dead-nonce-list.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2020, 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.
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23  * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
24  */
25 
26 #include "dead-nonce-list.hpp"
27 #include "common/city-hash.hpp"
28 #include "common/global.hpp"
29 #include "common/logger.hpp"
30 
31 namespace nfd {
32 
33 NFD_LOG_INIT(DeadNonceList);
34 
35 const time::nanoseconds DeadNonceList::DEFAULT_LIFETIME = 6_s;
36 const time::nanoseconds DeadNonceList::MIN_LIFETIME = 1_ms;
37 const size_t DeadNonceList::INITIAL_CAPACITY = 1 << 7;
38 const size_t DeadNonceList::MIN_CAPACITY = 1 << 3;
39 const size_t DeadNonceList::MAX_CAPACITY = 1 << 24;
40 const DeadNonceList::Entry DeadNonceList::MARK = 0;
41 const size_t DeadNonceList::EXPECTED_MARK_COUNT = 5;
42 const double DeadNonceList::CAPACITY_UP = 1.2;
43 const double DeadNonceList::CAPACITY_DOWN = 0.9;
44 const size_t DeadNonceList::EVICT_LIMIT = 1 << 6;
45 
46 DeadNonceList::DeadNonceList(time::nanoseconds lifetime)
47  : m_lifetime(lifetime)
48  , m_queue(m_index.get<0>())
49  , m_ht(m_index.get<1>())
50  , m_capacity(INITIAL_CAPACITY)
51  , m_markInterval(m_lifetime / EXPECTED_MARK_COUNT)
52  , m_adjustCapacityInterval(m_lifetime)
53 {
54  if (m_lifetime < MIN_LIFETIME) {
55  NDN_THROW(std::invalid_argument("lifetime is less than MIN_LIFETIME"));
56  }
57 
58  for (size_t i = 0; i < EXPECTED_MARK_COUNT; ++i) {
59  m_queue.push_back(MARK);
60  }
61 
62  m_markEvent = getScheduler().schedule(m_markInterval, [this] { mark(); });
63  m_adjustCapacityEvent = getScheduler().schedule(m_adjustCapacityInterval, [this] { adjustCapacity(); });
64 }
65 
67 {
68  m_markEvent.cancel();
69  m_adjustCapacityEvent.cancel();
70 
71  BOOST_ASSERT_MSG(DEFAULT_LIFETIME >= MIN_LIFETIME, "DEFAULT_LIFETIME is too small");
72  static_assert(INITIAL_CAPACITY >= MIN_CAPACITY, "INITIAL_CAPACITY is too small");
73  static_assert(INITIAL_CAPACITY <= MAX_CAPACITY, "INITIAL_CAPACITY is too large");
74  BOOST_ASSERT_MSG(static_cast<size_t>(MIN_CAPACITY * CAPACITY_UP) > MIN_CAPACITY,
75  "CAPACITY_UP must be able to increase from MIN_CAPACITY");
76  BOOST_ASSERT_MSG(static_cast<size_t>(MAX_CAPACITY * CAPACITY_DOWN) < MAX_CAPACITY,
77  "CAPACITY_DOWN must be able to decrease from MAX_CAPACITY");
78  BOOST_ASSERT_MSG(CAPACITY_UP > 1.0, "CAPACITY_UP must adjust up");
79  BOOST_ASSERT_MSG(CAPACITY_DOWN < 1.0, "CAPACITY_DOWN must adjust down");
80  static_assert(EVICT_LIMIT >= 1, "EVICT_LIMIT must be at least 1");
81 }
82 
83 size_t
85 {
86  return m_queue.size() - this->countMarks();
87 }
88 
89 bool
90 DeadNonceList::has(const Name& name, Interest::Nonce nonce) const
91 {
92  Entry entry = DeadNonceList::makeEntry(name, nonce);
93  return m_ht.find(entry) != m_ht.end();
94 }
95 
96 void
97 DeadNonceList::add(const Name& name, Interest::Nonce nonce)
98 {
99  Entry entry = DeadNonceList::makeEntry(name, nonce);
100  m_queue.push_back(entry);
101 
102  this->evictEntries();
103 }
104 
105 DeadNonceList::Entry
106 DeadNonceList::makeEntry(const Name& name, Interest::Nonce nonce)
107 {
108  Block nameWire = name.wireEncode();
109  uint32_t n;
110  std::memcpy(&n, nonce.data(), sizeof(n));
111  return CityHash64WithSeed(reinterpret_cast<const char*>(nameWire.wire()), nameWire.size(), n);
112 }
113 
114 size_t
115 DeadNonceList::countMarks() const
116 {
117  return m_ht.count(MARK);
118 }
119 
120 void
121 DeadNonceList::mark()
122 {
123  m_queue.push_back(MARK);
124  size_t nMarks = this->countMarks();
125  m_actualMarkCounts.insert(nMarks);
126 
127  NFD_LOG_TRACE("mark nMarks=" << nMarks);
128 
129  m_markEvent = getScheduler().schedule(m_markInterval, [this] { mark(); });
130 }
131 
132 void
133 DeadNonceList::adjustCapacity()
134 {
135  auto equalRange = m_actualMarkCounts.equal_range(EXPECTED_MARK_COUNT);
136  if (equalRange.second == m_actualMarkCounts.begin()) {
137  // all counts are above expected count, adjust down
138  m_capacity = std::max(MIN_CAPACITY, static_cast<size_t>(m_capacity * CAPACITY_DOWN));
139  NFD_LOG_TRACE("adjustCapacity DOWN capacity=" << m_capacity);
140  }
141  else if (equalRange.first == m_actualMarkCounts.end()) {
142  // all counts are below expected count, adjust up
143  m_capacity = std::min(MAX_CAPACITY, static_cast<size_t>(m_capacity * CAPACITY_UP));
144  NFD_LOG_TRACE("adjustCapacity UP capacity=" << m_capacity);
145  }
146 
147  m_actualMarkCounts.clear();
148  this->evictEntries();
149 
150  m_adjustCapacityEvent = getScheduler().schedule(m_adjustCapacityInterval, [this] { adjustCapacity(); });
151 }
152 
153 void
154 DeadNonceList::evictEntries()
155 {
156  ssize_t nOverCapacity = m_queue.size() - m_capacity;
157  if (nOverCapacity <= 0) // not over capacity
158  return;
159 
160  for (ssize_t nEvict = std::min<ssize_t>(nOverCapacity, EVICT_LIMIT); nEvict > 0; --nEvict) {
161  m_queue.erase(m_queue.begin());
162  }
163  BOOST_ASSERT(m_queue.size() >= m_capacity);
164 }
165 
166 } // namespace nfd
#define NFD_LOG_TRACE
Definition: logger.hpp:37
Scheduler & getScheduler()
Returns the global Scheduler instance for the calling thread.
Definition: global.cpp:45
Copyright (c) 2014-2015, Regents of the University of California, Arizona Board of Regents...
Definition: algorithm.hpp:32
uint64 CityHash64WithSeed(const char *s, size_t len, uint64 seed)
Definition: city-hash.cpp:397
DeadNonceList(time::nanoseconds lifetime=DEFAULT_LIFETIME)
Constructs the Dead Nonce List.
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
static const time::nanoseconds MIN_LIFETIME
Minimum entry lifetime.
bool has(const Name &name, Interest::Nonce nonce) const
Determines if name+nonce exists.
size_t size() const
void add(const Name &name, Interest::Nonce nonce)
Records name+nonce.
static const time::nanoseconds DEFAULT_LIFETIME
Default entry lifetime.