random-strategy.cpp
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25 
26 #include "random-strategy.hpp"
27 #include "algorithm.hpp"
28 
29 #include <ndn-cxx/util/random.hpp>
30 
31 namespace nfd::fw {
32 
35 
36 RandomStrategy::RandomStrategy(Forwarder& forwarder, const Name& name)
37  : Strategy(forwarder)
38  , ProcessNackTraits(this)
39 {
41  if (!parsed.parameters.empty()) {
42  NDN_THROW(std::invalid_argument("RandomStrategy does not accept parameters"));
43  }
44  if (parsed.version && *parsed.version != getStrategyName()[-1].toVersion()) {
45  NDN_THROW(std::invalid_argument("RandomStrategy does not support version " +
46  std::to_string(*parsed.version)));
47  }
49 }
50 
51 const Name&
53 {
54  static const auto strategyName = Name("/localhost/nfd/strategy/random").appendVersion(1);
55  return strategyName;
56 }
57 
58 void
59 RandomStrategy::afterReceiveInterest(const Interest& interest, const FaceEndpoint& ingress,
60  const shared_ptr<pit::Entry>& pitEntry)
61 {
62  const fib::Entry& fibEntry = this->lookupFib(*pitEntry);
63  fib::NextHopList nhs;
64 
65  std::copy_if(fibEntry.getNextHops().begin(), fibEntry.getNextHops().end(), std::back_inserter(nhs),
66  [&] (const auto& nh) { return isNextHopEligible(ingress.face, interest, nh, pitEntry); });
67 
68  if (nhs.empty()) {
69  NFD_LOG_INTEREST_FROM(interest, ingress, "no-nexthop");
70  lp::NackHeader nackHeader;
71  nackHeader.setReason(lp::NackReason::NO_ROUTE);
72  this->sendNack(nackHeader, ingress.face, pitEntry);
73  this->rejectPendingInterest(pitEntry);
74  return;
75  }
76 
77  std::shuffle(nhs.begin(), nhs.end(), ndn::random::getRandomNumberEngine());
78  this->sendInterest(interest, nhs.front().getFace(), pitEntry);
79 }
80 
81 void
82 RandomStrategy::afterReceiveNack(const lp::Nack& nack, const FaceEndpoint& ingress,
83  const shared_ptr<pit::Entry>& pitEntry)
84 {
85  this->processNack(nack, ingress.face, pitEntry);
86 }
87 
88 } // namespace nfd::fw
This file contains common algorithms used by forwarding strategies.
Represents a face-endpoint pair in the forwarder.
Main class of NFD's forwarding engine.
Definition: forwarder.hpp:54
Represents an entry in the FIB.
Definition: fib-entry.hpp:91
const NextHopList & getNextHops() const noexcept
Definition: fib-entry.hpp:103
void processNack(const lp::Nack &nack, const Face &inFace, const shared_ptr< pit::Entry > &pitEntry)
A forwarding strategy that randomly chooses a nexthop.
static const Name & getStrategyName()
void afterReceiveNack(const lp::Nack &nack, const FaceEndpoint &ingress, const shared_ptr< pit::Entry > &pitEntry) override
Trigger after a Nack is received.
void afterReceiveInterest(const Interest &interest, const FaceEndpoint &ingress, const shared_ptr< pit::Entry > &pitEntry) override
Trigger after an Interest is received.
RandomStrategy(Forwarder &forwarder, const Name &name=getStrategyName())
Base class of all forwarding strategies.
Definition: strategy.hpp:46
void rejectPendingInterest(const shared_ptr< pit::Entry > &pitEntry)
Schedule the PIT entry for immediate deletion.
Definition: strategy.hpp:335
const fib::Entry & lookupFib(const pit::Entry &pitEntry) const
Performs a FIB lookup, considering Link object if present.
Definition: strategy.cpp:313
bool sendNack(const lp::NackHeader &header, Face &egress, const shared_ptr< pit::Entry > &pitEntry)
Send a Nack packet.
Definition: strategy.hpp:351
pit::OutRecord * sendInterest(const Interest &interest, Face &egress, const shared_ptr< pit::Entry > &pitEntry)
Send an Interest packet.
Definition: strategy.cpp:236
static ParsedInstanceName parseInstanceName(const Name &input)
Parse a strategy instance name.
Definition: strategy.cpp:123
void setInstanceName(const Name &name) noexcept
Set strategy instance name.
Definition: strategy.hpp:448
static Name makeInstanceName(const Name &input, const Name &strategyName)
Construct a strategy instance name.
Definition: strategy.cpp:134
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
std::vector< NextHop > NextHopList
A collection of nexthops in a FIB entry.
Definition: fib-entry.hpp:84
NFD_REGISTER_STRATEGY(SelfLearningStrategy)
#define NFD_LOG_INTEREST_FROM(interest, ingress, msg)
Logs the reception of interest on ingress, followed by msg, at DEBUG level.
Definition: strategy.hpp:542
std::optional< uint64_t > version
The strategy version number, if present.
Definition: strategy.hpp:420
PartialName parameters
Parameter components, may be empty.
Definition: strategy.hpp:421