timedata.h

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// Copyright (c) 2014-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef BITCOIN_TIMEDATA_H
#define BITCOIN_TIMEDATA_H
 
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <vector>
 
static const int64_t DEFAULT_MAX_TIME_ADJUSTMENT = 70 * 60;
 
class CNetAddr;
 
template <typename T> class CMedianFilter {
private:
    std::vector<T> vValues;
    std::vector<T> vSorted;
    unsigned int nSize;
 
public:
    CMedianFilter(unsigned int _size, T initial_value) : nSize(_size) {
        vValues.reserve(_size);
        vValues.push_back(initial_value);
        vSorted = vValues;
    }
 
    void input(T value) {
        if (vValues.size() == nSize) {
            vValues.erase(vValues.begin());
        }
        vValues.push_back(value);
 
        vSorted.resize(vValues.size());
        std::copy(vValues.begin(), vValues.end(), vSorted.begin());
        std::sort(vSorted.begin(), vSorted.end());
    }
 
    T median() const {
        int vSortedSize = vSorted.size();
        assert(vSortedSize > 0);
        if (vSortedSize & 1) {
            // Odd number of elements
            return vSorted[vSortedSize / 2];
        } else {
            // Even number of elements
            auto left = vSorted[vSortedSize / 2 - 1];
            auto right = vSorted[vSortedSize / 2];
            return left / 2 + right / 2 + (left & right & 1);
        }
    }
 
    int size() const { return vValues.size(); }
 
    std::vector<T> sorted() const { return vSorted; }
};
 
int64_t GetTimeOffset();
int64_t GetAdjustedTime();
void AddTimeData(const CNetAddr &ip, int64_t nTime);
 
#endif // BITCOIN_TIMEDATA_H