represents a forwarding strategy More...

#include <strategy.hpp>

Inheritance diagram for nfd::fw::Strategy:

[legend]

Collaboration diagram for nfd::fw::Strategy:

Classes
struct	ParsedInstanceName

Public Member Functions
	Strategy (Forwarder &forwarder)
	construct a strategy instance More...

virtual	~Strategy ()

const Name &	getInstanceName () const

virtual void	afterReceiveInterest (const Face &inFace, const Interest &interest, const shared_ptr< pit::Entry > &pitEntry)=0
	trigger after Interest is received More...

virtual void	beforeSatisfyInterest (const shared_ptr< pit::Entry > &pitEntry, const Face &inFace, const Data &data)
	trigger before PIT entry is satisfied More...

virtual void	afterContentStoreHit (const shared_ptr< pit::Entry > &pitEntry, const Face &inFace, const Data &data)
	trigger after a Data is matched in CS More...

virtual void	afterReceiveData (const shared_ptr< pit::Entry > &pitEntry, const Face &inFace, const Data &data)
	trigger after Data is received More...

virtual void	afterReceiveNack (const Face &inFace, const lp::Nack &nack, const shared_ptr< pit::Entry > &pitEntry)
	trigger after Nack is received More...

virtual void	onDroppedInterest (const Face &outFace, const Interest &interest)
	trigger after Interest dropped for exceeding allowed retransmissions More...

Static Public Member Functions
template<typename S >
static void	registerType (const Name &strategyName=S::getStrategyName())
	register a strategy type More...

static bool	canCreate (const Name &instanceName)

static unique_ptr< Strategy >	create (const Name &instanceName, Forwarder &forwarder)

static bool	areSameType (const Name &instanceNameA, const Name &instanceNameB)

static std::set< Name >	listRegistered ()

static const Name &	getStrategyName ()

Protected Member Functions
void	sendInterest (const shared_ptr< pit::Entry > &pitEntry, Face &outFace, const Interest &interest)
	send Interest to outFace More...

void	sendData (const shared_ptr< pit::Entry > &pitEntry, const Data &data, const Face &outFace)
	send `data` to `outFace` More...

void	sendDataToAll (const shared_ptr< pit::Entry > &pitEntry, const Face &inFace, const Data &data)
	send `data` to all matched and qualified faces More...

void	rejectPendingInterest (const shared_ptr< pit::Entry > &pitEntry)
	schedule the PIT entry for immediate deletion More...

void	sendNack (const shared_ptr< pit::Entry > &pitEntry, const Face &outFace, const lp::NackHeader &header)
	send Nack to outFace More...

void	sendNacks (const shared_ptr< pit::Entry > &pitEntry, const lp::NackHeader &header, std::initializer_list< const Face > exceptFaces=std::initializer_list< const Face >())
	send Nack to every face that has an in-record, except those in `exceptFaces` More...

void	setExpiryTimer (const shared_ptr< pit::Entry > &pitEntry, time::milliseconds duration)
	Schedule the PIT entry to be erased after `duration`. More...

const fib::Entry &	lookupFib (const pit::Entry &pitEntry) const
	performs a FIB lookup, considering Link object if present More...

MeasurementsAccessor &	getMeasurements ()

Face *	getFace (FaceId id) const

const FaceTable &	getFaceTable () const

void	setInstanceName (const Name &name)
	set strategy instance name More...

Static Protected Member Functions
static ParsedInstanceName	parseInstanceName (const Name &input)
	parse a strategy instance name More...

static Name	makeInstanceName (const Name &input, const Name &strategyName)
	construct a strategy instance name More...

Protected Attributes
signal::Signal< FaceTable, Face & > &	afterAddFace

signal::Signal< FaceTable, Face & > &	beforeRemoveFace

Detailed Description

represents a forwarding strategy

Definition at line 37 of file strategy.hpp.

Constructor & Destructor Documentation

◆ Strategy()

nfd::fw::Strategy::Strategy ( Forwarder & forwarder )

explicit

construct a strategy instance

Parameters

forwarder a reference to the forwarder, used to enable actions and accessors.

Note: Strategy subclass constructor should not retain a reference to the forwarder.

Definition at line 141 of file strategy.cpp.

◆ ~Strategy()

nfd::fw::Strategy::~Strategy ( )

virtualdefault

Member Function Documentation

◆ registerType()

template<typename S >

static void nfd::fw::Strategy::registerType ( const Name & strategyName = S::getStrategyName() )

inlinestatic

register a strategy type

Template Parameters

S	subclass of Strategy

Parameters

strategyName strategy program name, must contain version

Note: It is permitted to register the same strategy type under multiple names, which is useful in tests and for creating aliases.

Definition at line 48 of file strategy.hpp.

◆ canCreate()

bool nfd::fw::Strategy::canCreate ( const Name & instanceName )

static

Returns: whether a strategy instance can be created from instanceName

Parameters

instanceName strategy instance name, may contain version and parameters

Note: This function finds a strategy type using same rules as create , but does not attempt to construct an instance.

Definition at line 84 of file strategy.cpp.

◆ create()

unique_ptr< Strategy > nfd::fw::Strategy::create	(	const Name &	instanceName,
		Forwarder &	forwarder
	)

static

Returns: a strategy instance created from instanceName

Return values

nullptr if !canCreate(instanceName)

Exceptions

std::invalid_argument strategy type constructor does not accept specified version or parameters

Definition at line 90 of file strategy.cpp.

References NFD_LOG_DEBUG.

Referenced by nfd::strategy_choice::StrategyChoice::insert(), and nfd::strategy_choice::StrategyChoice::setDefaultStrategy().

◆ areSameType()

bool nfd::fw::Strategy::areSameType	(	const Name &	instanceNameA,
		const Name &	instanceNameB
	)

static

Returns: whether instanceNameA and instanceNameA will initiate same strategy type

Definition at line 106 of file strategy.cpp.

◆ listRegistered()

std::set< Name > nfd::fw::Strategy::listRegistered ( )

static

Returns: registered versioned strategy names

Definition at line 112 of file strategy.cpp.

◆ getStrategyName()

static const Name& nfd::fw::Strategy::getStrategyName ( )

static

Returns: strategy program name

The strategy name is defined by the strategy program. It must end with a version component.

◆ getInstanceName()

const Name& nfd::fw::Strategy::getInstanceName ( ) const

inline

Returns: strategy instance name

The instance name is assigned during instantiation. It contains a version component, and may have extra parameter components.

Definition at line 110 of file strategy.hpp.

Referenced by nfd::strategy_choice::Entry::getStrategyInstanceName(), and nfd::strategy_choice::StrategyChoice::insert().

◆ afterReceiveInterest()

virtual void nfd::fw::Strategy::afterReceiveInterest	(	const Face &	inFace,
		const Interest &	interest,
		const shared_ptr< pit::Entry > &	pitEntry
	)

pure virtual

trigger after Interest is received

The Interest:

does not violate Scope
is not looped
cannot be satisfied by ContentStore
is under a namespace managed by this strategy

The PIT entry is set to expire after InterestLifetime has elapsed at each downstream.

The strategy should decide whether and where to forward this Interest.

If the strategy decides to forward this Interest, invoke sendInterest for each upstream, either now or shortly after via a scheduler event, but before PIT entry expires. Optionally, the strategy can invoke setExpiryTimer to adjust how long it would wait for a response.
If the strategy has already forwarded this Interest previously and decides to continue waiting, do nothing. Optionally, the strategy can invoke setExpiryTimer to adjust how long it would wait for a response.
If the strategy concludes that this Interest cannot be satisfied, invoke rejectPendingInterest to erase the PIT entry.

Warning: The strategy must not retain shared_ptr<pit::Entry>, otherwise undefined behavior may occur. However, the strategy is allowed to store weak_ptr<pit::Entry>.

Implemented in nfd::fw::BestRouteStrategy2, nfd::fw::AccessStrategy, nfd::fw::asf::AsfStrategy, nfd::fw::MulticastStrategy, nfd::fw::NccStrategy, and nfd::fw::BestRouteStrategyBase.

◆ beforeSatisfyInterest()

void nfd::fw::Strategy::beforeSatisfyInterest	(	const shared_ptr< pit::Entry > &	pitEntry,
		const Face &	inFace,
		const Data &	data
	)

virtual

trigger before PIT entry is satisfied

This trigger is invoked when an incoming Data satisfies more than one PIT entry. The strategy can collect measurements information, but cannot manipulate Data forwarding. When an incoming Data satisfies only one PIT entry, afterReceiveData is invoked instead and given full control over Data forwarding. If a strategy does not override afterReceiveData, the default implementation invokes beforeSatisfyInterest.

Normally, PIT entries would be erased after receiving the first matching Data. If the strategy wishes to collect responses from additional upstream nodes, it should invoke setExpiryTimer within this function to prolong the PIT entry lifetime. If a Data arrives from another upstream during the extended PIT entry lifetime, this trigger will be invoked again. At that time, this function must invoke setExpiryTimer again to continue collecting more responses.

In this base class this method does nothing.

Warning: The strategy must not retain shared_ptr<pit::Entry>, otherwise undefined behavior may occur. However, the strategy is allowed to store weak_ptr<pit::Entry>.

Reimplemented in nfd::fw::AccessStrategy, nfd::fw::asf::AsfStrategy, and nfd::fw::NccStrategy.

Definition at line 152 of file strategy.cpp.

References nfd::face::Face::getId(), ndn::Data::getName(), and NFD_LOG_DEBUG.

Referenced by afterReceiveData().

◆ afterContentStoreHit()

void nfd::fw::Strategy::afterContentStoreHit	(	const shared_ptr< pit::Entry > &	pitEntry,
		const Face &	inFace,
		const Data &	data
	)

virtual

trigger after a Data is matched in CS

In the base class this method sends data to inFace

Definition at line 160 of file strategy.cpp.

References nfd::face::Face::getId(), ndn::Data::getName(), NFD_LOG_DEBUG, and sendData().

◆ afterReceiveData()

void nfd::fw::Strategy::afterReceiveData	(	const shared_ptr< pit::Entry > &	pitEntry,
		const Face &	inFace,
		const Data &	data
	)

virtual

trigger after Data is received

This trigger is invoked when an incoming Data satisfies exactly one PIT entry, and gives the strategy full control over Data forwarding.

When this trigger is invoked:

The Data has been verified to satisfy the PIT entry.
The PIT entry expiry timer is set to now

Within this function:

A strategy should return Data to downstream nodes via sendData or sendDataToAll.
A strategy can modify the Data as long as it still satisfies the PIT entry, such as adding or removing congestion marks.
A strategy can delay Data forwarding by prolonging the PIT entry lifetime via setExpiryTimer, and forward Data before the PIT entry is erased.
A strategy can collect measurements about the upstream.
A strategy can collect responses from additional upstream nodes by prolonging the PIT entry lifetime via setExpiryTimer every time a Data is received. Note that only one Data should be returned to each downstream node.

In the base class this method invokes beforeSatisfyInterest trigger and then returns the Data to downstream faces via sendDataToAll.

Definition at line 170 of file strategy.cpp.

References beforeSatisfyInterest(), nfd::face::Face::getId(), ndn::Data::getName(), NFD_LOG_DEBUG, and sendDataToAll().

◆ afterReceiveNack()

void nfd::fw::Strategy::afterReceiveNack	(	const Face &	inFace,
		const lp::Nack &	nack,
		const shared_ptr< pit::Entry > &	pitEntry
	)

virtual

trigger after Nack is received

This trigger is invoked when an incoming Nack is received in response to an forwarded Interest. The Nack has been confirmed to be a response to the last Interest forwarded to that upstream, i.e. the PIT out-record exists and has a matching Nonce. The NackHeader has been recorded in the PIT out-record.

If the PIT entry is not yet satisfied, its expiry timer remains unchanged. Otherwise, the PIT entry normally would expire immediately after this function returns.

If the strategy wishes to collect responses from additional upstream nodes, it should invoke setExpiryTimer within this function to retain the PIT entry. If a Nack arrives from another upstream during the extended PIT entry lifetime, this trigger will be invoked again. At that time, this function must invoke setExpiryTimer again to continue collecting more responses.

In the base class this method does nothing.

Warning: The strategy must not retain shared_ptr<pit::Entry>, otherwise undefined behavior may occur. However, the strategy is allowed to store weak_ptr<pit::Entry>.

Reimplemented in nfd::fw::BestRouteStrategy2, nfd::fw::asf::AsfStrategy, and nfd::fw::MulticastStrategy.

Definition at line 182 of file strategy.cpp.

References nfd::face::Face::getId(), and NFD_LOG_DEBUG.

◆ onDroppedInterest()

void nfd::fw::Strategy::onDroppedInterest	(	const Face &	outFace,
		const Interest &	interest
	)

virtual

trigger after Interest dropped for exceeding allowed retransmissions

In the base class this method does nothing.

Definition at line 190 of file strategy.cpp.

References nfd::face::Face::getId(), ndn::Interest::getName(), and NFD_LOG_DEBUG.

◆ sendInterest()

void nfd::fw::Strategy::sendInterest	(	const shared_ptr< pit::Entry > &	pitEntry,
		Face &	outFace,
		const Interest &	interest
	)

inlineprotected

send Interest to outFace

Parameters

pitEntry	PIT entry
outFace	face through which to send out the Interest
interest	the Interest packet

Definition at line 241 of file strategy.hpp.

Referenced by nfd::fw::BestRouteStrategyBase::afterReceiveInterest(), nfd::fw::NccStrategy::afterReceiveInterest(), nfd::fw::MulticastStrategy::afterReceiveInterest(), nfd::fw::BestRouteStrategy2::afterReceiveInterest(), and nfd::fw::NccStrategy::doPropagate().

◆ sendData()

void nfd::fw::Strategy::sendData	(	const shared_ptr< pit::Entry > &	pitEntry,
		const Data &	data,
		const Face &	outFace
	)

protected

send data to outFace

Parameters

pitEntry	PIT entry
data	the Data packet
outFace	face through which to send out the Data

Definition at line 196 of file strategy.cpp.

Referenced by afterContentStoreHit(), and sendDataToAll().

◆ sendDataToAll()

void nfd::fw::Strategy::sendDataToAll	(	const shared_ptr< pit::Entry > &	pitEntry,
		const Face &	inFace,
		const Data &	data
	)

protected

send data to all matched and qualified faces

A matched face is qualified if it is ad-hoc or it is NOT inFace

Parameters

pitEntry	PIT entry
inFace	face through which the Data comes from
data	the Data packet

Definition at line 208 of file strategy.cpp.

References nfd::face::Face::getId(), ndn::nfd::LINK_TYPE_AD_HOC, ndn::time::steady_clock::now(), and sendData().

Referenced by afterReceiveData().

◆ rejectPendingInterest()

void nfd::fw::Strategy::rejectPendingInterest ( const shared_ptr< pit::Entry > & pitEntry )

inlineprotected

schedule the PIT entry for immediate deletion

This helper function sets the PIT entry expiry time to zero. The strategy should invoke this function when it concludes that the Interest cannot be forwarded and it does not want to wait for responses from existing upstream nodes.

Definition at line 273 of file strategy.hpp.

References setExpiryTimer().

Referenced by nfd::fw::BestRouteStrategyBase::afterReceiveInterest(), nfd::fw::NccStrategy::afterReceiveInterest(), nfd::fw::MulticastStrategy::afterReceiveInterest(), nfd::fw::asf::AsfStrategy::afterReceiveInterest(), and nfd::fw::BestRouteStrategy2::afterReceiveInterest().

◆ sendNack()

void nfd::fw::Strategy::sendNack	(	const shared_ptr< pit::Entry > &	pitEntry,
		const Face &	outFace,
		const lp::NackHeader &	header
	)

inlineprotected

send Nack to outFace

Parameters

pitEntry	PIT entry
outFace	face through which to send out the Nack
header	Nack header

The outFace must have a PIT in-record, otherwise this method has no effect.

Definition at line 286 of file strategy.hpp.

Referenced by nfd::fw::MulticastStrategy::afterReceiveInterest(), nfd::fw::BestRouteStrategy2::afterReceiveInterest(), and sendNacks().

◆ sendNacks()

void nfd::fw::Strategy::sendNacks	(	const shared_ptr< pit::Entry > &	pitEntry,
		const lp::NackHeader &	header,
		std::initializer_list< const Face *>	exceptFaces = `std::initializer_list<const Face*>()`
	)

protected

send Nack to every face that has an in-record, except those in exceptFaces

Parameters

pitEntry	PIT entry
header	NACK header
exceptFaces	list of faces that should be excluded from sending Nacks

Note: This is not an action, but a helper that invokes the sendNack action.

Definition at line 230 of file strategy.cpp.

References nfd::pit::FaceRecord::getFace(), and sendNack().

◆ setExpiryTimer()

void nfd::fw::Strategy::setExpiryTimer	(	const shared_ptr< pit::Entry > &	pitEntry,
		time::milliseconds	duration
	)

inlineprotected

Schedule the PIT entry to be erased after duration.

Definition at line 306 of file strategy.hpp.

Referenced by rejectPendingInterest().

◆ lookupFib()

const fib::Entry & nfd::fw::Strategy::lookupFib ( const pit::Entry & pitEntry ) const

protected

performs a FIB lookup, considering Link object if present

Definition at line 252 of file strategy.cpp.

References ndn::DelegationList::empty(), nfd::fib::Fib::findLongestPrefixMatch(), nfd::Forwarder::getFib(), ndn::Interest::getForwardingHint(), nfd::pit::Entry::getInterest(), nfd::Forwarder::getNetworkRegionTable(), nfd::fib::Entry::getPrefix(), nfd::NetworkRegionTable::isInProducerRegion(), and NFD_LOG_TRACE.

Referenced by nfd::fw::BestRouteStrategyBase::afterReceiveInterest(), nfd::fw::NccStrategy::afterReceiveInterest(), nfd::fw::MulticastStrategy::afterReceiveInterest(), nfd::fw::asf::AsfStrategy::afterReceiveInterest(), nfd::fw::BestRouteStrategy2::afterReceiveInterest(), and nfd::fw::NccStrategy::doPropagate().

◆ getMeasurements()

MeasurementsAccessor& nfd::fw::Strategy::getMeasurements ( )

inlineprotected

Definition at line 318 of file strategy.hpp.

Referenced by nfd::fw::NccStrategy::beforeSatisfyInterest(), nfd::fw::NccStrategy::getMeasurementsEntryInfo(), and nfd::fw::NccStrategy::timeoutOnBestFace().

◆ getFace()

Face* nfd::fw::Strategy::getFace ( FaceId id ) const

inlineprotected

Definition at line 324 of file strategy.hpp.

References nfd::Forwarder::getFace().

Referenced by nfd::fw::NccStrategy::doPropagate().

◆ getFaceTable()

const FaceTable& nfd::fw::Strategy::getFaceTable ( ) const

inlineprotected

Definition at line 330 of file strategy.hpp.

References nfd::Forwarder::getFaceTable().

◆ parseInstanceName()

Strategy::ParsedInstanceName nfd::fw::Strategy::parseInstanceName ( const Name & input )

staticprotected

parse a strategy instance name

Parameters

input strategy instance name, may contain version and parameters

Exceptions

std::invalid_argument input format is unacceptable

Definition at line 121 of file strategy.cpp.

References ndn::Name::getPrefix(), ndn::Name::getSubName(), ndn::nullopt, and ndn::Name::size().

Referenced by nfd::fw::AccessStrategy::AccessStrategy(), nfd::fw::asf::AsfStrategy::AsfStrategy(), nfd::fw::BestRouteStrategy::BestRouteStrategy(), nfd::fw::BestRouteStrategy2::BestRouteStrategy2(), nfd::fw::ClientControlStrategy::ClientControlStrategy(), nfd::fw::MulticastStrategy::MulticastStrategy(), and nfd::fw::NccStrategy::NccStrategy().

◆ makeInstanceName()

Name nfd::fw::Strategy::makeInstanceName	(	const Name &	input,
		const Name &	strategyName
	)

staticprotected

construct a strategy instance name

Parameters

input	strategy instance name, may contain version and parameters
strategyName	strategy name with version but without parameters; typically this should be `getStrategyName()`

If input contains a version component, return input unchanged. Otherwise, return input plus the version component taken from strategyName. This allows a strategy instance to be constructed with an unversioned name, but its final instance name should contain the version.

Definition at line 132 of file strategy.cpp.

References ndn::Name::at(), ndn::name::Component::isVersion(), ns3::ndn::Name, ndn::Name::rbegin(), and ndn::Name::rend().

Referenced by nfd::fw::AccessStrategy::AccessStrategy(), nfd::fw::asf::AsfStrategy::AsfStrategy(), nfd::fw::BestRouteStrategy::BestRouteStrategy(), nfd::fw::BestRouteStrategy2::BestRouteStrategy2(), nfd::fw::ClientControlStrategy::ClientControlStrategy(), nfd::fw::MulticastStrategy::MulticastStrategy(), and nfd::fw::NccStrategy::NccStrategy().

◆ setInstanceName()

void nfd::fw::Strategy::setInstanceName ( const Name & name )

inlineprotected

set strategy instance name

Note: This must be called by strategy subclass constructor.

Definition at line 367 of file strategy.hpp.

Referenced by nfd::fw::AccessStrategy::AccessStrategy(), nfd::fw::asf::AsfStrategy::AsfStrategy(), nfd::fw::BestRouteStrategy::BestRouteStrategy(), nfd::fw::BestRouteStrategy2::BestRouteStrategy2(), nfd::fw::ClientControlStrategy::ClientControlStrategy(), nfd::fw::MulticastStrategy::MulticastStrategy(), and nfd::fw::NccStrategy::NccStrategy().

Member Data Documentation

◆ afterAddFace

signal::Signal<FaceTable, Face&>& nfd::fw::Strategy::afterAddFace

protected

Definition at line 383 of file strategy.hpp.

◆ beforeRemoveFace

signal::Signal<FaceTable, Face&>& nfd::fw::Strategy::beforeRemoveFace

protected

Definition at line 384 of file strategy.hpp.

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

ndnSIM/NFD/daemon/fw/strategy.hpp
ndnSIM/NFD/daemon/fw/strategy.cpp

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Strategy()

◆ ~Strategy()

Member Function Documentation

◆ registerType()

◆ canCreate()

◆ create()

◆ areSameType()

◆ listRegistered()

◆ getStrategyName()

◆ getInstanceName()

◆ afterReceiveInterest()

◆ beforeSatisfyInterest()

◆ afterContentStoreHit()

◆ afterReceiveData()

◆ afterReceiveNack()

◆ onDroppedInterest()

◆ sendInterest()

◆ sendData()

◆ sendDataToAll()

◆ rejectPendingInterest()

◆ sendNack()

◆ sendNacks()

◆ setExpiryTimer()

◆ lookupFib()

◆ getMeasurements()

◆ getFace()

◆ getFaceTable()

◆ parseInstanceName()

◆ makeInstanceName()

◆ setInstanceName()

Member Data Documentation

◆ afterAddFace

◆ beforeRemoveFace