shayshim commented on a change in pull request #335: [CURATOR-549] Recipes based on Persistent Recursive Watchers URL: https://github.com/apache/curator/pull/335#discussion_r399646772
########## File path: curator-recipes/src/main/java/org/apache/curator/framework/recipes/cache/CuratorCacheImpl.java ########## @@ -0,0 +1,301 @@ +/** + * 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.curator.framework.recipes.cache; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Preconditions; +import com.google.common.collect.Sets; +import org.apache.curator.framework.CuratorFramework; +import org.apache.curator.framework.api.BackgroundCallback; +import org.apache.curator.framework.api.CuratorEvent; +import org.apache.curator.framework.listen.Listenable; +import org.apache.curator.framework.listen.StandardListenerManager; +import org.apache.curator.framework.recipes.watch.PersistentWatcher; +import org.apache.curator.utils.ThreadUtils; +import org.apache.curator.utils.ZKPaths; +import org.apache.zookeeper.KeeperException; +import org.apache.zookeeper.WatchedEvent; +import org.apache.zookeeper.data.Stat; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import java.util.Collections; +import java.util.Optional; +import java.util.Set; +import java.util.concurrent.atomic.AtomicReference; +import java.util.function.Consumer; +import java.util.stream.Stream; + +import static org.apache.curator.framework.recipes.cache.CuratorCacheListener.Type.*; +import static org.apache.zookeeper.KeeperException.Code.NONODE; +import static org.apache.zookeeper.KeeperException.Code.OK; + +class CuratorCacheImpl implements CuratorCache +{ + private final Logger log = LoggerFactory.getLogger(getClass()); + private final AtomicReference<State> state = new AtomicReference<>(State.LATENT); + private final PersistentWatcher persistentWatcher; + private final CuratorFramework client; + private final CuratorCacheStorage storage; + private final String path; + private final boolean recursive; + private final boolean compressedData; + private final boolean clearOnClose; + private final StandardListenerManager<CuratorCacheListener> listenerManager = StandardListenerManager.standard(); + private final Consumer<Exception> exceptionHandler; + private final OutstandingOps outstandingOps = new OutstandingOps(() -> callListeners(CuratorCacheListener::initialized)); + + private enum State + { + LATENT, + STARTED, + CLOSED + } + + CuratorCacheImpl(CuratorFramework client, CuratorCacheStorage storage, String path, Options[] optionsArg, Consumer<Exception> exceptionHandler) + { + Set<Options> options = (optionsArg != null) ? Sets.newHashSet(optionsArg) : Collections.emptySet(); + this.client = client; + this.storage = (storage != null) ? storage : CuratorCacheStorage.standard(); + this.path = path; + recursive = !options.contains(Options.SINGLE_NODE_CACHE); + compressedData = options.contains(Options.COMPRESSED_DATA); + clearOnClose = !options.contains(Options.DO_NOT_CLEAR_ON_CLOSE); + persistentWatcher = new PersistentWatcher(client, path, recursive); + persistentWatcher.getListenable().addListener(this::processEvent); + persistentWatcher.getResetListenable().addListener(this::rebuild); + this.exceptionHandler = (exceptionHandler != null) ? exceptionHandler : e -> log.error("CuratorCache error", e); + } + + @Override + public void start() + { + Preconditions.checkState(state.compareAndSet(State.LATENT, State.STARTED), "Already started"); + persistentWatcher.start(); + } + + @Override + public void close() + { + if ( state.compareAndSet(State.STARTED, State.CLOSED) ) + { + persistentWatcher.close(); + if ( clearOnClose ) + { + storage.clear(); + } + } + } + + @Override + public Listenable<CuratorCacheListener> listenable() + { + return listenerManager; + } + + @Override + public Optional<ChildData> get(String path) + { + return storage.get(path); + } + + @Override + public int size() + { + return storage.size(); + } + + @Override + public Stream<ChildData> stream() + { + return storage.stream(); + } + + @VisibleForTesting + CuratorCacheStorage storage() + { + return storage; + } + + private void rebuild() + { + if ( state.get() != State.STARTED ) + { + return; + } + + // rebuild from the root first + nodeChanged(path); Review comment: This call is going to also get all data of children recursively, and update the storage accordingly, so why do we need to pass the storage again as below? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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