public class SortedIterator extends java.lang.Object implements SequenceIterator, LastPositionFinder, LookaheadIterator, Sortable
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protected SequenceIterator |
base |
protected AtomicComparer[] |
comparators |
protected XPathContext |
context |
protected int |
count |
protected java.lang.Object[] |
nodeKeys |
protected int |
position |
protected int |
recordSize |
protected SortKeyEvaluator |
sortKeyEvaluator |
GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD
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SortedIterator(XPathContext context,
SequenceIterator base,
SortKeyEvaluator sortKeyEvaluator,
AtomicComparer[] comparators)
Create a sorted iterator
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protected void |
buildArray()
Create an array holding the items to be sorted and the values of their sort keys
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void |
close()
Close the iterator.
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int |
compare(int a,
int b)
Compare two items in sorted sequence
(needed to implement the Sortable interface)
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Item |
current()
Get the current value in the sequence (the one returned by the
most recent call on next()).
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SequenceIterator |
getAnother()
Get another SequenceIterator that iterates over the same items as the original,
but which is repositioned at the start of the sequence.
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int |
getLastPosition()
Get the last position (that is, the number of items in the sequence).
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int |
getProperties()
Get properties of this iterator, as a bit-significant integer.
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boolean |
hasNext()
Determine whether there are more items to come.
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Item |
next()
Get the next item, in sorted order
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int |
position()
Get the current position.
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void |
setHostLanguage(int language)
Set the host language
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void |
swap(int a,
int b)
Swap two items (needed to implement the Sortable interface)
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protected SequenceIterator base
protected SortKeyEvaluator sortKeyEvaluator
protected AtomicComparer[] comparators
protected int recordSize
protected java.lang.Object[] nodeKeys
protected int count
protected int position
protected XPathContext context
public SortedIterator(XPathContext context, SequenceIterator base, SortKeyEvaluator sortKeyEvaluator, AtomicComparer[] comparators)
context
- the dynamic XPath evaluation contextbase
- an iterator over the sequence to be sortedsortKeyEvaluator
- an object that allows the n'th sort key for a given item to be evaluatedcomparators
- an array of AtomicComparers, one for each sort key, for comparing sort key valuespublic void setHostLanguage(int language)
language
- the host language (for example Configuration.XQUERY
)public boolean hasNext()
SequenceIterator.LOOKAHEAD
hasNext
???? LookaheadIterator
public Item next() throws XPathException
next
???? SequenceIterator
XPathException
- if an error occurs retrieving the next itempublic Item current()
SequenceIterator
current
???? SequenceIterator
public int position()
SequenceIterator
This method does not change the state of the iterator.
position
???? SequenceIterator
public int getLastPosition() throws XPathException
LastPositionFinder
SequenceIterator.LAST_POSITION_FINDER
getLastPosition
???? LastPositionFinder
XPathException
public void close()
SequenceIterator
(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)
close
???? SequenceIterator
public SequenceIterator getAnother() throws XPathException
SequenceIterator
This method allows access to all the items in the sequence without disturbing the current position of the iterator. Internally, its main use is in evaluating the last() function.
This method does not change the state of the iterator.
getAnother
???? SequenceIterator
XPathException
- if any error occurspublic int getProperties()
getProperties
???? SequenceIterator
SequenceIterator.GROUNDED
, SequenceIterator.LAST_POSITION_FINDER
,
and SequenceIterator.LOOKAHEAD
. It is always
acceptable to return the value zero, indicating that there are no known special properties.
It is acceptable for the properties of the iterator to change depending on its state.protected void buildArray() throws XPathException
XPathException
public int compare(int a, int b)