org.apache.zookeeper.ZKUtil Maven / Gradle / Ivy
Show all versions of datacap-shaded-pinot Show documentation
/**
* 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.zookeeper;
import java.util.ArrayList;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
import org.apache.zookeeper.AsyncCallback.VoidCallback;
import org.apache.zookeeper.common.PathUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class ZKUtil {
private static final Logger LOG = LoggerFactory.getLogger(ZKUtil.class);
/**
* Recursively delete the node with the given path.
*
* Important: All versions, of all nodes, under the given node are deleted.
*
* If there is an error with deleting one of the sub-nodes in the tree,
* this operation would abort and would be the responsibility of the app to handle the same.
*
* See {@link #delete(String, int)} for more details.
*
* @throws IllegalArgumentException if an invalid path is specified
*/
public static void deleteRecursive(ZooKeeper zk, final String pathRoot)
throws InterruptedException, KeeperException
{
PathUtils.validatePath(pathRoot);
List tree = listSubTreeBFS(zk, pathRoot);
LOG.debug("Deleting " + tree);
LOG.debug("Deleting " + tree.size() + " subnodes ");
for (int i = tree.size() - 1; i >= 0 ; --i) {
//Delete the leaves first and eventually get rid of the root
zk.delete(tree.get(i), -1); //Delete all versions of the node with -1.
}
}
/**
* Recursively delete the node with the given path. (async version).
*
*
* Important: All versions, of all nodes, under the given node are deleted.
*
* If there is an error with deleting one of the sub-nodes in the tree,
* this operation would abort and would be the responsibility of the app to handle the same.
*
* @param zk the zookeeper handle
* @param pathRoot the path to be deleted
* @param cb call back method
* @param ctx the context the callback method is called with
* @throws IllegalArgumentException if an invalid path is specified
*/
public static void deleteRecursive(ZooKeeper zk, final String pathRoot, VoidCallback cb,
Object ctx)
throws InterruptedException, KeeperException
{
PathUtils.validatePath(pathRoot);
List tree = listSubTreeBFS(zk, pathRoot);
LOG.debug("Deleting " + tree);
LOG.debug("Deleting " + tree.size() + " subnodes ");
for (int i = tree.size() - 1; i >= 0 ; --i) {
//Delete the leaves first and eventually get rid of the root
zk.delete(tree.get(i), -1, cb, ctx); //Delete all versions of the node with -1.
}
}
/**
* BFS Traversal of the system under pathRoot, with the entries in the list, in the
* same order as that of the traversal.
*
* Important: This is not an atomic snapshot of the tree ever, but the
* state as it exists across multiple RPCs from zkClient to the ensemble.
* For practical purposes, it is suggested to bring the clients to the ensemble
* down (i.e. prevent writes to pathRoot) to 'simulate' a snapshot behavior.
*
* @param zk the zookeeper handle
* @param pathRoot The znode path, for which the entire subtree needs to be listed.
* @throws InterruptedException
* @throws KeeperException
*/
public static List listSubTreeBFS(ZooKeeper zk, final String pathRoot) throws
KeeperException, InterruptedException {
Deque queue = new LinkedList();
List tree = new ArrayList();
queue.add(pathRoot);
tree.add(pathRoot);
while (true) {
String node = queue.pollFirst();
if (node == null) {
break;
}
List children = zk.getChildren(node, false);
for (final String child : children) {
final String childPath = node + "/" + child;
queue.add(childPath);
tree.add(childPath);
}
}
return tree;
}
}