com.saxonica.stream

Class ManualGroupIterator

java.lang.Object

net.sf.saxon.tree.iter.ManualIterator

com.saxonica.stream.ManualGroupIterator

All Implemented Interfaces:

LastPositionFinder, GroupIterator, SequenceIterator, GroundedIterator, LookaheadIterator, ReversibleIterator, UnfailingIterator

Direct Known Subclasses:

GroupByIterator.ManualGroupByIterator, MergeGroupingIterator.ManualMergGroupingIterator

public abstract 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.

Field Summary

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

GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
ManualGroupIterator	getSnapShot(XPathContext context) Get a sequence which is a snapshot of this sequence at the current position
boolean	hasCurrentGroup() Ask whether this iterator has a current group
boolean	hasCurrentGroupingKey() Ask whether this iterator has a current grouping key
void	setGroupSlot(int groupSlot) Set the slot number of the variable holding the current group
void	setKeySlot(int keySlot) Set the slot number of the variable holding the current grouping key

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

close, current, getAnother, getLength, getProperties, getReverseIterator, hasNext, incrementPosition, materialize, next, position, setContextItem, setLastPositionFinder, setPosition

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.expr.sort.GroupIterator

getCurrentGroupingKey, iterateCurrentGroup

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

close, current, getAnother, getProperties, next, position

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

setGroupSlot

public void setGroupSlot(int groupSlot)

Set the slot number of the variable holding the current group

Specified by:

setGroupSlot in interface GroupIterator

Parameters:

groupSlot - the stack frame position of the variable holding the current group

setKeySlot

public void setKeySlot(int keySlot)

Set the slot number of the variable holding the current grouping key

Specified by:

setKeySlot in interface GroupIterator

Parameters:

keySlot - the stack frame position of the variable holding the current grouping key

hasCurrentGroup

public boolean hasCurrentGroup()

Description copied from interface: GroupIterator

Ask whether this iterator has a current group

Specified by:

hasCurrentGroup in interface GroupIterator

Returns:

false if the controlling xsl:for-each-group element binds a group variable, true if it delivers results using the current-group() function

hasCurrentGroupingKey

public boolean hasCurrentGroupingKey()

Description copied from interface: GroupIterator

Ask whether this iterator has a current grouping key

Specified by:

hasCurrentGroupingKey in interface GroupIterator

Returns:

false if the controlling xsl:for-each-group element binds a grouping-key variable, true if it delivers results using the current-grouping-key() function

getSnapShot

public ManualGroupIterator getSnapShot(XPathContext context)
                                throws XPathException

Description copied from interface: GroupIterator

Get a sequence which is a snapshot of this sequence at the current position

Specified by:

getSnapShot in interface GroupIterator

Throws:

XPathException