/**
* 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<
String>
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>
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<
String>
children;
try
{
children =
zookeeper.
getChildren(
path, null);
}
catch (
KeeperException.
NoNodeException e)
{
// someone else has deleted the node since we checked
return;
}
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 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<
String>
getSortedChildren(
ZooKeeper zookeeper,
String path) throws
InterruptedException,
KeeperException
{
List<
String>
children =
zookeeper.
getChildren(
path, false);
List<
String>
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;
}
}