diff options
author | Max Kellermann <max.kellermann@gmail.com> | 2021-08-10 19:44:52 +0200 |
---|---|---|
committer | Max Kellermann <max@musicpd.org> | 2021-08-10 19:53:53 +0200 |
commit | a2387210bf886d4c098d2d521b9bb014e73bfedb (patch) | |
tree | 0a61f59d3bd3d46e46cba30847673c4d3426fc2c | |
parent | d7e7adb4963e6acc8c0d287e18ea062bdd7f3fb3 (diff) |
time/FileTime: move code to SystemClock.hxx
-rw-r--r-- | src/time/FileTime.hxx | 19 | ||||
-rw-r--r-- | src/time/SystemClock.hxx | 62 |
2 files changed, 67 insertions, 14 deletions
diff --git a/src/time/FileTime.hxx b/src/time/FileTime.hxx index a5c79a422..a325794e9 100644 --- a/src/time/FileTime.hxx +++ b/src/time/FileTime.hxx @@ -1,5 +1,5 @@ /* - * Copyright 2013-2019 Max Kellermann <max.kellermann@gmail.com> + * Copyright 2013-2021 Max Kellermann <max.kellermann@gmail.com> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -30,6 +30,8 @@ #ifndef FILE_TIME_HXX #define FILE_TIME_HXX +#include "SystemClock.hxx" + #include <fileapi.h> #include <chrono> @@ -108,15 +110,7 @@ FileTimeToUnixEpochDuration(FILETIME ft) noexcept inline std::chrono::system_clock::time_point FileTimeToChrono(FILETIME ft) noexcept { - /* this is guaranteed to be 0 in C++20 */ - const auto unix_epoch = std::chrono::system_clock::from_time_t(0); - - const auto windows_duration = FileTimeToUnixEpochDuration(ft); - const auto sys_duration = - std::chrono::duration_cast<std::chrono::system_clock::duration> - (windows_duration); - - return unix_epoch + sys_duration; + return TimePointAfterUnixEpoch(FileTimeToUnixEpochDuration(ft)); } constexpr FILETIME @@ -143,10 +137,7 @@ UnixEpochDurationToFileTime(FileTimeDuration d) noexcept inline FILETIME ChronoToFileTime(std::chrono::system_clock::time_point tp) noexcept { - /* this is guaranteed to be 0 in C++20 */ - const auto unix_epoch = std::chrono::system_clock::from_time_t(0); - - const auto since_unix_epoch = tp - unix_epoch; + const auto since_unix_epoch = DurationSinceUnixEpoch(tp); const auto ft_since_unix_epoch = std::chrono::duration_cast<FileTimeDuration>(since_unix_epoch); diff --git a/src/time/SystemClock.hxx b/src/time/SystemClock.hxx new file mode 100644 index 000000000..870d4b9e2 --- /dev/null +++ b/src/time/SystemClock.hxx @@ -0,0 +1,62 @@ +/* + * Copyright 2021 Max Kellermann <max.kellermann@gmail.com> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#pragma once + +#include <chrono> + +/** + * Calculate a std::chrono::system_clock::time_point from a duration + * relative to the UNIX epoch (1970-01-01T00:00Z). + */ +template<class Rep, class Period> +[[gnu::const]] +std::chrono::system_clock::time_point +TimePointAfterUnixEpoch(const std::chrono::duration<Rep,Period> &d) noexcept +{ + /* this is guaranteed to be 0 in C++20 */ + const auto unix_epoch = std::chrono::system_clock::from_time_t(0); + + return unix_epoch + + std::chrono::duration_cast<std::chrono::system_clock::duration>(d); +} + +/** + * Calculate the duration that has passed since the UNIX epoch + * (1970-01-01T00:00Z). + */ +[[gnu::const]] +inline std::chrono::system_clock::duration +DurationSinceUnixEpoch(const std::chrono::system_clock::time_point &tp) noexcept +{ + /* this is guaranteed to be 0 in C++20 */ + const auto unix_epoch = std::chrono::system_clock::from_time_t(0); + + return tp - unix_epoch; +} |