Package com.saxonica.ee.stream

Class ManualGroupIterator

java.lang.Object

net.sf.saxon.tree.iter.ManualIterator

com.saxonica.ee.stream.ManualGroupIterator

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, LastPositionFinder, GroupIterator, FocusIterator, SequenceIterator, GroundedIterator, LookaheadIterator, ReversibleIterator

public class ManualGroupIterator
extends ManualIterator
implements GroupIterator

The class ManualGroupIterator represents an iterator that is never repositioned, but can be used to represent the focus in the dynamic context. It is used as a snapshot copy of a real grouping iterator for use when asynchronous threads are forked, as in xsl:result-document; the purpose of taking a snapshot is to ensure that changes to the base iterator in one thread do not affect the focus of another thread. It is also used when streaming with xsl:fork, which involves pseudo-parallel processing of groups.

Constructor Summary

Constructors

Constructor	Description
ManualGroupIterator(Item item, int position)	Create a manual grouping iterator

Method Summary

Modifier and Type	Method	Description
void	appendToCurrentGroup(Item item)
GroundedValue	currentGroup()	Get a sequence containing the members of the current group, in population order.
boolean	currentGroupContains(NodeInfo node)
AtomicSequence	getCurrentGroupingKey()	Get the grouping key of the current group
ManualGroupIterator	getSnapShot(XPathContext context)	Get a pseudo-iterator which represents a snapshot of this sequence at the current position
void	setCurrentGroup(GroundedValue group)
void	setCurrentGroupingKey(AtomicSequence key)
void	startNewCurrentGroup(Item item)

Methods inherited from class net.sf.saxon.tree.iter.ManualIterator

current, getLength, getResidue, getReverseIterator, hasNext, incrementPosition, isActuallyGrounded, materialize, next, position, setContextItem, setLengthFinder, setPosition, supportsGetLength, supportsHasNext

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.saxon.om.SequenceIterator

close, next

Constructor Detail

ManualGroupIterator

public ManualGroupIterator(Item item,
                           int position)

Create a manual grouping iterator

Parameters:

item - the context item

position - the context position

Method Detail

getSnapShot

public ManualGroupIterator getSnapShot(XPathContext context)

Description copied from interface: GroupIterator

Get a pseudo-iterator which represents a snapshot of this sequence at the current position

Specified by:

getSnapShot in interface GroupIterator

Parameters:

context - the XPath context

Returns:

the snapshot sequence

setCurrentGroupingKey

public void setCurrentGroupingKey(AtomicSequence key)

getCurrentGroupingKey

public AtomicSequence getCurrentGroupingKey()

Description copied from interface: GroupIterator

Get the grouping key of the current group

Specified by:

getCurrentGroupingKey in interface GroupIterator

Returns:

the current grouping key in the case of group-by or group-adjacent, or null in the case of group-starting-with and group-ending-with

setCurrentGroup

public void setCurrentGroup(GroundedValue group)

appendToCurrentGroup

public void appendToCurrentGroup(Item item)

startNewCurrentGroup

public void startNewCurrentGroup(Item item)

currentGroup

public GroundedValue currentGroup()
                           throws XPathException

Description copied from interface: GroupIterator

Get a sequence containing the members of the current group, in population order. This may be a MemoSequence rather than a grounded value

Specified by:

currentGroup in interface GroupIterator

Returns:

a sequence containing all the members of the current group, in population order.

Throws:

XPathException - if a dynamic error occurs

currentGroupContains

public boolean currentGroupContains(NodeInfo node)
                             throws XPathException

Throws:

XPathException