org.elasticsearch.index.fieldvisitor.CustomFieldsVisitor Maven / Gradle / Ivy
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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.index.fieldvisitor;
import org.apache.lucene.index.FieldInfo;
import org.elasticsearch.index.mapper.internal.SourceFieldMapper;
import org.elasticsearch.index.mapper.internal.UidFieldMapper;
import java.io.IOException;
import java.util.Set;
/**
* A field visitor that allows to load a selection of the stored fields.
* The Uid field is always loaded.
* The class is optimized for source loading as it is a common use case.
*/
public class CustomFieldsVisitor extends FieldsVisitor {
private final boolean loadSource;
private final Set fields;
public CustomFieldsVisitor(Set fields, boolean loadSource) {
this.loadSource = loadSource;
this.fields = fields;
}
@Override
public Status needsField(FieldInfo fieldInfo) throws IOException {
if (loadSource && SourceFieldMapper.NAME.equals(fieldInfo.name)) {
return Status.YES;
}
if (UidFieldMapper.NAME.equals(fieldInfo.name)) {
return Status.YES;
}
return fields.contains(fieldInfo.name) ? Status.YES : Status.NO;
}
}