Line data    Source code

       1              : // Copyright (c) 2024-present 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_NODE_TIMEOFFSETS_H
       6              : #define BITCOIN_NODE_TIMEOFFSETS_H
       7              : 
       8              : #include <sync.h>
       9              : 
      10              : #include <chrono>
      11              : #include <cstddef>
      12              : #include <deque>
      13              : 
      14              : namespace node {
      15              : class Warnings;
      16              : } // namespace node
      17              : 
      18            5 : class TimeOffsets
      19              : {
      20              : public:
      21         1095 :     TimeOffsets(node::Warnings& warnings) : m_warnings{warnings} {}
      22              : 
      23              : private:
      24              :     //! Maximum number of timeoffsets stored.
      25              :     static constexpr size_t MAX_SIZE{50};
      26              :     //! Minimum difference between system and network time for a warning to be raised.
      27              :     static constexpr std::chrono::minutes WARN_THRESHOLD{10};
      28              : 
      29              :     mutable Mutex m_mutex;
      30              :     /** The observed time differences between our local clock and those of our outbound peers. A
      31              :      * positive offset means our peer's clock is ahead of our local clock. */
      32              :     std::deque<std::chrono::seconds> m_offsets GUARDED_BY(m_mutex){};
      33              : 
      34              :     node::Warnings& m_warnings;
      35              : 
      36              : public:
      37              :     /** Add a new time offset sample. */
      38              :     void Add(std::chrono::seconds offset) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      39              : 
      40              :     /** Compute and return the median of the collected time offset samples. The median is returned
      41              :      * as 0 when there are less than 5 samples. */
      42              :     std::chrono::seconds Median() const EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      43              : 
      44              :     /** Raise warnings if the median time offset exceeds the warnings threshold. Returns true if
      45              :      * warnings were raised. */
      46              :     bool WarnIfOutOfSync() const EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      47              : };
      48              : 
      49              : #endif // BITCOIN_NODE_TIMEOFFSETS_H