ceph/src/boost/boost/date_time/filetime_functions.hpp

   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
  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__