org.elasticsearch.search.fetch.parent.ParentFieldSubFetchPhase.java Source code

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Here is the source code for org.elasticsearch.search.fetch.parent.ParentFieldSubFetchPhase.java

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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.parent;

import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.SortedDocValues;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.ExceptionsHelper;
import org.elasticsearch.index.mapper.internal.ParentFieldMapper;
import org.elasticsearch.search.SearchHitField;
import org.elasticsearch.search.SearchParseElement;
import org.elasticsearch.search.fetch.FetchSubPhase;
import org.elasticsearch.search.fetch.innerhits.InnerHitsContext;
import org.elasticsearch.search.internal.InternalSearchHit;
import org.elasticsearch.search.internal.InternalSearchHitField;
import org.elasticsearch.search.internal.SearchContext;

import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class ParentFieldSubFetchPhase implements FetchSubPhase {

    @Override
    public Map<String, ? extends SearchParseElement> parseElements() {
        return Collections.emptyMap();
    }

    @Override
    public boolean hitExecutionNeeded(SearchContext context) {
        return true;
    }

    @Override
    public void hitExecute(SearchContext context, HitContext hitContext) {
        ParentFieldMapper parentFieldMapper = context.mapperService().documentMapper(hitContext.hit().type())
                .parentFieldMapper();
        if (parentFieldMapper.active() == false) {
            return;
        }

        String parentId = getParentId(parentFieldMapper, hitContext.reader(), hitContext.docId());
        Map<String, SearchHitField> fields = hitContext.hit().fieldsOrNull();
        if (fields == null) {
            fields = new HashMap<>();
            hitContext.hit().fields(fields);
        }
        fields.put(ParentFieldMapper.NAME,
                new InternalSearchHitField(ParentFieldMapper.NAME, Collections.singletonList(parentId)));
    }

    @Override
    public boolean hitsExecutionNeeded(SearchContext context) {
        return false;
    }

    @Override
    public void hitsExecute(SearchContext context, InternalSearchHit[] hits) {
    }

    public static String getParentId(ParentFieldMapper fieldMapper, LeafReader reader, int docId) {
        try {
            SortedDocValues docValues = reader.getSortedDocValues(fieldMapper.name());
            BytesRef parentId = docValues.get(docId);
            assert parentId.length > 0;
            return parentId.utf8ToString();
        } catch (IOException e) {
            throw ExceptionsHelper.convertToElastic(e);
        }
    }

}