Attribute Class Reference
[Attributes]

Base class for representing data attributes of packet aggregates. More...

#include <Attribute.h>

Inheritance diagram for Attribute:

List of all members.

Public Member Functions
	Attribute (void)
	create a new Attribute
	Attribute (const PacketFilter &filter)
	create a new Attribute which only considers packets meeting its filter
	Attribute (const Attribute &toCopy)
virtual Attribute *	clone (void) const
int	getType (void)
virtual const Attribute &	getAttrib (const std::string &ident) const throw ( UnknownAttributeException )
	Get a subattribute of this attribute.
virtual void	linkToAggregate (Aggregate &parent)
	Notify the Attribute that it is being linked to a particular aggregate.
virtual void	handlePassedPacket (TraceIterator &packet)
	Notify the attribute of a new packet to be included in the computation.
virtual void	compute (void)
	Compute the value of the attribute.
virtual void	reset (void) throw ( NotResettableException )
	Reset the value of the attribute.
virtual std::string	toString (void) const
virtual void	handlePacket (TraceIterator &newPkt)
Static Public Attributes
static const int	TYPE_UNKNOWN = 0
static const int	TYPE_SCALAR = 1
static const int	TYPE_DISTRIB = 17
static const int	TYPE_HISTOGRAM = 25
static const int	TYPE_ARRAY = 33
static const int	TYPE_SET = 34
Protected Attributes
Aggregate *	aggr
int	attribType
bool	dirty
Friends
std::ostream &	operator<< (std::ostream &os, const Attribute &attrib)

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Detailed Description

Base class for representing data attributes of packet aggregates.

An Attribute is, in very general terms, some information about an aggregation of packets. It could be a scalar value (ScalarAttribute) computed from the packets (count) or from other attributes (mean length), it could be a statistical distribution over a set of values from the packets, it could be a histogram (HistogramAttribute) over the values of the packets (e.g. a histogram over the interpacket delay), and so on.

Note:

When attribute instances are copied (copy ctor, clone method, operator=), the running state of the attribute is not copied; i.e. any information accumulated by the attribute due to calls to handlePassedPacket() etc. are not propagated. The main reason for this is the use of archetype instances - Attribute instances attached to Aggregate instances that exist only to be cloned.

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Constructor & Destructor Documentation

Attribute::Attribute (  const Attribute &  toCopy  )

Note: copied attributes are NOT by default part of the same aggregate as the original!

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Member Function Documentation

void Attribute::compute (  void   )  [virtual]

Compute the value of the attribute. Used to update an offline attribute. Reimplemented in ArithmeticAttribute< lType, rType, resType >, ByteCountAttribute, DurationAttribute, and SumAttribute< T >.

void FilteredPacketListener::handlePacket (  TraceIterator &  newPkt  )  [virtual, inherited]

checks the packet against the filter and calls handlePassedPacket if it passes or if the filter is NULL Implements PacketListener.

void Attribute::handlePassedPacket (  TraceIterator &  packet  )  [virtual]

Notify the attribute of a new packet to be included in the computation. For an online attribute, update the attribute. For an offline attribute, set the dirty bit. (default) Implements FilteredPacketListener. Reimplemented in ArithmeticAttribute< lType, rType, resType >, ByteCountAttribute, ConversationTrackerAttribute, DurationAttribute, HistogramAttribute< T >, MemoryAttribute< T >, PacketDrivenMemoryAttribute< T >, SampledMemoryAttribute< T >, PacketCountAttribute, and SumAttribute< T >.

void Attribute::linkToAggregate (  Aggregate &  parent  )  [virtual]

Notify the Attribute that it is being linked to a particular aggregate. Parameters: parent  New parent aggregate - will supplant any previous parent Note: If an Attribute subclass is only intended for use with a particular subtype of aggregate, override this method and add type checking. e.g.: Trace *trace = dynamic_cast<Trace*>(parent); if( NULL != trace ) {...} else throw InvalidAggregateException(...); Reimplemented in ArithmeticAttribute< lType, rType, resType >, and SumAttribute< T >.

void Attribute::reset (  void   )  throw ( NotResettableException ) [virtual]

Reset the value of the attribute. Exceptions: NotResettableException  if the Attribute cannot be properly reset, e.g. if it is a wrapper for a subattribute. Reimplemented in SumAttribute< T >.

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Member Data Documentation

const int Attribute::TYPE_ARRAY = 33 [static]

array

const int Attribute::TYPE_DISTRIB = 17 [static]

statistical distribution

const int Attribute::TYPE_HISTOGRAM = 25 [static]

histogram

const int Attribute::TYPE_SCALAR = 1 [static]

single-valued type

const int Attribute::TYPE_SET = 34 [static]

set

const int Attribute::TYPE_UNKNOWN = 0 [static]

unknown type

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The documentation for this class was generated from the following files:

• data_structures/Attribute.h
• data_structures/Attribute.cc

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