msfroh commented on code in PR #13054: URL: https://github.com/apache/lucene/pull/13054#discussion_r1701025192
########## lucene/analysis/common/src/java/org/apache/lucene/analysis/synonym/SynonymMapDirectory.java: ########## @@ -0,0 +1,191 @@ +/* + * 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.analysis.synonym; + +import java.io.Closeable; +import java.io.IOException; +import java.nio.file.Path; +import java.util.List; +import org.apache.lucene.store.Directory; +import org.apache.lucene.store.FSDirectory; +import org.apache.lucene.store.IOContext; +import org.apache.lucene.store.IndexInput; +import org.apache.lucene.store.IndexOutput; +import org.apache.lucene.util.BytesRef; +import org.apache.lucene.util.fst.ByteSequenceOutputs; +import org.apache.lucene.util.fst.FST; +import org.apache.lucene.util.fst.OffHeapFSTStore; + +/** + * Wraps an {@link FSDirectory} to read and write a compiled {@link SynonymMap}. When reading, the + * FST and output words are kept off-heap. Review Comment: At this point, if you're using `SynonymMapDirectory`, you get off-heap FST and on-heap words. If you don't use `SynonymMapDirectory` (i.e. you're using the existing constructor or the arg-less version of `SynonymMap.Builder.build()`), then everything is on-heap like before. The numbers I posted in https://github.com/apache/lucene/pull/13054#issuecomment-1935491971 (which, granted, was just a single synthetic benchmark) seemed to suggest (to me, at least) that the "sweet spot" is off-heap FST with on-heap words. The performance hit from moving words off-heap (at least with my implementation) was pretty bad. Lots of `seek`ing involved. Also, the vast majority of heap savings came from moving the FST. I'm happy to bring back off-heap words as an option if we think someone would be willing to take that perf hit for slightly lower heap utilization. -- 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
