/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.solr.search.grouping.distributed.shardresultserializer;
import org.apache.lucene.search.Sort;
import org.apache.solr.common.util.NamedList;
import java.io.IOException;
/**
* A <code>ShardResultTransformer</code> is responsible for transforming a grouped shard result into group related
* structures (such as {@link org.apache.lucene.search.grouping.TopGroups} and {@link org.apache.lucene.search.grouping.SearchGroup})
* and visa versa.
*
* @lucene.experimental
*/
public interface ShardResultTransformer<T, R> {
/**
* Transforms data to a {@link NamedList} structure for serialization purposes.
*
* @param data The data to be transformed
* @return {@link NamedList} structure
* @throws IOException If I/O related errors occur during transforming
*/
NamedList transform(T data) throws IOException;
/**
* Transforms the specified shard response into native structures.
*
* @param shardResponse The shard response containing data in a {@link NamedList} structure
* @param groupSort The group sort
* @param withinGroupSort The sort inside a group
* @param shard The shard address where the response originated from
* @return native structure of the data
*/
R transformToNative(NamedList<NamedList> shardResponse, Sort groupSort, Sort withinGroupSort, String shard);
}