solr/core/src/java/org/apache/solr/search/grouping/distributed/ShardRequestFactory.java

/*
 * 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;

import org.apache.solr.handler.component.ResponseBuilder;
import org.apache.solr.handler.component.ShardRequest;

/**
 * Responsible for creating shard requests to the shards in the cluster to perform distributed grouping.
 *
 * @lucene.experimental
 */
public interface ShardRequestFactory {

  /**
   * Returns {@link ShardRequest} instances.
   * Never returns <code>null</code>. If no {@link ShardRequest} instances are constructed an empty array is returned.
   *
   * @param rb The response builder
   * @return {@link ShardRequest} instances
   */
  ShardRequest[] constructRequest(ResponseBuilder rb);

}