Package com.github.basking2.sdsai.itrex.iterators.splitjoin

Class CloseableUncertainIterator<T>

java.lang.Object

com.github.basking2.sdsai.itrex.iterators.splitjoin.CloseableUncertainIterator<T>

All Implemented Interfaces:

UncertainIterator<T>, AutoCloseable

public class CloseableUncertainIterator<T>
extends Object
implements UncertainIterator<T>, AutoCloseable

An uncertain iterator that may be closed, signalling it will receive or generate no more elements.

Nested Class Summary

Nested classes/interfaces inherited from interface com.github.basking2.sdsai.itrex.iterators.splitjoin.UncertainIterator

UncertainIterator.HAS_NEXT

Constructor Summary

Constructors

Constructor	Description
CloseableUncertainIterator()	Calls CloseableUncertainIterator(Queue) with a ConcurrentLinkedQueue instance.
CloseableUncertainIterator(Queue<T> queue)	Construct this using the given queue for data.

Method Summary

Modifier and Type	Method	Description
void	close()
UncertainIterator.HAS_NEXT	hasNext()	Return TRUE if elements are ready, FALSE if they are not or MAYBE if we do not know.
T	next()	Get the next value or throw NoSuchElementException.
boolean	offer(T t)	This calls Queue.offer(Object) on the backing queue and returns the result.

Methods inherited from class java.lang.Object

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

Constructor Details

CloseableUncertainIterator

public CloseableUncertainIterator(Queue<T> queue)

Construct this using the given queue for data. When the queue has data hasNext() will reeturn UncertainIterator.HAS_NEXT.TRUE. When the queue is empty hasNext() will return UncertainIterator.HAS_NEXT.MAYBE. When the queue is empty and this object has been close()ed, then UncertainIterator.HAS_NEXT.FALSE is returned.

Parameters:

queue - The queue to read elements from.

CloseableUncertainIterator

public CloseableUncertainIterator()

Calls CloseableUncertainIterator(Queue) with a ConcurrentLinkedQueue instance.

Method Details

next

public T next()

Description copied from interface: UncertainIterator

Get the next value or throw NoSuchElementException.

Specified by:

next in interface UncertainIterator<T>

Returns:

The next element.

hasNext

public UncertainIterator.HAS_NEXT hasNext()

Description copied from interface: UncertainIterator

Return TRUE if elements are ready, FALSE if they are not or MAYBE if we do not know. If no other sources of data are available and the state of the computation system cannot be changed, then MAYBE should be considered FALSE.

Specified by:

hasNext in interface UncertainIterator<T>

Returns:

TRUE if elements are ready, FALSE if they are not or MAYBE if we do not know.

close

public void close()
           throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception

offer

public boolean offer(T t)

This calls Queue.offer(Object) on the backing queue and returns the result. If the user would like to use custom enqueuing semantics they should provide their own thread-safe queue to the constructor.

Parameters:

t - The element to enqueue.

Returns:

True on success, false otherwise.