Bitcoin ABC  0.26.3
P2P Digital Currency
timedata.h
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1 // Copyright (c) 2014-2016 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_TIMEDATA_H
6 #define BITCOIN_TIMEDATA_H
7 
8 #include <util/time.h>
9 
10 #include <algorithm>
11 #include <cassert>
12 #include <chrono>
13 #include <cstdint>
14 #include <vector>
15 
16 static const int64_t DEFAULT_MAX_TIME_ADJUSTMENT = 70 * 60;
17 
18 class CNetAddr;
19 
24 template <typename T> class CMedianFilter {
25 private:
26  std::vector<T> vValues;
27  std::vector<T> vSorted;
28  unsigned int nSize;
29 
30 public:
31  CMedianFilter(unsigned int _size, T initial_value) : nSize(_size) {
32  vValues.reserve(_size);
33  vValues.push_back(initial_value);
34  vSorted = vValues;
35  }
36 
37  void input(T value) {
38  if (vValues.size() == nSize) {
39  vValues.erase(vValues.begin());
40  }
41  vValues.push_back(value);
42 
43  vSorted.resize(vValues.size());
44  std::copy(vValues.begin(), vValues.end(), vSorted.begin());
45  std::sort(vSorted.begin(), vSorted.end());
46  }
47 
48  T median() const {
49  int vSortedSize = vSorted.size();
50  assert(vSortedSize > 0);
51  if (vSortedSize & 1) {
52  // Odd number of elements
53  return vSorted[vSortedSize / 2];
54  } else {
55  // Even number of elements
56  auto left = vSorted[vSortedSize / 2 - 1];
57  auto right = vSorted[vSortedSize / 2];
58  return left / 2 + right / 2 + (left & right & 1);
59  }
60  }
61 
62  int size() const { return vValues.size(); }
63 
64  std::vector<T> sorted() const { return vSorted; }
65 };
66 
68 int64_t GetTimeOffset();
71  return Now<NodeSeconds>() + std::chrono::seconds{GetTimeOffset()};
72 }
73 void AddTimeData(const CNetAddr &ip, int64_t nTime);
74 
80 
81 #endif // BITCOIN_TIMEDATA_H
Median filter over a stream of values.
Definition: timedata.h:24
std::vector< T > sorted() const
Definition: timedata.h:64
int size() const
Definition: timedata.h:62
unsigned int nSize
Definition: timedata.h:28
std::vector< T > vSorted
Definition: timedata.h:27
CMedianFilter(unsigned int _size, T initial_value)
Definition: timedata.h:31
T median() const
Definition: timedata.h:48
void input(T value)
Definition: timedata.h:37
std::vector< T > vValues
Definition: timedata.h:26
Network address.
Definition: netaddress.h:121
std::chrono::time_point< NodeClock > time_point
Definition: time.h:19
std::chrono::time_point< NodeClock, std::chrono::seconds > NodeSeconds
Definition: time.h:25
static const int64_t DEFAULT_MAX_TIME_ADJUSTMENT
Definition: timedata.h:16
int64_t GetTimeOffset()
Functions to keep track of adjusted P2P time.
Definition: timedata.cpp:30
void TestOnlyResetTimeData()
Reset the internal state of GetTimeOffset(), GetAdjustedTime() and AddTimeData().
Definition: timedata.cpp:127
NodeClock::time_point GetAdjustedTime()
Definition: timedata.cpp:35
NodeSeconds AdjustedTime()
Definition: timedata.h:70
void AddTimeData(const CNetAddr &ip, int64_t nTime)
Definition: timedata.cpp:45
assert(!tx.IsCoinBase())