org.apache.zookeeper.server

Class DataTree

java.lang.Object

org.apache.zookeeper.server.DataTree

public class DataTree
extends Object

This class maintains the tree data structure. It doesn't have any networking or client connection code in it so that it can be tested in a stand alone way.

The tree maintains two parallel data structures: a hashtable that maps from full paths to DataNodes and a tree of DataNodes. All accesses to a path is through the hashtable. The tree is traversed only when serializing to disk.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DataTree.ProcessTxnResult

Field Summary

Fields

Modifier and Type	Field and Description
long	lastProcessedZxid

Constructor Summary

Constructors

Constructor and Description
DataTree()

Method Summary

Modifier and Type	Method and Description
int	aclCacheSize()
void	addConfigNode() create a /zookeeper/config node for maintaining the configuration (membership and quorum system) info for zookeeper
long	approximateDataSize() Get the size of the nodes based on path and data length.
boolean	containsWatcher(String path, Watcher.WatcherType type, Watcher watcher)
static void	copyStat(Stat from, Stat to)
static void	copyStatPersisted(StatPersisted from, StatPersisted to)
void	createNode(String path, byte[] data, List<ACL> acl, long ephemeralOwner, int parentCVersion, long zxid, long time) Add a new node to the DataTree.
void	createNode(String path, byte[] data, List<ACL> acl, long ephemeralOwner, int parentCVersion, long zxid, long time, Stat outputStat) Add a new node to the DataTree.
void	deleteNode(String path, long zxid) remove the path from the datatree
void	deserialize(InputArchive ia, String tag)
void	dumpEphemerals(PrintWriter pwriter) Write a text dump of all the ephemerals in the datatree.
void	dumpWatches(PrintWriter pwriter, boolean byPath) Write a text dump of all the watches on the datatree.
void	dumpWatchesSummary(PrintWriter pwriter) Summary of the watches on the datatree.
List<ACL>	getACL(DataNode node)
List<ACL>	getACL(String path, Stat stat)
List<String>	getChildren(String path, Stat stat, Watcher watcher)
Set<String>	getContainers()
byte[]	getData(String path, Stat stat, Watcher watcher)
Map<Long,Set<String>>	getEphemerals() Returns a mapping of session ID to ephemeral znodes.
Set<String>	getEphemerals(long sessionId)
int	getEphemeralsCount()
String	getMaxPrefixWithQuota(String path) If there is a quota set, return the appropriate prefix for that quota Else return null
DataNode	getNode(String path)
int	getNodeCount()
ReferenceCountedACLCache	getReferenceCountedAclCache()
Collection<Long>	getSessions()
Set<String>	getTtls()
int	getWatchCount()
WatchesReport	getWatches() Returns a watch report.
WatchesPathReport	getWatchesByPath() Returns a watch report by path.
WatchesSummary	getWatchesSummary() Returns a watch summary.
DataTree.ProcessTxnResult	processTxn(TxnHeader header, Record txn)
DataTree.ProcessTxnResult	processTxn(TxnHeader header, Record txn, boolean isSubTxn)
void	removeCnxn(Watcher watcher)
boolean	removeWatch(String path, Watcher.WatcherType type, Watcher watcher)
void	serialize(OutputArchive oa, String tag)
void	serializeNodeData(OutputArchive oa, String path, DataNode node)
Stat	setACL(String path, List<ACL> acl, int version)
void	setCversionPzxid(String path, int newCversion, long zxid) This method sets the Cversion and Pzxid for the specified node to the values passed as arguments.
Stat	setData(String path, byte[] data, int version, long zxid, long time)
void	setWatches(long relativeZxid, List<String> dataWatches, List<String> existWatches, List<String> childWatches, Watcher watcher)
Stat	statNode(String path, Watcher watcher)
void	updateBytes(String lastPrefix, long diff) update the count of bytes of this stat datanode
void	updateCount(String lastPrefix, int diff) update the count of this stat datanode

Methods inherited from class java.lang.Object

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

Field Detail

lastProcessedZxid

public volatile long lastProcessedZxid

Constructor Detail

DataTree

public DataTree()

Method Detail

getEphemerals

public Set<String> getEphemerals(long sessionId)

getContainers

public Set<String> getContainers()

getTtls

public Set<String> getTtls()

getSessions

public Collection<Long> getSessions()

getNode

public DataNode getNode(String path)

getNodeCount

public int getNodeCount()

getWatchCount

public int getWatchCount()

getEphemeralsCount

public int getEphemeralsCount()

approximateDataSize

public long approximateDataSize()

Get the size of the nodes based on path and data length.

Returns:

size of the data

addConfigNode

public void addConfigNode()

create a /zookeeper/config node for maintaining the configuration (membership and quorum system) info for zookeeper

copyStatPersisted

public static void copyStatPersisted(StatPersisted from,
                                     StatPersisted to)

copyStat

public static void copyStat(Stat from,
                            Stat to)

updateCount

public void updateCount(String lastPrefix,
                        int diff)

update the count of this stat datanode

Parameters:

lastPrefix - the path of the node that is quotaed.

diff - the diff to be added to the count

updateBytes

public void updateBytes(String lastPrefix,
                        long diff)

update the count of bytes of this stat datanode

Parameters:

lastPrefix - the path of the node that is quotaed

diff - the diff to added to number of bytes

Throws:

IOException - if path is not found

createNode

public void createNode(String path,
                       byte[] data,
                       List<ACL> acl,
                       long ephemeralOwner,
                       int parentCVersion,
                       long zxid,
                       long time)
                throws KeeperException.NoNodeException,
                       KeeperException.NodeExistsException

Add a new node to the DataTree.

Parameters:

path - Path for the new node.

data - Data to store in the node.

acl - Node acls

ephemeralOwner - the session id that owns this node. -1 indicates this is not an ephemeral node.

zxid - Transaction ID

time -

Throws:

KeeperException.NodeExistsException

KeeperException.NoNodeException

KeeperException

createNode

public void createNode(String path,
                       byte[] data,
                       List<ACL> acl,
                       long ephemeralOwner,
                       int parentCVersion,
                       long zxid,
                       long time,
                       Stat outputStat)
                throws KeeperException.NoNodeException,
                       KeeperException.NodeExistsException

Add a new node to the DataTree.

Parameters:

path - Path for the new node.

data - Data to store in the node.

acl - Node acls

ephemeralOwner - the session id that owns this node. -1 indicates this is not an ephemeral node.

zxid - Transaction ID

time -

outputStat - A Stat object to store Stat output results into.

Throws:

KeeperException.NodeExistsException

KeeperException.NoNodeException

KeeperException

deleteNode

public void deleteNode(String path,
                       long zxid)
                throws KeeperException.NoNodeException

remove the path from the datatree

Parameters:

path - the path to of the node to be deleted

zxid - the current zxid

Throws:

KeeperException.NoNodeException

setData

public Stat setData(String path,
                    byte[] data,
                    int version,
                    long zxid,
                    long time)
             throws KeeperException.NoNodeException

Throws:

KeeperException.NoNodeException

getMaxPrefixWithQuota

public String getMaxPrefixWithQuota(String path)

If there is a quota set, return the appropriate prefix for that quota Else return null

Parameters:

path - The ZK path to check for quota

Returns:

Max quota prefix, or null if none

getData

public byte[] getData(String path,
                      Stat stat,
                      Watcher watcher)
               throws KeeperException.NoNodeException

Throws:

KeeperException.NoNodeException

statNode

public Stat statNode(String path,
                     Watcher watcher)
              throws KeeperException.NoNodeException

Throws:

KeeperException.NoNodeException

getChildren

public List<String> getChildren(String path,
                                Stat stat,
                                Watcher watcher)
                         throws KeeperException.NoNodeException

Throws:

KeeperException.NoNodeException

setACL

public Stat setACL(String path,
                   List<ACL> acl,
                   int version)
            throws KeeperException.NoNodeException

Throws:

KeeperException.NoNodeException

getACL

public List<ACL> getACL(String path,
                        Stat stat)
                 throws KeeperException.NoNodeException

Throws:

KeeperException.NoNodeException

getACL

public List<ACL> getACL(DataNode node)

aclCacheSize

public int aclCacheSize()

processTxn

public DataTree.ProcessTxnResult processTxn(TxnHeader header,
                                            Record txn)

processTxn

public DataTree.ProcessTxnResult processTxn(TxnHeader header,
                                            Record txn,
                                            boolean isSubTxn)

serializeNodeData

public void serializeNodeData(OutputArchive oa,
                              String path,
                              DataNode node)
                       throws IOException

Throws:

IOException

serialize

public void serialize(OutputArchive oa,
                      String tag)
               throws IOException

Throws:

IOException

deserialize

public void deserialize(InputArchive ia,
                        String tag)
                 throws IOException

Throws:

IOException

dumpWatchesSummary

public void dumpWatchesSummary(PrintWriter pwriter)

Summary of the watches on the datatree.

Parameters:

pwriter - the output to write to

dumpWatches

public void dumpWatches(PrintWriter pwriter,
                        boolean byPath)

Write a text dump of all the watches on the datatree. Warning, this is expensive, use sparingly!

Parameters:

pwriter - the output to write to

getWatches

public WatchesReport getWatches()

Returns a watch report.

Returns:

watch report

See Also:

WatchesReport

getWatchesByPath

public WatchesPathReport getWatchesByPath()

Returns a watch report by path.

Returns:

watch report

See Also:

WatchesPathReport

getWatchesSummary

public WatchesSummary getWatchesSummary()

Returns a watch summary.

Returns:

watch summary

See Also:

WatchesSummary

dumpEphemerals

public void dumpEphemerals(PrintWriter pwriter)

Write a text dump of all the ephemerals in the datatree.

Parameters:

pwriter - the output to write to

getEphemerals

public Map<Long,Set<String>> getEphemerals()

Returns a mapping of session ID to ephemeral znodes.

Returns:

map of session ID to sets of ephemeral znodes

removeCnxn

public void removeCnxn(Watcher watcher)

setWatches

public void setWatches(long relativeZxid,
                       List<String> dataWatches,
                       List<String> existWatches,
                       List<String> childWatches,
                       Watcher watcher)

setCversionPzxid

public void setCversionPzxid(String path,
                             int newCversion,
                             long zxid)
                      throws KeeperException.NoNodeException

This method sets the Cversion and Pzxid for the specified node to the values passed as arguments. The values are modified only if newCversion is greater than the current Cversion. A NoNodeException is thrown if a znode for the specified path is not found.

Parameters:

path - Full path to the znode whose Cversion needs to be modified. A "/" at the end of the path is ignored.

newCversion - Value to be assigned to Cversion

zxid - Value to be assigned to Pzxid

Throws:

KeeperException.NoNodeException - If znode not found.

containsWatcher

public boolean containsWatcher(String path,
                               Watcher.WatcherType type,
                               Watcher watcher)

removeWatch

public boolean removeWatch(String path,
                           Watcher.WatcherType type,
                           Watcher watcher)

getReferenceCountedAclCache

public ReferenceCountedACLCache getReferenceCountedAclCache()