ceph/src/boost/libs/date_time/include/boost/date_time/local_time/posix_time_zone.hpp

   1 #ifndef _DATE_TIME_POSIX_TIME_ZONE__
   2 #define _DATE_TIME_POSIX_TIME_ZONE__
   3
   4 /* Copyright (c) 2003-2005 CrystalClear Software, Inc.
   5  * Subject to the Boost Software License, Version 1.0. (See accompanying
   6  * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
   7  * Author: Jeff Garland, Bart Garst
   8  * $Date$
   9  */
  10
  11 #include <string>
  12 #include <sstream>
  13 #include <stdexcept>
  14 #include <boost/tokenizer.hpp>
  15 #include <boost/throw_exception.hpp>
  16 #include <boost/date_time/gregorian/gregorian.hpp>
  17 #include <boost/date_time/time_zone_names.hpp>
  18 #include <boost/date_time/time_zone_base.hpp>
  19 #include <boost/date_time/local_time/dst_transition_day_rules.hpp>
  20 #include <boost/date_time/posix_time/posix_time.hpp>
  21 #include <boost/date_time/string_convert.hpp>
  22 #include <boost/date_time/time_parsing.hpp>
  23
  24 namespace boost{
  25 namespace local_time{
  26
  27   //! simple exception for UTC and Daylight savings start/end offsets
  28   struct bad_offset : public std::out_of_range
  29   {
  30     bad_offset(std::string const& msg = std::string()) :
  31       std::out_of_range(std::string("Offset out of range: " + msg)) {}
  32   };
  33   //! simple exception for UTC daylight savings adjustment
  34   struct bad_adjustment : public std::out_of_range
  35   {
  36     bad_adjustment(std::string const& msg = std::string()) :
  37       std::out_of_range(std::string("Adjustment out of range: " + msg)) {}
  38   };
  39
  40   typedef boost::date_time::dst_adjustment_offsets<boost::posix_time::time_duration> dst_adjustment_offsets;
  41
  42   //! A time zone class constructed from a POSIX time zone string
  43   /*! A POSIX time zone string takes the form of:<br>
  44    * "std offset dst [offset],start[/time],end[/time]" (w/no spaces)
  45    * 'std' specifies the abbrev of the time zone.<br>
  46    * 'offset' is the offset from UTC.<br>
  47    * 'dst' specifies the abbrev of the time zone during daylight savings time.<br>
  48    * The second offset is how many hours changed during DST. Default=1<br>
  49    * 'start' and'end' are the dates when DST goes into (and out of) effect.<br>
  50    * 'offset' takes the form of: [+|-]hh[:mm[:ss]] {h=0-23, m/s=0-59}<br>
  51    * 'time' and 'offset' take the same form. Time defaults=02:00:00<br>
  52    * 'start' and 'end' can be one of three forms:<br>
  53    * Mm.w.d {month=1-12, week=1-5 (5 is always last), day=0-6}<br>
  54    * Jn {n=1-365 Feb29 is never counted}<br>
  55    * n  {n=0-365 Feb29 is counted in leap years}<br>
  56    * Example "PST-5PDT01:00:00,M4.1.0/02:00:00,M10.1.0/02:00:00"
  57    * <br>
  58    * Exceptions will be thrown under these conditions:<br>
  59    * An invalid date spec (see date class)<br>
  60    * A boost::local_time::bad_offset exception will be thrown for:<br>
  61    * A DST start or end offset that is negative or more than 24 hours<br>
  62    * A UTC zone that is greater than +14 or less than -12 hours<br>
  63    * A boost::local_time::bad_adjustment exception will be thrown for:<br>
  64    * A DST adjustment that is 24 hours or more (positive or negative)<br>
  65    *
  66    * Note that UTC zone offsets can be greater than +12:
  67    * http://www.worldtimezone.com/utc/utc+1200.html
  68    */
  69   template<class CharT>
  70   class posix_time_zone_base : public date_time::time_zone_base<posix_time::ptime,CharT> {
  71   public:
  72     typedef boost::posix_time::time_duration time_duration_type;
  73     typedef date_time::time_zone_names_base<CharT> time_zone_names;
  74     typedef date_time::time_zone_base<posix_time::ptime,CharT> base_type;
  75     typedef typename base_type::string_type string_type;
  76     typedef CharT char_type;
  77     typedef typename base_type::stringstream_type stringstream_type;
  78     typedef boost::char_separator<char_type, std::char_traits<char_type> > char_separator_type;
  79     typedef boost::tokenizer<char_separator_type,
  80                              typename string_type::const_iterator,
  81                              string_type> tokenizer_type;
  82     typedef typename tokenizer_type::iterator tokenizer_iterator_type;
  83
  84     //! Construct from a POSIX time zone string
  85     posix_time_zone_base(const string_type& s) :
  86       //zone_names_("std_name","std_abbrev","no-dst","no-dst"),
  87       zone_names_(),
  88       has_dst_(false),
  89       base_utc_offset_(posix_time::hours(0)),
  90       dst_offsets_(posix_time::hours(0),posix_time::hours(0),posix_time::hours(0)),
  91       dst_calc_rules_()
  92     {
  93 #ifdef __HP_aCC
  94       // Work around bug in aC++ compiler: see QXCR1000880488 in the
  95       // HP bug tracking system
  96       const char_type sep_chars[2] = {',',0};
  97 #else
  98       const char_type sep_chars[2] = {','};
  99 #endif
 100       char_separator_type sep(sep_chars);
 101       tokenizer_type tokens(s, sep);
 102       tokenizer_iterator_type it = tokens.begin(), end = tokens.end();
 103       if (it == end)
 104         BOOST_THROW_EXCEPTION(std::invalid_argument("Could not parse time zone name"));
 105       calc_zone(*it++);
 106       if(has_dst_)
 107       {
 108         if (it == end)
 109           BOOST_THROW_EXCEPTION(std::invalid_argument("Could not parse DST begin time"));
 110         string_type dst_begin = *it++;
 111
 112         if (it == end)
 113           BOOST_THROW_EXCEPTION(std::invalid_argument("Could not parse DST end time"));
 114         string_type dst_end = *it;
 115         calc_rules(dst_begin, dst_end);
 116       }
 117     }
 118     virtual ~posix_time_zone_base() {}
 119     //!String for the zone when not in daylight savings (eg: EST)
 120     virtual string_type std_zone_abbrev()const
 121     {
 122       return zone_names_.std_zone_abbrev();
 123     }
 124     //!String for the timezone when in daylight savings (eg: EDT)
 125     /*! For those time zones that have no DST, an empty string is used */
 126     virtual string_type dst_zone_abbrev() const
 127     {
 128       return zone_names_.dst_zone_abbrev();
 129     }
 130     //!String for the zone when not in daylight savings (eg: Eastern Standard Time)
 131     /*! The full STD name is not extracted from the posix time zone string.
 132      * Therefore, the STD abbreviation is used in it's place */
 133     virtual string_type std_zone_name()const
 134     {
 135       return zone_names_.std_zone_name();
 136     }
 137     //!String for the timezone when in daylight savings (eg: Eastern Daylight Time)
 138     /*! The full DST name is not extracted from the posix time zone string.
 139      * Therefore, the STD abbreviation is used in it's place. For time zones
 140      * that have no DST, an empty string is used */
 141     virtual string_type dst_zone_name()const
 142     {
 143       return zone_names_.dst_zone_name();
 144     }
 145     //! True if zone uses daylight savings adjustments otherwise false
 146     virtual bool has_dst()const
 147     {
 148       return has_dst_;
 149     }
 150     //! Local time that DST starts -- NADT if has_dst is false
 151     virtual posix_time::ptime dst_local_start_time(gregorian::greg_year y)const
 152     {
 153       gregorian::date d(gregorian::not_a_date_time);
 154       if(has_dst_)
 155       {
 156         d = dst_calc_rules_->start_day(y);
 157       }
 158       return posix_time::ptime(d, dst_offsets_.dst_start_offset_);
 159     }
 160     //! Local time that DST ends -- NADT if has_dst is false
 161     virtual posix_time::ptime dst_local_end_time(gregorian::greg_year y)const
 162     {
 163       gregorian::date d(gregorian::not_a_date_time);
 164       if(has_dst_)
 165       {
 166         d = dst_calc_rules_->end_day(y);
 167       }
 168       return posix_time::ptime(d, dst_offsets_.dst_end_offset_);
 169     }
 170     //! Base offset from UTC for zone (eg: -07:30:00)
 171     virtual time_duration_type base_utc_offset()const
 172     {
 173       return base_utc_offset_;
 174     }
 175     //! Adjustment forward or back made while DST is in effect
 176     virtual time_duration_type dst_offset()const
 177     {
 178       return dst_offsets_.dst_adjust_;
 179     }
 180
 181     //! Returns a POSIX time_zone string for this object
 182     virtual string_type to_posix_string() const
 183     {
 184       // std offset dst [offset],start[/time],end[/time] - w/o spaces
 185       stringstream_type ss;
 186       ss.fill('0');
 187       boost::shared_ptr<dst_calc_rule> no_rules;
 188       // std
 189       ss << std_zone_abbrev();
 190       // offset
 191       if(base_utc_offset().is_negative()) {
 192         // inverting the sign guarantees we get two digits
 193         ss << '-' << std::setw(2) << base_utc_offset().invert_sign().hours();
 194       }
 195       else {
 196         ss << '+' << std::setw(2) << base_utc_offset().hours();
 197       }
 198       if(base_utc_offset().minutes() != 0 || base_utc_offset().seconds() != 0) {
 199         ss << ':' << std::setw(2) << base_utc_offset().minutes();
 200         if(base_utc_offset().seconds() != 0) {
 201           ss << ':' << std::setw(2) << base_utc_offset().seconds();
 202         }
 203       }
 204       if(dst_calc_rules_ != no_rules) {
 205         // dst
 206         ss << dst_zone_abbrev();
 207         // dst offset
 208         if(dst_offset().is_negative()) {
 209         // inverting the sign guarantees we get two digits
 210           ss << '-' << std::setw(2) << dst_offset().invert_sign().hours();
 211         }
 212         else {
 213           ss << '+' << std::setw(2) << dst_offset().hours();
 214         }
 215         if(dst_offset().minutes() != 0 || dst_offset().seconds() != 0) {
 216           ss << ':' << std::setw(2) << dst_offset().minutes();
 217           if(dst_offset().seconds() != 0) {
 218             ss << ':' << std::setw(2) << dst_offset().seconds();
 219           }
 220         }
 221         // start/time
 222         ss << ',' << date_time::convert_string_type<char, char_type>(dst_calc_rules_->start_rule_as_string()) << '/'
 223            << std::setw(2) << dst_offsets_.dst_start_offset_.hours() << ':'
 224            << std::setw(2) << dst_offsets_.dst_start_offset_.minutes();
 225         if(dst_offsets_.dst_start_offset_.seconds() != 0) {
 226           ss << ':' << std::setw(2) << dst_offsets_.dst_start_offset_.seconds();
 227         }
 228         // end/time
 229         ss << ',' << date_time::convert_string_type<char, char_type>(dst_calc_rules_->end_rule_as_string()) << '/'
 230            << std::setw(2) << dst_offsets_.dst_end_offset_.hours() << ':'
 231            << std::setw(2) << dst_offsets_.dst_end_offset_.minutes();
 232         if(dst_offsets_.dst_end_offset_.seconds() != 0) {
 233           ss << ':' << std::setw(2) << dst_offsets_.dst_end_offset_.seconds();
 234         }
 235       }
 236
 237       return ss.str();
 238     }
 239   private:
 240     time_zone_names zone_names_;
 241     bool has_dst_;
 242     time_duration_type base_utc_offset_;
 243     dst_adjustment_offsets dst_offsets_;
 244     boost::shared_ptr<dst_calc_rule> dst_calc_rules_;
 245
 246     /*! Extract time zone abbreviations for STD & DST as well
 247      * as the offsets for the time shift that occurs and how
 248      * much of a shift. At this time full time zone names are
 249      * NOT extracted so the abbreviations are used in their place */
 250     void calc_zone(const string_type& obj){
 251       const char_type empty_string[2] = {'\0'};
 252       stringstream_type ss(empty_string);
 253       typename string_type::const_pointer sit = obj.c_str(), obj_end = sit + obj.size();
 254       string_type l_std_zone_abbrev, l_dst_zone_abbrev;
 255
 256       // get 'std' name/abbrev
 257       while(std::isalpha(*sit)){
 258         ss << *sit++;
 259       }
 260       l_std_zone_abbrev = ss.str();
 261       ss.str(empty_string);
 262
 263       // get UTC offset
 264       if(sit != obj_end){
 265         // get duration
 266         while(sit != obj_end && !std::isalpha(*sit)){
 267           ss << *sit++;
 268         }
 269         base_utc_offset_ = date_time::str_from_delimited_time_duration<time_duration_type,char_type>(ss.str());
 270         ss.str(empty_string);
 271
 272         // base offset must be within range of -12 hours to +14 hours
 273         if(base_utc_offset_ < time_duration_type(-12,0,0) ||
 274           base_utc_offset_ > time_duration_type(14,0,0))
 275         {
 276           boost::throw_exception(bad_offset(posix_time::to_simple_string(base_utc_offset_)));
 277         }
 278       }
 279
 280       // get DST data if given
 281       if(sit != obj_end){
 282         has_dst_ = true;
 283
 284         // get 'dst' name/abbrev
 285         while(sit != obj_end && std::isalpha(*sit)){
 286           ss << *sit++;
 287         }
 288         l_dst_zone_abbrev = ss.str();
 289         ss.str(empty_string);
 290
 291         // get DST offset if given
 292         if(sit != obj_end){
 293           // get duration
 294           while(sit != obj_end && !std::isalpha(*sit)){
 295             ss << *sit++;
 296           }
 297           dst_offsets_.dst_adjust_ = date_time::str_from_delimited_time_duration<time_duration_type,char_type>(ss.str());
 298           ss.str(empty_string);
 299         }
 300         else{ // default DST offset
 301           dst_offsets_.dst_adjust_ = posix_time::hours(1);
 302         }
 303
 304         // adjustment must be within +|- 1 day
 305         if(dst_offsets_.dst_adjust_ <= time_duration_type(-24,0,0) ||
 306             dst_offsets_.dst_adjust_ >= time_duration_type(24,0,0))
 307         {
 308           boost::throw_exception(bad_adjustment(posix_time::to_simple_string(dst_offsets_.dst_adjust_)));
 309         }
 310       }
 311       // full names not extracted so abbrevs used in their place
 312       zone_names_ = time_zone_names(l_std_zone_abbrev, l_std_zone_abbrev, l_dst_zone_abbrev, l_dst_zone_abbrev);
 313     }
 314
 315     void calc_rules(const string_type& start, const string_type& end){
 316 #ifdef __HP_aCC
 317       // Work around bug in aC++ compiler: see QXCR1000880488 in the
 318       // HP bug tracking system
 319       const char_type sep_chars[2] = {'/',0};
 320 #else
 321       const char_type sep_chars[2] = {'/'};
 322 #endif
 323       char_separator_type sep(sep_chars);
 324       tokenizer_type st_tok(start, sep);
 325       tokenizer_type et_tok(end, sep);
 326       tokenizer_iterator_type sit = st_tok.begin();
 327       tokenizer_iterator_type eit = et_tok.begin();
 328
 329       // generate date spec
 330       char_type x = string_type(*sit).at(0);
 331       if(x == 'M'){
 332         M_func(*sit, *eit);
 333       }
 334       else if(x == 'J'){
 335         julian_no_leap(*sit, *eit);
 336       }
 337       else{
 338         julian_day(*sit, *eit);
 339       }
 340
 341       ++sit;
 342       ++eit;
 343       // generate durations
 344       // starting offset
 345       if(sit != st_tok.end()){
 346         dst_offsets_.dst_start_offset_ =  date_time::str_from_delimited_time_duration<time_duration_type,char_type>(*sit);
 347       }
 348       else{
 349         // default
 350         dst_offsets_.dst_start_offset_ = posix_time::hours(2);
 351       }
 352       // start/end offsets must fall on given date
 353       if(dst_offsets_.dst_start_offset_ < time_duration_type(0,0,0) ||
 354           dst_offsets_.dst_start_offset_ >= time_duration_type(24,0,0))
 355       {
 356         boost::throw_exception(bad_offset(posix_time::to_simple_string(dst_offsets_.dst_start_offset_)));
 357       }
 358
 359       // ending offset
 360       if(eit != et_tok.end()){
 361         dst_offsets_.dst_end_offset_ =  date_time::str_from_delimited_time_duration<time_duration_type,char_type>(*eit);
 362       }
 363       else{
 364         // default
 365         dst_offsets_.dst_end_offset_ = posix_time::hours(2);
 366       }
 367       // start/end offsets must fall on given date
 368       if(dst_offsets_.dst_end_offset_ < time_duration_type(0,0,0) ||
 369         dst_offsets_.dst_end_offset_ >= time_duration_type(24,0,0))
 370       {
 371         boost::throw_exception(bad_offset(posix_time::to_simple_string(dst_offsets_.dst_end_offset_)));
 372       }
 373     }
 374
 375     /* Parses out a start/end date spec from a posix time zone string.
 376      * Date specs come in three possible formats, this function handles
 377      * the 'M' spec. Ex "M2.2.4" => 2nd month, 2nd week, 4th day .
 378      */
 379     void M_func(const string_type& s, const string_type& e){
 380       typedef gregorian::nth_kday_of_month nkday;
 381       unsigned short sm=0,sw=0,sd=0,em=0,ew=0,ed=0; // start/end month,week,day
 382 #ifdef __HP_aCC
 383       // Work around bug in aC++ compiler: see QXCR1000880488 in the
 384       // HP bug tracking system
 385       const char_type sep_chars[3] = {'M','.',0};
 386 #else
 387       const char_type sep_chars[3] = {'M','.'};
 388 #endif
 389       char_separator_type sep(sep_chars);
 390       tokenizer_type stok(s, sep), etok(e, sep);
 391
 392       tokenizer_iterator_type it = stok.begin();
 393       sm = lexical_cast<unsigned short>(*it++);
 394       sw = lexical_cast<unsigned short>(*it++);
 395       sd = lexical_cast<unsigned short>(*it);
 396
 397       it = etok.begin();
 398       em = lexical_cast<unsigned short>(*it++);
 399       ew = lexical_cast<unsigned short>(*it++);
 400       ed = lexical_cast<unsigned short>(*it);
 401
 402       dst_calc_rules_ = shared_ptr<dst_calc_rule>(
 403         new nth_kday_dst_rule(
 404           nth_last_dst_rule::start_rule(
 405             static_cast<nkday::week_num>(sw),sd,sm),
 406           nth_last_dst_rule::start_rule(
 407             static_cast<nkday::week_num>(ew),ed,em)
 408           )
 409       );
 410     }
 411
 412     //! Julian day. Feb29 is never counted, even in leap years
 413     // expects range of 1-365
 414     void julian_no_leap(const string_type& s, const string_type& e){
 415       typedef gregorian::gregorian_calendar calendar;
 416       const unsigned short year = 2001; // Non-leap year
 417       unsigned short sm=1;
 418       int sd=0;
 419       sd = lexical_cast<int>(s.substr(1)); // skip 'J'
 420       while(sd >= calendar::end_of_month_day(year,sm)){
 421         sd -= calendar::end_of_month_day(year,sm++);
 422       }
 423       unsigned short em=1;
 424       int ed=0;
 425       ed = lexical_cast<int>(e.substr(1)); // skip 'J'
 426       while(ed > calendar::end_of_month_day(year,em)){
 427         ed -= calendar::end_of_month_day(year,em++);
 428       }
 429
 430       dst_calc_rules_ = shared_ptr<dst_calc_rule>(
 431         new partial_date_dst_rule(
 432           partial_date_dst_rule::start_rule(
 433             static_cast<unsigned short>(sd), static_cast<date_time::months_of_year>(sm)),
 434           partial_date_dst_rule::end_rule(
 435             static_cast<unsigned short>(ed), static_cast<date_time::months_of_year>(em))
 436           )
 437       );
 438     }
 439
 440     //! Julian day. Feb29 is always counted, but exception thrown in non-leap years
 441     // expects range of 0-365
 442     void julian_day(const string_type& s, const string_type& e){
 443       int sd=0, ed=0;
 444       sd = lexical_cast<int>(s);
 445       ed = lexical_cast<int>(e);
 446       dst_calc_rules_ = shared_ptr<dst_calc_rule>(
 447         new partial_date_dst_rule(
 448           partial_date_dst_rule::start_rule(++sd),// args are 0-365
 449           partial_date_dst_rule::end_rule(++ed) // pd expects 1-366
 450           )
 451       );
 452     }
 453
 454     //! helper function used when throwing exceptions
 455     static std::string td_as_string(const time_duration_type& td)
 456     {
 457       std::string s;
 458 #if defined(USE_DATE_TIME_PRE_1_33_FACET_IO)
 459       s = posix_time::to_simple_string(td);
 460 #else
 461       std::stringstream ss;
 462       ss << td;
 463       s = ss.str();
 464 #endif
 465       return s;
 466     }
 467   };
 468
 469   typedef posix_time_zone_base<char> posix_time_zone;
 470
 471 } } // namespace boost::local_time
 472
 473
 474 #endif // _DATE_TIME_POSIX_TIME_ZONE__