boost/date_time/filetime_functions.hpp
#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: 2009-02-01 06:29:43 -0500 (Sun, 01 Feb 2009) $
*/
/*! @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
#if defined(BOOST_USE_WINDOWS_H)
# include <windows.h>
#endif
#include <boost/cstdint.hpp>
#include <boost/date_time/time.hpp>
#include <boost/date_time/date_defs.hpp>
namespace boost {
namespace date_time {
namespace winapi {
#if !defined(BOOST_USE_WINDOWS_H)
extern "C" {
struct FILETIME
{
boost::uint32_t dwLowDateTime;
boost::uint32_t dwHighDateTime;
};
struct SYSTEMTIME
{
boost::uint16_t wYear;
boost::uint16_t wMonth;
boost::uint16_t wDayOfWeek;
boost::uint16_t wDay;
boost::uint16_t wHour;
boost::uint16_t wMinute;
boost::uint16_t wSecond;
boost::uint16_t wMilliseconds;
};
__declspec(dllimport) void __stdcall GetSystemTimeAsFileTime(FILETIME* lpFileTime);
__declspec(dllimport) int __stdcall FileTimeToLocalFileTime(const FILETIME* lpFileTime, FILETIME* lpLocalFileTime);
__declspec(dllimport) void __stdcall GetSystemTime(SYSTEMTIME* lpSystemTime);
__declspec(dllimport) int __stdcall SystemTimeToFileTime(const SYSTEMTIME* lpSystemTime, FILETIME* lpFileTime);
} // extern "C"
#endif // defined(BOOST_USE_WINDOWS_H)
typedef FILETIME file_time;
typedef SYSTEMTIME system_time;
inline void get_system_time_as_file_time(file_time& ft)
{
#if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3205))
// Some runtime library implementations expect local times as the norm for ctime.
file_time ft_utc;
GetSystemTimeAsFileTime(&ft_utc);
FileTimeToLocalFileTime(&ft_utc, &ft);
#elif defined(BOOST_NO_GETSYSTEMTIMEASFILETIME)
system_time st;
GetSystemTime(&st);
SystemTimeToFileTime(&st, &ft);
#else
GetSystemTimeAsFileTime(&ft);
#endif
}
/*!
* The function converts file_time into number of microseconds elapsed since 1970-Jan-01
*
* \note Only dates after 1970-Jan-01 are supported. Dates before will be wrapped.
*
* \note The function is templated on the FILETIME type, so that
* it can be used with both native FILETIME and the ad-hoc
* boost::date_time::winapi::file_time type.
*/
template< typename FileTimeT >
inline boost::uint64_t file_time_to_microseconds(FileTimeT const& ft)
{
/* shift is difference between 1970-Jan-01 & 1601-Jan-01
* in 100-nanosecond intervals */
const uint64_t c1 = 27111902UL;
const uint64_t c2 = 3577643008UL; // issues warning without 'UL'
const uint64_t shift = (c1 << 32) + c2;
union {
FileTimeT as_file_time;
uint64_t as_integer; // 100-nanos since 1601-Jan-01
} caster;
caster.as_file_time = ft;
caster.as_integer -= shift; // filetime is now 100-nanos since 1970-Jan-01
return (caster.as_integer / 10); // truncate to microseconds
}
} // namespace winapi
//! 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::date_time::winapi::file_time 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 file_time_to_microseconds function. This allows to
// avoid integer wrapping for dates before 1970-Jan-01.
union {
FileTimeT as_file_time;
uint64_t as_integer; // 100-nanos since 1601-Jan-01
} caster;
caster.as_file_time = ft;
uint64_t sec = caster.as_integer / 10000000UL;
uint32_t sub_sec = (caster.as_integer % 10000000UL) // 100-nanoseconds since the last second
#if !defined(BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG)
/ 10; // microseconds since the last second
#else
* 100; // 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__