NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.3: NDN, CCN, CCNx, content centric networks
API Documentation
nfd::fw::BestRouteStrategy2 Class Reference

Best Route strategy version 4. More...

#include <best-route-strategy2.hpp>

Inheritance diagram for nfd::fw::BestRouteStrategy2:
Collaboration diagram for nfd::fw::BestRouteStrategy2:

Public Member Functions

 BestRouteStrategy2 (Forwarder &forwarder, const Name &name=STRATEGY_NAME)
 
virtual void afterReceiveInterest (const Face &inFace, const Interest &interest, const shared_ptr< pit::Entry > &pitEntry) override
 trigger after Interest is received More...
 
virtual void afterReceiveNack (const Face &inFace, const lp::Nack &nack, const shared_ptr< pit::Entry > &pitEntry) override
 trigger after Nack is received More...
 
- Public Member Functions inherited from nfd::fw::Strategy
 Strategy (Forwarder &forwarder, const Name &name)
 construct a strategy instance More...
 
virtual ~Strategy ()
 
const NamegetName () const
 
virtual void beforeSatisfyInterest (const shared_ptr< pit::Entry > &pitEntry, const Face &inFace, const Data &data)
 trigger before PIT entry is satisfied More...
 
virtual void beforeExpirePendingInterest (const shared_ptr< pit::Entry > &pitEntry)
 trigger before PIT entry expires More...
 

Static Public Attributes

static const Name STRATEGY_NAME
 

Additional Inherited Members

- Protected Member Functions inherited from nfd::fw::Strategy
void sendInterest (const shared_ptr< pit::Entry > &pitEntry, Face &outFace, const Interest &interest)
 send Interest to outFace More...
 
 DEPRECATED (void sendInterest(const shared_ptr< pit::Entry > &pitEntry, Face &outFace, bool wantNewNonce=false))
 send Interest to outFace More...
 
void rejectPendingInterest (const shared_ptr< pit::Entry > &pitEntry)
 decide that a pending Interest cannot be forwarded 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...
 
const fib::EntrylookupFib (const pit::Entry &pitEntry) const
 performs a FIB lookup, considering Link object if present More...
 
MeasurementsAccessorgetMeasurements ()
 
FacegetFace (FaceId id) const
 
const FaceTablegetFaceTable () const
 
- Protected Attributes inherited from nfd::fw::Strategy
signal::Signal< FaceTable, Face & > & afterAddFace
 
signal::Signal< FaceTable, Face & > & beforeRemoveFace
 

Detailed Description

Best Route strategy version 4.

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 52 of file best-route-strategy2.hpp.

Constructor & Destructor Documentation

◆ BestRouteStrategy2()

nfd::fw::BestRouteStrategy2::BestRouteStrategy2 ( Forwarder forwarder,
const Name name = STRATEGY_NAME 
)
explicit

Definition at line 41 of file best-route-strategy2.cpp.

Member Function Documentation

◆ afterReceiveInterest()

void nfd::fw::BestRouteStrategy2::afterReceiveInterest ( const Face inFace,
const Interest interest,
const shared_ptr< pit::Entry > &  pitEntry 
)
overridevirtual

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 strategy should decide whether and where to forward this Interest.

  • If the strategy decides to forward this Interest, invoke this->sendInterest one or more times, either now or shortly after
  • If strategy concludes that this Interest cannot be forwarded, invoke this->rejectPendingInterest so that PIT entry will be deleted shortly
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 109 of file best-route-strategy2.cpp.

References nfd::fw::RetxSuppressionExponential::decide(), nfd::fw::findEligibleNextHopWithEarliestOutRecord(), nfd::face::Face::getId(), nfd::fib::Entry::getNextHops(), nfd::fw::isNextHopEligible(), nfd::fw::Strategy::lookupFib(), nfd::fw::RetxSuppression::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::RetxSuppression::SUPPRESS.

◆ afterReceiveNack()

void nfd::fw::BestRouteStrategy2::afterReceiveNack ( const Face inFace,
const lp::Nack nack,
const shared_ptr< pit::Entry > &  pitEntry 
)
overridevirtual

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.

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 189 of file best-route-strategy2.cpp.

References nfd::fw::compareLessSevere(), nfd::face::Face::getId(), ndn::lp::Nack::getInterest(), ndn::lp::NackHeader::getReason(), ndn::lp::Nack::getReason(), NFD_LOG_DEBUG, ndn::lp::NONE, nfd::fw::Strategy::sendNack(), nfd::fw::Strategy::sendNacks(), and ndn::lp::NackHeader::setReason().

Member Data Documentation

◆ STRATEGY_NAME

const Name nfd::fw::BestRouteStrategy2::STRATEGY_NAME
static

Definition at line 67 of file best-route-strategy2.hpp.


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