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| author | Remko Tronçon <git@el-tramo.be> | 2009-06-01 08:48:42 (GMT) |
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| committer | Remko Tronçon <git@el-tramo.be> | 2009-06-01 09:24:28 (GMT) |
| commit | 2812bddd81f8a1b804c7460f4e14cd0aa393d129 (patch) | |
| tree | d46294f35150c4f0f43deaf2d31fceaf945ae715 /3rdParty/Boost/boost/date_time/dst_rules.hpp | |
| download | swift-contrib-2812bddd81f8a1b804c7460f4e14cd0aa393d129.zip swift-contrib-2812bddd81f8a1b804c7460f4e14cd0aa393d129.tar.bz2 | |
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Diffstat (limited to '3rdParty/Boost/boost/date_time/dst_rules.hpp')
| -rw-r--r-- | 3rdParty/Boost/boost/date_time/dst_rules.hpp | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/3rdParty/Boost/boost/date_time/dst_rules.hpp b/3rdParty/Boost/boost/date_time/dst_rules.hpp new file mode 100644 index 0000000..20cb40b --- /dev/null +++ b/3rdParty/Boost/boost/date_time/dst_rules.hpp @@ -0,0 +1,391 @@ +#ifndef DATE_TIME_DST_RULES_HPP__ +#define DATE_TIME_DST_RULES_HPP__ + +/* Copyright (c) 2002,2003, 2007 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: 2008-02-27 15:00:24 -0500 (Wed, 27 Feb 2008) $ + */ + +/*! @file dst_rules.hpp + Contains template class to provide static dst rule calculations +*/ + +#include "boost/date_time/date_generators.hpp" +#include "boost/date_time/period.hpp" +#include "boost/date_time/date_defs.hpp" +#include <stdexcept> + +namespace boost { + namespace date_time { + + enum time_is_dst_result {is_not_in_dst, is_in_dst, + ambiguous, invalid_time_label}; + + + //! Dynamic class used to caluclate dst transition information + template<class date_type_, + class time_duration_type_> + class dst_calculator + { + public: + typedef time_duration_type_ time_duration_type; + typedef date_type_ date_type; + + //! Check the local time offset when on dst start day + /*! On this dst transition, the time label between + * the transition boundary and the boudary + the offset + * are invalid times. If before the boundary then still + * not in dst. + *@param time_of_day Time offset in the day for the local time + *@param dst_start_offset_minutes Local day offset for start of dst + *@param dst_length_minutes Number of minutes to adjust clock forward + *@retval status of time label w.r.t. dst + */ + static time_is_dst_result + process_local_dst_start_day(const time_duration_type& time_of_day, + unsigned int dst_start_offset_minutes, + long dst_length_minutes) + { + //std::cout << "here" << std::endl; + if (time_of_day < time_duration_type(0,dst_start_offset_minutes,0)) { + return is_not_in_dst; + } + long offset = dst_start_offset_minutes + dst_length_minutes; + if (time_of_day >= time_duration_type(0,offset,0)) { + return is_in_dst; + } + return invalid_time_label; + } + + //! Check the local time offset when on the last day of dst + /*! This is the calculation for the DST end day. On that day times + * prior to the conversion time - dst_length (1 am in US) are still + * in dst. Times between the above and the switch time are + * ambiguous. Times after the start_offset are not in dst. + *@param time_of_day Time offset in the day for the local time + *@param dst_end_offset_minutes Local time of day for end of dst + *@retval status of time label w.r.t. dst + */ + static time_is_dst_result + process_local_dst_end_day(const time_duration_type& time_of_day, + unsigned int dst_end_offset_minutes, + long dst_length_minutes) + { + //in US this will be 60 so offset in day is 1,0,0 + int offset = dst_end_offset_minutes-dst_length_minutes; + if (time_of_day < time_duration_type(0,offset,0)) { + return is_in_dst; + } + if (time_of_day >= time_duration_type(0,dst_end_offset_minutes,0)) { + return is_not_in_dst; + } + return ambiguous; + } + + //! Calculates if the given local time is dst or not + /*! Determines if the time is really in DST or not. Also checks for + * invalid and ambiguous. + * @param current_day The day to check for dst + * @param time_of_day Time offset within the day to check + * @param dst_start_day Starting day of dst for the given locality + * @param dst_start_offset Time offset within day for dst boundary + * @param dst_end_day Ending day of dst for the given locality + * @param dst_end_offset Time offset within day given in dst for dst boundary + * @param dst_length lenght of dst adjusment + * @retval The time is either ambiguous, invalid, in dst, or not in dst + */ + static time_is_dst_result + local_is_dst(const date_type& current_day, + const time_duration_type& time_of_day, + const date_type& dst_start_day, + const time_duration_type& dst_start_offset, + const date_type& dst_end_day, + const time_duration_type& dst_end_offset, + const time_duration_type& dst_length_minutes) + { + unsigned int start_minutes = + dst_start_offset.hours() * 60 + dst_start_offset.minutes(); + unsigned int end_minutes = + dst_end_offset.hours() * 60 + dst_end_offset.minutes(); + long length_minutes = + dst_length_minutes.hours() * 60 + dst_length_minutes.minutes(); + + return local_is_dst(current_day, time_of_day, + dst_start_day, start_minutes, + dst_end_day, end_minutes, + length_minutes); + } + + //! Calculates if the given local time is dst or not + /*! Determines if the time is really in DST or not. Also checks for + * invalid and ambiguous. + * @param current_day The day to check for dst + * @param time_of_day Time offset within the day to check + * @param dst_start_day Starting day of dst for the given locality + * @param dst_start_offset_minutes Offset within day for dst + * boundary (eg 120 for US which is 02:00:00) + * @param dst_end_day Ending day of dst for the given locality + * @param dst_end_offset_minutes Offset within day given in dst for dst + * boundary (eg 120 for US which is 02:00:00) + * @param dst_length_minutes Length of dst adjusment (eg: 60 for US) + * @retval The time is either ambiguous, invalid, in dst, or not in dst + */ + static time_is_dst_result + local_is_dst(const date_type& current_day, + const time_duration_type& time_of_day, + const date_type& dst_start_day, + unsigned int dst_start_offset_minutes, + const date_type& dst_end_day, + unsigned int dst_end_offset_minutes, + long dst_length_minutes) + { + //in northern hemisphere dst is in the middle of the year + if (dst_start_day < dst_end_day) { + if ((current_day > dst_start_day) && (current_day < dst_end_day)) { + return is_in_dst; + } + if ((current_day < dst_start_day) || (current_day > dst_end_day)) { + return is_not_in_dst; + } + } + else {//southern hemisphere dst is at begining /end of year + if ((current_day < dst_start_day) && (current_day > dst_end_day)) { + return is_not_in_dst; + } + if ((current_day > dst_start_day) || (current_day < dst_end_day)) { + return is_in_dst; + } + } + + if (current_day == dst_start_day) { + return process_local_dst_start_day(time_of_day, + dst_start_offset_minutes, + dst_length_minutes); + } + + if (current_day == dst_end_day) { + return process_local_dst_end_day(time_of_day, + dst_end_offset_minutes, + dst_length_minutes); + } + //you should never reach this statement + return invalid_time_label; + } + + }; + + + //! Compile-time configurable daylight savings time calculation engine + /* This template provides the ability to configure a daylight savings + * calculation at compile time covering all the cases. Unfortunately + * because of the number of dimensions related to daylight savings + * calculation the number of parameters is high. In addition, the + * start and end transition rules are complex types that specify + * an algorithm for calculation of the starting day and ending + * day of daylight savings time including the month and day + * specifications (eg: last sunday in October). + * + * @param date_type A type that represents dates, typically gregorian::date + * @param time_duration_type Used for the offset in the day calculations + * @param dst_traits A set of traits that define the rules of dst + * calculation. The dst_trait must include the following: + * start_rule_functor - Rule to calculate the starting date of a + * dst transition (eg: last_kday_of_month). + * start_day - static function that returns month of dst start for + * start_rule_functor + * start_month -static function that returns day or day of week for + * dst start of dst + * end_rule_functor - Rule to calculate the end of dst day. + * end_day - static fucntion that returns end day for end_rule_functor + * end_month - static function that returns end month for end_rule_functor + * dst_start_offset_minutes - number of minutes from start of day to transition to dst -- 120 (or 2:00 am) is typical for the U.S. and E.U. + * dst_start_offset_minutes - number of minutes from start of day to transition off of dst -- 180 (or 3:00 am) is typical for E.U. + * dst_length_minutes - number of minutes that dst shifts clock + */ + template<class date_type, + class time_duration_type, + class dst_traits> + class dst_calc_engine + { + public: + typedef typename date_type::year_type year_type; + typedef typename date_type::calendar_type calendar_type; + typedef dst_calculator<date_type, time_duration_type> dstcalc; + + //! Calculates if the given local time is dst or not + /*! Determines if the time is really in DST or not. Also checks for + * invalid and ambiguous. + * @retval The time is either ambiguous, invalid, in dst, or not in dst + */ + static time_is_dst_result local_is_dst(const date_type& d, + const time_duration_type& td) + { + + year_type y = d.year(); + date_type dst_start = local_dst_start_day(y); + date_type dst_end = local_dst_end_day(y); + return dstcalc::local_is_dst(d,td, + dst_start, + dst_traits::dst_start_offset_minutes(), + dst_end, + dst_traits::dst_end_offset_minutes(), + dst_traits::dst_shift_length_minutes()); + + } + + static bool is_dst_boundary_day(date_type d) + { + year_type y = d.year(); + return ((d == local_dst_start_day(y)) || + (d == local_dst_end_day(y))); + } + + //! The time of day for the dst transition (eg: typically 01:00:00 or 02:00:00) + static time_duration_type dst_offset() + { + return time_duration_type(0,dst_traits::dst_shift_length_minutes(),0); + } + + static date_type local_dst_start_day(year_type year) + { + return dst_traits::local_dst_start_day(year); + } + + static date_type local_dst_end_day(year_type year) + { + return dst_traits::local_dst_end_day(year); + } + + + }; + + //! Depricated: Class to calculate dst boundaries for US time zones + /* Use dst_calc_engine instead. + * In 2007 US/Canada DST rules changed + * (http://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005#Change_to_daylight_saving_time). + */ + template<class date_type_, + class time_duration_type_, + unsigned int dst_start_offset_minutes=120, //from start of day + short dst_length_minutes=60> //1 hour == 60 min in US + class us_dst_rules + { + public: + typedef time_duration_type_ time_duration_type; + typedef date_type_ date_type; + typedef typename date_type::year_type year_type; + typedef typename date_type::calendar_type calendar_type; + typedef date_time::last_kday_of_month<date_type> lkday; + typedef date_time::first_kday_of_month<date_type> fkday; + typedef date_time::nth_kday_of_month<date_type> nkday; + typedef dst_calculator<date_type, time_duration_type> dstcalc; + + //! Calculates if the given local time is dst or not + /*! Determines if the time is really in DST or not. Also checks for + * invalid and ambiguous. + * @retval The time is either ambiguous, invalid, in dst, or not in dst + */ + static time_is_dst_result local_is_dst(const date_type& d, + const time_duration_type& td) + { + + year_type y = d.year(); + date_type dst_start = local_dst_start_day(y); + date_type dst_end = local_dst_end_day(y); + return dstcalc::local_is_dst(d,td, + dst_start,dst_start_offset_minutes, + dst_end, dst_start_offset_minutes, + dst_length_minutes); + + } + + + static bool is_dst_boundary_day(date_type d) + { + year_type y = d.year(); + return ((d == local_dst_start_day(y)) || + (d == local_dst_end_day(y))); + } + + static date_type local_dst_start_day(year_type year) + { + if (year >= year_type(2007)) { + //second sunday in march + nkday ssim(nkday::second, Sunday, gregorian::Mar); + return ssim.get_date(year); + } else { + //first sunday in april + fkday fsia(Sunday, gregorian::Apr); + return fsia.get_date(year); + } + } + + static date_type local_dst_end_day(year_type year) + { + if (year >= year_type(2007)) { + //first sunday in november + fkday fsin(Sunday, gregorian::Nov); + return fsin.get_date(year); + } else { + //last sunday in october + lkday lsio(Sunday, gregorian::Oct); + return lsio.get_date(year); + } + } + + static time_duration_type dst_offset() + { + return time_duration_type(0,dst_length_minutes,0); + } + + private: + + + }; + + //! Used for local time adjustments in places that don't use dst + template<class date_type_, class time_duration_type_> + class null_dst_rules + { + public: + typedef time_duration_type_ time_duration_type; + typedef date_type_ date_type; + + + //! Calculates if the given local time is dst or not + /*! @retval Always is_not_in_dst since this is for zones without dst + */ + static time_is_dst_result local_is_dst(const date_type&, + const time_duration_type&) + { + return is_not_in_dst; + } + + //! Calculates if the given utc time is in dst + static time_is_dst_result utc_is_dst(const date_type&, + const time_duration_type&) + { + return is_not_in_dst; + } + + static bool is_dst_boundary_day(date_type d) + { + return false; + } + + static time_duration_type dst_offset() + { + return time_duration_type(0,0,0); + } + + }; + + + } } //namespace date_time + + + +#endif |