gaobinlong commented on code in PR #15936: URL: https://github.com/apache/lucene/pull/15936#discussion_r3353123018
########## lucene/grouping/src/java/org/apache/lucene/search/grouping/BlockGroupingCollectorManager.java: ########## @@ -0,0 +1,127 @@ +/* + * 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.grouping; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; +import org.apache.lucene.search.CollectorManager; +import org.apache.lucene.search.Sort; +import org.apache.lucene.search.Weight; + +/** + * A {@link CollectorManager} for {@link BlockGroupingCollector} that merges results from multiple + * collectors into a single {@link TopGroups}. This is intended for use with concurrent search, + * where each segment is searched by a separate {@link BlockGroupingCollector}. Review Comment: Changed that, thanks! ########## lucene/grouping/src/test/org/apache/lucene/search/grouping/TestBlockGrouping.java: ########## @@ -77,6 +77,64 @@ public void testSimple() throws IOException { shard.close(); } + public void testShardedBlockGrouping() throws IOException { Review Comment: Created a sub-IndexSearcher with passing an ExecutorService and overriding the slices() method so that the collector manager can work with intra-segment concurrency. Use this sub-IndexSearcher in all of the test method in this file. I found this testShardedGrouping() is not needed, since we can only compare the totalHitCount of the final result between a single collector manager and one collector manager per shard, that's because when sorting by relevance, the final top-5 groups reduced by collector manager may differ from the one collector manager per shard's top-5 due to different score distributions, so finally I removed this test. ########## lucene/grouping/src/java/org/apache/lucene/search/grouping/TopGroups.java: ########## @@ -290,4 +296,146 @@ public static <T> TopGroups<T> merge( totalMaxScore); } } + + private record MergedBlockGroup(Object[] topValues, int shardIndex, int groupIndex) {} + + private static class GroupComparator implements Comparator<MergedBlockGroup> { + @SuppressWarnings("rawtypes") + public final FieldComparator[] comparators; + + public final int[] reversed; + + @SuppressWarnings({"rawtypes"}) + public GroupComparator(Sort groupSort) { + final SortField[] sortFields = groupSort.getSort(); + comparators = new FieldComparator[sortFields.length]; + reversed = new int[sortFields.length]; + for (int compIDX = 0; compIDX < sortFields.length; compIDX++) { + final SortField sortField = sortFields[compIDX]; + comparators[compIDX] = sortField.getComparator(1, Pruning.NONE); + reversed[compIDX] = sortField.getReverse() ? -1 : 1; + } + } + + @Override + @SuppressWarnings({"unchecked"}) + public int compare(MergedBlockGroup group, MergedBlockGroup other) { + if (group == other) { + return 0; + } + final Object[] groupValues = group.topValues; + final Object[] otherValues = other.topValues; + for (int compIDX = 0; compIDX < comparators.length; compIDX++) { + final int c = + reversed[compIDX] + * comparators[compIDX].compareValues(groupValues[compIDX], otherValues[compIDX]); + if (c != 0) { + return c; + } + } + + assert group.shardIndex != other.shardIndex; + return group.shardIndex - other.shardIndex; + } + } + + /** + * Merge TopGroups that are partitioned into blocks per shard. This method assumes that within + * each shard, the groups are sorted according to the groupSort. + * + * @param shardGroups list of TopGroups, one per shard. + * @param groupSort The {@link Sort} used to sort the groups. The top sorted document within each + * * group according to groupSort, determines how that group sorts against other groups. This + * * must be non-null, ie, if you want to groupSort by relevance use Sort.RELEVANCE. + * @param groupOffset Which group to start from. + * @param topNGroups How many top groups to keep. + * @param docSort The sort to use within each group + * @return TopGroups instance or null if there are no groups. + */ + @SuppressWarnings("unchecked") + public static <T> TopGroups<T> mergeBlockGroups( + List<TopGroups<T>> shardGroups, + Sort groupSort, + int groupOffset, + int topNGroups, + Sort docSort) { + if (shardGroups.isEmpty()) { + return new TopGroups<>( + groupSort.getSort(), + docSort.getSort(), + 0, + 0, + (GroupDocs<T>[]) new GroupDocs<?>[0], + Float.NaN); + } + + int totalGroupCount = 0; + int totalHitCount = 0; + int totalGroupedHitCount = 0; + for (TopGroups<T> sg : shardGroups) { + totalGroupCount += sg.totalGroupCount; + totalHitCount += sg.totalHitCount; + } + + // k-way merge + GroupComparator groupComp = new GroupComparator(groupSort); + NavigableSet<MergedBlockGroup> queue = new TreeSet<>(groupComp); + + float totalMaxScore = Float.NaN; + final boolean groupSortByRelevance = groupSort.equals(Sort.RELEVANCE); + // init queue + for (int idx = 0; idx < shardGroups.size(); idx++) { + TopGroups<T> topGroups = shardGroups.get(idx); + if (topGroups.groups.length == 0) { + continue; + } + if (!groupSortByRelevance) { + totalMaxScore = nonNANmax(totalMaxScore, topGroups.maxScore); + } + GroupDocs<T> firstGroupDocs = topGroups.groups[0]; + queue.add(new MergedBlockGroup(firstGroupDocs.groupSortValues(), idx, 0)); + } + + if (groupSortByRelevance) { + totalMaxScore = shardGroups.get(queue.first().shardIndex).maxScore; Review Comment: Added a check for the queue. ########## lucene/grouping/src/java/org/apache/lucene/search/grouping/BlockGroupingCollectorManager.java: ########## @@ -0,0 +1,127 @@ +/* + * 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.grouping; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; +import org.apache.lucene.search.CollectorManager; +import org.apache.lucene.search.Sort; +import org.apache.lucene.search.Weight; + +/** + * A {@link CollectorManager} for {@link BlockGroupingCollector} that merges results from multiple + * collectors into a single {@link TopGroups}. This is intended for use with concurrent search, + * where each segment is searched by a separate {@link BlockGroupingCollector}. + * + * <p>Documents must be indexed as blocks using {@link + * org.apache.lucene.index.IndexWriter#addDocuments IndexWriter.addDocuments()} or {@link + * org.apache.lucene.index.IndexWriter#updateDocuments IndexWriter.updateDocuments()}. + * + * <p>See {@link BlockGroupingCollector} for more details. + * + * <p>Example usage: + * + * <pre class="prettyprint"> + * IndexSearcher searcher = new IndexSearcher(reader); + * Query lastDocPerGroupQuery = new TermQuery(new Term("groupEnd", "true")); + * Weight lastDocPerGroup = searcher.createWeight( + * searcher.rewrite(lastDocPerGroupQuery), ScoreMode.COMPLETE_NO_SCORES, 1); + * + * BlockGroupingCollectorManager<BytesRef> manager = new BlockGroupingCollectorManager<>( + * Sort.RELEVANCE, // groupSort + * 0, // groupOffset + * 10, // topNGroups + * true, // needsScores + * lastDocPerGroup, + * Sort.RELEVANCE, // withinGroupSort + * 0, // withinGroupOffset + * 5); // maxDocsPerGroup + * + * TopGroups<BytesRef> result = searcher.search(query, manager); + * </pre> + * + * @lucene.experimental + */ +public class BlockGroupingCollectorManager<T> + implements CollectorManager<BlockGroupingCollector, TopGroups<T>> { + + private final Sort groupSort; + private final int groupOffset; + private final int topNGroups; + private final boolean needsScores; + private final Weight lastDocPerGroup; + + private final Sort withinGroupSort; + private final int withinGroupOffset; + private final int maxDocsPerGroup; + + /** + * Creates a new BlockGroupingCollectorManager. + * + * @param groupSort the sort used to rank groups + * @param groupOffset the offset into the groups to start returning from + * @param topNGroups the number of top groups to collect + * @param needsScores whether scores are needed (must be true if groupSort or withinGroupSort uses + * scores) + * @param lastDocPerGroup a {@link Weight} that matches the last document in each group block + * @param withinGroupSort the sort used to rank documents within each group + * @param withinGroupOffset the offset into each group's documents to start returning from + * @param maxDocsPerGroup the maximum number of documents to return per group + */ + public BlockGroupingCollectorManager( + Sort groupSort, + int groupOffset, + int topNGroups, + boolean needsScores, + Weight lastDocPerGroup, + Sort withinGroupSort, + int withinGroupOffset, + int maxDocsPerGroup) { + this.groupSort = groupSort; + this.groupOffset = groupOffset; + this.topNGroups = topNGroups; + this.needsScores = needsScores; + this.lastDocPerGroup = lastDocPerGroup; + this.withinGroupSort = withinGroupSort; + this.withinGroupOffset = withinGroupOffset; + this.maxDocsPerGroup = maxDocsPerGroup; + } + + @Override + public BlockGroupingCollector newCollector() throws IOException { + return new BlockGroupingCollector(groupSort, topNGroups, needsScores, lastDocPerGroup); + } + + @SuppressWarnings("unchecked") + @Override + public TopGroups<T> reduce(Collection<BlockGroupingCollector> collectors) throws IOException { + // Merge results from multiple collectors Review Comment: Removed yet. -- This is an automated message from the Apache Git Service. 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