org.elasticsearch.search.rescore.Rescorer Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* 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.rescore;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.TopDocs;
import org.elasticsearch.action.search.SearchType;
import java.io.IOException;
import java.util.Set;
/**
* A query rescorer interface used to re-rank the Top-K results of a previously
* executed search.
*
* Subclasses should borrow heavily from {@link QueryRescorer} because it is
* fairly well behaved and documents that tradeoffs that it is making. There
* is also an {@code ExampleRescorer} that is worth looking at.
*/
public interface Rescorer {
/**
* Modifies the result of the previously executed search ({@link TopDocs})
* in place based on the given {@link RescoreContext}.
*
* @param topDocs the result of the previously executed search
* @param searcher the searcher used for this search. This will never be null
.
* @param rescoreContext the {@link RescoreContext}. This will never be null
* @throws IOException if an {@link IOException} occurs during rescoring
*/
TopDocs rescore(TopDocs topDocs, IndexSearcher searcher, RescoreContext rescoreContext) throws IOException;
/**
* Executes an {@link Explanation} phase on the rescorer.
*
* @param topLevelDocId the global / top-level document ID to explain
* @param searcher the searcher used for this search. This will never be null
.
* @param rescoreContext context for this rescorer
* @param sourceExplanation explanation of the source of the documents being fed into this rescore
* @return the explain for the given top level document ID.
* @throws IOException if an {@link IOException} occurs
*/
Explanation explain(int topLevelDocId, IndexSearcher searcher, RescoreContext rescoreContext,
Explanation sourceExplanation) throws IOException;
/**
* Extracts all terms needed to execute this {@link Rescorer}. This method
* is executed in a distributed frequency collection roundtrip for
* {@link SearchType#DFS_QUERY_THEN_FETCH}
*/
void extractTerms(IndexSearcher searcher, RescoreContext rescoreContext, Set termsSet) throws IOException;
}