Files
scylladb/gc_clock.hh
Jesse Haber-Kucharsky b0ad1ff447 Seal clock definitions
2017-06-23 11:35:35 -04:00

60 lines
1.9 KiB
C++

/*
* Copyright (C) 2015 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 "clocks-impl.hh"
#include <seastar/core/lowres_clock.hh>
#include <chrono>
#include <experimental/optional>
// FIXME: wraps around in 2038
class gc_clock final {
public:
using base = seastar::lowres_system_clock;
using rep = int32_t;
using period = std::ratio<1, 1>; // seconds
using duration = std::chrono::duration<rep, period>;
using time_point = std::chrono::time_point<gc_clock, duration>;
static constexpr auto is_steady = base::is_steady;
static constexpr std::time_t to_time_t(time_point t) {
return std::chrono::duration_cast<std::chrono::seconds>(t.time_since_epoch()).count();
}
static constexpr time_point from_time_t(std::time_t t) {
return time_point(std::chrono::duration_cast<duration>(std::chrono::seconds(t)));
}
static time_point now() {
return time_point(std::chrono::duration_cast<duration>(base::now().time_since_epoch())) + get_clocks_offset();
}
};
using expiry_opt = std::experimental::optional<gc_clock::time_point>;
using ttl_opt = std::experimental::optional<gc_clock::duration>;
// 20 years in seconds
static constexpr gc_clock::duration max_ttl = gc_clock::duration{20 * 365 * 24 * 60 * 60};