NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.5: NDN, CCN, CCNx, content centric networks
API Documentation
asf-measurements.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2018, 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
15  * of the GNU General Public License as published by the Free Software Foundation,
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20  * PURPOSE. See the GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License along with
23  * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
24  */
25 
26 #include "asf-measurements.hpp"
27 
28 namespace nfd {
29 namespace fw {
30 namespace asf {
31 
33 
36 const double RttStats::ALPHA = 0.125;
37 
39  : m_srtt(RTT_NO_MEASUREMENT)
40  , m_rtt(RTT_NO_MEASUREMENT)
41 {
42 }
43 
44 void
46 {
47  m_rtt = static_cast<RttStats::Rtt>(durationRtt.count());
48 
49  m_rttEstimator.addMeasurement(durationRtt);
50 
51  m_srtt = computeSrtt(m_srtt, m_rtt);
52 }
53 
55 RttStats::computeSrtt(Rtt previousSrtt, Rtt currentRtt)
56 {
57  if (previousSrtt == RTT_NO_MEASUREMENT) {
58  return currentRtt;
59  }
60 
61  return Rtt(ALPHA * currentRtt + (1 - ALPHA) * previousSrtt);
62 }
63 
66 
68  : m_isTimeoutScheduled(false)
69  , m_nSilentTimeouts(0)
70 {
71 }
72 
74 {
76  scheduler::cancel(m_measurementExpirationId);
77 }
78 
79 void
80 FaceInfo::setTimeoutEvent(const scheduler::EventId& id, const Name& interestName)
81 {
82  if (!m_isTimeoutScheduled) {
83  m_timeoutEventId = id;
84  m_isTimeoutScheduled = true;
85  m_lastInterestName = interestName;
86  }
87  else {
88  BOOST_THROW_EXCEPTION(FaceInfo::Error("Tried to schedule a timeout for a face that already has a timeout scheduled."));
89  }
90 }
91 
92 void
93 FaceInfo::cancelTimeoutEvent()
94 {
95  scheduler::cancel(m_timeoutEventId);
96  m_isTimeoutScheduled = false;
97 }
98 
99 void
100 FaceInfo::cancelTimeoutEvent(const Name& prefix)
101 {
102  if (isTimeoutScheduled() && doesNameMatchLastInterest(prefix)) {
104  }
105 }
106 
107 bool
108 FaceInfo::doesNameMatchLastInterest(const Name& name)
109 {
110  return m_lastInterestName.isPrefixOf(name);
111 }
112 
113 void
114 FaceInfo::recordRtt(const shared_ptr<pit::Entry>& pitEntry, const Face& inFace)
115 {
116  // Calculate RTT
117  pit::OutRecordCollection::const_iterator outRecord = pitEntry->getOutRecord(inFace);
118 
119  if (outRecord == pitEntry->out_end()) { // no out-record
120  NFD_LOG_TRACE(pitEntry->getInterest() << " dataFrom inFace=" << inFace.getId() << " no-out-record");
121  return;
122  }
123 
124  time::steady_clock::Duration steadyRtt = time::steady_clock::now() - outRecord->getLastRenewed();
125  RttEstimator::Duration durationRtt = time::duration_cast<RttEstimator::Duration>(steadyRtt);
126 
127  m_rttStats.addRttMeasurement(durationRtt);
128 
129  NFD_LOG_TRACE("Recording RTT for FaceId: " << inFace.getId()
130  << " RTT: " << m_rttStats.getRtt()
131  << " SRTT: " << m_rttStats.getSrtt());
132 }
133 
134 void
135 FaceInfo::recordTimeout(const Name& interestName)
136 {
137  m_rttStats.recordTimeout();
138  cancelTimeoutEvent(interestName);
139 }
140 
143 
145  : m_isProbingDue(false)
146  , m_hasFirstProbeBeenScheduled(false)
147 {
148 }
149 
150 FaceInfo*
152 {
153  FaceInfoTable::iterator it = m_fit.find(faceId);
154 
155  if (it != m_fit.end()) {
156  return &it->second;
157  }
158  else {
159  return nullptr;
160  }
161 }
162 
163 FaceInfo&
165 {
166  FaceInfoTable::iterator it = m_fit.find(faceId);
167 
168  FaceInfo* info = nullptr;
169 
170  if (it == m_fit.end()) {
171  const auto& pair = m_fit.emplace(faceId, FaceInfo());
172  info = &pair.first->second;
173 
174  extendFaceInfoLifetime(*info, faceId);
175  }
176  else {
177  info = &it->second;
178  }
179 
180  return *info;
181 }
182 
183 void
185 {
186  m_fit.erase(faceId);
187 }
188 
189 void
191 {
192  // Cancel previous expiration
194 
195  // Refresh measurement
198 }
199 
202 
203 constexpr time::microseconds AsfMeasurements::MEASUREMENTS_LIFETIME;
204 
206  : m_measurements(measurements)
207 {
208 }
209 
210 FaceInfo*
211 AsfMeasurements::getFaceInfo(const fib::Entry& fibEntry, const Interest& interest, FaceId faceId)
212 {
213  NamespaceInfo& info = getOrCreateNamespaceInfo(fibEntry, interest);
214  return info.getFaceInfo(fibEntry, faceId);
215 }
216 
217 FaceInfo&
219  FaceId faceId)
220 {
221  NamespaceInfo& info = getOrCreateNamespaceInfo(fibEntry, interest);
222  return info.getOrCreateFaceInfo(fibEntry, faceId);
223 }
224 
227 {
228  measurements::Entry* me = m_measurements.findLongestPrefixMatch(prefix);
229  if (me == nullptr) {
230  return nullptr;
231  }
232 
233  // Set or update entry lifetime
234  extendLifetime(*me);
235 
236  NamespaceInfo* info = me->insertStrategyInfo<NamespaceInfo>().first;
237  BOOST_ASSERT(info != nullptr);
238  return info;
239 }
240 
243 {
244  measurements::Entry* me = m_measurements.get(fibEntry);
245 
246  // If the FIB entry is not under the strategy's namespace, find a part of the prefix
247  // that falls under the strategy's namespace
248  for (size_t prefixLen = fibEntry.getPrefix().size() + 1;
249  me == nullptr && prefixLen <= interest.getName().size(); ++prefixLen) {
250  me = m_measurements.get(interest.getName().getPrefix(prefixLen));
251  }
252 
253  // Either the FIB entry or the Interest's name must be under this strategy's namespace
254  BOOST_ASSERT(me != nullptr);
255 
256  // Set or update entry lifetime
257  extendLifetime(*me);
258 
259  NamespaceInfo* info = me->insertStrategyInfo<NamespaceInfo>().first;
260  BOOST_ASSERT(info != nullptr);
261  return *info;
262 }
263 
264 void
265 AsfMeasurements::extendLifetime(measurements::Entry& me)
266 {
267  m_measurements.extendLifetime(me, MEASUREMENTS_LIFETIME);
268 }
269 
270 } // namespace asf
271 } // namespace fw
272 } // namespace nfd
PartialName getPrefix(ssize_t nComponents) const
Extract a prefix of the name.
Definition: name.hpp:203
const Name & getPrefix() const
Definition: fib-entry.hpp:58
Helper class to retrieve and create strategy measurements.
FaceInfo & getOrCreateFaceInfo(const fib::Entry &fibEntry, FaceId faceId)
void recordRtt(const shared_ptr< pit::Entry > &pitEntry, const Face &inFace)
time::microseconds Duration
void setMeasurementExpirationEventId(const scheduler::EventId &id)
generalization of a network interface
Definition: face.hpp:67
represents a FIB entry
Definition: fib-entry.hpp:51
void addRttMeasurement(RttEstimator::Duration &durationRtt)
static time_point now() noexcept
Definition: time.cpp:80
bool isPrefixOf(const Name &other) const
Check if this name is a prefix of another name.
Definition: name.cpp:251
void extendFaceInfoLifetime(FaceInfo &info, FaceId faceId)
FaceInfo & getOrCreateFaceInfo(const fib::Entry &fibEntry, const Interest &interest, FaceId faceId)
const scheduler::EventId & getMeasurementExpirationEventId()
AsfMeasurements(MeasurementsAccessor &measurements)
Represents an Interest packet.
Definition: interest.hpp:44
stores stategy information about each face in this namespace
void extendLifetime(Entry &entry, const time::nanoseconds &lifetime)
extend lifetime of an entry
Entry * findLongestPrefixMatch(const Name &name, const EntryPredicate &pred=AnyEntry()) const
perform a longest prefix match for name
static const Rtt RTT_TIMEOUT
void cancelTimeoutEvent(const Name &prefix)
represents a Measurements entry
Table::const_iterator iterator
Definition: cs-internal.hpp:41
void expireFaceInfo(FaceId faceId)
void cancel(EventId eventId)
Cancel a scheduled event.
Definition: scheduler.hpp:49
void addMeasurement(Duration measure)
Copyright (c) 2011-2015 Regents of the University of California.
Definition: ndn-common.hpp:40
#define NFD_LOG_TRACE
Definition: logger.hpp:37
FaceId getId() const
Definition: face.hpp:233
NamespaceInfo & getOrCreateNamespaceInfo(const fib::Entry &fibEntry, const Interest &interest)
static const Rtt RTT_NO_MEASUREMENT
static constexpr time::microseconds MEASUREMENTS_LIFETIME
Represents an absolute name.
Definition: name.hpp:43
void setTimeoutEvent(const scheduler::EventId &id, const Name &interestName)
std::pair< T *, bool > insertStrategyInfo(A &&... args)
insert a StrategyInfo item
Strategy information for each face in a namespace.
size_t size() const
Get number of components.
Definition: name.hpp:147
allows Strategy to access portion of Measurements table under its namespace
NamespaceInfo * getNamespaceInfo(const Name &prefix)
EventId schedule(time::nanoseconds after, const EventCallback &event)
Schedule an event.
Definition: scheduler.cpp:48
Entry * get(const Name &name)
find or insert a Measurements entry for name
FaceInfo * getFaceInfo(const fib::Entry &fibEntry, FaceId faceId)
void recordTimeout(const Name &interestName)
FaceInfo * getFaceInfo(const fib::Entry &fibEntry, const Interest &interest, FaceId faceId)
uint64_t FaceId
identifies a face
Definition: face.hpp:39
A handle of scheduled event.
Definition: scheduler.hpp:55
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
time::duration< double, boost::micro > Rtt
const Name & getName() const
Definition: interest.hpp:134