random-strategy.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2019, Regents of the University of California,
4  * Arizona Board of Regents,
5  * Colorado State University,
6  * University Pierre & Marie Curie, Sorbonne University,
7  * Washington University in St. Louis,
8  * Beijing Institute of Technology,
9  * The University of Memphis.
10  *
11  * This file is part of NFD (Named Data Networking Forwarding Daemon).
12  * See AUTHORS.md for complete list of NFD authors and contributors.
13  *
14  * NFD is free software: you can redistribute it and/or modify it under the terms
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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 {
32 namespace fw {
33 
34 NFD_REGISTER_STRATEGY(RandomStrategy);
35 NFD_LOG_INIT(RandomStrategy);
36 
37 RandomStrategy::RandomStrategy(Forwarder& forwarder, const Name& name)
38  : Strategy(forwarder)
39  , ProcessNackTraits(this)
40 {
42  if (!parsed.parameters.empty()) {
43  NDN_THROW(std::invalid_argument("RandomStrategy does not accept parameters"));
44  }
45  if (parsed.version && *parsed.version != getStrategyName()[-1].toVersion()) {
46  NDN_THROW(std::invalid_argument(
47  "RandomStrategy does not support version " + to_string(*parsed.version)));
48  }
50 }
51 
52 const Name&
54 {
55  static Name strategyName("/localhost/nfd/strategy/random/%FD%01");
56  return strategyName;
57 }
58 
59 void
60 RandomStrategy::afterReceiveInterest(const FaceEndpoint& ingress, const Interest& interest,
61  const shared_ptr<pit::Entry>& pitEntry)
62 {
63  const fib::Entry& fibEntry = this->lookupFib(*pitEntry);
64  const Face& inFace = ingress.face;
65  fib::NextHopList nhs;
66 
67  std::copy_if(fibEntry.getNextHops().begin(), fibEntry.getNextHops().end(), std::back_inserter(nhs),
68  [&] (const auto& nh) { return isNextHopEligible(inFace, interest, nh, pitEntry); });
69 
70  if (nhs.empty()) {
71  NFD_LOG_DEBUG(interest << " from=" << ingress << " no nexthop");
72 
73  lp::NackHeader nackHeader;
74  nackHeader.setReason(lp::NackReason::NO_ROUTE);
75  this->sendNack(pitEntry, ingress, nackHeader);
76  this->rejectPendingInterest(pitEntry);
77  return;
78  }
79 
80  std::shuffle(nhs.begin(), nhs.end(), ndn::random::getRandomNumberEngine());
81  this->sendInterest(pitEntry, FaceEndpoint(nhs.front().getFace(), 0), interest);
82 }
83 
84 void
85 RandomStrategy::afterReceiveNack(const FaceEndpoint& ingress, const lp::Nack& nack,
86  const shared_ptr<pit::Entry>& pitEntry)
87 {
88  this->processNack(ingress.face, nack, pitEntry);
89 }
90 
91 } // namespace fw
92 } // namespace nfd
Main class of NFD&#39;s forwarding engine.
Definition: forwarder.hpp:51
void setInstanceName(const Name &name)
set strategy instance name
Definition: strategy.hpp:382
void sendNack(const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &egress, const lp::NackHeader &header)
send Nack to egress
Definition: strategy.hpp:302
represents a FIB entry
Definition: fib-entry.hpp:53
static Name makeInstanceName(const Name &input, const Name &strategyName)
construct a strategy instance name
Definition: strategy.cpp:134
void afterReceiveInterest(const FaceEndpoint &ingress, const Interest &interest, const shared_ptr< pit::Entry > &pitEntry) override
trigger after Interest is received
void sendInterest(const shared_ptr< pit::Entry > &pitEntry, const FaceEndpoint &egress, const Interest &interest)
send Interest to egress
Definition: strategy.cpp:197
Represents a face-endpoint pair in the forwarder.
void afterReceiveNack(const FaceEndpoint &ingress, const lp::Nack &nack, const shared_ptr< pit::Entry > &pitEntry) override
trigger after Nack is received
Copyright (c) 2014-2015, Regents of the University of California, Arizona Board of Regents...
Definition: algorithm.hpp:32
bool isNextHopEligible(const Face &inFace, const Interest &interest, const fib::NextHop &nexthop, const shared_ptr< pit::Entry > &pitEntry, bool wantUnused, time::steady_clock::TimePoint now)
determines whether a NextHop is eligible i.e.
Definition: algorithm.cpp:154
Represents a collection of nexthops.
Definition: fib-entry.hpp:39
PartialName parameters
parameter components
Definition: strategy.hpp:355
RandomStrategy(Forwarder &forwarder, const Name &name=getStrategyName())
represents a forwarding strategy
Definition: strategy.hpp:37
This file contains common algorithms used by forwarding strategies.
#define NFD_LOG_DEBUG
Definition: logger.hpp:38
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
static ParsedInstanceName parseInstanceName(const Name &input)
parse a strategy instance name
Definition: strategy.cpp:123
void processNack(const Face &inFace, const lp::Nack &nack, const shared_ptr< pit::Entry > &pitEntry)
NFD_REGISTER_STRATEGY(SelfLearningStrategy)
const NextHopList & getNextHops() const
Definition: fib-entry.hpp:66
static const Name & getStrategyName()
void rejectPendingInterest(const shared_ptr< pit::Entry > &pitEntry)
schedule the PIT entry for immediate deletion
Definition: strategy.hpp:289
const fib::Entry & lookupFib(const pit::Entry &pitEntry) const
performs a FIB lookup, considering Link object if present
Definition: strategy.cpp:288
optional< uint64_t > version
whether strategyName contains a version component
Definition: strategy.hpp:354