vigyasharma commented on code in PR #13951: URL: https://github.com/apache/lucene/pull/13951#discussion_r1820163993
########## lucene/core/src/java/org/apache/lucene/index/IndexWriterRAMManager.java: ########## @@ -0,0 +1,116 @@ +/* + * 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.index; + +import java.io.IOException; +import java.util.Collection; +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.atomic.AtomicInteger; + +/** + * For managing multiple instances of {@link IndexWriter} sharing the same buffer (configured by + * {@link IndexWriterConfig#setRAMBufferSizeMB}) + */ +public class IndexWriterRAMManager { + + private final IndexWriterConfig config; + private final Map<Integer, IndexWriter> idToWriter = new ConcurrentHashMap<>(); + private final AtomicInteger idGenerator = new AtomicInteger(); + + /** + * Default constructor + * + * @param config the index writer config containing the max RAM buffer size + */ + public IndexWriterRAMManager(IndexWriterConfig config) { + this.config = config; + } + + private int registerWriter(IndexWriter writer) { + int id = idGenerator.incrementAndGet(); + idToWriter.put(id, writer); + return id; + } + + private void removeWriter(int id) { + if (idToWriter.containsKey(id) == false) { + throw new IllegalArgumentException( + "Writer " + id + " has not been registered or has been removed already"); + } + idToWriter.remove(id); + } + + private void flushIfNecessary(int id) throws IOException { + if (idToWriter.containsKey(id) == false) { + throw new IllegalArgumentException( + "Writer " + id + " has not been registered or has been removed already"); + } + long totalRam = 0L; + for (IndexWriter writer : idToWriter.values()) { + totalRam += writer.ramBytesUsed(); + } + if (totalRam >= config.getRAMBufferSizeMB() * 1024 * 1024) { + IndexWriter writerToFlush = chooseWriterToFlush(idToWriter.values(), idToWriter.get(id)); + writerToFlush.flushNextBuffer(); + } + } + + /** + * Chooses which writer should be flushed. Default implementation chooses the writer with most RAM + * usage + * + * @param writers list of writers registered with this {@link IndexWriterRAMManager} + * @param callingWriter the writer calling {@link IndexWriterRAMManager#flushIfNecessary} + * @return the IndexWriter to flush + */ + protected static IndexWriter chooseWriterToFlush( + Collection<IndexWriter> writers, IndexWriter callingWriter) { Review Comment: Do we need the calling writer here? -- 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
