/*
* 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.explain;
import com.google.common.collect.ImmutableMap;
import org.apache.lucene.search.Explanation;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.search.SearchParseElement;
import org.elasticsearch.search.fetch.FetchPhaseExecutionException;
import org.elasticsearch.search.fetch.FetchSubPhase;
import org.elasticsearch.search.internal.InternalSearchHit;
import org.elasticsearch.search.internal.SearchContext;
import org.elasticsearch.search.rescore.RescoreSearchContext;
import java.io.IOException;
import java.util.Map;
/**
*
*/
public class ExplainFetchSubPhase implements FetchSubPhase {
@Override
public Map<String, ? extends SearchParseElement> parseElements() {
return ImmutableMap.of("explain", new ExplainParseElement());
}
@Override
public boolean hitsExecutionNeeded(SearchContext context) {
return false;
}
@Override
public void hitsExecute(SearchContext context, InternalSearchHit[] hits) throws ElasticsearchException {
}
@Override
public boolean hitExecutionNeeded(SearchContext context) {
return context.explain();
}
@Override
public void hitExecute(SearchContext context, HitContext hitContext) throws ElasticsearchException {
try {
final int topLevelDocId = hitContext.hit().docId();
Explanation explanation = context.searcher().explain(context.query(), topLevelDocId);
for (RescoreSearchContext rescore : context.rescore()) {
explanation = rescore.rescorer().explain(topLevelDocId, context, rescore, explanation);
}
// we use the top level doc id, since we work with the top level searcher
hitContext.hit().explanation(explanation);
} catch (IOException e) {
throw new FetchPhaseExecutionException(context, "Failed to explain doc [" + hitContext.hit().type() + "#" + hitContext.hit().id() + "]", e);
}
}
}