Caideyipi commented on code in PR #17732: URL: https://github.com/apache/iotdb/pull/17732#discussion_r3345726074
########## iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/executable/ReferenceCountedJarMetaKeeper.java: ########## @@ -0,0 +1,121 @@ +/* + * 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.iotdb.commons.executable; + +import org.apache.tsfile.utils.ReadWriteIOUtils; + +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; + +public class ReferenceCountedJarMetaKeeper { + + private final Map<String, String> jarNameToMd5Map = new HashMap<>(); + private final Map<String, Integer> jarNameToReferenceCountMap = new HashMap<>(); + + public synchronized boolean containsJar(final String jarName) { + return jarNameToMd5Map.containsKey(jarName); + } + + public synchronized boolean needToSaveJar(final String jarName) { + return !containsJar(jarName); + } + + public synchronized boolean jarNameExistsAndMatchesMd5(final String jarName, final String md5) { + return containsJar(jarName) && Objects.equals(jarNameToMd5Map.get(jarName), md5); + } + + public synchronized void addReference(final String jarName, final String md5) { + if (jarNameToReferenceCountMap.containsKey(jarName)) { + jarNameToReferenceCountMap.put(jarName, jarNameToReferenceCountMap.get(jarName) + 1); + return; + } + + jarNameToReferenceCountMap.put(jarName, 1); + jarNameToMd5Map.put(jarName, md5); + } + + public synchronized void removeReference(final String jarName) { + final Integer referenceCount = jarNameToReferenceCountMap.get(jarName); + if (referenceCount == null || referenceCount <= 1) { + jarNameToReferenceCountMap.remove(jarName); + jarNameToMd5Map.remove(jarName); + return; + } + + jarNameToReferenceCountMap.put(jarName, referenceCount - 1); + } + + public synchronized void clear() { + jarNameToMd5Map.clear(); + jarNameToReferenceCountMap.clear(); + } + + public synchronized Map<String, String> getJarNameToMd5Map() { + return new HashMap<>(jarNameToMd5Map); + } + + public synchronized void serializeJarNameToMd5(final OutputStream outputStream) + throws IOException { + ReadWriteIOUtils.write(jarNameToMd5Map.size(), outputStream); + for (final Map.Entry<String, String> entry : jarNameToMd5Map.entrySet()) { + ReadWriteIOUtils.write(entry.getKey(), outputStream); + ReadWriteIOUtils.write(entry.getValue(), outputStream); + } + } + + public synchronized void deserializeJarNameToMd5(final InputStream inputStream) + throws IOException { + clear(); + + int size = ReadWriteIOUtils.readInt(inputStream); + while (size > 0) { + addReference( + ReadWriteIOUtils.readString(inputStream), ReadWriteIOUtils.readString(inputStream)); + size--; + } + } + + public synchronized void serializeJarNameToMd5AndReferenceCount(final OutputStream outputStream) + throws IOException { + ReadWriteIOUtils.write(jarNameToMd5Map.size(), outputStream); + for (final Map.Entry<String, String> entry : jarNameToMd5Map.entrySet()) { + final String jarName = entry.getKey(); + ReadWriteIOUtils.write(jarName, outputStream); + ReadWriteIOUtils.write(entry.getValue(), outputStream); + ReadWriteIOUtils.write(jarNameToReferenceCountMap.getOrDefault(jarName, 0), outputStream); + } + } Review Comment: Good point. A zero reference count should not be serialized: under the normal add/remove path, removeReference removes both maps when the count reaches zero. I updated the snapshot logic to serialize only entries with a positive reference count and matching md5 metadata, and to skip non-positive counts when loading snapshots as a defensive cleanup. Added a regression test for the zero-count snapshot case as well. -- 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]
