jira-importer commented on issue #554: URL: https://github.com/apache/curator/issues/554#issuecomment-2604695695
<i><a href="https://issues.apache.org/jira/secure/ViewProfile.jspa?name=githubbot";>githubbot</a>:</i> <p>Github user Randgalt commented on a diff in the pull request:</p> <p> <a href="https://github.com/apache/curator/pull/17#discussion_r15658282"; class="external-link" target="_blank" rel="nofollow noopener">https://github.com/apache/curator/pull/17#discussion_r15658282</a></p> <p> — Diff: curator-recipes/src/main/java/org/apache/curator/framework/recipes/cache/TreeCache.java —<br/> @@ -0,0 +1,605 @@<br/> +/**<br/> + * Licensed to the Apache Software Foundation (ASF) under one<br/> + * or more contributor license agreements. See the NOTICE file<br/> + * distributed with this work for additional information<br/> + * regarding copyright ownership. The ASF licenses this file<br/> + * to you under the Apache License, Version 2.0 (the<br/> + * "License"); you may not use this file except in compliance<br/> + * with the License. You may obtain a copy of the License at<br/> + *<br/> + * <a href="http://www.apache.org/licenses/LICENSE-2.0"; class="external-link" target="_blank" rel="nofollow noopener">http://www.apache.org/licenses/LICENSE-2.0</a><br/> + *<br/> + * Unless required by applicable law or agreed to in writing,<br/> + * software distributed under the License is distributed on an<br/> + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY<br/> + * KIND, either express or implied. See the License for the<br/> + * specific language governing permissions and limitations<br/> + * under the License.<br/> + */<br/> +<br/> +package org.apache.curator.framework.recipes.cache;<br/> +<br/> +import com.google.common.base.Function;<br/> +import com.google.common.collect.ImmutableSortedSet;<br/> +import com.google.common.collect.Maps;<br/> +import org.apache.curator.framework.CuratorFramework;<br/> +import org.apache.curator.framework.api.BackgroundCallback;<br/> +import org.apache.curator.framework.api.CuratorEvent;<br/> +import org.apache.curator.framework.listen.ListenerContainer;<br/> +import org.apache.curator.framework.state.ConnectionState;<br/> +import org.apache.curator.framework.state.ConnectionStateListener;<br/> +import org.apache.curator.utils.CloseableExecutorService;<br/> +import org.apache.curator.utils.ThreadUtils;<br/> +import org.apache.curator.utils.ZKPaths;<br/> +import org.apache.zookeeper.KeeperException;<br/> +import org.apache.zookeeper.WatchedEvent;<br/> +import org.apache.zookeeper.Watcher;<br/> +import org.apache.zookeeper.data.Stat;<br/> +import org.slf4j.Logger;<br/> +import org.slf4j.LoggerFactory;<br/> +import java.io.Closeable;<br/> +import java.io.IOException;<br/> +import java.util.ArrayList;<br/> +import java.util.Collections;<br/> +import java.util.List;<br/> +import java.util.SortedSet;<br/> +import java.util.concurrent.ConcurrentMap;<br/> +import java.util.concurrent.ExecutorService;<br/> +import java.util.concurrent.Executors;<br/> +import java.util.concurrent.ThreadFactory;<br/> +import java.util.concurrent.atomic.AtomicLong;<br/> +import java.util.concurrent.atomic.AtomicReference;<br/> +<br/> +/**<br/> + * <p>A utility that attempts to keep all data from all children of a ZK path locally cached. This class<br/> + * will watch the ZK path, respond to update/create/delete events, pull down the data, etc. You can<br/> + * register a listener that will get notified when changes occur.</p><br/> + * <p></p><br/> + * <p><b>IMPORTANT</b> - it's not possible to stay transactionally in sync. Users of this class must<br/> + * be prepared for false-positives and false-negatives. Additionally, always use the version number<br/> + * when updating data to avoid overwriting another process' change.</p><br/> + */<br/> +public class TreeCache implements Closeable<br/> +{<br/> + private static final Logger LOG = LoggerFactory.getLogger(TreeCache.class);<br/> +<br/> + private enum NodeState<br/> + </p> { +PENDING, LIVE, DEAD + } <p> +<br/> + final class TreeNode implements Watcher, BackgroundCallback<br/> + {<br/> +private final AtomicReference<NodeState> nodeState = new AtomicReference<NodeState>(NodeState.PENDING);<br/> +private final String path;<br/> +private final TreeNode parent;<br/> +private final AtomicReference<Stat> stat = new AtomicReference<Stat>();<br/> +private final AtomicReference<byte[]> data = new AtomicReference<byte[]>();<br/> +private final AtomicReference<ConcurrentMap<String, TreeNode>> children = new AtomicReference<ConcurrentMap<String, TreeNode>>();<br/> +<br/> +TreeNode(String path, TreeNode parent)<br/> +</p> { + this.path = path; + this.parent = parent; +} <p> +<br/> +private void refreshChildren() throws Exception<br/> +</p> { + outstandingOps.incrementAndGet(); + client.getChildren().usingWatcher(this).inBackground(this).forPath(path); +} <p> +<br/> +private void refreshData() throws Exception<br/> +{<br/> + outstandingOps.incrementAndGet();<br/> + if ( dataIsCompressed )<br/> + </p> { +client.getData().decompressed().usingWatcher(this).inBackground(this).forPath(path); + } <p> + else<br/> + </p> { +client.getData().usingWatcher(this).inBackground(this).forPath(path); + } <p> +}<br/> +<br/> +private void wasReconnected() throws Exception<br/> +{<br/> + refreshData();<br/> + refreshChildren();<br/> + ConcurrentMap<String, TreeNode> childMap = children.get();<br/> + if ( childMap != null )<br/> + {<br/> +for ( TreeNode child : childMap.values() )<br/> +</p> { + child.wasReconnected(); +} <p> + }<br/> +}<br/> +<br/> +private void wasCreated() throws Exception<br/> +</p> { + refreshData(); + refreshChildren(); +} <p> +<br/> +private void wasDeleted() throws Exception<br/> +{<br/> + stat.set(null);<br/> + data.set(null);<br/> + client.clearWatcherReferences(this);<br/> + ConcurrentMap<String, TreeNode> childMap = children.getAndSet(null);<br/> + if ( childMap != null )<br/> + {<br/> +ArrayList<TreeNode> childCopy = new ArrayList<TreeNode>(childMap.values());<br/> +childMap.clear();<br/> +for ( TreeNode child : childCopy )<br/> +</p> { + child.wasDeleted(); +} <p> + }<br/> +<br/> + if ( treeState.get() == TreeState.CLOSED )<br/> + </p> { +return; + } <p> +<br/> + if ( nodeState.compareAndSet(NodeState.LIVE, NodeState.DEAD) )<br/> + </p> { +publishEvent(TreeCacheEvent.Type.NODE_REMOVED, path); + } <p> +<br/> + if ( parent == null )<br/> + </p> { +// Root node; use an exist query to watch for existence. +client.checkExists().usingWatcher(this).inBackground().forPath(path); + } <p> + else<br/> + {<br/> +// Remove from parent if we're currently a child<br/> +ConcurrentMap<String, TreeNode> parentChildMap = parent.children.get();<br/> +if ( parentChildMap != null )<br/> +</p> { + parentChildMap.remove(ZKPaths.getNodeFromPath(path), this); +} <p> + }<br/> +}<br/> +<br/> +@Override<br/> +public void process(WatchedEvent event)<br/> +{<br/> + try<br/> + {<br/> +switch ( event.getType() )<br/> +{<br/> +case NodeCreated:<br/> + assert parent == null;<br/> — End diff –</p> <p> Use Guava Preconditions instead with a reasonable message</p> -- This is an automated message from the Apache Git Service. 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