org.cdlib.xtf.lazyTree
Class ProxyElement

Object
  NodeImpl
      ProxyElement

All Implemented Interfaces:

Source, SourceLocator, FingerprintedNode, Item, NodeInfo, ValueRepresentation, SearchElement, SearchNode

public final class ProxyElement
extends NodeImpl
implements NodeInfo, FingerprintedNode, SourceLocator, SearchElement

A very lazy element. It assumes the attributes of the element can be known in advance without actually loading that element. If that assumption proves incorrect (i.e. by accessing anything else), the real element is loaded and its actual attributes are used. This class is used by SearchTree for many of its synthetic nodes.

Author:

Martin Haye

Field Summary

(package private) int[]	attrNames Pre-computed attribute names
(package private) String[]	attrValues Pre-computed attribute values
(package private) LazyDocument	document Document to use for loading
(package private) ElementImpl	element The actual element (null until loaded)
(package private) int	nodeNum Node number represented by this element

Fields inherited from class NodeImpl

nameCode, nextSibNum, NODE_LETTER, parentNum, prevSibNum

Fields inherited from interface NodeInfo

ALL_NAMESPACES, EMPTY_NAMESPACE_LIST, IS_DTD_TYPE, IS_NILLED, LOCAL_NAMESPACES, NO_NAMESPACES

Fields inherited from interface ValueRepresentation

EMPTY_VALUE_ARRAY

Constructor Summary

ProxyElement(LazyDocument realDocument)
General constructor, attaches to a given lazy-loading document

Method Summary

void	allocateAttributes(int nAttrs) Allocate the attribute array.
Value	atomize() Get the typed value.
int	compareOrder(NodeInfo other) Loads the real node and defers to it
void	copy(Receiver out, int whichNamespaces, boolean copyAnnotations, int locationId) Loads the real node and defers to it
void	generateId(FastStringBuffer buffer) Loads the real node and defers to it
String	getAttributeValue(int fingerprint) Loads the real node and defers to it
String	getBaseURI() Loads the real node and defers to it
int	getColumnNumber() Loads the real node and defers to it
Configuration	getConfiguration() Get the configuration
int[]	getDeclaredNamespaces(int[] buffer) Loads the real node and defers to it
String	getDisplayName() Loads the real node and defers to it
int	getDocumentNumber() Loads the real node and defers to it
DocumentInfo	getDocumentRoot() Loads the real node and defers to it
int	getFingerprint() Loads the real node and defers to it
int	getLineNumber() Loads the real node and defers to it
String	getLocalPart() Loads the real node and defers to it
int	getNameCode() Loads the real node and defers to it
NamePool	getNamePool() Loads the real node and defers to it
int	getNodeKind() Loads the real node and defers to it
NodeInfo	getParent() Loads the real node and defers to it
String	getPrefix() Loads the real node and defers to it
String	getPublicId() Loads the real node and defers to it
NodeInfo	getRoot() Loads the real node and defers to it
long	getSequenceNumber() Loads the real node and defers to it
String	getStringValue() Loads the real node and defers to it
CharSequence	getStringValueCS() Loads the real node and defers to it
String	getSystemId() Loads the real node and defers to it
int	getTypeAnnotation() Loads the real node and defers to it
SequenceIterator	getTypedValue() Loads the real node and defers to it
String	getURI() Loads the real node and defers to it
boolean	hasChildNodes() Loads the real node and defers to it
boolean	isSameNodeInfo(NodeInfo other) Loads the real node and defers to it
AxisIterator	iterateAxis(byte axisNumber) Loads the real node and defers to it
AxisIterator	iterateAxis(byte axisNumber, NodeTest nodeTest) If only the attributes are accessed, uses ProxyAttributeEnumeration to serve up the pre-computed attributes.
private ElementImpl	real() Obtain the real underlying ElementImpl.
void	sendNamespaceDeclarations(Receiver out, boolean includeAncestors) Loads the real node and defers to it
void	setAttribute(int attrNum, int nameCode, String value) Set an attribute
void	setChildNum(int num) Establish the child node number
void	setNameCode(int code) Establish a name for this node
void	setNextSibNum(int num) Establish the next sibling node number
void	setNodeNum(int nodeNum) Set the node number for this node.
void	setParentNum(int newParentNum) Establish the parent node number
void	setPrevSibNum(int num) Establish the previous sibling node number
void	setSystemId(String systemId) Loads the real node and defers to it

Methods inherited from class NodeImpl

equals, getFirstChild, getLastChild, getNextInDocument, getNextSibling, getPreviousInDocument, getPreviousSibling, hashCode, init

Methods inherited from class Object

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

Methods inherited from interface NodeInfo

equals, hashCode

Field Detail

element

ElementImpl element

The actual element (null until loaded)

document

LazyDocument document

Document to use for loading

nodeNum

int nodeNum

Node number represented by this element

attrNames

int[] attrNames

Pre-computed attribute names

attrValues

String[] attrValues

Pre-computed attribute values

Constructor Detail

ProxyElement

public ProxyElement(LazyDocument realDocument)

General constructor, attaches to a given lazy-loading document

Method Detail

setNodeNum

public void setNodeNum(int nodeNum)

Set the node number for this node.

Specified by:

setNodeNum in interface SearchNode

allocateAttributes

public void allocateAttributes(int nAttrs)

Allocate the attribute array.

Specified by:

allocateAttributes in interface SearchElement

setAttribute

public void setAttribute(int attrNum,
                         int nameCode,
                         String value)

Set an attribute

Specified by:

setAttribute in interface SearchElement

setParentNum

public void setParentNum(int newParentNum)

Establish the parent node number

Specified by:

setParentNum in interface SearchNode

setChildNum

public void setChildNum(int num)

Establish the child node number

Specified by:

setChildNum in interface SearchElement

setNextSibNum

public void setNextSibNum(int num)

Establish the next sibling node number

Specified by:

setNextSibNum in interface SearchNode

setPrevSibNum

public void setPrevSibNum(int num)

Establish the previous sibling node number

Specified by:

setPrevSibNum in interface SearchNode

setNameCode

public void setNameCode(int code)

Establish a name for this node

Specified by:

setNameCode in interface SearchElement

real

private final ElementImpl real()

Obtain the real underlying ElementImpl. If not loaded, load it now.

getSequenceNumber

public long getSequenceNumber()

Loads the real node and defers to it

Overrides:

getSequenceNumber in class NodeImpl

compareOrder

public int compareOrder(NodeInfo other)

Loads the real node and defers to it

Specified by:

compareOrder in interface NodeInfo

Overrides:

compareOrder in class NodeImpl

Parameters:

other - The other node, whose position is to be compared with this node

Returns:

-1 if this node precedes the other node, +1 if it follows the other node, or 0 if they are the same node. (In this case, isSameNode() will always return true, and the two nodes will produce the same result for generateId())

getConfiguration

public Configuration getConfiguration()

Description copied from class: NodeImpl

Get the configuration

Specified by:

getConfiguration in interface NodeInfo

Overrides:

getConfiguration in class NodeImpl

generateId

public void generateId(FastStringBuffer buffer)

Loads the real node and defers to it

Specified by:

generateId in interface NodeInfo

Overrides:

generateId in class NodeImpl

getAttributeValue

public String getAttributeValue(int fingerprint)

Loads the real node and defers to it

Specified by:

getAttributeValue in interface NodeInfo

Overrides:

getAttributeValue in class NodeImpl

Parameters:

fingerprint - The fingerprint of the attribute name

Returns:

the attribute value if it exists or null if not

getBaseURI

public String getBaseURI()

Loads the real node and defers to it

Specified by:

getBaseURI in interface NodeInfo

Overrides:

getBaseURI in class NodeImpl

getFingerprint

public int getFingerprint()

Loads the real node and defers to it

Specified by:

getFingerprint in interface NodeInfo

Overrides:

getFingerprint in class NodeImpl

getLocalPart

public String getLocalPart()

Loads the real node and defers to it

Specified by:

getLocalPart in interface NodeInfo

Overrides:

getLocalPart in class NodeImpl

Returns:

The local name of this node. For a node with no name, return "",.

getNameCode

public int getNameCode()

Loads the real node and defers to it

Specified by:

getNameCode in interface NodeInfo

Overrides:

getNameCode in class NodeImpl

getParent

public NodeInfo getParent()

Loads the real node and defers to it

Specified by:

getParent in interface NodeInfo

Overrides:

getParent in class NodeImpl

Returns:

The Node object describing the containing element or root node.

getStringValue

public String getStringValue()

Loads the real node and defers to it

Specified by:

getStringValue in interface Item

Specified by:

getStringValue in interface NodeInfo

Specified by:

getStringValue in interface ValueRepresentation

getSystemId

public String getSystemId()

Loads the real node and defers to it

Specified by:

getSystemId in interface Source

Specified by:

getSystemId in interface SourceLocator

Specified by:

getSystemId in interface NodeInfo

Overrides:

getSystemId in class NodeImpl

getURI

public String getURI()

Loads the real node and defers to it

Specified by:

getURI in interface NodeInfo

Overrides:

getURI in class NodeImpl

Returns:

The URI of the namespace of this node. For the default namespace, return an empty string. For an unnamed node, return the empty string.

hasChildNodes

public boolean hasChildNodes()

Loads the real node and defers to it

Specified by:

hasChildNodes in interface NodeInfo

Overrides:

hasChildNodes in class NodeImpl

Returns:

true if the node has any children, false if the node has no children.

isSameNodeInfo

public boolean isSameNodeInfo(NodeInfo other)

Loads the real node and defers to it

Specified by:

isSameNodeInfo in interface NodeInfo

Overrides:

isSameNodeInfo in class NodeImpl

Returns:

true if this Node object and the supplied Node object represent the same node in the tree.

iterateAxis

public AxisIterator iterateAxis(byte axisNumber,
                                NodeTest nodeTest)

If only the attributes are accessed, uses ProxyAttributeEnumeration to serve up the pre-computed attributes. Otherwise, we load the real element and defer to it.

Specified by:

iterateAxis in interface NodeInfo

Overrides:

iterateAxis in class NodeImpl

Parameters:

axisNumber - The axis to be iterated over

nodeTest - A pattern to be matched by the returned nodes

Returns:

an AxisIterator that scans the nodes reached by the axis in turn.

getPrefix

public String getPrefix()

Loads the real node and defers to it

Specified by:

getPrefix in interface NodeInfo

Overrides:

getPrefix in class NodeImpl

Returns:

the prefix part of the name. For an unnamed node, return an empty string.

copy

public void copy(Receiver out,
                 int whichNamespaces,
                 boolean copyAnnotations,
                 int locationId)
          throws XPathException

Loads the real node and defers to it

Specified by:

copy in interface NodeInfo

Throws:

XPathException

getNamePool

public NamePool getNamePool()

Loads the real node and defers to it

Specified by:

getNamePool in interface NodeInfo

Overrides:

getNamePool in class NodeImpl

getNodeKind

public int getNodeKind()

Loads the real node and defers to it

Specified by:

getNodeKind in interface NodeInfo

iterateAxis

public AxisIterator iterateAxis(byte axisNumber)

Loads the real node and defers to it

Specified by:

iterateAxis in interface NodeInfo

Overrides:

iterateAxis in class NodeImpl

Parameters:

axisNumber - The axis to be iterated over

Returns:

an AxisIterator that scans the nodes reached by the axis in turn.

setSystemId

public void setSystemId(String systemId)

Loads the real node and defers to it

Specified by:

setSystemId in interface Source

Overrides:

setSystemId in class NodeImpl

getDisplayName

public String getDisplayName()

Loads the real node and defers to it

Specified by:

getDisplayName in interface NodeInfo

Overrides:

getDisplayName in class NodeImpl

Returns:

The display name of this node. For a node with no name, return an empty string.

getDocumentNumber

public int getDocumentNumber()

Loads the real node and defers to it

Specified by:

getDocumentNumber in interface NodeInfo

Overrides:

getDocumentNumber in class NodeImpl

getDocumentRoot

public DocumentInfo getDocumentRoot()

Loads the real node and defers to it

Specified by:

getDocumentRoot in interface NodeInfo

Overrides:

getDocumentRoot in class NodeImpl

Returns:

the DocumentInfo representing the containing document

getRoot

public NodeInfo getRoot()

Loads the real node and defers to it

Specified by:

getRoot in interface NodeInfo

Overrides:

getRoot in class NodeImpl

Returns:

the NodeInfo representing the containing document

getTypeAnnotation

public int getTypeAnnotation()

Loads the real node and defers to it

Specified by:

getTypeAnnotation in interface NodeInfo

Overrides:

getTypeAnnotation in class NodeImpl

sendNamespaceDeclarations

public void sendNamespaceDeclarations(Receiver out,
                                      boolean includeAncestors)
                               throws XPathException

Loads the real node and defers to it

Specified by:

sendNamespaceDeclarations in interface NodeInfo

Overrides:

sendNamespaceDeclarations in class NodeImpl

Parameters:

out - The relevant outputter

includeAncestors - True if namespaces declared on ancestor elements must

Throws:

XPathException

getColumnNumber

public int getColumnNumber()

Loads the real node and defers to it

Specified by:

getColumnNumber in interface SourceLocator

Overrides:

getColumnNumber in class NodeImpl

getDeclaredNamespaces

public int[] getDeclaredNamespaces(int[] buffer)

Loads the real node and defers to it

Specified by:

getDeclaredNamespaces in interface NodeInfo

Overrides:

getDeclaredNamespaces in class NodeImpl

Parameters:

buffer - If this is non-null, and the result array fits in this buffer, then the result may overwrite the contents of this array, to avoid the cost of allocating a new array on the heap.

Returns:

An array of integers representing the namespace declarations and undeclarations present on this element. For a node other than an element, return null. Otherwise, the returned array is a sequence of namespace codes, whose meaning may be interpreted by reference to the name pool. The top half word of each namespace code represents the prefix, the bottom half represents the URI. If the bottom half is zero, then this is a namespace undeclaration rather than a declaration. The XML namespace is never included in the list. If the supplied array is larger than required, then the first unused entry will be set to -1.

For a node other than an element, the method returns null.

getLineNumber

public int getLineNumber()

Loads the real node and defers to it

Specified by:

getLineNumber in interface SourceLocator

Specified by:

getLineNumber in interface NodeInfo

Overrides:

getLineNumber in class NodeImpl

getPublicId

public String getPublicId()

Loads the real node and defers to it

Specified by:

getPublicId in interface SourceLocator

Overrides:

getPublicId in class NodeImpl

getStringValueCS

public CharSequence getStringValueCS()

Loads the real node and defers to it

Specified by:

getStringValueCS in interface Item

Specified by:

getStringValueCS in interface ValueRepresentation

Overrides:

getStringValueCS in class NodeImpl

getTypedValue

public SequenceIterator getTypedValue()
                               throws XPathException

Loads the real node and defers to it

Specified by:

getTypedValue in interface Item

Overrides:

getTypedValue in class NodeImpl

Throws:

XPathException

atomize

public Value atomize()
              throws XPathException

Description copied from class: NodeImpl

Get the typed value. The result of this method will always be consistent with the method Item.getTypedValue(). However, this method is often more convenient and may be more efficient, especially in the common case where the value is expected to be a singleton.

Specified by:

atomize in interface NodeInfo

Overrides:

atomize in class NodeImpl

Returns:

the typed value. If requireSingleton is set to true, the result will always be an AtomicValue. In other cases it may be a Value representing a sequence whose items are atomic values.

Throws:

XPathException