mirror of
https://github.com/scylladb/scylladb.git
synced 2026-04-25 19:10:42 +00:00
74 lines
2.1 KiB
C++
74 lines
2.1 KiB
C++
/*
|
|
* Copyright (C) 2020-present ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* This file is part of Scylla.
|
|
*
|
|
* Scylla is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* Scylla is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#pragma once
|
|
|
|
#include <chrono>
|
|
#include <ostream>
|
|
|
|
namespace raft {
|
|
|
|
// Raft protocol state machine clock ticks at different speeds
|
|
// depending on the environment. A typical clock tick for
|
|
// a production system is 100ms, while a test system can
|
|
// tick it at the speed of the hardware clock.
|
|
//
|
|
// Every state machine has an own instance of logical clock,
|
|
// this enables tests when different state machines run at
|
|
// different clock speeds.
|
|
class logical_clock final {
|
|
public:
|
|
using rep = int64_t;
|
|
// There is no realistic period for a logical clock,
|
|
// just use the smallest period possible.
|
|
using period = std::chrono::nanoseconds::period;
|
|
using duration = std::chrono::duration<rep, period>;
|
|
using time_point = std::chrono::time_point<logical_clock, duration>;
|
|
|
|
static constexpr bool is_steady = true;
|
|
|
|
void advance(duration diff = duration{1}) {
|
|
_now += diff;
|
|
}
|
|
time_point now() const noexcept {
|
|
return _now;
|
|
}
|
|
|
|
static constexpr time_point min() {
|
|
return time_point(duration{0});
|
|
}
|
|
private:
|
|
time_point _now = min();
|
|
};
|
|
|
|
inline std::ostream& operator<<(std::ostream& os, const logical_clock::time_point& p) {
|
|
return os << (p - logical_clock::min()).count();
|
|
}
|
|
|
|
} // end of namespace raft
|
|
|
|
namespace std {
|
|
|
|
inline std::ostream& operator<<(std::ostream& os, const raft::logical_clock::duration& d) {
|
|
return os << d.count();
|
|
}
|
|
|
|
} // end of namespace std
|