1 #ifndef DATE_TIME_FILETIME_FUNCTIONS_HPP__
2 #define DATE_TIME_FILETIME_FUNCTIONS_HPP__
3
4 /* Copyright (c) 2004 CrystalClear Software, Inc.
5 * Use, modification and distribution is subject to the
6 * Boost Software License, Version 1.0. (See accompanying
7 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
8 * Author: Jeff Garland, Bart Garst
9 * $Date$
10 */
11
12 /*! @file filetime_functions.hpp
13 * Function(s) for converting between a FILETIME structure and a
14 * time object. This file is only available on systems that have
15 * BOOST_HAS_FTIME defined.
16 */
17
18 #include <boost/date_time/compiler_config.hpp>
19
20 #if defined(BOOST_HAS_FTIME) // skip this file if no FILETIME
21
22 #include <boost/cstdint.hpp>
23 #include <boost/date_time/time.hpp>
24 #include <boost/date_time/date_defs.hpp>
25
26 namespace boost {
27
28 namespace date_time {
29
30 //! Create a time object from an initialized FILETIME struct.
31 /*!
32 * Create a time object from an initialized FILETIME struct.
33 * A FILETIME struct holds 100-nanosecond units (0.0000001). When
34 * built with microsecond resolution the file_time's sub second value
35 * will be truncated. Nanosecond resolution has no truncation.
36 *
37 * \note The function is templated on the FILETIME type, so that
38 * it can be used with both native FILETIME and the ad-hoc
39 * boost::detail::winapi::FILETIME_ type.
40 */
41 template< typename TimeT, typename FileTimeT >
42 inline
time_from_ftime(const FileTimeT & ft)43 TimeT time_from_ftime(const FileTimeT& ft)
44 {
45 typedef typename TimeT::date_type date_type;
46 typedef typename TimeT::date_duration_type date_duration_type;
47 typedef typename TimeT::time_duration_type time_duration_type;
48
49 // https://svn.boost.org/trac/boost/ticket/2523
50 // Since this function can be called with arbitrary times, including ones that
51 // are before 1970-Jan-01, we'll have to cast the time a bit differently,
52 // than it is done in the microsec_clock::file_time_to_microseconds function. This allows to
53 // avoid integer wrapping for dates before 1970-Jan-01.
54
55 // 100-nanos since 1601-Jan-01
56 uint64_t ft_as_integer = (static_cast< uint64_t >(ft.dwHighDateTime) << 32) | static_cast< uint64_t >(ft.dwLowDateTime);
57 uint64_t sec = ft_as_integer / 10000000UL;
58 uint32_t sub_sec = static_cast< uint32_t >(ft_as_integer % 10000000UL) // 100-nanoseconds since the last second
59 #if !defined(BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG)
60 / 10U; // microseconds since the last second
61 #else
62 * 100U; // nanoseconds since the last second
63 #endif
64
65 // split sec into usable chunks: days, hours, minutes, & seconds
66 const uint32_t sec_per_day = 86400; // seconds per day
67 uint32_t days = static_cast< uint32_t >(sec / sec_per_day);
68 uint32_t tmp = static_cast< uint32_t >(sec % sec_per_day);
69 uint32_t hours = tmp / 3600; // sec_per_hour
70 tmp %= 3600;
71 uint32_t minutes = tmp / 60; // sec_per_min
72 tmp %= 60;
73 uint32_t seconds = tmp; // seconds
74
75 date_duration_type dd(days);
76 date_type d = date_type(1601, Jan, 01) + dd;
77 return TimeT(d, time_duration_type(hours, minutes, seconds, sub_sec));
78 }
79
80 }} // boost::date_time
81
82 #endif // BOOST_HAS_FTIME
83
84 #endif // DATE_TIME_FILETIME_FUNCTIONS_HPP__
85