62 lines
1.9 KiB
C++
62 lines
1.9 KiB
C++
//
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// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#include "td/utils/port/Clocks.h"
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#include <chrono>
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#include <ctime>
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namespace td {
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double Clocks::monotonic() {
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// TODO write system specific functions, because std::chrono::steady_clock is steady only under Windows
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auto duration = std::chrono::steady_clock::now().time_since_epoch();
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return static_cast<double>(std::chrono::duration_cast<std::chrono::nanoseconds>(duration).count()) * 1e-9;
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}
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double Clocks::system() {
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auto duration = std::chrono::system_clock::now().time_since_epoch();
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return static_cast<double>(std::chrono::duration_cast<std::chrono::nanoseconds>(duration).count()) * 1e-9;
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}
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int Clocks::tz_offset() {
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// not thread-safe on POSIX, so calculate the offset only once
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static int offset = [] {
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auto now = std::time(nullptr);
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auto time_ptr = std::localtime(&now);
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if (time_ptr == nullptr) {
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return 0;
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}
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auto local_time = *time_ptr;
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time_ptr = std::gmtime(&now);
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if (time_ptr == nullptr) {
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return 0;
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}
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auto utc_time = *time_ptr;
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int minute_offset = local_time.tm_min - utc_time.tm_min;
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int hour_offset = local_time.tm_hour - utc_time.tm_hour;
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int day_offset = local_time.tm_mday - utc_time.tm_mday;
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if (day_offset >= 20) {
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day_offset = -1;
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} else if (day_offset <= -20) {
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day_offset = 1;
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}
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int sec_offset = day_offset * 86400 + hour_offset * 3600 + minute_offset * 60;
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if (sec_offset >= 15 * 3600 || sec_offset <= -15 * 3600) {
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return 0;
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}
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return sec_offset / 900 * 900; // round to 900 just in case
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}();
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return offset;
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}
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static int init_tz_offset = Clocks::tz_offset();
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} // namespace td
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