com.bigdata.bop.ap.filter

Class BOpFilterBase

java.lang.Object

com.bigdata.bop.CoreBaseBOp

com.bigdata.bop.BOpBase

com.bigdata.bop.ap.filter.BOpFilterBase

All Implemented Interfaces:

BOp, IFilter, IPropertySet, Serializable, Cloneable

Direct Known Subclasses:

BOpFilter, BOpFilterNOP, BOpResolver, BOpTupleFilter, DistinctFilter, NativeDistinctFilter

public abstract class BOpFilterBase
extends BOpBase
implements IFilter

Base class for operators which apply striterator patterns for access paths.

The striterator pattern is enacted slightly differently here. The filter chain is formed by stacking BOpFilterBases as child operands. Each operand specified to a BOpFilterBase must be a BOpFilterBase and layers on another filter, so you can stack filters as nested operands or as a sequence of operands.

Version:

$Id$

Author:

Bryan Thompson

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	BOpFilterBase.Annotations

Field Summary

Fields inherited from class com.bigdata.bop.CoreBaseBOp

DEFAULT_INITIAL_CAPACITY

Fields inherited from interface com.bigdata.bop.BOp

NOANNS, NOARGS

Constructor Summary

Constructors

Constructor and Description
BOpFilterBase(BOp[] args, Map<String,Object> annotations) Shallow copy.
BOpFilterBase(BOpFilterBase op) Deep copy.

Method Summary

Methods

Modifier and Type	Method and Description
Iterator	filter(Iterator src, Object context) The filter method is provided to allow the creation of the filtering iterator.
protected abstract Iterator	filterOnce(Iterator src, Object context) Wrap the source iterator with this filter.

Methods inherited from class com.bigdata.bop.BOpBase

__replaceArg, _clearProperty, _set, _setProperty, annotations, annotationsCopy, annotationsEqual, annotationsRef, argIterator, args, argsCopy, arity, clearAnnotations, clearProperty, deepCopy, deepCopy, get, getProperty, setArg, setProperty, setUnboundProperty, toArray, toArray

Methods inherited from class com.bigdata.bop.CoreBaseBOp

annotationsEqual, annotationsToString, annotationsToString, annotationValueToString, checkArgs, clone, equals, getEvaluationContext, getId, getProperty, getRequiredProperty, hashCode, indent, isController, mutation, shortenName, toShortString, toString, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface cutthecrap.utils.striterators.IPropertySet

getProperty

Constructor Detail

BOpFilterBase

public BOpFilterBase(BOpFilterBase op)

Deep copy.

Parameters:

op -

BOpFilterBase

public BOpFilterBase(BOp[] args,
             Map<String,Object> annotations)

Shallow copy.

Parameters:

args -

annotations -

Method Detail

filter

public final Iterator filter(Iterator src,
              Object context)

Description copied from interface: IFilter

The filter method is provided to allow the creation of the filtering iterator.

Any implementation should follow the following pattern:

  public Iterator filter(Iterator src, Object context) {
                return new Filterator(src, context, this);
        }
  

This pattern makes the source iterator, the evaluation context, and the IPropertySet annotations visible to the runtime striterator implementation.

Specified by:

filter in interface IFilter

filterOnce

protected abstract Iterator filterOnce(Iterator src,
                  Object context)

Wrap the source iterator with this filter.

Parameters:

src - The source iterator.

context - The iterator evaluation context.

Returns:

The wrapped iterator.