ext-boost/boost/date_time/filetime_functions.hpp
2019-08-24 15:39:04 +02:00

85 lines
3.1 KiB
C++

#ifndef DATE_TIME_FILETIME_FUNCTIONS_HPP__
#define DATE_TIME_FILETIME_FUNCTIONS_HPP__
/* Copyright (c) 2004 CrystalClear Software, Inc.
* Use, modification and distribution is subject to the
* Boost Software License, Version 1.0. (See accompanying
* file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
* Author: Jeff Garland, Bart Garst
* $Date$
*/
/*! @file filetime_functions.hpp
* Function(s) for converting between a FILETIME structure and a
* time object. This file is only available on systems that have
* BOOST_HAS_FTIME defined.
*/
#include <boost/date_time/compiler_config.hpp>
#if defined(BOOST_HAS_FTIME) // skip this file if no FILETIME
#include <boost/cstdint.hpp>
#include <boost/date_time/time.hpp>
#include <boost/date_time/date_defs.hpp>
namespace boost {
namespace date_time {
//! Create a time object from an initialized FILETIME struct.
/*!
* Create a time object from an initialized FILETIME struct.
* A FILETIME struct holds 100-nanosecond units (0.0000001). When
* built with microsecond resolution the file_time's sub second value
* will be truncated. Nanosecond resolution has no truncation.
*
* \note The function is templated on the FILETIME type, so that
* it can be used with both native FILETIME and the ad-hoc
* boost::detail::winapi::FILETIME_ type.
*/
template< typename TimeT, typename FileTimeT >
inline
TimeT time_from_ftime(const FileTimeT& ft)
{
typedef typename TimeT::date_type date_type;
typedef typename TimeT::date_duration_type date_duration_type;
typedef typename TimeT::time_duration_type time_duration_type;
// https://svn.boost.org/trac/boost/ticket/2523
// Since this function can be called with arbitrary times, including ones that
// are before 1970-Jan-01, we'll have to cast the time a bit differently,
// than it is done in the microsec_clock::file_time_to_microseconds function. This allows to
// avoid integer wrapping for dates before 1970-Jan-01.
// 100-nanos since 1601-Jan-01
uint64_t ft_as_integer = (static_cast< uint64_t >(ft.dwHighDateTime) << 32) | static_cast< uint64_t >(ft.dwLowDateTime);
uint64_t sec = ft_as_integer / 10000000UL;
uint32_t sub_sec = static_cast< uint32_t >(ft_as_integer % 10000000UL) // 100-nanoseconds since the last second
#if !defined(BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG)
/ 10U; // microseconds since the last second
#else
* 100U; // nanoseconds since the last second
#endif
// split sec into usable chunks: days, hours, minutes, & seconds
const uint32_t sec_per_day = 86400; // seconds per day
uint32_t days = static_cast< uint32_t >(sec / sec_per_day);
uint32_t tmp = static_cast< uint32_t >(sec % sec_per_day);
uint32_t hours = tmp / 3600; // sec_per_hour
tmp %= 3600;
uint32_t minutes = tmp / 60; // sec_per_min
tmp %= 60;
uint32_t seconds = tmp; // seconds
date_duration_type dd(days);
date_type d = date_type(1601, Jan, 01) + dd;
return TimeT(d, time_duration_type(hours, minutes, seconds, sub_sec));
}
}} // boost::date_time
#endif // BOOST_HAS_FTIME
#endif // DATE_TIME_FILETIME_FUNCTIONS_HPP__