org.jrdf.graph.local.disk.iterator
Class DiskIteratorFactory

java.lang.Object
  org.jrdf.graph.local.disk.iterator.DiskIteratorFactory

All Implemented Interfaces:

IteratorFactory

public final class DiskIteratorFactory
extends Object
implements IteratorFactory

Default implementation of the IteratorFactory. Simply uses the normal iterators and an in memory backend.

Version:

$Id: DiskIteratorFactory.java 1822 2008-01-17 22:20:02Z newmana $

Author:

Andrew Newman

Constructor Summary

DiskIteratorFactory(LongIndex[] newLongIndexes, GraphHandler[] newGraphHandlers, NodePool newNodePool, Localizer newLocalizer, TripleBTree[] newTrees)

Method Summary

ClosableIterator<Triple>	newEmptyClosableIterator() Return an new EmptyClosableIterator - indicates no results found.
ClosableIterator<Triple>	newGraphIterator() Return an new GraphIterator - result of an unconstrained find.
ClosableIterator<Triple>	newOneFixedIterator(Long fixedFirstNode, int index) Return a new FixedIterator - bound by one node.
ClosableIterator<PredicateNode>	newPredicateIterator() Return a new PredicateIterator - all unique predicates.
ClosableIterator<PredicateNode>	newPredicateIterator(Long resource) Return a new PredicateIterator - all unique predicates for a given resource (subject and object).
ClosableIterator<Triple>	newThreeFixedIterator(Long[] newNodes) Return a new FixedIterator - bound by three nodes.
ClosableIterator<Triple>	newTwoFixedIterator(Long fixedFirstNode, Long fixedSecondNode, int index) Return a new FixedItereator - bound by two nodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

DiskIteratorFactory

public DiskIteratorFactory(LongIndex[] newLongIndexes,
                           GraphHandler[] newGraphHandlers,
                           NodePool newNodePool,
                           Localizer newLocalizer,
                           TripleBTree[] newTrees)

Method Detail

newEmptyClosableIterator

public ClosableIterator<Triple> newEmptyClosableIterator()

Description copied from interface: IteratorFactory

Return an new EmptyClosableIterator - indicates no results found.

Specified by:

newEmptyClosableIterator in interface IteratorFactory

Returns:

an empty closable iterator - always hasNext false and next throws exception.

newGraphIterator

public ClosableIterator<Triple> newGraphIterator()

Description copied from interface: IteratorFactory

Return an new GraphIterator - result of an unconstrained find.

Specified by:

newGraphIterator in interface IteratorFactory

Returns:

a graph iterator - goes through all triples in the graph.

newOneFixedIterator

public ClosableIterator<Triple> newOneFixedIterator(Long fixedFirstNode,
                                                    int index)

Description copied from interface: IteratorFactory

Return a new FixedIterator - bound by one node.

Specified by:

newOneFixedIterator in interface IteratorFactory

Parameters:

fixedFirstNode - the node to find.

index - which index (from the three) to use.

Returns:

a new FixedIterator - goes through the graph and returns all given triples with the given node.

newTwoFixedIterator

public ClosableIterator<Triple> newTwoFixedIterator(Long fixedFirstNode,
                                                    Long fixedSecondNode,
                                                    int index)

Description copied from interface: IteratorFactory

Return a new FixedItereator - bound by two nodes.

Specified by:

newTwoFixedIterator in interface IteratorFactory

Parameters:

fixedFirstNode - the first node to find.

fixedSecondNode - the second node to find.

index - which index (from the three) to use.

Returns:

a new FixedIterator - goes through the graph and returns all given triples with the two given nodes.

newThreeFixedIterator

public ClosableIterator<Triple> newThreeFixedIterator(Long[] newNodes)

Description copied from interface: IteratorFactory

Return a new FixedIterator - bound by three nodes.

Specified by:

newThreeFixedIterator in interface IteratorFactory

Parameters:

newNodes - the triple to find.

Returns:

a new FixedIterator - either one or none triples.

newPredicateIterator

public ClosableIterator<PredicateNode> newPredicateIterator()

Description copied from interface: IteratorFactory

Return a new PredicateIterator - all unique predicates.

Specified by:

newPredicateIterator in interface IteratorFactory

Returns:

a new PredicateIterator - all unique predicates.

newPredicateIterator

public ClosableIterator<PredicateNode> newPredicateIterator(Long resource)

Description copied from interface: IteratorFactory

Return a new PredicateIterator - all unique predicates for a given resource (subject and object).

Specified by:

newPredicateIterator in interface IteratorFactory

Parameters:

resource - all unique predicate for a given resource.

Returns:

a new PredicateIterator - all unique predicate for a given resource (subject and object).