Adaptive SRTT-based Forwarding Strategy. More...

#include <asf-strategy.hpp>

Inheritance diagram for nfd::fw::asf::AsfStrategy:

Collaboration diagram for nfd::fw::asf::AsfStrategy:

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

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

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

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

Public Member Functions inherited from nfd::fw::Strategy
	Strategy (Forwarder &forwarder)
	Construct a strategy instance. More...

virtual	~Strategy ()

const Name &	getInstanceName () const

virtual void	afterReceiveLoopedInterest (const FaceEndpoint &ingress, const Interest &interest, pit::Entry &pitEntry)
	trigger after a looped Interest is received More...

virtual void	satisfyInterest (const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data, std::set< std::pair< Face , EndpointId >> &satisfiedDownstreams, std::set< std::pair< Face , EndpointId >> &unsatisfiedDownstreams)

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

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

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

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

Static Public Member Functions
static const Name &	getStrategyName ()

Static Public Member Functions inherited from nfd::fw::Strategy
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 ()

Additional Inherited Members
Protected Member Functions inherited from nfd::fw::Strategy
NFD_VIRTUAL_WITH_TESTS pit::OutRecord *	sendInterest (const Interest &interest, Face &egress, const shared_ptr< pit::Entry > &pitEntry)
	Send an Interest packet. More...

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

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

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

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

void	sendNacks (const lp::NackHeader &header, const shared_ptr< pit::Entry > &pitEntry, 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...

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

signal::Signal< FaceTable, Face > &	beforeRemoveFace

Detailed Description

Adaptive SRTT-based Forwarding Strategy.

See also: Vince Lehman, Ashlesh Gawande, Rodrigo Aldecoa, Dmitri Krioukov, Beichuan Zhang, Lixia Zhang, and Lan Wang, "An Experimental Investigation of Hyperbolic Routing with a Smart Forwarding Plane in NDN", NDN Technical Report NDN-0042, 2016. https://named-data.net/publications/techreports/ndn-0042-1-asf/

Definition at line 45 of file asf-strategy.hpp.

Constructor & Destructor Documentation

◆ AsfStrategy()

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

explicit

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

References nfd::fw::asf::ProbingModule::getProbingInterval(), getStrategyName(), nfd::fw::Strategy::makeInstanceName(), NDN_THROW, NFD_LOG_DEBUG, nfd::fw::Strategy::ParsedInstanceName::parameters, nfd::fw::Strategy::parseInstanceName(), nfd::fw::Strategy::setInstanceName(), ndn::to_string(), and nfd::fw::Strategy::ParsedInstanceName::version.

Member Function Documentation

◆ getStrategyName()

const Name & nfd::fw::asf::AsfStrategy::getStrategyName ( )

static

Definition at line 65 of file asf-strategy.cpp.

References ns3::ndn::Name.

Referenced by AsfStrategy().

◆ afterReceiveInterest()

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

overridevirtual

Trigger after an 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 the 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 a copy of the pitEntry shared_ptr after this function returns, otherwise undefined behavior may occur. However, the strategy is allowed to construct and keep a weak_ptr to pitEntry.

Implements nfd::fw::Strategy.

Definition at line 112 of file asf-strategy.cpp.

References nfd::fw::RetxSuppressionExponential::decidePerUpstream(), nfd::FaceEndpoint::face, nfd::fw::findEligibleNextHopWithEarliestOutRecord(), nfd::fw::FORWARD, nfd::fw::hasPendingOutRecords(), nfd::fw::RetxSuppressionExponential::incrementIntervalForOutRecord(), nfd::fw::Strategy::lookupFib(), NFD_LOG_DEBUG, nfd::fw::Strategy::sendInterest(), and nfd::fw::SUPPRESS.

◆ beforeSatisfyInterest()

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

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 178 of file asf-strategy.cpp.

References nfd::fw::asf::FaceInfo::cancelTimeout(), nfd::fw::asf::NamespaceInfo::extendFaceInfoLifetime(), nfd::FaceEndpoint::face, nfd::fw::asf::NamespaceInfo::getFaceInfo(), nfd::fw::asf::FaceInfo::getLastRtt(), ndn::Data::getName(), nfd::fw::asf::AsfMeasurements::getNamespaceInfo(), nfd::fw::asf::FaceInfo::getSrtt(), NFD_LOG_DEBUG, ndn::time::steady_clock::now(), nfd::fw::asf::FaceInfo::recordRtt(), and nfd::fw::Strategy::setExpiryTimer().

◆ afterReceiveNack()

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

overridevirtual

Trigger after a 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 will normally 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 prolong the PIT entry lifetime. If a Nack arrives from another upstream during the extended PIT entry lifetime, this trigger will be invoked again. At that time, the strategy must invoke setExpiryTimer() again to continue collecting more responses.

In the base class, this method does nothing.

Warning: The strategy must not retain a copy of the pitEntry shared_ptr after this function returns, otherwise undefined behavior may occur. However, the strategy is allowed to construct and keep a weak_ptr to pitEntry.

Reimplemented from nfd::fw::Strategy.

Definition at line 212 of file asf-strategy.cpp.

References nfd::fw::asf::ProbingModule::afterForwardingProbe(), nfd::fw::asf::NamespaceInfo::extendFaceInfoLifetime(), Face, nfd::FaceEndpoint::face, nfd::fw::asf::ProbingModule::getFaceToProbe(), ndn::lp::Nack::getInterest(), ndn::Interest::getName(), nfd::fw::asf::AsfMeasurements::getOrCreateFaceInfo(), nfd::fw::asf::AsfMeasurements::getOrCreateNamespaceInfo(), nfd::fib::Entry::getPrefix(), ndn::lp::Nack::getReason(), nfd::fw::asf::ProbingModule::isProbingNeeded(), nfd::fw::asf::FaceInfo::isTimeoutScheduled(), NFD_LOG_DEBUG, NFD_LOG_TRACE, ndn::Interest::refreshNonce(), nfd::fw::asf::FaceInfo::scheduleTimeout(), nfd::fw::Strategy::sendInterest(), and websocketpp::transport::error::timeout.

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

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

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ AsfStrategy()

Member Function Documentation

◆ getStrategyName()

◆ afterReceiveInterest()

◆ beforeSatisfyInterest()

◆ afterReceiveNack()