msokolov commented on a change in pull request #238: URL: https://github.com/apache/lucene/pull/238#discussion_r684771694
########## File path: lucene/core/src/java/org/apache/lucene/search/KnnVectorQuery.java ########## @@ -0,0 +1,318 @@ +/* + * 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 static org.apache.lucene.search.DocIdSetIterator.NO_MORE_DOCS; + +import java.io.IOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.Objects; +import org.apache.lucene.codecs.KnnVectorsReader; +import org.apache.lucene.document.KnnVectorField; +import org.apache.lucene.index.IndexReader; +import org.apache.lucene.index.LeafReaderContext; + +/** Uses {@link KnnVectorsReader#search} to perform nearest Neighbour search. */ +public class KnnVectorQuery extends Query { + + private static final TopDocs NO_RESULTS = + new TopDocs(new TotalHits(0, TotalHits.Relation.EQUAL_TO), new ScoreDoc[0]); + + private final String field; + private final float[] target; + private final int k; + + /** + * Find the <code>k</code> nearest documents to the target vector according to the vectors in the + * given field. <code>target</code> vector. + * + * @param field a field that has been indexed as a {@link KnnVectorField}. + * @param target the target of the search + * @param k the number of documents to find + * @throws IllegalArgumentException if <code>k</code> is less than 1 + */ + public KnnVectorQuery(String field, float[] target, int k) { + this.field = field; + this.target = target; + this.k = k; + if (k < 1) { + throw new IllegalArgumentException("k must be at least 1, got: " + k); + } + } + + @Override + public Query rewrite(IndexReader reader) throws IOException { Review comment: There was discussion about this on the [JIRA](https://issues.apache.org/jira/browse/LUCENE-9614) issue. I think we concluded that this is not so different from other `rewrite()` methods like those for `MultiTermQuery`, but do you have an alternative suggestion? Another way I considered was to implement in `createWeight()`, but it leads to problems with caching. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
