jpountz commented on a change in pull request #240: URL: https://github.com/apache/lucene/pull/240#discussion_r694981562
########## File path: lucene/core/src/java/org/apache/lucene/search/TopFieldCollectorManager.java ########## @@ -0,0 +1,175 @@ +/* + * 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.lucene.search; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; + +/** + * Create a TopFieldCollectorManager which uses a shared hit counter to maintain number of hits and + * a shared {@link MaxScoreAccumulator} to propagate the minimum score across segments if the + * primary sort is by relevancy. + * + * <p>Note that a new collectorManager should be created for each search due to its internal states. + */ +public class TopFieldCollectorManager implements CollectorManager<TopFieldCollector, TopFieldDocs> { + private final Sort sort; + private final int numHits; + private final FieldDoc after; + private final HitsThresholdChecker hitsThresholdChecker; + private final MaxScoreAccumulator minScoreAcc; + private final List<TopFieldCollector> collectors; + + /** + * Creates a new {@link TopFieldCollectorManager} from the given arguments. + * + * <p><b>NOTE</b>: The instances returned by this method pre-allocate a full array of length + * <code>numHits</code>. + * + * @param sort the sort criteria (SortFields). + * @param numHits the number of results to collect. + * @param after the previous doc after which matching docs will be collected. + * @param totalHitsThreshold the number of docs to count accurately. If the query matches more + * than {@code totalHitsThreshold} hits then its hit count will be a lower bound. On the other + * hand if the query matches less than or exactly {@code totalHitsThreshold} hits then the hit + * count of the result will be accurate. {@link Integer#MAX_VALUE} may be used to make the hit + * count accurate, but this will also make query processing slower. + * @param supportsConcurrency to use thread-safe and slower internal states for count tracking. + */ + public TopFieldCollectorManager( + Sort sort, int numHits, FieldDoc after, int totalHitsThreshold, boolean supportsConcurrency) { + if (totalHitsThreshold < 0) { + throw new IllegalArgumentException( + "totalHitsThreshold must be >= 0, got " + totalHitsThreshold); + } + + this.sort = sort; + this.numHits = numHits; + this.after = after; + this.hitsThresholdChecker = + supportsConcurrency + ? HitsThresholdChecker.createShared(Math.max(totalHitsThreshold, numHits)) + : HitsThresholdChecker.create(Math.max(totalHitsThreshold, numHits)); Review comment: let's also store `supportsConcurrency` in a member of this class so that we can check that users never create more than one collector when it is false? ########## File path: lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java ########## @@ -527,7 +503,10 @@ public TopDocs search(Query query, int n) throws IOException { * * @throws TooManyClauses If a query would exceed {@link IndexSearcher#getMaxClauseCount()} * clauses. + * @deprecated This method is being deprecated in favor of {@link IndexSearcher#search(Query, Review comment: I think we should try to keep `IndexSearcher#search(Query, Collector)` and the `TopXXXCollector#create` factory methods during the 9.x series, as I expect it to be quite commonly used. However in my opinion it would be fine to cut over expert classes like those in the benchmark module without providing such long bw compatibility. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
