org.apache.manifoldcf.core.lockmanager

Class ZooKeeperConnection

java.lang.Object

org.apache.manifoldcf.core.lockmanager.ZooKeeperConnection

public class ZooKeeperConnection
extends java.lang.Object

An instance of this class is the Zookeeper analog to a database connection. Basically, it bundles up the Zookeeper functionality we need in a nice package, which we can share between users as needed. These connections will be pooled, and will be closed when the process they live in is shut down.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ZooKeeperConnection.ExistsWatcher Watcher class for exists state changes, so we get notified about deletions of lock request nodes.
protected static class	ZooKeeperConnection.ZooKeeperWatcher Watcher class for zookeeper, so we get notified about zookeeper events.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	_rcsid
protected java.lang.String	connectString
protected java.lang.String	lockNode
protected byte[]	nodeData
protected java.lang.String	nodePath
protected int	sessionTimeout
protected org.apache.zookeeper.ZooKeeper	zookeeper
protected ZooKeeperConnection.ZooKeeperWatcher	zookeeperWatcher

Constructor Summary

Constructors

Constructor and Description
ZooKeeperConnection(java.lang.String connectString, int sessionTimeout) Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	checkGlobalFlag(java.lang.String flagPath)
boolean	checkNodeExists(java.lang.String nodePath) Check whether a node exists.
void	clearGlobalFlag(java.lang.String flagPath)
void	close() Close this connection.
void	createChild(java.lang.String nodePath, java.lang.String childName) Create a persistent child of a node.
void	createNode(java.lang.String nodePath, byte[] nodeData) Create a transient node.
protected void	createPersistentPath(java.lang.String path, byte[] data)
protected java.lang.String	createSequentialChild(java.lang.String mainNode, java.lang.String childPrefix) Create a node and a sequential child node.
protected void	createSession()
void	deleteChild(java.lang.String nodePath, java.lang.String childName) Delete the child of a node.
void	deleteNode() Delete a node.
void	deleteNodeChildren(java.lang.String nodePath) Delete all a node's children.
java.util.List<java.lang.String>	getChildren(java.lang.String nodePath) Get the relative paths of all node's children.
byte[]	getNodeData(java.lang.String nodePath) Get node data.
protected void	handleEphemeralNodeKeeperException(org.apache.zookeeper.KeeperException e, boolean recreate) Handle keeper exceptions that may involve ephemeral node creation.
protected void	handleKeeperException(org.apache.zookeeper.KeeperException e, boolean recreate) Handle keeper exceptions that don't involve ephemeral node creation.
void	obtainNonExWriteLock(java.lang.String lockPath) Obtain a non-ex-write lock, with wait.
boolean	obtainNonExWriteLockNoWait(java.lang.String lockPath) Obtain a non-ex-write lock, with no wait.
void	obtainReadLock(java.lang.String lockPath) Obtain a read lock, with wait.
boolean	obtainReadLockNoWait(java.lang.String lockPath) Obtain a read lock, with no wait.
void	obtainWriteLock(java.lang.String lockPath) Obtain a write lock, with wait.
boolean	obtainWriteLockNoWait(java.lang.String lockPath) Obtain a write lock, with no wait.
byte[]	readData(java.lang.String resourcePath)
void	releaseLock() Release the (saved) lock.
void	setGlobalFlag(java.lang.String flagPath)
void	setNodeData(byte[] data) Set node data.
void	writeData(java.lang.String resourcePath, byte[] data)
static java.lang.String	zooKeeperDecodeSafeName(java.lang.String input)
static java.lang.String	zooKeeperSafeName(java.lang.String input)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

_rcsid

public static final java.lang.String _rcsid

See Also:

Constant Field Values

connectString

protected final java.lang.String connectString

sessionTimeout

protected final int sessionTimeout

zookeeper

protected org.apache.zookeeper.ZooKeeper zookeeper

zookeeperWatcher

protected ZooKeeperConnection.ZooKeeperWatcher zookeeperWatcher

lockNode

protected java.lang.String lockNode

nodePath

protected java.lang.String nodePath

nodeData

protected byte[] nodeData

Constructor Detail

ZooKeeperConnection

public ZooKeeperConnection(java.lang.String connectString,
                           int sessionTimeout)
                    throws ManifoldCFException,
                           java.lang.InterruptedException

Constructor.

Throws:

ManifoldCFException

java.lang.InterruptedException

Method Detail

createSession

protected void createSession()
                      throws ManifoldCFException,
                             java.lang.InterruptedException

Throws:

ManifoldCFException

java.lang.InterruptedException

createNode

public void createNode(java.lang.String nodePath,
                       byte[] nodeData)
                throws ManifoldCFException,
                       java.lang.InterruptedException

Create a transient node.

Throws:

ManifoldCFException

java.lang.InterruptedException

checkNodeExists

public boolean checkNodeExists(java.lang.String nodePath)
                        throws ManifoldCFException,
                               java.lang.InterruptedException

Check whether a node exists.

Parameters:

nodePath - is the path of the node.

Returns:

the data, if the node if exists, otherwise null.

Throws:

ManifoldCFException

java.lang.InterruptedException

getNodeData

public byte[] getNodeData(java.lang.String nodePath)
                   throws ManifoldCFException,
                          java.lang.InterruptedException

Get node data.

Parameters:

nodePath - is the path of the node.

Returns:

the data, if the node if exists, otherwise null.

Throws:

ManifoldCFException

java.lang.InterruptedException

setNodeData

public void setNodeData(byte[] data)
                 throws ManifoldCFException,
                        java.lang.InterruptedException

Set node data.

Throws:

ManifoldCFException

java.lang.InterruptedException

deleteNode

public void deleteNode()
                throws ManifoldCFException,
                       java.lang.InterruptedException

Delete a node.

Throws:

ManifoldCFException

java.lang.InterruptedException

deleteNodeChildren

public void deleteNodeChildren(java.lang.String nodePath)
                        throws ManifoldCFException,
                               java.lang.InterruptedException

Delete all a node's children.

Throws:

ManifoldCFException

java.lang.InterruptedException

getChildren

public java.util.List<java.lang.String> getChildren(java.lang.String nodePath)
                                             throws ManifoldCFException,
                                                    java.lang.InterruptedException

Get the relative paths of all node's children. If the node does not exist, return an empty list.

Throws:

ManifoldCFException

java.lang.InterruptedException

createChild

public void createChild(java.lang.String nodePath,
                        java.lang.String childName)
                 throws ManifoldCFException,
                        java.lang.InterruptedException

Create a persistent child of a node.

Throws:

ManifoldCFException

java.lang.InterruptedException

createPersistentPath

protected void createPersistentPath(java.lang.String path,
                                    byte[] data)
                             throws org.apache.zookeeper.KeeperException,
                                    java.lang.InterruptedException

Throws:

org.apache.zookeeper.KeeperException

java.lang.InterruptedException

deleteChild

public void deleteChild(java.lang.String nodePath,
                        java.lang.String childName)
                 throws ManifoldCFException,
                        java.lang.InterruptedException

Delete the child of a node.

Throws:

ManifoldCFException

java.lang.InterruptedException

obtainWriteLockNoWait

public boolean obtainWriteLockNoWait(java.lang.String lockPath)
                              throws ManifoldCFException,
                                     java.lang.InterruptedException

Obtain a write lock, with no wait.

Parameters:

lockPath - is the lock node path.

Returns:

true if the lock was obtained, false otherwise.

Throws:

ManifoldCFException

java.lang.InterruptedException

obtainWriteLock

public void obtainWriteLock(java.lang.String lockPath)
                     throws ManifoldCFException,
                            java.lang.InterruptedException

Obtain a write lock, with wait.

Parameters:

lockPath - is the lock node path.

Throws:

ManifoldCFException

java.lang.InterruptedException

obtainNonExWriteLockNoWait

public boolean obtainNonExWriteLockNoWait(java.lang.String lockPath)
                                   throws ManifoldCFException,
                                          java.lang.InterruptedException

Obtain a non-ex-write lock, with no wait.

Parameters:

lockPath - is the lock node path.

Returns:

true if the lock was obtained, false otherwise.

Throws:

ManifoldCFException

java.lang.InterruptedException

obtainNonExWriteLock

public void obtainNonExWriteLock(java.lang.String lockPath)
                          throws ManifoldCFException,
                                 java.lang.InterruptedException

Obtain a non-ex-write lock, with wait.

Parameters:

lockPath - is the lock node path.

Throws:

ManifoldCFException

java.lang.InterruptedException

obtainReadLockNoWait

public boolean obtainReadLockNoWait(java.lang.String lockPath)
                             throws ManifoldCFException,
                                    java.lang.InterruptedException

Obtain a read lock, with no wait.

Parameters:

lockPath - is the lock node path.

Returns:

true if the lock was obtained, false otherwise.

Throws:

ManifoldCFException

java.lang.InterruptedException

obtainReadLock

public void obtainReadLock(java.lang.String lockPath)
                    throws ManifoldCFException,
                           java.lang.InterruptedException

Obtain a read lock, with wait.

Parameters:

lockPath - is the lock node path.

Throws:

ManifoldCFException

java.lang.InterruptedException

releaseLock

public void releaseLock()
                 throws ManifoldCFException,
                        java.lang.InterruptedException

Release the (saved) lock.

Throws:

ManifoldCFException

java.lang.InterruptedException

readData

public byte[] readData(java.lang.String resourcePath)
                throws ManifoldCFException,
                       java.lang.InterruptedException

Throws:

ManifoldCFException

java.lang.InterruptedException

writeData

public void writeData(java.lang.String resourcePath,
                      byte[] data)
               throws ManifoldCFException,
                      java.lang.InterruptedException

Throws:

ManifoldCFException

java.lang.InterruptedException

setGlobalFlag

public void setGlobalFlag(java.lang.String flagPath)
                   throws ManifoldCFException,
                          java.lang.InterruptedException

Throws:

ManifoldCFException

java.lang.InterruptedException

clearGlobalFlag

public void clearGlobalFlag(java.lang.String flagPath)
                     throws ManifoldCFException,
                            java.lang.InterruptedException

Throws:

ManifoldCFException

java.lang.InterruptedException

checkGlobalFlag

public boolean checkGlobalFlag(java.lang.String flagPath)
                        throws ManifoldCFException,
                               java.lang.InterruptedException

Throws:

ManifoldCFException

java.lang.InterruptedException

close

public void close()
           throws java.lang.InterruptedException

Close this connection.

Throws:

java.lang.InterruptedException

handleEphemeralNodeKeeperException

protected void handleEphemeralNodeKeeperException(org.apache.zookeeper.KeeperException e,
                                                  boolean recreate)
                                           throws ManifoldCFException,
                                                  java.lang.InterruptedException

Handle keeper exceptions that may involve ephemeral node creation.

Throws:

ManifoldCFException

java.lang.InterruptedException

handleKeeperException

protected void handleKeeperException(org.apache.zookeeper.KeeperException e,
                                     boolean recreate)
                              throws ManifoldCFException,
                                     java.lang.InterruptedException

Handle keeper exceptions that don't involve ephemeral node creation.

Throws:

ManifoldCFException

java.lang.InterruptedException

zooKeeperSafeName

public static java.lang.String zooKeeperSafeName(java.lang.String input)

zooKeeperDecodeSafeName

public static java.lang.String zooKeeperDecodeSafeName(java.lang.String input)

createSequentialChild

protected java.lang.String createSequentialChild(java.lang.String mainNode,
                                                 java.lang.String childPrefix)
                                          throws org.apache.zookeeper.KeeperException,
                                                 java.lang.InterruptedException

Create a node and a sequential child node. Neither node has any data.

Throws:

org.apache.zookeeper.KeeperException

java.lang.InterruptedException