suyu/src/common/time_zone.cpp
lat9nq de1fe66d81 time_zone: Handle offset time zones
time_zone: Remove maybe_unused

time_zone: Use s64 storages

time_zone: Catch by reference
2023-06-05 15:15:23 -04:00

104 lines
3.6 KiB
C++

// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include <chrono>
#include <exception>
#include <iomanip>
#include <sstream>
#include <stdexcept>
#include <fmt/chrono.h>
#include <fmt/core.h>
#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<const char*, 46>& GetTimeZoneStrings() {
return timezones;
}
std::string GetDefaultTimeZone() {
return "GMT";
}
static std::string GetOsTimeZoneOffset() {
const std::time_t t{std::time(nullptr)};
const std::tm tm{*std::localtime(&t)};
return fmt::format("{:%z}", tm);
}
static int ConvertOsTimeZoneOffsetToInt(const std::string& timezone) {
try {
return std::stoi(timezone);
} catch (const std::invalid_argument&) {
LOG_CRITICAL(Common, "invalid_argument with {}!", timezone);
return 0;
} catch (const std::out_of_range&) {
LOG_CRITICAL(Common, "out_of_range with {}!", timezone);
return 0;
}
}
std::chrono::seconds GetCurrentOffsetSeconds() {
const int offset{ConvertOsTimeZoneOffsetToInt(GetOsTimeZoneOffset())};
int seconds{(offset / 100) * 60 * 60}; // Convert hour component to seconds
seconds += (offset % 100) * 60; // Convert minute component to seconds
return std::chrono::seconds{seconds};
}
// Key is [Hours * 100 + Minutes], multiplied by 100 if DST
const static std::map<s64, const char*> off_timezones = {
{530, "Asia/Calcutta"}, {930, "Australia/Darwin"}, {845, "Australia/Eucla"},
{103000, "Australia/Adelaide"}, {1030, "Australia/Lord_Howe"}, {630, "Indian/Cocos"},
{1245, "Pacific/Chatham"}, {134500, "Pacific/Chatham"}, {-330, "Canada/Newfoundland"},
{-23000, "Canada/Newfoundland"}, {430, "Asia/Kabul"}, {330, "Asia/Tehran"},
{43000, "Asia/Tehran"}, {545, "Asia/Kathmandu"}, {-930, "Asia/Marquesas"},
};
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
const s64 seconds = static_cast<s64>(GetCurrentOffsetSeconds().count());
const s64 minutes = seconds / 60;
const s64 hours = minutes / 60;
const s64 minutes_off = minutes - hours * 60;
if (minutes_off != 0) {
const auto the_time = std::time(nullptr);
const struct std::tm& local = *std::localtime(&the_time);
const bool is_dst = local.tm_isdst != 0;
const s64 tz_index = (hours * 100 + minutes_off) * (is_dst ? 100 : 1);
try {
return off_timezones.at(tz_index);
} catch (std::out_of_range&) {
LOG_ERROR(Common, "Time zone {} not handled, defaulting to hour offset.", tz_index);
}
}
return fmt::format("Etc/GMT{:s}{:d}", hours > 0 ? "-" : "+", std::abs(hours));
#endif
}
} // namespace Common::TimeZone