com.bigdata.striterator

Class ChunkedWrappedIterator<E>

java.lang.Object

com.bigdata.striterator.ChunkedWrappedIterator<E>

All Implemented Interfaces:

IChunkedIterator<E>, IChunkedOrderedIterator<E>, ICloseable, ICloseableIterator<E>, Iterator<E>

public class ChunkedWrappedIterator<E>
extends Object
implements IChunkedOrderedIterator<E>

Converts an Iterator into chunked iterator.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

Fields inherited from interface com.bigdata.striterator.IChunkedIterator

DEFAULT_CHUNK_SIZE

Constructor Summary

Constructors

Constructor and Description
ChunkedWrappedIterator(Iterator<E> src) Create an iterator that reads from the source.
ChunkedWrappedIterator(Iterator<E> src, int chunkSize)
ChunkedWrappedIterator(Iterator<E> src, int chunkSize, Class<? extends E> elementClass)
ChunkedWrappedIterator(Iterator<E> src, int chunkSize, Class<? extends E> elementClass, IKeyOrder<E> keyOrder, IElementFilter<E> filter) Create an iterator that reads from the source.
ChunkedWrappedIterator(Iterator<E> src, int chunkSize, IKeyOrder<E> keyOrder, IElementFilter<E> filter)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the iterator, releasing any associated resources.
IKeyOrder<E>	getKeyOrder() The natural order in which elements are being visited.
boolean	hasNext() Return true if there are elements in the source iterator.
E	next() The next element from the source iterator.
E[]	nextChunk() The next chunk of elements in whatever order the were visited by next().
E[]	nextChunk(IKeyOrder<E> keyOrder) Return the next "chunk" of elements.
void	remove() Delegated to the source iterator.

Methods inherited from class java.lang.Object

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

Constructor Detail

ChunkedWrappedIterator

public ChunkedWrappedIterator(Iterator<E> src)

Create an iterator that reads from the source.

Parameters:

src - The source iterator.

ChunkedWrappedIterator

public ChunkedWrappedIterator(Iterator<E> src,
                      int chunkSize)

ChunkedWrappedIterator

public ChunkedWrappedIterator(Iterator<E> src,
                      int chunkSize,
                      Class<? extends E> elementClass)

ChunkedWrappedIterator

public ChunkedWrappedIterator(Iterator<E> src,
                      int chunkSize,
                      IKeyOrder<E> keyOrder,
                      IElementFilter<E> filter)

ChunkedWrappedIterator

public ChunkedWrappedIterator(Iterator<E> src,
                      int chunkSize,
                      Class<? extends E> elementClass,
                      IKeyOrder<E> keyOrder,
                      IElementFilter<E> filter)

Create an iterator that reads from the source.

Parameters:

src - The source iterator.

chunkSize - The desired chunk size.

elementClass - The class for the array component type (optional, but the default will use the runtime type of the first element of the array which can be too restrictive).

keyOrder - The order in which the elements will be visited by the source iterator if known and null otherwise.

filter - Optional filter. When non-null only elements accepted by the filter will be visited by this iterator.

Method Detail

close

public void close()

Description copied from interface: ICloseableIterator

Closes the iterator, releasing any associated resources. This method MAY be invoked safely if the iterator is already closed. Implementations of this interface MUST invoke ICloseableIterator.close() if Iterator.hasNext() method returns false to ensure that the iterator is closed (and its resources release) as soon as it is exhausted.

Note: Implementations that support Iterator.remove() MUST NOT eagerly close the iterator when it is exhausted since that would make it impossible to remove the last visited statement. Instead they MUST wait for an explicit ICloseableIterator.close() by the application.

Specified by:

close in interface ICloseable

Specified by:

close in interface ICloseableIterator<E>

hasNext

public boolean hasNext()

Return true if there are elements in the source iterator.

Specified by:

hasNext in interface Iterator<E>

next

public E next()

The next element from the source iterator.

Specified by:

next in interface IChunkedIterator<E>

Specified by:

next in interface Iterator<E>

nextChunk

public E[] nextChunk()

The next chunk of elements in whatever order the were visited by next().

Specified by:

nextChunk in interface IChunkedIterator<E>

Returns:

The next chunk.

remove

public void remove()

Delegated to the source iterator.

Specified by:

remove in interface IChunkedIterator<E>

Specified by:

remove in interface Iterator<E>

getKeyOrder

public IKeyOrder<E> getKeyOrder()

Description copied from interface: IChunkedOrderedIterator

The natural order in which elements are being visited.

Specified by:

getKeyOrder in interface IChunkedOrderedIterator<E>

Returns:

The natural order in which the elements are being visited -or- null if not known.

nextChunk

public E[] nextChunk(IKeyOrder<E> keyOrder)

Description copied from interface: IChunkedOrderedIterator

Return the next "chunk" of elements. The elements will be in the specified order. If IChunkedOrderedIterator.getKeyOrder() would return non-null and the request order corresponds to the value that would be returned by IChunkedOrderedIterator.getKeyOrder() then the elements in the next chunk are NOT sorted. Otherwise the elements in the next chunk are sorted before they are returned. The size of the chunk is up to the implementation.

Specified by:

nextChunk in interface IChunkedOrderedIterator<E>

Parameters:

keyOrder - The natural order for the elements in the chunk.

Returns:

The next chunk of elements in the specified order.