gerlowskija commented on code in PR #1286: URL: https://github.com/apache/solr/pull/1286#discussion_r1087105926
########## solr/core/src/java/org/apache/solr/jersey/JerseyAppHandlerCache.java: ########## @@ -0,0 +1,98 @@ +/* + * 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.solr.jersey; + +import java.lang.invoke.MethodHandles; +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; +import java.util.function.Function; +import java.util.function.Supplier; +import org.apache.solr.core.ConfigSet; +import org.apache.solr.core.SolrConfig; +import org.apache.solr.core.SolrCore; +import org.apache.solr.util.RefCounted; +import org.glassfish.jersey.server.ApplicationHandler; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Stores Jersey 'ApplicationHandler' instances by an ID or hash derived from their {@link + * ConfigSet}. + * + * <p>ApplicationHandler creation is expensive; caching these objects allows them to be shared by + * multiple cores with the same configuration. + */ +public class JerseyAppHandlerCache { + + private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); + + private final Map<String, RefCounted<ApplicationHandler>> applicationByConfigSetId; + + public JerseyAppHandlerCache() { + this.applicationByConfigSetId = new ConcurrentHashMap<>(); + } + + /** + * Return the 'ApplicationHandler' associated with the provided ID, creating it first if + * necessary. + * + * <p>This method is thread-safe by virtue of its delegation to {@link + * ConcurrentHashMap#computeIfAbsent(Object, Function)} internally. + * + * @param effectiveConfigSetId an ID to associate the ApplicationHandler with. Usually created via + * {@link #generateIdForConfigSet(ConfigSet)}. + * @param createApplicationHandler a Supplier producing an ApplicationHandler + */ + public RefCounted<ApplicationHandler> computeIfAbsent( + String effectiveConfigSetId, Supplier<ApplicationHandler> createApplicationHandler) { + final Function<String, RefCounted<ApplicationHandler>> wrapper = + s -> { + return new RefCounted<>(createApplicationHandler.get()) { + @Override + public void close() { + log.info( + "Removing AppHandler from cache for 'effective configset' [{}]", + effectiveConfigSetId); Review Comment: I think this is at least potentially useful in case of some weird bug or interaction caused by the AppHandler reuse, but I'll definitely drop it down to be debug-level so no one else has to see the noise until they want it. -- 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]
