org.apache.curator.utils.ZKPaths Maven / Gradle / Ivy
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* 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.utils;
import com.google.common.base.Splitter;
import com.google.common.collect.Lists;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.ACL;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Collections;
import java.util.List;
public class ZKPaths
{
/**
* Zookeeper's path separator character.
*/
public static final String PATH_SEPARATOR = "/";
private static final CreateMode NON_CONTAINER_MODE = CreateMode.PERSISTENT;
/**
* @return {@link CreateMode#CONTAINER} if the ZK JAR supports it. Otherwise {@link CreateMode#PERSISTENT}
*/
public static CreateMode getContainerCreateMode()
{
return CreateModeHolder.containerCreateMode;
}
/**
* Returns true if the version of ZooKeeper client in use supports containers
*
* @return true/false
*/
public static boolean hasContainerSupport()
{
return getContainerCreateMode() != NON_CONTAINER_MODE;
}
private static class CreateModeHolder
{
private static final Logger log = LoggerFactory.getLogger(ZKPaths.class);
private static final CreateMode containerCreateMode;
static
{
CreateMode localCreateMode;
try
{
localCreateMode = CreateMode.valueOf("CONTAINER");
}
catch ( IllegalArgumentException ignore )
{
localCreateMode = NON_CONTAINER_MODE;
log.warn("The version of ZooKeeper being used doesn't support Container nodes. CreateMode.PERSISTENT will be used instead.");
}
containerCreateMode = localCreateMode;
}
}
/**
* Apply the namespace to the given path
*
* @param namespace namespace (can be null)
* @param path path
* @return adjusted path
*/
public static String fixForNamespace(String namespace, String path)
{
return fixForNamespace(namespace, path, false);
}
/**
* Apply the namespace to the given path
*
* @param namespace namespace (can be null)
* @param path path
* @param isSequential if the path is being created with a sequential flag
* @return adjusted path
*/
public static String fixForNamespace(String namespace, String path, boolean isSequential)
{
// Child path must be valid in and of itself.
PathUtils.validatePath(path, isSequential);
if ( namespace != null )
{
return makePath(namespace, path);
}
return path;
}
/**
* Given a full path, return the node name. i.e. "/one/two/three" will return "three"
*
* @param path the path
* @return the node
*/
public static String getNodeFromPath(String path)
{
PathUtils.validatePath(path);
int i = path.lastIndexOf(PATH_SEPARATOR);
if ( i < 0 )
{
return path;
}
if ( (i + 1) >= path.length() )
{
return "";
}
return path.substring(i + 1);
}
public static class PathAndNode
{
private final String path;
private final String node;
public PathAndNode(String path, String node)
{
this.path = path;
this.node = node;
}
public String getPath()
{
return path;
}
public String getNode()
{
return node;
}
}
/**
* Given a full path, return the node name and its path. i.e. "/one/two/three" will return {"/one/two", "three"}
*
* @param path the path
* @return the node
*/
public static PathAndNode getPathAndNode(String path)
{
PathUtils.validatePath(path);
int i = path.lastIndexOf(PATH_SEPARATOR);
if ( i < 0 )
{
return new PathAndNode(path, "");
}
if ( (i + 1) >= path.length() )
{
return new PathAndNode(PATH_SEPARATOR, "");
}
String node = path.substring(i + 1);
String parentPath = (i > 0) ? path.substring(0, i) : PATH_SEPARATOR;
return new PathAndNode(parentPath, node);
}
private static final Splitter PATH_SPLITTER = Splitter.on(PATH_SEPARATOR).omitEmptyStrings();
/**
* Given a full path, return the the individual parts, without slashes.
* The root path will return an empty list.
*
* @param path the path
* @return an array of parts
*/
public static List split(String path)
{
PathUtils.validatePath(path);
return PATH_SPLITTER.splitToList(path);
}
/**
* Make sure all the nodes in the path are created. NOTE: Unlike File.mkdirs(), Zookeeper doesn't distinguish
* between directories and files. So, every node in the path is created. The data for each node is an empty blob
*
* @param zookeeper the client
* @param path path to ensure
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException Zookeeper errors
*/
public static void mkdirs(ZooKeeper zookeeper, String path) throws InterruptedException, KeeperException
{
mkdirs(zookeeper, path, true, null, false);
}
/**
* Make sure all the nodes in the path are created. NOTE: Unlike File.mkdirs(), Zookeeper doesn't distinguish
* between directories and files. So, every node in the path is created. The data for each node is an empty blob
*
* @param zookeeper the client
* @param path path to ensure
* @param makeLastNode if true, all nodes are created. If false, only the parent nodes are created
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException Zookeeper errors
*/
public static void mkdirs(ZooKeeper zookeeper, String path, boolean makeLastNode) throws InterruptedException, KeeperException
{
mkdirs(zookeeper, path, makeLastNode, null, false);
}
/**
* Make sure all the nodes in the path are created. NOTE: Unlike File.mkdirs(), Zookeeper doesn't distinguish
* between directories and files. So, every node in the path is created. The data for each node is an empty blob
*
* @param zookeeper the client
* @param path path to ensure
* @param makeLastNode if true, all nodes are created. If false, only the parent nodes are created
* @param aclProvider if not null, the ACL provider to use when creating parent nodes
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException Zookeeper errors
*/
public static void mkdirs(ZooKeeper zookeeper, String path, boolean makeLastNode, InternalACLProvider aclProvider) throws InterruptedException, KeeperException
{
mkdirs(zookeeper, path, makeLastNode, aclProvider, false);
}
/**
* Make sure all the nodes in the path are created. NOTE: Unlike File.mkdirs(), Zookeeper doesn't distinguish
* between directories and files. So, every node in the path is created. The data for each node is an empty blob
*
* @param zookeeper the client
* @param path path to ensure
* @param makeLastNode if true, all nodes are created. If false, only the parent nodes are created
* @param aclProvider if not null, the ACL provider to use when creating parent nodes
* @param asContainers if true, nodes are created as {@link CreateMode#CONTAINER}
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException Zookeeper errors
*/
public static void mkdirs(ZooKeeper zookeeper, String path, boolean makeLastNode, InternalACLProvider aclProvider, boolean asContainers) throws InterruptedException, KeeperException
{
PathUtils.validatePath(path);
int pos = 1; // skip first slash, root is guaranteed to exist
do
{
pos = path.indexOf(PATH_SEPARATOR, pos + 1);
if ( pos == -1 )
{
if ( makeLastNode )
{
pos = path.length();
}
else
{
break;
}
}
String subPath = path.substring(0, pos);
if ( zookeeper.exists(subPath, false) == null )
{
try
{
List acl = null;
if ( aclProvider != null )
{
acl = aclProvider.getAclForPath(subPath);
if ( acl == null )
{
acl = aclProvider.getDefaultAcl();
}
}
if ( acl == null )
{
acl = ZooDefs.Ids.OPEN_ACL_UNSAFE;
}
zookeeper.create(subPath, new byte[0], acl, getCreateMode(asContainers));
}
catch ( KeeperException.NodeExistsException e )
{
// ignore... someone else has created it since we checked
}
}
}
while ( pos < path.length() );
}
/**
* Recursively deletes children of a node.
*
* @param zookeeper the client
* @param path path of the node to delete
* @param deleteSelf flag that indicates that the node should also get deleted
* @throws InterruptedException
* @throws KeeperException
*/
public static void deleteChildren(ZooKeeper zookeeper, String path, boolean deleteSelf) throws InterruptedException, KeeperException
{
PathUtils.validatePath(path);
List children = zookeeper.getChildren(path, null);
for ( String child : children )
{
String fullPath = makePath(path, child);
deleteChildren(zookeeper, fullPath, true);
}
if ( deleteSelf )
{
try
{
zookeeper.delete(path, -1);
}
catch ( KeeperException.NotEmptyException e )
{
//someone has created a new child since we checked ... delete again.
deleteChildren(zookeeper, path, true);
}
catch ( KeeperException.NoNodeException e )
{
// ignore... someone else has deleted the node it since we checked
}
}
}
/**
* Return the children of the given path sorted by sequence number
*
* @param zookeeper the client
* @param path the path
* @return sorted list of children
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException zookeeper errors
*/
public static List getSortedChildren(ZooKeeper zookeeper, String path) throws InterruptedException, KeeperException
{
List children = zookeeper.getChildren(path, false);
List sortedList = Lists.newArrayList(children);
Collections.sort(sortedList);
return sortedList;
}
/**
* Given a parent path and a child node, create a combined full path
*
* @param parent the parent
* @param child the child
* @return full path
*/
public static String makePath(String parent, String child)
{
StringBuilder path = new StringBuilder();
joinPath(path, parent, child);
return path.toString();
}
/**
* Given a parent path and a list of children nodes, create a combined full path
*
* @param parent the parent
* @param firstChild the first children in the path
* @param restChildren the rest of the children in the path
* @return full path
*/
public static String makePath(String parent, String firstChild, String... restChildren)
{
StringBuilder path = new StringBuilder();
joinPath(path, parent, firstChild);
if ( restChildren == null )
{
return path.toString();
}
else
{
for ( String child : restChildren )
{
joinPath(path, "", child);
}
return path.toString();
}
}
/**
* Given a parent and a child node, join them in the given {@link StringBuilder path}
*
* @param path the {@link StringBuilder} used to make the path
* @param parent the parent
* @param child the child
*/
private static void joinPath(StringBuilder path, String parent, String child)
{
// Add parent piece, with no trailing slash.
if ( (parent != null) && (parent.length() > 0) )
{
if ( !parent.startsWith(PATH_SEPARATOR) )
{
path.append(PATH_SEPARATOR);
}
if ( parent.endsWith(PATH_SEPARATOR) )
{
path.append(parent.substring(0, parent.length() - 1));
}
else
{
path.append(parent);
}
}
if ( (child == null) || (child.length() == 0) || (child.equals(PATH_SEPARATOR)) )
{
// Special case, empty parent and child
if ( path.length() == 0 )
{
path.append(PATH_SEPARATOR);
}
return;
}
// Now add the separator between parent and child.
path.append(PATH_SEPARATOR);
if ( child.startsWith(PATH_SEPARATOR) )
{
child = child.substring(1);
}
if ( child.endsWith(PATH_SEPARATOR) )
{
child = child.substring(0, child.length() - 1);
}
// Finally, add the child.
path.append(child);
}
private ZKPaths()
{
}
private static CreateMode getCreateMode(boolean asContainers)
{
return asContainers ? getContainerCreateMode() : CreateMode.PERSISTENT;
}
}
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