org.apache.zookeeper.server

Class DataNode

java.lang.Object

org.apache.zookeeper.server.DataNode

All Implemented Interfaces:

Record

public class DataNode
extends Object
implements Record

This class contains the data for a node in the data tree.

A data node contains a reference to its parent, a byte array as its data, an array of ACLs, a stat object, and a set of its children's paths.

Field Summary

Fields

Modifier and Type	Field and Description
StatPersisted	stat the stat for this node that is persisted to disk.

Constructor Summary

Constructors

Constructor and Description
DataNode(byte[] data, Long acl, StatPersisted stat) create a DataNode with parent, data, acls and stat

Method Summary

Modifier and Type	Method and Description
boolean	addChild(String child) Method that inserts a child into the children set
void	copyStat(Stat to)
void	deserialize(InputArchive archive, String tag)
Set<String>	getChildren() convenience methods to get the children
byte[]	getData()
long	getDigest()
boolean	isDigestCached()
boolean	removeChild(String child) Method that removes a child from the children set
void	serialize(OutputArchive archive, String tag)
void	setChildren(HashSet<String> children) convenience method for setting the children for this datanode
void	setDigest(long digest)
void	setDigestCached(boolean digestCached)

Methods inherited from class java.lang.Object

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

Field Detail

stat

public StatPersisted stat

the stat for this node that is persisted to disk.

Constructor Detail

DataNode

public DataNode(byte[] data,
                Long acl,
                StatPersisted stat)

create a DataNode with parent, data, acls and stat

Parameters:

data - the data to be set

acl - the acls for this node

stat - the stat for this node.

Method Detail

addChild

public boolean addChild(String child)

Method that inserts a child into the children set

Parameters:

child - to be inserted

Returns:

true if this set did not already contain the specified element

removeChild

public boolean removeChild(String child)

Method that removes a child from the children set

Parameters:

child -

Returns:

true if this set contained the specified element

setChildren

public void setChildren(HashSet<String> children)

convenience method for setting the children for this datanode

Parameters:

children -

getChildren

public Set<String> getChildren()

convenience methods to get the children

Returns:

the children of this datanode. If the datanode has no children, empty set is returned

copyStat

public void copyStat(Stat to)

deserialize

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

Specified by:

deserialize in interface Record

Throws:

IOException

serialize

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

Specified by:

serialize in interface Record

Throws:

IOException

isDigestCached

public boolean isDigestCached()

setDigestCached

public void setDigestCached(boolean digestCached)

getDigest

public long getDigest()

setDigest

public void setDigest(long digest)

getData

public byte[] getData()