com.bigdata.relation.rule.eval

Class AbstractSolutionBuffer<R>

java.lang.Object

com.bigdata.relation.accesspath.AbstractArrayBuffer<ISolution<R>[]>

com.bigdata.relation.rule.eval.AbstractSolutionBuffer<R>

Type Parameters:

R - The generic type of the [R]elation elements.

All Implemented Interfaces:

IBuffer<ISolution<R>[]>

Direct Known Subclasses:

AbstractSolutionBuffer.DeleteSolutionBuffer, AbstractSolutionBuffer.InsertSolutionBuffer, RDFJoinNexus.InsertSPOAndJustificationBuffer

public abstract class AbstractSolutionBuffer<R>
extends AbstractArrayBuffer<ISolution<R>[]>

Base class for IBuffer whose target is a mutation (insert, delete, or update) of some IMutableRelation. Note that this buffers chunks of ISolutions NOT relation elements.

Version:

$Id$

Author:

Bryan Thompson

See Also:

IMutableRelation

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractSolutionBuffer.DeleteSolutionBuffer<E> Buffer writes on IMutableRelation.delete(IChunkedOrderedIterator) when it is flushed.
static class	AbstractSolutionBuffer.InsertSolutionBuffer<E> Buffer writes on IMutableRelation#insert(IChunkedIterator) when it is flushed.

Field Summary

Fields inherited from class com.bigdata.relation.accesspath.AbstractArrayBuffer

buffer, capacity, cls, filter, size

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSolutionBuffer(int capacity, IMutableRelation<R> relation)

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract long	flush(IChunkedOrderedIterator<ISolution<R>> itr) Concrete implementations must process the ISolutions, causing the appropriate mutation on the target IRelation.
protected long	flush(int n, ISolution<R>[][] a) Combines chunks of solutions together into a single chunk and then delegates to flush(IChunkedOrderedIterator).
protected IMutableRelation<R>	getRelation()

Methods inherited from class com.bigdata.relation.accesspath.AbstractArrayBuffer

accept, add, flush, isEmpty, reset, size

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractSolutionBuffer

protected AbstractSolutionBuffer(int capacity,
                      IMutableRelation<R> relation)

Parameters:

capacity -

Method Detail

getRelation

protected IMutableRelation<R> getRelation()

flush

protected final long flush(int n,
         ISolution<R>[][] a)

Combines chunks of solutions together into a single chunk and then delegates to flush(IChunkedOrderedIterator).

Note: Combining chunks together is a huge performance win if the source chunks tend to be small (100). For example, this is true for scale-out joins such as LUBM U1 EDS. There the performance gain is better than 20:1.

Specified by:

flush in class AbstractArrayBuffer<ISolution<R>[]>

Parameters:

n - The #of elements in the array.

a - The array of elements.

Returns:

The #of elements that were modified in the backing relation when the buffer was flushed (unlike AbstractArrayBuffer.flush(), this is not a cumulative counter, but the #of modified elements in the relation for this operation only).

flush

protected abstract long flush(IChunkedOrderedIterator<ISolution<R>> itr)

Concrete implementations must process the ISolutions, causing the appropriate mutation on the target IRelation.

Note: The ISolutions generally appear in an arbitrary order. They can either be resolved to IRelation elements or be sorted into ordered ISolution chunks using a SolutionComparator.

Parameters:

itr - The iterator (the order of the elements is unknown).

Returns:

The #of elements that were modified in the backing relation when the buffer was flushed