kaivalnp commented on code in PR #14178: URL: https://github.com/apache/lucene/pull/14178#discussion_r2109499282
########## lucene/sandbox/src/java/org/apache/lucene/sandbox/codecs/faiss/FaissKnnVectorsFormat.java: ########## @@ -0,0 +1,93 @@ +/* + * 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.sandbox.codecs.faiss; + +import java.io.IOException; +import java.util.Locale; +import org.apache.lucene.codecs.KnnVectorsFormat; +import org.apache.lucene.codecs.KnnVectorsReader; +import org.apache.lucene.codecs.KnnVectorsWriter; +import org.apache.lucene.codecs.hnsw.FlatVectorScorerUtil; +import org.apache.lucene.codecs.hnsw.FlatVectorsFormat; +import org.apache.lucene.codecs.lucene99.Lucene99FlatVectorsFormat; +import org.apache.lucene.index.SegmentReadState; +import org.apache.lucene.index.SegmentWriteState; + +/** + * A format which uses <a href="https://github.com/facebookresearch/faiss";>Faiss</a> to create and + * search vector indexes, using {@link LibFaissC} to interact with the native library. + * + * <p>A separate Faiss index is created per-segment, and uses the following files: + * + * <ul> + * <li><code>.faissm</code> (metadata file): stores field number, offset and length of actual + * Faiss index in data file. + * <li><code>.faissd</code> (data file): stores concatenated Faiss indexes for all fields. + * <li>All files required by {@link Lucene99FlatVectorsFormat} for storing raw vectors. + * </ul> + * + * <p>Note: Set the {@code $OMP_NUM_THREADS} environment variable to control internal threading. + * + * @lucene.experimental Review Comment: I do see some [references](https://github.com/search?q=repo%3Afacebookresearch%2Ffaiss%20compatibility&type=code) of backwards compatibility, and an [old comment](https://github.com/facebookresearch/faiss/issues/2373#issuecomment-1175895577) which says that newer versions of Faiss can read older indexes -- but I couldn't find documentation for it.. Further, we may change some internals of the codec making it incompatible with earlier versions -- but I'll add a comment saying there's no guarantee today, and a TODO to figure that out -- 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
