A forwarding strategy similar to CCNx 0.7.2. More...

#include <daemon/fw/ncc-strategy.hpp>

Inheritance diagram for nfd::fw::NccStrategy:

Collaboration diagram for nfd::fw::NccStrategy:

Classes
class	MeasurementsEntryInfo
	StrategyInfo on measurements::Entry. More...

class	PitEntryInfo
	StrategyInfo on pit::Entry. More...

Public Member Functions
	NccStrategy (Forwarder &forwarder, const Name &name=getStrategyName())

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

virtual void	afterNewNextHop (const fib::NextHop &nextHop, const shared_ptr< pit::Entry > &pitEntry)
	Trigger after new nexthop is added. More...

virtual void	afterReceiveData (const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data)
	Trigger after Data is received. More...

void	afterReceiveInterest (const FaceEndpoint &ingress, const Interest &interest, const shared_ptr< pit::Entry > &pitEntry) override
	Trigger after Interest is received. More...

virtual void	afterReceiveNack (const FaceEndpoint &ingress, const lp::Nack &nack, const shared_ptr< pit::Entry > &pitEntry)
	Trigger after Nack is received. More...

void	beforeSatisfyInterest (const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data) override
	Trigger before PIT entry is satisfied. More...

const Name &	getInstanceName () const

virtual void	onDroppedInterest (const Face &egress, const Interest &interest)
	Trigger after Interest dropped (e.g., for exceeding allowed retransmissions) More...

bool	wantNewNextHopTrigger () const

Static Public Member Functions
static bool	areSameType (const Name &instanceNameA, const Name &instanceNameB)

static bool	canCreate (const Name &instanceName)

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

static const Name &	getStrategyName ()

static std::set< Name >	listRegistered ()

template<typename S >
static void	registerType (const Name &strategyName=S::getStrategyName())
	Register a strategy type. More...

Protected Member Functions
void	doPropagate (FaceId inFaceId, weak_ptr< pit::Entry > pitEntryWeak)
	propagate to another upstream More...

void	enableNewNextHopTrigger (bool enabled)
	Set whether the afterNewNextHop trigger should be invoked for this strategy. More...

Face *	getFace (FaceId id) const

const FaceTable &	getFaceTable () const

MeasurementsAccessor &	getMeasurements ()

MeasurementsEntryInfo &	getMeasurementsEntryInfo (measurements::Entry *entry)

MeasurementsEntryInfo &	getMeasurementsEntryInfo (const shared_ptr< pit::Entry > &entry)

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

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

bool	sendData (const shared_ptr< pit::Entry > &pitEntry, const Data &data, Face &egress)
	Send a Data packet. More...

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

pit::OutRecord *	sendInterest (const shared_ptr< pit::Entry > &pitEntry, Face &egress, const Interest &interest)
	Send an Interest packet. More...

bool	sendNack (const shared_ptr< pit::Entry > &pitEntry, Face &egress, const lp::NackHeader &header)
	Send a Nack packet. More...

void	sendNacks (const shared_ptr< pit::Entry > &pitEntry, const lp::NackHeader &header, std::initializer_list< const Face *> exceptFaces={})
	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...

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

void	timeoutOnBestFace (weak_ptr< pit::Entry > pitEntryWeak)
	best face did not reply within prediction More...

Static Protected Member Functions
static Name	makeInstanceName (const Name &input, const Name &strategyName)
	Construct a strategy instance name. More...

static ParsedInstanceName	parseInstanceName (const Name &input)
	Parse a strategy instance name. More...

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

signal::Signal< FaceTable, Face > &	beforeRemoveFace

Static Protected Attributes
static const time::microseconds	DEFER_FIRST_WITHOUT_BEST_FACE = 4_ms

static const time::microseconds	DEFER_RANGE_WITHOUT_BEST_FACE = 75_ms

static const time::nanoseconds	MEASUREMENTS_LIFETIME = 16_s

static const int	UPDATE_MEASUREMENTS_N_LEVELS = 2

Detailed Description

A forwarding strategy similar to CCNx 0.7.2.

Definition at line 36 of file ncc-strategy.hpp.

Constructor & Destructor Documentation

◆ NccStrategy()

nfd::fw::NccStrategy::NccStrategy	(	Forwarder &	forwarder,
		const Name &	name = `getStrategyName()`
	)

explicit

Definition at line 41 of file ncc-strategy.cpp.

Member Function Documentation

◆ afterContentStoreHit()

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

virtualinherited

Trigger after a Data is matched in CS.

In the base class this method sends data to ingress

Definition at line 162 of file strategy.cpp.

◆ afterNewNextHop()

void nfd::fw::Strategy::afterNewNextHop	(	const fib::NextHop &	nextHop,
		const shared_ptr< pit::Entry > &	pitEntry
	)

virtualinherited

Trigger after new nexthop is added.

The strategy should decide whether to send the buffered Interests to the new nexthop. In the base class, this method does nothing.

Definition at line 208 of file strategy.cpp.

◆ afterReceiveData()

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

virtualinherited

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.

Reimplemented in nfd::fw::SelfLearningStrategy.

Definition at line 172 of file strategy.cpp.

◆ afterReceiveInterest()

void nfd::fw::NccStrategy::afterReceiveInterest	(	const FaceEndpoint &	ingress,
		const Interest &	interest,
		const shared_ptr< pit::Entry > &	pitEntry
	)

overridevirtual

Trigger after Interest is received.

The Interest:

has not exceeded HopLimit
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>.

Implements nfd::fw::Strategy.

Definition at line 63 of file ncc-strategy.cpp.

◆ afterReceiveNack()

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

virtualinherited

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::SelfLearningStrategy, nfd::fw::BestRouteStrategy2, nfd::fw::asf::AsfStrategy, nfd::fw::RandomStrategy, and nfd::fw::MulticastStrategy.

Definition at line 184 of file strategy.cpp.

◆ areSameType()

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

staticinherited

Returns: Whether instanceNameA and instanceNameA will initiate same strategy type

Definition at line 108 of file strategy.cpp.

◆ beforeSatisfyInterest()

void nfd::fw::NccStrategy::beforeSatisfyInterest	(	const shared_ptr< pit::Entry > &	pitEntry,
		const FaceEndpoint &	ingress,
		const Data &	data
	)

overridevirtual

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 from nfd::fw::Strategy.

Definition at line 210 of file ncc-strategy.cpp.

◆ canCreate()

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

staticinherited

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 86 of file strategy.cpp.

◆ create()

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

staticinherited

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 92 of file strategy.cpp.

◆ doPropagate()

void nfd::fw::NccStrategy::doPropagate	(	FaceId	inFaceId,
		weak_ptr< pit::Entry >	pitEntryWeak
	)

protected

propagate to another upstream

Definition at line 136 of file ncc-strategy.cpp.

◆ enableNewNextHopTrigger()

void nfd::fw::Strategy::enableNewNextHopTrigger ( bool enabled )

inlineprotectedinherited

Set whether the afterNewNextHop trigger should be invoked for this strategy.

Definition at line 395 of file strategy.hpp.

◆ getFace()

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

inlineprotectedinherited

Definition at line 343 of file strategy.hpp.

◆ getFaceTable()

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

inlineprotectedinherited

Definition at line 349 of file strategy.hpp.

◆ getInstanceName()

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

inlineinherited

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 112 of file strategy.hpp.

◆ getMeasurements()

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

inlineprotectedinherited

Definition at line 337 of file strategy.hpp.

◆ getMeasurementsEntryInfo() [1/2]

NccStrategy::MeasurementsEntryInfo & nfd::fw::NccStrategy::getMeasurementsEntryInfo ( measurements::Entry * entry )

protected

Definition at line 255 of file ncc-strategy.cpp.

◆ getMeasurementsEntryInfo() [2/2]

NccStrategy::MeasurementsEntryInfo & nfd::fw::NccStrategy::getMeasurementsEntryInfo ( const shared_ptr< pit::Entry > & entry )

protected

Definition at line 248 of file ncc-strategy.cpp.

◆ getStrategyName()

const Name & nfd::fw::NccStrategy::getStrategyName ( )

static

Definition at line 56 of file ncc-strategy.cpp.

◆ listRegistered()

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

staticinherited

Returns: Registered versioned strategy names

Definition at line 114 of file strategy.cpp.

◆ lookupFib()

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

protectedinherited

Performs a FIB lookup, considering Link object if present.

Definition at line 282 of file strategy.cpp.

◆ makeInstanceName()

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

staticprotectedinherited

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 134 of file strategy.cpp.

◆ onDroppedInterest()

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

virtualinherited

Trigger after Interest dropped (e.g., for exceeding allowed retransmissions)

In the base class this method does nothing.

Definition at line 191 of file strategy.cpp.

◆ parseInstanceName()

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

staticprotectedinherited

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 123 of file strategy.cpp.

◆ registerType()

template<typename S >

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

inlinestaticinherited

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.

◆ rejectPendingInterest()

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

inlineprotectedinherited

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 291 of file strategy.hpp.

◆ sendData()

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

protectedinherited

Send a Data packet.

Parameters

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

Returns: Whether the Data was sent (true) or dropped (false)

Definition at line 215 of file strategy.cpp.

◆ sendDataToAll()

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

protectedinherited

Send a Data packet to all matched and qualified faces.

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

Parameters

pitEntry	the PIT entry
inFace	face on which the Data arrived
data	the Data packet

Definition at line 238 of file strategy.cpp.

◆ sendInterest()

pit::OutRecord * nfd::fw::Strategy::sendInterest	(	const shared_ptr< pit::Entry > &	pitEntry,
		Face &	egress,
		const Interest &	interest
	)

protectedinherited

Send an Interest packet.

Parameters

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

Returns: A pointer to the out-record created or nullptr if the Interest was dropped

Definition at line 197 of file strategy.cpp.

◆ sendNack()

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

inlineprotectedinherited

Send a Nack packet.

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

Parameters

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

Returns: Whether the Nack was sent (true) or dropped (false)

Definition at line 306 of file strategy.hpp.

◆ sendNacks()

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

protectedinherited

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

Parameters

pitEntry	the PIT entry
header	the 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 261 of file strategy.cpp.

◆ setExpiryTimer()

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

inlineprotectedinherited

Schedule the PIT entry to be erased after duration.

Definition at line 325 of file strategy.hpp.

◆ setInstanceName()

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

inlineprotectedinherited

Set strategy instance name.

Note: This must be called by strategy subclass constructor.

Definition at line 386 of file strategy.hpp.

◆ timeoutOnBestFace()

void nfd::fw::NccStrategy::timeoutOnBestFace ( weak_ptr< pit::Entry > pitEntryWeak )

protected

best face did not reply within prediction

Definition at line 187 of file ncc-strategy.cpp.

◆ wantNewNextHopTrigger()

bool nfd::fw::Strategy::wantNewNextHopTrigger ( ) const

inlineinherited

Returns: Whether the afterNewNextHop trigger should be invoked for this strategy.

Definition at line 120 of file strategy.hpp.

Member Data Documentation

◆ afterAddFace

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

protectedinherited

Definition at line 411 of file strategy.hpp.

◆ beforeRemoveFace

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

protectedinherited

Definition at line 412 of file strategy.hpp.

◆ DEFER_FIRST_WITHOUT_BEST_FACE

const time::microseconds nfd::fw::NccStrategy::DEFER_FIRST_WITHOUT_BEST_FACE = 4_ms

staticprotected

Definition at line 134 of file ncc-strategy.hpp.

◆ DEFER_RANGE_WITHOUT_BEST_FACE

const time::microseconds nfd::fw::NccStrategy::DEFER_RANGE_WITHOUT_BEST_FACE = 75_ms

staticprotected

Definition at line 135 of file ncc-strategy.hpp.

◆ MEASUREMENTS_LIFETIME

const time::nanoseconds nfd::fw::NccStrategy::MEASUREMENTS_LIFETIME = 16_s

staticprotected

Definition at line 137 of file ncc-strategy.hpp.

◆ UPDATE_MEASUREMENTS_N_LEVELS

const int nfd::fw::NccStrategy::UPDATE_MEASUREMENTS_N_LEVELS = 2

staticprotected

Definition at line 136 of file ncc-strategy.hpp.

NFD: Named Data Networking Forwarding Daemon 0.7.1 documentation

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ NccStrategy()

Member Function Documentation

◆ afterContentStoreHit()

◆ afterNewNextHop()

◆ afterReceiveData()

◆ afterReceiveInterest()

◆ afterReceiveNack()

◆ areSameType()

◆ beforeSatisfyInterest()

◆ canCreate()

◆ create()

◆ doPropagate()

◆ enableNewNextHopTrigger()

◆ getFace()

◆ getFaceTable()

◆ getInstanceName()

◆ getMeasurements()

◆ getMeasurementsEntryInfo() [1/2]

◆ getMeasurementsEntryInfo() [2/2]

◆ getStrategyName()

◆ listRegistered()

◆ lookupFib()

◆ makeInstanceName()

◆ onDroppedInterest()

◆ parseInstanceName()

◆ registerType()

◆ rejectPendingInterest()

◆ sendData()

◆ sendDataToAll()

◆ sendInterest()

◆ sendNack()

◆ sendNacks()

◆ setExpiryTimer()

◆ setInstanceName()

◆ timeoutOnBestFace()

◆ wantNewNextHopTrigger()

Member Data Documentation

◆ afterAddFace

◆ beforeRemoveFace

◆ DEFER_FIRST_WITHOUT_BEST_FACE

◆ DEFER_RANGE_WITHOUT_BEST_FACE

◆ MEASUREMENTS_LIFETIME

◆ UPDATE_MEASUREMENTS_N_LEVELS