PacketDrivenMemoryAttribute< T > Class Template Reference

MemoryAttribute for remembering values from packets. More...

#include <MemoryAttribute.h>

Inheritance diagram for PacketDrivenMemoryAttribute< T >:

List of all members.

Public Member Functions
	PacketDrivenMemoryAttribute (const std::string &ident, uint32_t aType, uint32_t memSize=0, bool scroll=true)
	create a PacketDrivenMemoryAttribute
	PacketDrivenMemoryAttribute (const PacketFilter &filter, const std::string &ident, uint32_t aType, uint32_t memSize=0, bool scroll=true)
	create a filtered PacketDrivenMemoryAttribute
	PacketDrivenMemoryAttribute (const std::string &ident, uint32_t aType, const Timeval &window, bool scroll=true)
	create a PacketDrivenMemoryAttribute that functions as a time window
	PacketDrivenMemoryAttribute (const PacketFilter &filter, const std::string &ident, uint32_t aType, const Timeval &window, bool scroll=true)
	create a filtered PacketDrivenMemoryAttribute that functions as a time window
	PacketDrivenMemoryAttribute (const PacketDrivenMemoryAttribute< T > &toCopy)
PacketDrivenMemoryAttribute< T > *	clone (void) const
virtual void	handlePassedPacket (TraceIterator &packet)
	Notify the attribute of a new packet to be included in the computation.
virtual void	update (void)
	update the attribute to the given time
virtual T	getInstanceValue (void) const throw ( UnknownAttributeException )
	get the current value of the attribute to remember
virtual T	getInstanceValue (TraceIterator &packet) const throw ( UnknownAttributeException )
	get the current value of the attribute to remember
virtual const Attribute &	getAttrib (const std::string &ident) const throw ( UnknownAttributeException )
	get an attribute of the attribute
virtual T	getSum (void) const throw ( InvalidDataTypeException )
	get the sum of the elements in the memory if they are of an appropriate data type
virtual T	getMax (void) const throw ( InvalidDataTypeException )
	get the maximum element in the memory if they are of an appropriate data type
virtual T	getMin (void) const throw ( InvalidDataTypeException )
	get the minimum element in the memory if they are of an appropriate data type
std::vector< T >::const_iterator	begin (void) const
	get a const iterator pointing to the first (oldest) element of the window
std::vector< T >::iterator	begin (void)
	get an iterator pointing to the first (oldest) element of the window
std::vector< T >::const_iterator	end (void) const
	get a const iterator pointing to the last (newest) element of the window
std::vector< T >::iterator	end (void)
	get an iterator pointing to the last (newest) element of the window
int	getType (void)
virtual void	linkToAggregate (Aggregate &parent)
	Notify the Attribute that it is being linked to a particular aggregate.
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 uint32_t	ATTRIB_TYPE_AGGREGATE = 1
	types of attributes that can be remembered
static const uint32_t	ATTRIB_TYPE_PACKET = 2
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 Member Functions
void	append (const Timeval &time, T val)
	add a value to the end of the queue
void	remove (uint32_t count=1)
	remove the n first/earliest values from the queue, defaults to removing the first one
void	buildVector (void) const
	build or rebuild the vector copy of q
void	prune (void)
	remove values from the queue based on max size or time window
uint32_t	size (void) const
	return the number of values in the memory
Protected Attributes
Aggregate *	aggr
Friends
std::ostream &	operator<< (std::ostream &os, const Attribute &attrib)

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Detailed Description

template<class T>
class PacketDrivenMemoryAttribute< T >

MemoryAttribute for remembering values from packets.

PacketDrivenMemoryAttributes are those which record a value every time a packet arrives; these are generally used to record values extracted from the packets themselves, but could also be used to sample an attribute aggregate value each time a packet arrives.

A PacketDrivenMemoryAttribute has two methods of updating: handlePassedPacket() and update(). handlePassedPacket is invoked at the time one would expect - when those of the other attributes of the same tier as the PacketDrivenMemoryAttribute are called. However, the update() method is called by a Clock (set when the PacketDrivenMemoryAttribute is created), which is likely to be called either only after or only before the Aggregate's callListeners() method is called. It is, however, also called after the body of handlePassedPacket(), so that the attribute is up-to-date after its tier is finished; no guarantees as to what state it's in before then, though.

Examples:

profile_streams_thesis.cc.

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Member Function Documentation

template<class T> vector< T >::const_iterator MemoryAttribute< T >::begin (  void   )  const [virtual, inherited]

get a const iterator pointing to the first (oldest) element of the window Note: Should alias vector<T>::const_iterator to MemoryAttribute<T>::const_iterator for future flexibility Todo: should push all the iterator stuff up to ArrayAttribute, there's no need for it to be here. Implements ArrayAttribute< T >.

template<class T> void MemoryAttribute< T >::buildVector (  void   )  const [protected, inherited]

build or rebuild the vector copy of q Note: Yes, this changes a data member, but in order to use it in a const context, it needs to be const - therefore it uses const_cast to muck around with what it's not technically supposed to be mucking around with.

void Attribute::compute (  void   )  [virtual, inherited]

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

template<class T> const Attribute & MemoryAttribute< T >::getAttrib (  const std::string &  ident  )  const throw ( UnknownAttributeException ) [virtual, inherited]

get an attribute of the attribute Todo: actually implement this, e.g. first and last - will need to template-ize StaticScalarAttribute, though Reimplemented from Attribute.

template<class T> T MemoryAttribute< T >::getInstanceValue (  TraceIterator &  packet  )  const throw ( UnknownAttributeException ) [virtual, inherited]

get the current value of the attribute to remember Parameters: packet  current packet - needed for getting packet attributes

template<class T> double MemoryAttribute< T >::getMax (  void   )  const throw ( InvalidDataTypeException ) [virtual, inherited]

get the maximum element in the memory if they are of an appropriate data type Exceptions: InvalidDataTypeException  if the data type can't be compared

template<class T> double MemoryAttribute< T >::getMin (  void   )  const throw ( InvalidDataTypeException ) [virtual, inherited]

get the minimum element in the memory if they are of an appropriate data type Exceptions: InvalidDataTypeException  if the data type can't be compared

template<class T> double MemoryAttribute< T >::getSum (  void   )  const throw ( InvalidDataTypeException ) [virtual, inherited]

get the sum of the elements in the memory if they are of an appropriate data type Exceptions: InvalidDataTypeException  if the data type can't be summed Todo: this functionality should be implemented in ArrayAttribute. Will need to find a good way to do getAttrib hierarchically first, though, e.g. always call super::getAttrib() before throwing an UnknownAttributeException if you don't know the ident.

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.

template<class T> void PacketDrivenMemoryAttribute< T >::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 MemoryAttribute< T >.

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

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, inherited]

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 >.

template<class T> void PacketDrivenMemoryAttribute< T >::update (  void   )  [virtual]

update the attribute to the given time Note: idempotent - if it's called n times with the same value for tick, the state is the same as if it'd just been called once with that tick value. Implements MemoryAttribute< T >.

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Member Data Documentation

template<class T> const uint32_t MemoryAttribute< T >::ATTRIB_TYPE_AGGREGATE = 1 [static, inherited]

types of attributes that can be remembered Specifically these indicate where the MemoryAttribute needs to look to find the identifier. identifier refers to an attribute attached to the aggregate

template<class T> const uint32_t MemoryAttribute< T >::ATTRIB_TYPE_PACKET = 2 [static, inherited]

identifier refers to an attribute of the packets seen

const int Attribute::TYPE_ARRAY = 33 [static, inherited]

array

const int Attribute::TYPE_DISTRIB = 17 [static, inherited]

statistical distribution

const int Attribute::TYPE_HISTOGRAM = 25 [static, inherited]

histogram

const int Attribute::TYPE_SCALAR = 1 [static, inherited]

single-valued type

const int Attribute::TYPE_SET = 34 [static, inherited]

set

const int Attribute::TYPE_UNKNOWN = 0 [static, inherited]

unknown type

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

• attributes/MemoryAttribute.h
• attributes/MemoryAttribute.cc

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