| /* |
| * 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.geode.cache.lucene.internal.distributed; |
| |
| import java.util.Collection; |
| |
| import org.apache.geode.cache.lucene.internal.repository.IndexRepository; |
| import org.apache.geode.cache.lucene.internal.repository.IndexResultCollector; |
| |
| /** |
| * {@link CollectorManager}s create instances of {@link IndexResultCollector} and utility methods to |
| * aggregate results collected by individual collectors. The collectors created by this class are |
| * primarily used for collecting results from {@link IndexRepository}s. The collectors can also be |
| * used for aggregating results of other collectors of same type. Typically search result |
| * aggregation is completed in two phases. First at a member level for merging results from local |
| * buckets. And then at search coordinator level for merging results from members. Use of same |
| * collector in both phases is expected to produce deterministic merge result irrespective of the |
| * way buckets are distributed. |
| * |
| * @param <C> Type of IndexResultCollector created by this manager |
| */ |
| public interface CollectorManager<C extends IndexResultCollector> { |
| /** |
| * Creates a new collector to store the results of a Lucene query. |
| * |
| * @param name Name/Identifier for this collector. For e.g. region name/bucketId. |
| * @return a new {@link IndexResultCollector}. This must return a different instance on each call. |
| * A new collector would be created for each bucket on a member node. |
| */ |
| C newCollector(String name); |
| |
| /** |
| * Reduce the results of individual collectors into a meaningful result. This method must be |
| * called after collection is finished on all provided collectors. |
| * |
| * @param results - Collection of the results of a Lucene query execution. |
| * @return IndexResultCollector containing a reduced set of the results of the Lucene query. |
| * |
| */ |
| C reduce(Collection<C> results); |
| } |