org.exist.dom
Class VirtualNodeSet

java.lang.Object
  org.exist.xquery.value.AbstractSequence
      org.exist.dom.AbstractNodeSet
          org.exist.dom.VirtualNodeSet

All Implemented Interfaces:

org.w3c.dom.NodeList, NodeSet, Sequence

public class VirtualNodeSet

extends AbstractNodeSet

This node set is called virtual because it is just a placeholder for the set of relevant nodes. For XPath expressions like //* or //node(), it would be totally unefficient to actually retrieve all descendant nodes. In many cases, the expression can be resolved at a later point in time without retrieving the whole node set. VirtualNodeSet basically provides method getFirstParent to retrieve the first matching descendant of its context according to the primary type axis. Class LocationStep will always return an instance of VirtualNodeSet if it finds something like descendant::* etc..

Author:

Wolfgang Meier, Timo Boehme

Field Summary

protected int	axis
protected NodeSet	context
protected int	contextId
protected boolean	inPredicate
protected NodeSet	realSet
protected boolean	realSetIsComplete
protected NodeTest	test
protected boolean	useSelfAsContext

Fields inherited from class org.exist.dom.AbstractNodeSet

hasMixedContent, hasTextIndex, indexType, LOG

Fields inherited from interface org.exist.dom.NodeSet

ANCESTOR, DESCENDANT, EMPTY_SET, FOLLOWING, PRECEDING

Fields inherited from interface org.exist.xquery.value.Sequence

EMPTY_SEQUENCE

Constructor Summary

VirtualNodeSet(int axis, NodeTest test, int contextId, NodeSet context)

Method Summary

void	add(DocumentImpl doc, long nodeId)
void	add(org.w3c.dom.Node node)
void	add(NodeProxy proxy) Add a new proxy object to the node set.
void	addAll(org.w3c.dom.NodeList other)
void	addAll(NodeSet other) Add all nodes from the given node set.
void	clearContext()
boolean	contains(DocumentImpl doc, long nodeId)
boolean	contains(NodeProxy p) Check if this node set contains a node matching the document and node-id of the given NodeProxy object.
NodeProxy	get(DocumentImpl doc, long gid) Get a node from this node set matching the document and node id.
NodeProxy	get(int pos) Get the node at position pos within this node set.
NodeProxy	get(NodeProxy proxy) Get a node from this node set matching the document and node id of the given NodeProxy.
DocumentSet	getDocumentSet() Returns the set of documents from which the node items in this sequence have been selected.
int	getLength() Return the number of nodes contained in this node set.
boolean	hasIndex()
NodeSet	intersection(NodeSet other) Return a new node set, which represents the intersection of the current node set with the given node set.
org.w3c.dom.Node	item(int pos)
Item	itemAt(int pos) Returns the item located at the specified position within this sequence.
SequenceIterator	iterate() Returns an iterator over all items in the sequence.
NodeSetIterator	iterator() Return an iterator on the nodes in this list.
NodeProxy	nodeHasParent(DocumentImpl doc, long gid, boolean directParent, boolean includeSelf)
NodeProxy	nodeHasParent(NodeProxy node, boolean directParent, boolean includeSelf)
NodeProxy	parentWithChild(DocumentImpl doc, long gid, boolean directParent, boolean includeSelf, int level) Check if the node identified by its node id has an ancestor contained in this node set and return the ancestor found.
NodeProxy	parentWithChild(NodeProxy proxy, boolean directParent, boolean includeSelf, int level) Check if the given node has an ancestor contained in this node set and return the ancestor found.
void	realize()
void	remove(NodeProxy node) Remove a node.
void	set(int position, DocumentImpl doc, long nodeId)
void	setContextId(int contextId)
void	setInPredicate(boolean predicate)
void	setNodeTest(NodeTest test)
void	setSelfIsContext()
java.lang.String	toString()
NodeSet	union(NodeSet other) Return a new node set which represents the union of the current node set and the given node set.
SequenceIterator	unorderedIterator() Returns an iterator over all items in the sequence.

Methods inherited from class org.exist.dom.AbstractNodeSet

add, add, addAll, clearContext, containsDoc, deepIntersection, directSelectAttribute, except, getAncestors, getContextNodes, getIndexType, getItemType, getParents, getRange, getSizeHint, getState, hasChanged, hasChildrenInSet, hasMixedContent, hasTextIndex, isCached, isPersistentSet, parentWithChild, parentWithChild, removeDuplicates, selectAncestorDescendant, selectAncestors, selectFollowing, selectFollowingSiblings, selectParentChild, selectParentChild, selectPreceding, selectPrecedingSiblings, setIsCached, toNodeSet

Methods inherited from class org.exist.xquery.value.AbstractSequence

conversionPreference, convertTo, effectiveBooleanValue, getCardinality, getStringValue, setSelfAsContext, toJavaObject

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.exist.xquery.value.Sequence

conversionPreference, convertTo, effectiveBooleanValue, getCardinality, getStringValue, setSelfAsContext, toJavaObject

Field Detail

axis

protected int axis

test

protected NodeTest test

context

protected NodeSet context

realSet

protected NodeSet realSet

realSetIsComplete

protected boolean realSetIsComplete

inPredicate

protected boolean inPredicate

useSelfAsContext

protected boolean useSelfAsContext

contextId

protected int contextId

Constructor Detail

VirtualNodeSet

public VirtualNodeSet(int axis,
                      NodeTest test,
                      int contextId,
                      NodeSet context)

Method Detail

setNodeTest

public void setNodeTest(NodeTest test)

contains

public boolean contains(DocumentImpl doc,
                        long nodeId)

contains

public boolean contains(NodeProxy p)

Description copied from class: AbstractNodeSet

Check if this node set contains a node matching the document and node-id of the given NodeProxy object.

Specified by:

contains in interface NodeSet

Specified by:

contains in class AbstractNodeSet

Parameters:

p -

Returns:

setInPredicate

public void setInPredicate(boolean predicate)

getDocumentSet

public DocumentSet getDocumentSet()

Description copied from interface: Sequence

Returns the set of documents from which the node items in this sequence have been selected. This is for internal use only.

Specified by:

getDocumentSet in interface NodeSet

Overrides:

getDocumentSet in class AbstractNodeSet

nodeHasParent

public NodeProxy nodeHasParent(DocumentImpl doc,
                               long gid,
                               boolean directParent,
                               boolean includeSelf)

nodeHasParent

public NodeProxy nodeHasParent(NodeProxy node,
                               boolean directParent,
                               boolean includeSelf)

parentWithChild

public NodeProxy parentWithChild(DocumentImpl doc,
                                 long gid,
                                 boolean directParent,
                                 boolean includeSelf,
                                 int level)

Description copied from class: AbstractNodeSet

Check if the node identified by its node id has an ancestor contained in this node set and return the ancestor found. If directParent is true, only immediate ancestors (parents) are considered. Otherwise the method will call itself recursively for all the node's parents. If includeSelf is true, the method returns also true if the node itself is contained in the node set.

Specified by:

parentWithChild in interface NodeSet

Overrides:

parentWithChild in class AbstractNodeSet

parentWithChild

public NodeProxy parentWithChild(NodeProxy proxy,
                                 boolean directParent,
                                 boolean includeSelf,
                                 int level)

Description copied from class: AbstractNodeSet

Check if the given node has an ancestor contained in this node set and return the ancestor found. If directParent is true, only immediate ancestors (parents) are considered. Otherwise the method will call itself recursively for all the node's parents. If includeSelf is true, the method returns also true if the node itself is contained in the node set.

Specified by:

parentWithChild in interface NodeSet

Overrides:

parentWithChild in class AbstractNodeSet

realize

public final void realize()

setSelfIsContext

public void setSelfIsContext()

setContextId

public void setContextId(int contextId)

hasIndex

public boolean hasIndex()

add

public void add(DocumentImpl doc,
                long nodeId)

add

public void add(org.w3c.dom.Node node)

add

public void add(NodeProxy proxy)

Description copied from class: AbstractNodeSet

Add a new proxy object to the node set. Please note: node set implementations may allow duplicates.

Specified by:

add in interface NodeSet

Specified by:

add in class AbstractNodeSet

Parameters:

proxy -

addAll

public void addAll(org.w3c.dom.NodeList other)

addAll

public void addAll(NodeSet other)

Description copied from class: AbstractNodeSet

Add all nodes from the given node set.

Specified by:

addAll in interface NodeSet

Specified by:

addAll in class AbstractNodeSet

Parameters:

other -

set

public void set(int position,
                DocumentImpl doc,
                long nodeId)

remove

public void remove(NodeProxy node)

Description copied from class: AbstractNodeSet

Remove a node. By default, this method throws a RuntimeException.

Overrides:

remove in class AbstractNodeSet

Parameters:

node -

getLength

public int getLength()

Description copied from class: AbstractNodeSet

Return the number of nodes contained in this node set.

Specified by:

getLength in interface NodeSet

Specified by:

getLength in class AbstractNodeSet

item

public org.w3c.dom.Node item(int pos)

Specified by:

item in interface org.w3c.dom.NodeList

Specified by:

item in class AbstractNodeSet

get

public NodeProxy get(int pos)

Description copied from class: AbstractNodeSet

Get the node at position pos within this node set.

Specified by:

get in interface NodeSet

Specified by:

get in class AbstractNodeSet

Parameters:

pos -

Returns:

itemAt

public Item itemAt(int pos)

Description copied from interface: Sequence

Returns the item located at the specified position within this sequence. Items are counted beginning at 0.

Specified by:

itemAt in interface Sequence

Specified by:

itemAt in class AbstractSequence

get

public NodeProxy get(DocumentImpl doc,
                     long gid)

Description copied from class: AbstractNodeSet

Get a node from this node set matching the document and node id.

Specified by:

get in interface NodeSet

Specified by:

get in class AbstractNodeSet

Parameters:

doc -

gid -

Returns:

get

public NodeProxy get(NodeProxy proxy)

Description copied from class: AbstractNodeSet

Get a node from this node set matching the document and node id of the given NodeProxy.

Specified by:

get in interface NodeSet

Specified by:

get in class AbstractNodeSet

Parameters:

proxy -

Returns:

iterator

public NodeSetIterator iterator()

Description copied from class: AbstractNodeSet

Return an iterator on the nodes in this list. The iterator returns nodes according to the internal ordering of nodes (i.e. level first), not in document- order.

Specified by:

iterator in interface NodeSet

Specified by:

iterator in class AbstractNodeSet

Returns:

iterate

public SequenceIterator iterate()

Description copied from interface: Sequence

Returns an iterator over all items in the sequence. The items are returned in document order where applicable.

Specified by:

iterate in interface Sequence

Specified by:

iterate in class AbstractNodeSet

unorderedIterator

public SequenceIterator unorderedIterator()

Description copied from interface: Sequence

Returns an iterator over all items in the sequence. The returned items may - but need not - to be in document order.

Specified by:

unorderedIterator in interface Sequence

Specified by:

unorderedIterator in class AbstractNodeSet

intersection

public NodeSet intersection(NodeSet other)

Description copied from class: AbstractNodeSet

Return a new node set, which represents the intersection of the current node set with the given node set.

Specified by:

intersection in interface NodeSet

Overrides:

intersection in class AbstractNodeSet

Parameters:

other -

Returns:

union

public NodeSet union(NodeSet other)

Description copied from class: AbstractNodeSet

Return a new node set which represents the union of the current node set and the given node set.

Specified by:

union in interface NodeSet

Overrides:

union in class AbstractNodeSet

Parameters:

other -

Returns:

clearContext

public void clearContext()

toString

public java.lang.String toString()

Overrides:

toString in class AbstractNodeSet