msokolov commented on code in PR #13260: URL: https://github.com/apache/lucene/pull/13260#discussion_r1550342370
########## lucene/test-framework/src/java/org/apache/lucene/tests/util/hnsw/HnswTestUtil.java: ########## @@ -0,0 +1,132 @@ +/* + * 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.tests.util.hnsw; + +import static org.apache.lucene.search.DocIdSetIterator.NO_MORE_DOCS; + +import java.io.IOException; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Deque; +import java.util.List; +import org.apache.lucene.codecs.HnswGraphProvider; +import org.apache.lucene.codecs.perfield.PerFieldKnnVectorsFormat; +import org.apache.lucene.index.CodecReader; +import org.apache.lucene.index.IndexReader; +import org.apache.lucene.index.LeafReaderContext; +import org.apache.lucene.util.FixedBitSet; +import org.apache.lucene.util.hnsw.HnswGraph; + +/** Utilities for use in tests involving HNSW graphs */ +public class HnswTestUtil { + + /** + * Returns true iff level 0 of the graph is fully connected - that is every node is reachable from + * any entry point. + */ + public static boolean isFullyConnected(HnswGraph knnValues) throws IOException { + return componentSizes(knnValues).size() < 2; + } + + /** + * Returns the sizes of the distinct graph components on level 0. If the graph is fully-connected + * there will only be a single component. If the graph is empty, the returned list will be empty. + */ + public static List<Integer> componentSizes(HnswGraph hnsw) throws IOException { Review Comment: Yes this is a tiny bit if lookahead. I would like to be able to use this to identify distinct components so we can patch them up while merging. TBH I look at this whole class as somewhat provisional and expect it to eventually move into the normal util package, and get tested better. In the mean time I agree we can reduce the cost of isFullyConnected in the best case; I can do that. But I'd like to hold on to the componentSizes method even though it will then be unused. -- 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
