org.jrdf.query.relation.operation.mem.union
Class SubsumptionEngine

java.lang.Object
  org.jrdf.query.relation.operation.mem.union.SubsumptionEngine

All Implemented Interfaces:

TupleEngine

public class SubsumptionEngine
extends Object
implements TupleEngine

Constructor Summary

SubsumptionEngine(TupleFactory tupleFactory, RelationHelper relationHelper)

Method Summary

SortedSet<Attribute>	getHeading(Relation relation1, Relation relation2)
void	process(SortedSet<Attribute> headings, SortedSet<AttributeValuePair> avps1, SortedSet<AttributeValuePair> avps2, SortedSet<Tuple> result) Returns the tuples to be subsumed in the result set.
int	subsumes(SortedSet<Attribute> headings, SortedSet<AttributeValuePair> avps1, SortedSet<AttributeValuePair> avps2) -1 indicates 2 subsumes 1, 1 indicates 1 subsumes 2, 0 means that they are not subsumed.

Methods inherited from class java.lang.Object

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

Constructor Detail

SubsumptionEngine

public SubsumptionEngine(TupleFactory tupleFactory,
                         RelationHelper relationHelper)

Method Detail

getHeading

public SortedSet<Attribute> getHeading(Relation relation1,
                                       Relation relation2)

Specified by:

getHeading in interface TupleEngine

process

public void process(SortedSet<Attribute> headings,
                    SortedSet<AttributeValuePair> avps1,
                    SortedSet<AttributeValuePair> avps2,
                    SortedSet<Tuple> result)

Returns the tuples to be subsumed in the result set.

Specified by:

process in interface TupleEngine

Parameters:

headings - the headings of the resultant tuple.

avps1 - the first set of avps to consider.

avps2 - the second set of avps to consider.

result - the tuples to be subsumed.

subsumes

public int subsumes(SortedSet<Attribute> headings,
                    SortedSet<AttributeValuePair> avps1,
                    SortedSet<AttributeValuePair> avps2)

-1 indicates 2 subsumes 1, 1 indicates 1 subsumes 2, 0 means that they are not subsumed.

Parameters:

headings - the headings to use.

avps1 - The set of avps to compare.

avps2 - The set of avps to compare.

Returns:

-1 indicates avps2 subsumes avps1, 1 indicates avps1 subsumes avps2 and 0 means they do not share any common values or are equal.