abhishekbafna commented on code in PR #17678: URL: https://github.com/apache/pinot/pull/17678#discussion_r2840405352
########## pinot-common/src/main/java/org/apache/pinot/common/utils/LogicalTableConfigSerDeProvider.java: ########## @@ -0,0 +1,75 @@ +/** + * 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.pinot.common.utils; + +import com.google.common.annotations.VisibleForTesting; +import java.util.ServiceLoader; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +/** + * Singleton holder for {@link LogicalTableConfigSerDe}, loaded via {@link ServiceLoader}. + * + * <p>When multiple implementations are discovered, the one with the highest + * {@link LogicalTableConfigSerDe#getPriority()} is selected</p> + */ +public class LogicalTableConfigSerDeProvider { + private static final Logger LOGGER = LoggerFactory.getLogger(LogicalTableConfigSerDeProvider.class); + + private static volatile LogicalTableConfigSerDe _instance = fromServiceLoader(); + + private LogicalTableConfigSerDeProvider() { + } + + public static LogicalTableConfigSerDe getInstance() { + return _instance; + } + + /** + * Overrides the singleton instance. Useful for testing. + */ + @VisibleForTesting + public static void setInstance(LogicalTableConfigSerDe serDe) { + _instance = serDe; + } + + private static LogicalTableConfigSerDe fromServiceLoader() { + LogicalTableConfigSerDe best = null; + int bestPriority = Integer.MIN_VALUE; + + for (LogicalTableConfigSerDe serDe : ServiceLoader.load(LogicalTableConfigSerDe.class)) { + LOGGER.info("Discovered LogicalTableConfigSerDe: {} with priority {}", + serDe.getClass().getName(), serDe.getPriority()); + if (serDe.getPriority() > bestPriority) { + best = serDe; + bestPriority = serDe.getPriority(); + } + } + + if (best == null) { + throw new RuntimeException("No implementation of LogicalTableConfigSerDe found"); + } Review Comment: Instead of the exception, it can init with the default SerDe which is implemented in the PR. What is the advantage of exception over default initialisation? -- 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]
