95 lines
2.8 KiB
C++
95 lines
2.8 KiB
C++
/*
|
|
* Copyright 2013-2019 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.
|
|
*/
|
|
|
|
#ifndef FILE_TIME_HXX
|
|
#define FILE_TIME_HXX
|
|
|
|
#include <fileapi.h>
|
|
|
|
#include <chrono>
|
|
#include <cstdint>
|
|
|
|
constexpr uint_least64_t
|
|
ConstructUint64(DWORD lo, DWORD hi) noexcept
|
|
{
|
|
return uint_least64_t(lo) | (uint_least64_t(hi) << 32);
|
|
}
|
|
|
|
constexpr uint_least64_t
|
|
ToUint64(FILETIME ft) noexcept
|
|
{
|
|
return ConstructUint64(ft.dwLowDateTime, ft.dwHighDateTime);
|
|
}
|
|
|
|
constexpr int_least64_t
|
|
ToInt64(FILETIME ft) noexcept
|
|
{
|
|
return ToUint64(ft);
|
|
}
|
|
|
|
/* "A file time is a 64-bit value that represents the number of
|
|
100-nanosecond intervals"
|
|
https://docs.microsoft.com/en-us/windows/win32/sysinfo/file-times */
|
|
using FileTimeResolution = std::ratio<1, 10000000>;
|
|
|
|
using FileTimeDuration = std::chrono::duration<int_least64_t,
|
|
FileTimeResolution>;
|
|
|
|
/**
|
|
* Calculate a std::chrono::duration specifying the duration of the
|
|
* FILETIME since its epoch (1601-01-01T00:00).
|
|
*/
|
|
constexpr auto
|
|
FileTimeToChronoDuration(FILETIME ft) noexcept
|
|
{
|
|
return FileTimeDuration(ToInt64(ft));
|
|
}
|
|
|
|
constexpr time_t
|
|
FileTimeToTimeT(FILETIME ft) noexcept
|
|
{
|
|
return (ToInt64(ft) - 116444736000000000) / 10000000;
|
|
}
|
|
|
|
inline std::chrono::system_clock::time_point
|
|
FileTimeToChrono(FILETIME ft) noexcept
|
|
{
|
|
// TODO: eliminate the time_t roundtrip, preserve sub-second resolution
|
|
return std::chrono::system_clock::from_time_t(FileTimeToTimeT(ft));
|
|
}
|
|
|
|
constexpr std::chrono::seconds
|
|
DeltaFileTimeS(FILETIME a, FILETIME b) noexcept
|
|
{
|
|
return std::chrono::duration_cast<std::chrono::seconds>
|
|
(FileTimeToChronoDuration(a) - FileTimeToChronoDuration(b));
|
|
}
|
|
|
|
#endif
|