org.planx.xmlstore.koala.io
Class VirtualRawNode

java.lang.Object
  org.planx.xmlstore.koala.io.RawNode
      org.planx.xmlstore.koala.io.VirtualRawNode

public class VirtualRawNode
extends RawNode

A RawNode that only exists in memory and have no underlying byte representation. This type of node is useful for roots of a graph. That is, nodes that are not part of the actual data but merely used for 'administration'.

A VirtualRawNode is given a unique Locator to identify it. The locator has a SourceId provided in the constructor. To distinguish it from other nodes, it is given a fake locator position equal to minus a unique number. This way it will never be equivalent to a real node (with a positive position), and is improbable to be (wrongly) equivalent with another VirtualRawNode.

Author:

Thomas Ambus

Constructor Summary

VirtualRawNode(SourceId fsi, List<RawNode> children)

VirtualRawNode(SourceId fsi, List<RawNode> children, byte val)
Constructs a VirtualRawNode with the specified children that will act as if it is associated with the specified SourceId.

Method Summary

int	childCount()
List<List<Byte>>	getAttributes() Return the empty list.
RawNode	getChild(NodeFileSystem fs, int index)
List<Locator>	getChildren() Returns the locators of the children given in the constructor.
byte	getType() Returns ELEMENT.
List<Byte>	getValue()
boolean	isDirty(int index)
boolean	isVirtual()
Locator	save(NodeFileSystem fs, boolean doLazySave) Does nothing.
void	setChild(int index, Locator child)
void	setChild(int index, RawNode child) Changes a child pointer of this node in its in-memory representation.
void	setIsShared(boolean isShared) Does nothing.
long	size() Returns the number of bytes that the byte representation of this RawNode occupies.
String	toString()

Methods inherited from class org.planx.xmlstore.koala.io.RawNode

createNode, equals, getHeight, getLocator, getVisitToken, hashCode, setHeight, setVisitToken

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

VirtualRawNode

public VirtualRawNode(SourceId fsi,
                      List<RawNode> children)

VirtualRawNode

public VirtualRawNode(SourceId fsi,
                      List<RawNode> children,
                      byte val)

Constructs a VirtualRawNode with the specified children that will act as if it is associated with the specified SourceId. More specifically, the RawNode.getLocator() method will return a Locator with the specified SourceId.

Method Detail

save

public Locator save(NodeFileSystem fs,
                    boolean doLazySave)
             throws IOException

Does nothing.

Specified by:

save in class RawNode

Throws:

IOException

setIsShared

public void setIsShared(boolean isShared)
                 throws IOException

Does nothing.

Specified by:

setIsShared in class RawNode

Throws:

IOException

isVirtual

public boolean isVirtual()

Specified by:

isVirtual in class RawNode

getType

public byte getType()

Returns ELEMENT.

Specified by:

getType in class RawNode

getValue

public List<Byte> getValue()

Specified by:

getValue in class RawNode

getAttributes

public List<List<Byte>> getAttributes()

Return the empty list.

Specified by:

getAttributes in class RawNode

getChildren

public List<Locator> getChildren()

Returns the locators of the children given in the constructor.

Specified by:

getChildren in class RawNode

childCount

public int childCount()

Specified by:

childCount in class RawNode

getChild

public RawNode getChild(NodeFileSystem fs,
                        int index)
                 throws IOException

Specified by:

getChild in class RawNode

Throws:

IOException

setChild

public void setChild(int index,
                     Locator child)
              throws IOException

Specified by:

setChild in class RawNode

Throws:

IOException

setChild

public void setChild(int index,
                     RawNode child)
              throws IOException

Description copied from class: RawNode

Changes a child pointer of this node in its in-memory representation. The actual update of the underlying byte representation can be postponed until the RawNode.save(NodeFileSystem,boolean) method is called.

Specified by:

setChild in class RawNode

Throws:

IOException

isDirty

public boolean isDirty(int index)

Specified by:

isDirty in class RawNode

size

public long size()

Description copied from class: RawNode

Returns the number of bytes that the byte representation of this RawNode occupies.

Specified by:

size in class RawNode

toString

public String toString()

Overrides:

toString in class RawNode