xyuanlu commented on code in PR #2612: URL: https://github.com/apache/helix/pull/2612#discussion_r1321001470
########## meta-client/src/main/java/org/apache/helix/metaclient/impl/zk/ZkMetaClientCache.java: ########## @@ -0,0 +1,104 @@ +package org.apache.helix.metaclient.impl.zk; + +/* + * 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. + */ + +import org.apache.helix.metaclient.api.ChildChangeListener; +import org.apache.helix.metaclient.api.MetaClientCacheInterface; +import org.apache.helix.metaclient.datamodel.DataRecord; +import org.apache.helix.metaclient.exception.MetaClientException; +import org.apache.helix.metaclient.factories.MetaClientConfig; +import org.apache.helix.metaclient.impl.zk.factory.ZkMetaClientConfig; +import org.apache.helix.metaclient.impl.zk.factory.ZkMetaClientFactory; +import org.apache.helix.metaclient.recipes.lock.LockInfoSerializer; +import org.apache.helix.zookeeper.zkclient.ZkClient; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.List; +import java.util.Map; + +public class ZkMetaClientCache<T> extends ZkMetaClient<T> implements MetaClientCacheInterface<T> { + + private Map<String, DataRecord> _dataCacheMap; + private final String _rootEntry; + private TrieNode _childrenCacheTree; + private ChildChangeListener _eventListener; + private boolean _cacheData; + private boolean _cacheChildren; + private boolean _lazyCaching; + private static final Logger LOG = LoggerFactory.getLogger(ZkMetaClientCache.class); + private ZkClient _cacheClient; + + /** + * Creates a cached metaclient with ZooKeeper as the underlying data storage. + * @param config Configuration file to setup a zkmetaclient + * @param key The root node of the entry to be cached. + * @param cacheData Indicates whether the data should be cached. + * @param cacheChildren Indicates whether the children of the nodes should be cached. + * @param lazyCaching Indicates whether lazy loading of the cache is enabled. + */ + public ZkMetaClientCache(ZkMetaClientConfig config, String key, Boolean cacheData, + Boolean cacheChildren, Boolean lazyCaching) { + super(config); + _cacheClient = getZkClient(); + _rootEntry = key; + _lazyCaching = lazyCaching; + _cacheData = cacheData; + _cacheChildren = cacheChildren; + } + + private void setLazyLoading(boolean lazyLoading) { + _lazyCaching = lazyLoading; + } + + @Override + public Stat exists(String key) { + throw new MetaClientException("Not implemented yet."); + } + + @Override + public T get(final String key) { + throw new MetaClientException("Not implemented yet."); + } + + @Override + public List<String> getDirectChildrenKeys(final String key) { + throw new MetaClientException("Not implemented yet."); + } + + @Override + public int countDirectChildren(final String key) { + throw new MetaClientException("Not implemented yet."); + } + + @Override + public List<T> get(List<String> keys) { + throw new MetaClientException("Not implemented yet."); + } + + @Override + public List<Stat> exists(List<String> keys) { + throw new MetaClientException("Not implemented yet."); + } + + public ZkClient getCacheClient() { Review Comment: Why we need this API? -- 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]
