| // Copyright 2016 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #if defined(_WIN32) || defined(_WIN64) |
| #define _CRT_SECURE_NO_WARNINGS 1 |
| #endif |
| |
| #include "time_zone_libc.h" |
| |
| #include <chrono> |
| #include <ctime> |
| #include <tuple> |
| #include <utility> |
| |
| #include "absl/time/internal/cctz/include/cctz/civil_time.h" |
| #include "absl/time/internal/cctz/include/cctz/time_zone.h" |
| |
| namespace absl { |
| namespace time_internal { |
| namespace cctz { |
| |
| namespace { |
| |
| // .first is seconds east of UTC; .second is the time-zone abbreviation. |
| using OffsetAbbr = std::pair<int, const char*>; |
| |
| // Defines a function that can be called as follows: |
| // |
| // std::tm tm = ...; |
| // OffsetAbbr off_abbr = get_offset_abbr(tm); |
| // |
| #if defined(_WIN32) || defined(_WIN64) |
| // Uses the globals: '_timezone', '_dstbias' and '_tzname'. |
| OffsetAbbr get_offset_abbr(const std::tm& tm) { |
| const bool is_dst = tm.tm_isdst > 0; |
| const int off = _timezone + (is_dst ? _dstbias : 0); |
| const char* abbr = _tzname[is_dst]; |
| return {off, abbr}; |
| } |
| #elif defined(__sun) |
| // Uses the globals: 'timezone', 'altzone' and 'tzname'. |
| OffsetAbbr get_offset_abbr(const std::tm& tm) { |
| const bool is_dst = tm.tm_isdst > 0; |
| const int off = is_dst ? altzone : timezone; |
| const char* abbr = tzname[is_dst]; |
| return {off, abbr}; |
| } |
| #elif defined(__native_client__) || defined(__myriad2__) || \ |
| defined(__EMSCRIPTEN__) |
| // Uses the globals: 'timezone' and 'tzname'. |
| OffsetAbbr get_offset_abbr(const std::tm& tm) { |
| const bool is_dst = tm.tm_isdst > 0; |
| const int off = _timezone + (is_dst ? 60 * 60 : 0); |
| const char* abbr = tzname[is_dst]; |
| return {off, abbr}; |
| } |
| #else |
| // |
| // Returns an OffsetAbbr using std::tm fields with various spellings. |
| // |
| #if !defined(tm_gmtoff) && !defined(tm_zone) |
| template <typename T> |
| OffsetAbbr get_offset_abbr(const T& tm, decltype(&T::tm_gmtoff) = nullptr, |
| decltype(&T::tm_zone) = nullptr) { |
| return {tm.tm_gmtoff, tm.tm_zone}; |
| } |
| #endif // !defined(tm_gmtoff) && !defined(tm_zone) |
| #if !defined(__tm_gmtoff) && !defined(__tm_zone) |
| template <typename T> |
| OffsetAbbr get_offset_abbr(const T& tm, decltype(&T::__tm_gmtoff) = nullptr, |
| decltype(&T::__tm_zone) = nullptr) { |
| return {tm.__tm_gmtoff, tm.__tm_zone}; |
| } |
| #endif // !defined(__tm_gmtoff) && !defined(__tm_zone) |
| #endif |
| |
| } // namespace |
| |
| TimeZoneLibC::TimeZoneLibC(const std::string& name) |
| : local_(name == "localtime") {} |
| |
| time_zone::absolute_lookup TimeZoneLibC::BreakTime( |
| const time_point<seconds>& tp) const { |
| time_zone::absolute_lookup al; |
| std::time_t t = ToUnixSeconds(tp); |
| std::tm tm; |
| if (local_) { |
| #if defined(_WIN32) || defined(_WIN64) |
| localtime_s(&tm, &t); |
| #else |
| localtime_r(&t, &tm); |
| #endif |
| std::tie(al.offset, al.abbr) = get_offset_abbr(tm); |
| } else { |
| #if defined(_WIN32) || defined(_WIN64) |
| gmtime_s(&tm, &t); |
| #else |
| gmtime_r(&t, &tm); |
| #endif |
| al.offset = 0; |
| al.abbr = "UTC"; |
| } |
| al.cs = civil_second(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, |
| tm.tm_hour, tm.tm_min, tm.tm_sec); |
| al.is_dst = tm.tm_isdst > 0; |
| return al; |
| } |
| |
| time_zone::civil_lookup TimeZoneLibC::MakeTime(const civil_second& cs) const { |
| time_zone::civil_lookup cl; |
| std::time_t t; |
| if (local_) { |
| // Does not handle SKIPPED/AMBIGUOUS or huge years. |
| std::tm tm; |
| tm.tm_year = static_cast<int>(cs.year() - 1900); |
| tm.tm_mon = cs.month() - 1; |
| tm.tm_mday = cs.day(); |
| tm.tm_hour = cs.hour(); |
| tm.tm_min = cs.minute(); |
| tm.tm_sec = cs.second(); |
| tm.tm_isdst = -1; |
| t = std::mktime(&tm); |
| } else { |
| t = cs - civil_second(); |
| } |
| cl.kind = time_zone::civil_lookup::UNIQUE; |
| cl.pre = cl.trans = cl.post = FromUnixSeconds(t); |
| return cl; |
| } |
| |
| bool TimeZoneLibC::NextTransition(const time_point<seconds>& tp, |
| time_zone::civil_transition* trans) const { |
| return false; |
| } |
| |
| bool TimeZoneLibC::PrevTransition(const time_point<seconds>& tp, |
| time_zone::civil_transition* trans) const { |
| return false; |
| } |
| |
| std::string TimeZoneLibC::Version() const { |
| return std::string(); // unknown |
| } |
| |
| std::string TimeZoneLibC::Description() const { |
| return local_ ? "localtime" : "UTC"; |
| } |
| |
| } // namespace cctz |
| } // namespace time_internal |
| } // namespace absl |