NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.5: NDN, CCN, CCNx, content centric networks
API Documentation
nfd::fw::SelfLearningStrategy Class Reference

Self-learning strategy. More...

#include <self-learning-strategy.hpp>

Inheritance diagram for nfd::fw::SelfLearningStrategy:
Collaboration diagram for nfd::fw::SelfLearningStrategy:

Classes

class  InRecordInfo
 StrategyInfo on pit::InRecord. More...
 
class  OutRecordInfo
 StrategyInfo on pit::OutRecord. More...
 

Public Member Functions

 SelfLearningStrategy (Forwarder &forwarder, const Name &name=getStrategyName())
 
void afterReceiveInterest (const FaceEndpoint &ingress, const Interest &interest, const shared_ptr< pit::Entry > &pitEntry) override
 trigger after Interest is received More...
 
void afterReceiveData (const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data) override
 trigger after Data is received More...
 
void afterReceiveNack (const FaceEndpoint &ingress, 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)
 Construct a strategy instance. More...
 
virtual ~Strategy ()
 
const NamegetInstanceName () const
 
bool wantNewNextHopTrigger () 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 shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data)
 trigger before PIT entry is satisfied More...
 
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 onDroppedInterest (const FaceEndpoint &egress, const Interest &interest)
 trigger after Interest dropped for exceeding allowed retransmissions More...
 
virtual void afterNewNextHop (const fib::NextHop &nextHop, const shared_ptr< pit::Entry > &pitEntry)
 trigger after new nexthop is added More...
 

Static Public Member Functions

static const NamegetStrategyName ()
 
- 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< Strategycreate (const Name &instanceName, Forwarder &forwarder)
 
static bool areSameType (const Name &instanceNameA, const Name &instanceNameB)
 
static std::set< NamelistRegistered ()
 
static const NamegetStrategyName ()
 

Additional Inherited Members

- Protected Member Functions inherited from nfd::fw::Strategy
void sendInterest (const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &egress, const Interest &interest)
 send Interest to egress More...
 
void sendData (const shared_ptr< pit::Entry > &pitEntry, const Data &data, const FaceEndpoint &egress)
 send data to egress More...
 
void sendDataToAll (const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &ingress, const Data &data)
 send data to all matched and qualified face-endpoint pairs 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 FaceEndpoint &egress, const lp::NackHeader &header)
 send Nack to egress More...
 
void sendNacks (const shared_ptr< pit::Entry > &pitEntry, const lp::NackHeader &header, std::initializer_list< FaceEndpoint > exceptFaceEndpoints={})
 send Nack to every face-endpoint pair that has an in-record, except those in exceptFaceEndpoints More...
 
void setExpiryTimer (const shared_ptr< pit::Entry > &pitEntry, time::milliseconds duration)
 Schedule the PIT entry to be erased after duration. 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
 
void setInstanceName (const Name &name)
 set strategy instance name More...
 
void enableNewNextHopTrigger (bool enabled)
 set whether the afterNewNextHop trigger should be invoked for this strategy 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

Self-learning strategy.

This strategy first broadcasts Interest to learn a single path towards data, then unicasts subsequent Interests along the learned path

See also
https://redmine.named-data.net/attachments/864/Self-learning-strategy-v1.pdf
Note
This strategy is not EndpointId-aware

Definition at line 45 of file self-learning-strategy.hpp.

Constructor & Destructor Documentation

◆ SelfLearningStrategy()

Member Function Documentation

◆ getStrategyName()

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

Definition at line 62 of file self-learning-strategy.cpp.

Referenced by SelfLearningStrategy().

◆ afterReceiveInterest()

void nfd::fw::SelfLearningStrategy::afterReceiveInterest ( const FaceEndpoint ingress,
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 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 69 of file self-learning-strategy.cpp.

References nfd::FaceEndpoint::face, nfd::fib::Entry::getNextHops(), ndn::TagHost::getTag(), nfd::fw::Strategy::lookupFib(), NFD_LOG_DEBUG, nfd::fw::Strategy::rejectPendingInterest(), nfd::fw::Strategy::sendNack(), ndn::lp::NackHeader::setReason(), and ndn::TagHost::setTag().

◆ afterReceiveData()

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

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 from nfd::fw::Strategy.

Definition at line 103 of file self-learning-strategy.cpp.

References nfd::FaceEndpoint::face, ndn::Data::getName(), ndn::TagHost::getTag(), nfd::fw::SelfLearningStrategy::OutRecordInfo::isNonDiscoveryInterest, NFD_LOG_DEBUG, and nfd::fw::Strategy::sendDataToAll().

◆ afterReceiveNack()

void nfd::fw::SelfLearningStrategy::afterReceiveNack ( const FaceEndpoint ingress,
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.

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 from nfd::fw::Strategy.

Definition at line 133 of file self-learning-strategy.cpp.

References nfd::FaceEndpoint::face, ndn::lp::Nack::getHeader(), nfd::face::Face::getId(), ndn::lp::Nack::getInterest(), ndn::Interest::getName(), ndn::lp::Nack::getReason(), nfd::fib::Entry::hasNextHops(), nfd::fw::Strategy::lookupFib(), NFD_LOG_DEBUG, and nfd::fw::Strategy::sendNacks().


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