Best Route strategy. More...

#include <best-route-strategy.hpp>

Inheritance diagram for nfd::fw::BestRouteStrategy:

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Collaboration diagram for nfd::fw::BestRouteStrategy:

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Public Member Functions
	BestRouteStrategy (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	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	beforeSatisfyInterest (const Data &data, const FaceEndpoint &ingress, const shared_ptr< pit::Entry > &pitEntry)
	trigger before PIT entry is satisfied 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 ()

Public Attributes
NFD_PUBLIC_WITH_TESTS_ELSE_PRIVATE	__pad0__: static const time::milliseconds RETX_SUPPRESSION_INITIAL

RetxSuppressionExponential	m_retxSuppression

friend	ProcessNackTraits< BestRouteStrategy >

Static Public Attributes
static const time::milliseconds	RETX_SUPPRESSION_MAX

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...

Protected Member Functions inherited from nfd::fw::ProcessNackTraits< BestRouteStrategy >
	ProcessNackTraits (BestRouteStrategy *strategy)

Protected Member Functions inherited from nfd::fw::ProcessNackTraitsBase
virtual	~ProcessNackTraitsBase ()=default

void	processNack (const lp::Nack &nack, const Face &inFace, const shared_ptr< pit::Entry > &pitEntry)

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

Best Route strategy.

This strategy forwards a new Interest to the lowest-cost nexthop (except downstream). After that, if consumer retransmits the Interest (and is not suppressed according to exponential backoff algorithm), the strategy forwards the Interest again to the lowest-cost nexthop (except downstream) that is not previously used. If all nexthops have been used, the strategy starts over with the first nexthop.

This strategy returns Nack to all downstreams with reason NoRoute if there is no usable nexthop, which may be caused by: (a) the FIB entry contains no nexthop; (b) the FIB nexthop happens to be the sole downstream; (c) the FIB nexthops violate scope.

This strategy returns Nack to all downstreams if all upstreams have returned Nacks. The reason of the sent Nack equals the least severe reason among received Nacks.

Definition at line 53 of file best-route-strategy.hpp.

Constructor & Destructor Documentation

◆ BestRouteStrategy()

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

explicit

Definition at line 39 of file best-route-strategy.cpp.

References getStrategyName(), nfd::fw::Strategy::makeInstanceName(), NDN_THROW, 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::BestRouteStrategy::getStrategyName ( )

static

Definition at line 58 of file best-route-strategy.cpp.

References ns3::ndn::Name.

Referenced by BestRouteStrategy(), and nfd::getDefaultStrategyName().

◆ afterReceiveInterest()

void nfd::fw::BestRouteStrategy::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 65 of file best-route-strategy.cpp.

References nfd::fw::RetxSuppressionExponential::decidePerPitEntry(), Face, nfd::FaceEndpoint::face, nfd::fw::findEligibleNextHopWithEarliestOutRecord(), nfd::fib::Entry::getNextHops(), nfd::fw::isNextHopEligible(), nfd::fw::Strategy::lookupFib(), m_retxSuppression, nfd::fw::NEW, NFD_LOG_DEBUG, ndn::time::steady_clock::now(), nfd::fw::Strategy::rejectPendingInterest(), nfd::fw::Strategy::sendInterest(), nfd::fw::Strategy::sendNack(), ndn::lp::NackHeader::setReason(), and nfd::fw::SUPPRESS.

◆ afterReceiveNack()

void nfd::fw::BestRouteStrategy::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 126 of file best-route-strategy.cpp.

References nfd::FaceEndpoint::face, and nfd::fw::ProcessNackTraitsBase::processNack().

Member Data Documentation

◆ pad0

NFD_PUBLIC_WITH_TESTS_ELSE_PRIVATE nfd::fw::BestRouteStrategy::__pad0__

Definition at line 73 of file best-route-strategy.hpp.

◆ RETX_SUPPRESSION_MAX

const time::milliseconds nfd::fw::BestRouteStrategy::RETX_SUPPRESSION_MAX

static

Definition at line 74 of file best-route-strategy.hpp.

◆ m_retxSuppression

RetxSuppressionExponential nfd::fw::BestRouteStrategy::m_retxSuppression

Definition at line 75 of file best-route-strategy.hpp.

Referenced by afterReceiveInterest().

◆ ProcessNackTraits< BestRouteStrategy >

friend nfd::fw::BestRouteStrategy::ProcessNackTraits< BestRouteStrategy >

Definition at line 77 of file best-route-strategy.hpp.

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

ndnSIM/NFD/daemon/fw/best-route-strategy.hpp
ndnSIM/NFD/daemon/fw/best-route-strategy.cpp

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Additional Inherited Members