From 3979c7daa478199cff7bc985fceabcf30fadbc3b Mon Sep 17 00:00:00 2001 From: lat9nq <22451773+lat9nq@users.noreply.github.com> Date: Tue, 23 May 2023 18:32:28 -0400 Subject: [PATCH] common: Move system time zone string detection Moves it from Settings to Common::TimeZone, since this algorithm doesn't depend on the setting. It also lets us use it in other libraries. common: Various fixes time_zone: Don't double up the std::abs Too many absolute values were causing mirrored time zones to resolve as the same. --- src/common/settings.cpp | 79 ++++------------------------------------ src/common/time_zone.cpp | 75 ++++++++++++++++++++++++++++++++++++-- src/common/time_zone.h | 6 +++ 3 files changed, 84 insertions(+), 76 deletions(-) diff --git a/src/common/settings.cpp b/src/common/settings.cpp index ed15b8b7d..115fba27d 100644 --- a/src/common/settings.cpp +++ b/src/common/settings.cpp @@ -3,18 +3,14 @@ #if __cpp_lib_chrono >= 201907L #include -#else -#include -#include #endif #include -#include -#include #include "common/assert.h" #include "common/fs/path_util.h" #include "common/logging/log.h" #include "common/settings.h" +#include "common/time_zone.h" namespace Settings { @@ -22,83 +18,22 @@ Values values; static bool configuring_global = true; std::string GetTimeZoneString() { - static constexpr std::array timezones{ - "GMT", "GMT", "CET", "CST6CDT", "Cuba", "EET", "Egypt", "Eire", - "EST", "EST5EDT", "GB", "GB-Eire", "GMT", "GMT+0", "GMT-0", "GMT0", - "Greenwich", "Hongkong", "HST", "Iceland", "Iran", "Israel", "Jamaica", "Japan", - "Kwajalein", "Libya", "MET", "MST", "MST7MDT", "Navajo", "NZ", "NZ-CHAT", - "Poland", "Portugal", "PRC", "PST8PDT", "ROC", "ROK", "Singapore", "Turkey", - "UCT", "Universal", "UTC", "W-SU", "WET", "Zulu", - }; - const auto time_zone_index = static_cast(values.time_zone_index.GetValue()); - ASSERT(time_zone_index < timezones.size()); + ASSERT(time_zone_index < Common::TimeZone::GetTimeZoneStrings().size()); + std::string location_name; - switch (time_zone_index) { - case 0: { // Auto + if (time_zone_index == 0) { // Auto #if __cpp_lib_chrono >= 201907L const struct std::chrono::tzdb& time_zone_data = std::chrono::get_tzdb(); const std::chrono::time_zone* current_zone = time_zone_data.current_zone(); std::string_view current_zone_name = current_zone->name(); location_name = current_zone_name; -#elif defined(MINGW) - // MinGW has broken strftime -- https://sourceforge.net/p/mingw-w64/bugs/793/ - // e.g. fmt::format("{:%z}") -- returns "Eastern Daylight Time" when it should be "-0400" - location_name = timezones[0]; - break; #else - static constexpr std::array offsets{ - 0, 0, 3600, -21600, -19768, 7200, 7509, -1521, -18000, -18000, - -75, -75, 0, 0, 0, 0, 0, 27402, -36000, -968, - 12344, 8454, -18430, 33539, 40160, 3164, 3600, -25200, -25200, -25196, - 41944, 44028, 5040, -2205, 29143, -28800, 29160, 30472, 24925, 6952, - 0, 0, 0, 9017, 0, 0, - }; - - static constexpr std::array dst{ - false, false, true, true, true, true, true, true, false, true, true, true, - false, false, false, false, false, true, false, false, true, true, true, true, - false, true, true, false, true, true, true, true, true, true, true, true, - true, true, true, true, false, false, false, true, true, false, - }; - - const auto now = std::time(nullptr); - const struct std::tm& local = *std::localtime(&now); - const std::string clock_offset_s = fmt::format("{:%z}", local); - if (clock_offset_s.empty()) { - location_name = timezones[0]; - break; - } - const int hours_offset = std::stoi(clock_offset_s) / 100; - const int minutes_offset = std::stoi(clock_offset_s) - hours_offset * 100; - const int system_offset = - hours_offset * 3600 + minutes_offset * 60 - (local.tm_isdst ? 3600 : 0); - - int min = std::numeric_limits::max(); - int min_index = -1; - for (u32 i = 2; i < offsets.size(); i++) { - // Skip if system is celebrating DST but considered time zone does not - if (local.tm_isdst && !dst[i]) { - continue; - } - - const auto offset = offsets[i]; - const int difference = std::abs(std::abs(offset) - std::abs(system_offset)); - if (difference < min) { - min = difference; - min_index = i; - } - } - - location_name = timezones[min_index]; + location_name = Common::TimeZone::FindSystemTimeZone(); #endif - break; + } else { + location_name = Common::TimeZone::GetTimeZoneStrings()[time_zone_index]; } - default: - location_name = timezones[time_zone_index]; - break; - } - return location_name; } diff --git a/src/common/time_zone.cpp b/src/common/time_zone.cpp index 126836b01..717d751ba 100644 --- a/src/common/time_zone.cpp +++ b/src/common/time_zone.cpp @@ -4,12 +4,29 @@ #include #include #include +#include +#include #include "common/logging/log.h" +#include "common/settings.h" #include "common/time_zone.h" namespace Common::TimeZone { +// Time zone strings +constexpr std::array timezones{ + "GMT", "GMT", "CET", "CST6CDT", "Cuba", "EET", "Egypt", "Eire", + "EST", "EST5EDT", "GB", "GB-Eire", "GMT", "GMT+0", "GMT-0", "GMT0", + "Greenwich", "Hongkong", "HST", "Iceland", "Iran", "Israel", "Jamaica", "Japan", + "Kwajalein", "Libya", "MET", "MST", "MST7MDT", "Navajo", "NZ", "NZ-CHAT", + "Poland", "Portugal", "PRC", "PST8PDT", "ROC", "ROK", "Singapore", "Turkey", + "UCT", "Universal", "UTC", "W-SU", "WET", "Zulu", +}; + +const std::array& GetTimeZoneStrings() { + return timezones; +} + std::string GetDefaultTimeZone() { return "GMT"; } @@ -18,10 +35,7 @@ static std::string GetOsTimeZoneOffset() { const std::time_t t{std::time(nullptr)}; const std::tm tm{*std::localtime(&t)}; - std::stringstream ss; - ss << std::put_time(&tm, "%z"); // Get the current timezone offset, e.g. "-400", as a string - - return ss.str(); + return fmt::format("{:%z}", tm); } static int ConvertOsTimeZoneOffsetToInt(const std::string& timezone) { @@ -45,4 +59,57 @@ std::chrono::seconds GetCurrentOffsetSeconds() { return std::chrono::seconds{seconds}; } +std::string FindSystemTimeZone() { +#if defined(MINGW) + // MinGW has broken strftime -- https://sourceforge.net/p/mingw-w64/bugs/793/ + // e.g. fmt::format("{:%z}") -- returns "Eastern Daylight Time" when it should be "-0400" + return timezones[0]; +#else + // Time zone offset in seconds from GMT + constexpr std::array offsets{ + 0, 0, 3600, -21600, -19768, 7200, 7509, -1521, -18000, -18000, -75, -75, + 0, 0, 0, 0, 0, 27402, -36000, -968, 12344, 8454, -18430, 33539, + 40160, 3164, 3600, -25200, -25200, -25196, 41944, 44028, 5040, -2205, 29143, -28800, + 29160, 30472, 24925, 6952, 0, 0, 0, 9017, 0, 0, + }; + + // If the time zone recognizes Daylight Savings Time + constexpr std::array dst{ + false, false, true, true, true, true, true, true, false, true, true, true, + false, false, false, false, false, true, false, false, true, true, true, true, + false, true, true, false, true, true, true, true, true, true, true, true, + true, true, true, true, false, false, false, true, true, false, + }; + + static std::string system_time_zone_cached{}; + if (!system_time_zone_cached.empty()) { + return system_time_zone_cached; + } + + const auto now = std::time(nullptr); + const struct std::tm& local = *std::localtime(&now); + + const s64 system_offset = GetCurrentOffsetSeconds().count() - (local.tm_isdst ? 3600 : 0); + + int min = std::numeric_limits::max(); + int min_index = -1; + for (u32 i = 2; i < offsets.size(); i++) { + // Skip if system is celebrating DST but considered time zone does not + if (local.tm_isdst && !dst[i]) { + continue; + } + + const auto offset = offsets[i]; + const int difference = static_cast(std::abs(offset - system_offset)); + if (difference < min) { + min = difference; + min_index = i; + } + } + + system_time_zone_cached = GetTimeZoneStrings()[min_index]; + return system_time_zone_cached; +#endif +} + } // namespace Common::TimeZone diff --git a/src/common/time_zone.h b/src/common/time_zone.h index 99cae6ef2..f574d5c04 100644 --- a/src/common/time_zone.h +++ b/src/common/time_zone.h @@ -3,15 +3,21 @@ #pragma once +#include #include #include namespace Common::TimeZone { +[[nodiscard]] const std::array& GetTimeZoneStrings(); + /// Gets the default timezone, i.e. "GMT" [[nodiscard]] std::string GetDefaultTimeZone(); /// Gets the offset of the current timezone (from the default), in seconds [[nodiscard]] std::chrono::seconds GetCurrentOffsetSeconds(); +/// Searches time zone offsets for the closest offset to the system time zone +[[nodiscard]] std::string FindSystemTimeZone(); + } // namespace Common::TimeZone