified";
}
Highlighter highlighter = highlighters.get(highlighterType);
if (highlighter == null) {
throw new IllegalArgumentException("unknown highlighter type [" + highlighterType
+ "] for the field [" + fieldName + "]");
}
Query highlightQuery = field.fieldOptions().highlightQuery();
if (highlightQuery == null) {
highlightQuery = context.parsedQuery().query();
}
HighlighterContext highlighterContext = new HighlighterContext(fieldType.name(),
field, fieldType, context, hitContext, highlightQuery);
if ((highlighter.canHighlight(fieldType) == false) && fieldNameContainsWildcards) {
// if several fieldnames matched the wildcard then we want to skip those that we cannot highlight
continue;
}
HighlightField highlightField = highlighter.highlight(highlighterContext);
if (highlightField != null) {
// Note that we make sure to use the original field name in the response. This is because the
// original field could be an alias, and highlighter implementations may instead reference the
// concrete field it points to.
highlightFields.put(fieldName,
new HighlightField(fieldName, highlightField.fragments()));
}
}
}
hitContext.hit().highlightFields(highlightFields);
}
}