com.bigdata.relation.accesspath
Class AbstractElementBuffer<R>

java.lang.Object
  com.bigdata.relation.accesspath.AbstractArrayBuffer<R>
      com.bigdata.relation.accesspath.AbstractElementBuffer<R>

Type Parameters:

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

All Implemented Interfaces:

IBuffer<R>

Direct Known Subclasses:

AbstractElementBuffer.DeleteBuffer, AbstractElementBuffer.InsertBuffer

public abstract class AbstractElementBuffer<R>
extends AbstractArrayBuffer<R>

Base class for IBuffer of IRelation elements whose target is a mutation (insert, delete, or update) of some IMutableRelation.

Version:

$Id: AbstractElementBuffer.java 2265 2009-10-26 12:51:06Z thompsonbry $

Author:

Bryan Thompson

See Also:

IMutableRelation

Nested Class Summary

static class	AbstractElementBuffer.DeleteBuffer<R> Buffer writes on IMutableRelation.delete(IChunkedOrderedIterator) when it is flushed.
static class	AbstractElementBuffer.InsertBuffer<R> Buffer writes on IMutableRelation.insert(IChunkedOrderedIterator) when it is flushed.

Field Summary

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

buffer, capacity, cls, DEBUG, filter, INFO, log, size

Constructor Summary

protected

AbstractElementBuffer(int capacity, IMutableRelation<R> relation, IKeyOrder<R> keyOrder, IElementFilter<R> filter)

Method Summary

protected abstract long	flush(IChunkedOrderedIterator<R> itr) Concrete implementations must process the elements, causing the appropriate mutation on the target IRelation.
protected long	flush(int n, R[] a) Delegates to flush(IChunkedOrderedIterator)
protected IKeyOrder<R>	getKeyOrder() The natural order in which the elements will appear in the buffer -or- null if you do not have a strong guarentee for that order (from the ctor).
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

AbstractElementBuffer

protected AbstractElementBuffer(int capacity,
                                IMutableRelation<R> relation,
                                IKeyOrder<R> keyOrder,
                                IElementFilter<R> filter)

Parameters:

capacity - The buffer capacity.

relation - The target relation.

keyOrder - The natural order in which the elements will appear in the buffer -or- null if you do not have a strong guarantee for that order.

filter - An optional filter for keeping elements out of the buffer.

Method Detail

getRelation

protected IMutableRelation<R> getRelation()

getKeyOrder

protected IKeyOrder<R> getKeyOrder()

The natural order in which the elements will appear in the buffer -or- null if you do not have a strong guarentee for that order (from the ctor).

flush

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

Delegates to flush(IChunkedOrderedIterator)

Specified by:

flush in class AbstractArrayBuffer<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<R> itr)

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

Note: The elements generally appear in an arbitrary order and need to be sorted into ordered chunks using IKeyOrder.getComparator() for the desired natural order(s).

Parameters:

itr -

Returns:

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