Class AbstractBlockIterator
- All Implemented Interfaces:
Closeable
,AutoCloseable
,SequenceIterator
- Direct Known Subclasses:
BlockIterator
-
Field Summary
FieldsModifier and TypeFieldDescriptionprotected XPathContext
protected SequenceIterator
protected int
protected int
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
close()
Close the iterator.void
Calling this method instructs the iterator to release any resources it holds, while still remaining able to deliver the remaining items in the sequence.abstract SequenceIterator
getNthChildIterator
(int n) void
init
(int size, XPathContext context) Initializer for use from bytecodenext()
Get the next item in the sequence.
-
Field Details
-
size
protected int size -
currentOperand
protected int currentOperand -
currentIter
-
context
-
-
Constructor Details
-
AbstractBlockIterator
public AbstractBlockIterator() -
AbstractBlockIterator
-
-
Method Details
-
init
Initializer for use from bytecode- Parameters:
size
- the sizecontext
- the XPath context
-
discharge
public void discharge()Description copied from interface:SequenceIterator
Calling this method instructs the iterator to release any resources it holds, while still remaining able to deliver the remaining items in the sequence. This may require the iterator to calculate the rest of the sequence eagerly. The method is called by a client if it anticipates that it might not read the iterator to completion, but it cannot guarantee thatSequenceIterator.close()
will be called when no more items are needed.- Specified by:
discharge
in interfaceSequenceIterator
-
next
Get the next item in the sequence.- Specified by:
next
in interfaceSequenceIterator
- Returns:
- the next item, or null if there are no more items.
-
getNthChildIterator
- Throws:
XPathException
-
close
public void close()Description copied from interface:SequenceIterator
Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.For example, the iterator returned by the unparsed-text-lines() function has a close() method that causes the underlying input stream to be closed, whether or not the file has been read to completion.
Closing an iterator is important 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.
Closing an iterator is not necessary if the iterator is read to completion: if a call on
SequenceIterator.next()
returns null, the iterator will be closed automatically. An explicit call onSequenceIterator.close()
is needed only when iteration is abandoned prematurely.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Specified by:
close
in interfaceSequenceIterator
-