Package com.tangosol.net.partition

Class AbstractPartitionedIterator<T>

java.lang.Object

com.oracle.coherence.common.collections.AbstractStableIterator<T>

com.tangosol.net.partition.AbstractPartitionedIterator<T>

All Implemented Interfaces:

Enumeration<T>, Iterator<T>

Direct Known Subclasses:

PartitionedIterator

public abstract class AbstractPartitionedIterator<T>
extends com.oracle.coherence.common.collections.AbstractStableIterator<T>

Abstract base class for partitioned iterators.

Author:

as 2015.01.27

Field Summary

Fields

Modifier and Type	Field	Description
protected NamedCache	m_cache	The cache to query from.
protected boolean	m_fByMember	Differentiates between by-member and by-partition iteration.
protected PartitionedFilter	m_filter	The filter to query with.
protected boolean	m_fRandom	An option to randomize the order of iteration to avoid harmonics in a clustered environment.
protected PartitionSet	m_setPids	The remaining set of partitions to iterate.
static final int	OPT_BY_MEMBER	An option to iterate one member at a time.
static final int	OPT_BY_PARTITION	An option to iterate one partition at a time.
static final int	OPT_RANDOMIZED	An option to iterate the members or partitions in a randomized order.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractPartitionedIterator(Filter filter, NamedCache cache, PartitionSet setPids)	Create AbstractPartitionedIterator instance.
protected	AbstractPartitionedIterator(Filter filter, NamedCache cache, PartitionSet setPids, boolean fByMember, boolean fRandom)	Create AbstractPartitionedIterator instance.

Method Summary

Modifier and Type	Method	Description
protected void	advance()	Advance to the next object.
protected abstract Iterable<T>	nextIterable(PartitionedFilter filter)	Obtain the next Iterable for a given filter.
protected void	remove(Object oPrev)	Remove the specified item.

Methods inherited from class com.oracle.coherence.common.collections.AbstractStableIterator

getPrevious, hasMoreElements, hasNext, next, nextElement, remove, setNext

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Enumeration

asIterator

Methods inherited from interface java.util.Iterator

forEachRemaining

Field Details

OPT_BY_PARTITION

public static final int OPT_BY_PARTITION

An option to iterate one partition at a time. This is the default.

See Also:

• Constant Field Values

OPT_BY_MEMBER

public static final int OPT_BY_MEMBER

An option to iterate one member at a time.

See Also:

• Constant Field Values

OPT_RANDOMIZED

public static final int OPT_RANDOMIZED

An option to iterate the members or partitions in a randomized order. Note that this does not refer to the order that the individual keys or entries themselves will be iterated.

See Also:

• Constant Field Values

m_cache

protected NamedCache m_cache

The cache to query from.

m_filter

protected PartitionedFilter m_filter

The filter to query with.

m_setPids

protected PartitionSet m_setPids

The remaining set of partitions to iterate.

m_fByMember

protected boolean m_fByMember

Differentiates between by-member and by-partition iteration. If true, all partitions of a given member are iterated in a single chunk; if false, each partition is iterated individually.

m_fRandom

protected boolean m_fRandom

An option to randomize the order of iteration to avoid harmonics in a clustered environment.

Constructor Details

AbstractPartitionedIterator

protected AbstractPartitionedIterator(Filter filter,
 NamedCache cache,
 PartitionSet setPids)

Create AbstractPartitionedIterator instance.

Parameters:

filter - the query expressed as a Filter

cache - the cache to query

setPids - the partitions to execute the query against

AbstractPartitionedIterator

protected AbstractPartitionedIterator(Filter filter,
 NamedCache cache,
 PartitionSet setPids,
 boolean fByMember,
 boolean fRandom)

Create AbstractPartitionedIterator instance.

Parameters:

filter - the query expressed as a Filter

cache - the cache to query

setPids - the partitions to execute the query against

fByMember - indicates whether it is by-member iterations

fRandom - indicates whether the order of iteration is randomized

Method Details

nextIterable

protected abstract Iterable<T> nextIterable(PartitionedFilter filter)

Obtain the next Iterable for a given filter. This method is called when the Iterable returned by the previous call is exhausted.

Parameters:

filter - filter to use

Returns:

a next Iterable or null if there is no more data to iterate

advance

protected void advance()

Description copied from class: com.oracle.coherence.common.collections.AbstractStableIterator

Advance to the next object.

This method must be implemented by the concrete sub-class by calling AbstractStableIterator.setNext(T) if there is a next object.

Specified by:

advance in class com.oracle.coherence.common.collections.AbstractStableIterator<T>

remove

protected void remove(Object oPrev)

Description copied from class: com.oracle.coherence.common.collections.AbstractStableIterator

Remove the specified item.

This is an optional operation. If the Iterator supports element removal, then it should implement this method, which is delegated to by the AbstractStableIterator.remove() method.

Overrides:

remove in class com.oracle.coherence.common.collections.AbstractStableIterator<T>

Parameters:

oPrev - the previously iterated object that should be removed