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https://issues.apache.org/jira/browse/CURATOR-549?focusedWorklogId=410157&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-410157
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ASF GitHub Bot logged work on CURATOR-549:
------------------------------------------
Author: ASF GitHub Bot
Created on: 26/Mar/20 09:08
Start Date: 26/Mar/20 09:08
Worklog Time Spent: 10m
Work Description: TisonKun commented on pull request #335: [CURATOR-549]
Recipes based on Persistent Recursive Watchers
URL: https://github.com/apache/curator/pull/335#discussion_r398353415
##########
File path:
curator-recipes/src/main/java/org/apache/curator/framework/recipes/cache/CuratorCache.java
##########
@@ -0,0 +1,133 @@
+/**
+ * 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 org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.listen.Listenable;
+import java.io.Closeable;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+/**
+ * <p>
+ * A utility that attempts to keep the data from a node locally cached.
Optionally the entire
+ * tree of children below the node can also be cached. Will respond to
update/create/delete events, pull
+ * down the data, etc. You can register listeners that will get notified
when changes occur.
+ * </p>
+ *
+ * <p>
+ * <b>IMPORTANT</b> - it's not possible to stay transactionally in sync.
Users of this class must
+ * be prepared for false-positives and false-negatives. Additionally,
always use the version number
+ * when updating data to avoid overwriting another process' change.
+ * </p>
+ */
+public interface CuratorCache extends Closeable, CuratorCacheAccessor
+{
+ /**
+ * cache build options
+ */
+ enum Options
+ {
+ /**
+ * Normally the entire tree of nodes starting at the given node are
cached. This option
+ * causes only the given node to be cached (i.e. a single node cache)
+ */
+ SINGLE_NODE_CACHE,
+
+ /**
+ * Decompress data via {@link
org.apache.curator.framework.api.GetDataBuilder#decompressed()}
+ */
+ COMPRESSED_DATA,
+
+ /**
+ * Normally, when the cache is closed via {@link
CuratorCache#close()}, the storage is cleared
+ * via {@link CuratorCacheStorage#clear()}. This option prevents the
storage from being cleared.
+ */
+ DO_NOT_CLEAR_ON_CLOSE
+ }
+
+ /**
+ * Return a Curator Cache for the given path with the given options using
a standard storage instance
+ *
+ * @param client Curator client
+ * @param path path to cache
+ * @param options any options
+ * @return cache (note it must be started via {@link #start()}
+ */
+ static CuratorCache build(CuratorFramework client, String path, Options...
options)
+ {
+ return builder(client, path).withOptions(options).build();
+ }
+
+ /**
+ * Start a Curator Cache builder
+ *
+ * @param client Curator client
+ * @param path path to cache
+ * @return builder
+ */
+ static CuratorCacheBuilder builder(CuratorFramework client, String path)
+ {
+ return new CuratorCacheBuilderImpl(client, path);
+ }
+
+ /**
+ * Start the cache. This will cause a complete refresh from the cache's
root node and generate
+ * events for all nodes found, etc.
+ */
+ void start();
+
+ /**
+ * Close the cache, stop responding to events, etc.
+ */
+ @Override
+ void close();
+
+ /**
+ * Return the listener container so that listeners can be registered to be
notified of changes to the cache
+ *
+ * @return listener container
+ */
+ Listenable<CuratorCacheListener> listenable();
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ Optional<ChildData> get(String path);
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ int size();
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ Stream<ChildData> stream();
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ Stream<ChildData> streamImmediateChildren(String fromParent);
Review comment:
Is this method for compatibility of `PathChildrenCache#getCurrentData`? If
so, shall we mention it?
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Issue Time Tracking
-------------------
Worklog Id: (was: 410157)
Time Spent: 10h 10m (was: 10h)
> ZooKeeper 3.6 will add support for Persistent Recursive Watchers - Add
> Curator support
> --------------------------------------------------------------------------------------
>
> Key: CURATOR-549
> URL: https://issues.apache.org/jira/browse/CURATOR-549
> Project: Apache Curator
> Issue Type: Improvement
> Components: Client, Documentation, Framework, Recipes, Tests
> Affects Versions: 4.2.0
> Reporter: Jordan Zimmerman
> Assignee: Jordan Zimmerman
> Priority: Major
> Fix For: 5.0.0
>
> Time Spent: 10h 10m
> Remaining Estimate: 0h
>
> ZOOKEEPER-1416 will add support for Persistent Recursive Watchers. This
> feature allows Curator to re-think/re-write the various cache recipes so that
> they're simpler, use less resources and more stable.
> * Change Curator to depend on ZooKeeper 3.6.x
> * Add a new module so that backward compatibility with 3.5 is ensured
> * Add new methods corresponding to {{ZooKeeper.addWatch()}}
> * Add a new recipe that enables a fully managed Persistent watch
> * Create new Cache recipes that use the new Persistent watch recipe
> * Replace internal usages of TreeCache/PathChildrenCache/NodeCache with new
> cache recipe
> * Deprecate TreeCache/PathChildrenCache/NodeCache
> * Updated docs/tests/etc
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