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date/tz.cpp
Howard Hinnant 28eadffa06 Implement '%z'
2015-08-08 18:11:35 -04:00

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// The MIT License (MIT)
//
// Copyright (c) 2015 Howard Hinnant
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#include "tz_private.h"
#include <algorithm>
#include <cctype>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <iterator>
#include <memory>
#include <sstream>
#include <string>
#include <tuple>
#include <vector>
#include <sys/stat.h>
#ifdef WIN32
#include <locale>
#include <codecvt>
#endif
#if TIMEZONE_MAPPING
// Timezone mapping is mapping native timezone names to "Standard" ones.
// Mapping reades a CSV file for the data and currently uses
// std::quoted to do that which is a C++14 feature found in iomanip.
// VS2015 supports std::quoted but MSVC has a mixed rather
// than strict standard support so there is no -std=c++14 flag for MSVC.
// MingW is a Windows based platform so requires mapping and thefore C++14.
// Linux/Mac currently do not require mapping so C++14 isn't needed for this
// so C++11 should work.
#include <iomanip>
#endif
// unistd.h is used on some platforms as part of the the means to get
// the current time zone. However unistd.h only somtimes exists on Win32.
// gcc/mingw support unistd.h on Win32 but MSVC does not.
// However on Win32 we don't need unistd.h anyway to get the current timezone
// as Windows.h provides a means to do it
#ifdef _WIN32
#include <Windows.h>
#else
#include <unistd.h>
#endif
// Until filesystem arrives.
static const char folder_delimiter =
#ifdef _WIN32
'\\';
#else
'/';
#endif
#ifdef _WIN32
// Win32 support requires calling OS functions.
// This routine maps OS error codes to readable text strngs.
static std::string get_win32_message(DWORD error_code)
{
struct free_message {
void operator()(char buf[]) {
if (buf != nullptr)
{
auto result = HeapFree(GetProcessHeap(), 0, buf);
assert(result != 0);
}
}
};
char* msg = nullptr;
auto result = FormatMessageA(
FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM
| FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
reinterpret_cast<char*>(&msg), 0, NULL );
std::unique_ptr<char[], free_message> message_buffer(msg);
if (result == 0) // If there is no error message, still give the code.
{
std::string err = "Error getting message for error number ";
err += std::to_string(error_code);
return err;
}
assert(message_buffer.get() != nullptr);
return std::string(message_buffer.get());
}
#endif
namespace date
{
// +---------------------+
// | Begin Configuration |
// +---------------------+
#if _WIN32 // TODO: sensible default for all platforms.
static std::string install{ "c:\\tzdata" };
#else
static std::string install{ "/Users/howardhinnant/Downloads/tzdata2015e" };
#endif
static const std::vector<std::string> files =
{
"africa", "antarctica", "asia", "australasia", "backward", "etcetera", "europe",
"pacificnew", "northamerica", "southamerica", "systemv", "leapseconds"
};
// These can be used to reduce the range of the database to save memory
CONSTDATA auto min_year = date::year::min();
CONSTDATA auto max_year = date::year::max();
// Arbitrary day of the year that will be away from any limits.
// Used with year::min() and year::max().
CONSTDATA auto boring_day = date::aug/18;
// +-------------------+
// | End Configuration |
// +-------------------+
#if _MSC_VER && ! defined(__clang__) && ! defined( __GNUG__)
// We can't use static_assert here for MSVC (yet) because
// the expression isn't constexpr in MSVC yet.
// FIXME! Remove this when MSVC's constexpr support improves.
#else
static_assert(min_year <= max_year, "Configuration error");
#endif
#if __cplusplus >= 201402
static_assert(boring_day.ok(), "Configuration error");
#endif
#if TIMEZONE_MAPPING
namespace // Put types in an aonymous name space.
{
// A simple type to manage RAII for key handles and to
// implement the trivial registry interface we need.
// Not itended to be general purpose.
class reg_key
{
private:
// Note there is no value documented to be an invalid handle value.
// Not NULL nor INVALID_HANDLE_VALUE. We must rely on is_open.
HKEY m_key = NULL;
bool m_is_open = false;
public:
HKEY handle()
{
return m_key;
}
bool is_open() const
{
return m_is_open;
}
LONG open(const wchar_t* key_name)
{
LONG result;
result = RegOpenKeyExW(HKEY_LOCAL_MACHINE, key_name, 0, KEY_READ, &m_key);
if (result == ERROR_SUCCESS)
m_is_open = true;
return result;
}
LONG close()
{
if (m_is_open)
{
auto result = RegCloseKey(m_key);
assert(result == ERROR_SUCCESS);
if (result == ERROR_SUCCESS)
{
m_is_open = false;
m_key = NULL;
}
return result;
}
return ERROR_SUCCESS;
}
// WARNING: this function has a hard code value size limit.
// It is not a general purpose function.
// It should be sufficient for our use cases.
// The function could be made workable for any size string
// but we don't need the complexity of implementing that
// for our meagre purposes right now.
bool get_string(const wchar_t* key_name, std::string& value)
{
value.clear();
wchar_t value_buffer[256];
// in/out parameter. Documentation say that size is a count of bytes not chars.
DWORD size = sizeof(value_buffer);
DWORD tzi_type = REG_SZ;
if (RegQueryValueExW(handle(), key_name, nullptr, &tzi_type,
reinterpret_cast<LPBYTE>(value_buffer), &size) == ERROR_SUCCESS)
{
// Function does not guarantee to null terminate.
value_buffer[size] = L'\0';
std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;
value = converter.to_bytes(value_buffer);
return true;
}
return false;
}
bool get_binary(const wchar_t* key_name, void* value, int value_size)
{
DWORD size = value_size;
DWORD type = REG_BINARY;
if (RegQueryValueExW(handle(), key_name, nullptr, &type,
reinterpret_cast<LPBYTE>(value), &size) == ERROR_SUCCESS
&& (int) size == value_size)
return true;
return false;
}
~reg_key()
{
close();
}
};
} // anonymous namespace
template < typename T, size_t N >
static inline size_t countof(T(&arr)[N])
{
return std::extent< T[N] >::value;
}
// This function return an exhaustive list of time zone information
// from the Windows registry.
// The routine tries to to obtain as much information as possible despite errors.
// If there is an error with any key, it is silently ignored to move on to the next.
// We don't have a logger to log such errors and it might disruptive to log anyway.
// We don't want the whole database of information disrupted just because
// one record of in it can't be read.
// The expectation is that the errors will eventually manifest to the
// caller as a missing time zone which they will need to investigate.
static void get_windows_timezone_info(std::vector<timezone_info>& tz_list)
{
tz_list.clear();
LONG result;
// Open the parent time zone key that has the list of timzeones in.
reg_key zones_key;
static const wchar_t zones_key_name[] = { L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones" };
result = zones_key.open(zones_key_name);
// TODO! Review if this should happen here or be signalled later.
// We don't want process to fail on startup because of this or something.
if (result != ERROR_SUCCESS)
throw std::runtime_error("Time Zone registry key could not be opened: " + get_win32_message(result));
DWORD size;
wchar_t zone_key_name[256];
std::wstring value;
// Iterate through the list of keys of the parent time zones key to get
// each key that identifies each individual timezone.
std::wstring full_zone_key_name;
for (DWORD zone_index = 0; ; ++zone_index)
{
timezone_info tz;
size = (DWORD) sizeof(zone_key_name);
auto status = RegEnumKeyExW(zones_key.handle(), zone_index, zone_key_name, &size,
nullptr, nullptr, nullptr, nullptr);
if (status != ERROR_SUCCESS && status != ERROR_NO_MORE_ITEMS)
throw std::runtime_error("Can't enumerate time zone registry key" + get_win32_message(status));
if (status == ERROR_NO_MORE_ITEMS)
break;
zone_key_name[size] = L'\0';
std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;
tz.timezone_id = converter.to_bytes(zone_key_name);
full_zone_key_name = zones_key_name;
full_zone_key_name += L'\\';
full_zone_key_name += zone_key_name;
// If any field fails to be found consider the whole time zone
// entry corrupt and move onto the next. See comments
// at top of function.
reg_key zone_key;
if (zone_key.open(full_zone_key_name.c_str()) != ERROR_SUCCESS)
continue;
if (!zone_key.get_string(L"Std", tz.standard_name))
continue;
#if 0
// TBD if these fields are not required yet.
// The might be useful for test cases though.
if (!zone_key.get_string("Display", tz.display_name))
continue;
if (!zone_key.get_binary("TZI", &tz.tzi, sizeof(TZI)))
continue;
#endif
auto result = zone_key.close();
tz_list.push_back(std::move(tz));
}
result = zones_key.close();
}
// standard_name is the StandardName field from the Windows
// TIME_ZONE_INFORMATION structure.
// See the Windows API function GetTimeZoneInformation.
// The standard_name is also the value from STD field of
// under the windows registry key Time Zones.
// To be clear standard_name does NOT represent a windows timezone id
// or an IANA tzid
static const timezone_info* find_native_timezone_by_standard_name(
const std::string& standard_name)
{
// TODO! we can improve on linear search.
const auto& native_zones = get_tzdb().native_zones;
for (const auto& tz : native_zones)
{
if (tz.standard_name == standard_name)
return &tz;
}
return nullptr;
}
// Read CSV file of "other","territory","type".
// See timezone_mapping structure for more info.
// This function should be kept in sync the code/ that writes this file.
static std::vector<timezone_mapping>
load_timezone_mappings_from_csv_file(const std::string& input_path)
{
size_t line = 1;
std::vector<timezone_mapping> mappings;
std::ifstream is(input_path, std::ios_base::in | std::ios_base::binary);
if (!is.is_open())
{
// We don't emit file exceptions because that's an implementation detail.
std::string msg = "Error opening time zone mapping file: ";
msg += input_path;
throw std::runtime_error(msg);
}
auto error = [&](const char* info)
{
std::string msg = "Error reading zone mapping file at line ";
msg += std::to_string(line);
msg += ": ";
msg += info;
throw std::runtime_error(msg);
};
auto read_field_delim = [&]()
{
char field_delim;
is.read(&field_delim, 1);
if (is.gcount() != 1 || field_delim != ',')
error("delimiter ',' expected");
};
std::string copyright;
for (int i = 0; i < 4; ++i)
getline(is, copyright);
for (;;)
{
timezone_mapping zm{};
is >> std::quoted(zm.other);
if (is.eof())
break;
read_field_delim();
is >> std::quoted(zm.territory);
read_field_delim();
is >> std::quoted(zm.type);
char record_delim;
is.read(&record_delim, 1);
if (is.gcount() != 1 || record_delim != '\n')
error("record delimiter LF expected");
if (is.fail() || is.eof())
error("unexpected end of file, file read error or formatting error.");
++line;
mappings.push_back(std::move(zm));
}
is.close();
return mappings;
}
static bool
native_to_standard_timezone_name(const std::string& native_tz_name, std::string& standard_tz_name)
{
// TOOD! Need be a case insensitive compare?
if (native_tz_name == "UTC")
{
standard_tz_name = "Etc/UTC";
return true;
}
standard_tz_name.clear();
// TODO! we can improve on linear search.
const auto& mappings = date::get_tzdb().mappings;
for (const auto& tzm : mappings)
{
if (tzm.other == native_tz_name)
{
standard_tz_name = tzm.type;
return true;
}
}
return false;
}
#endif
// Parsing helpers
static
std::string
parse3(std::istream& in)
{
std::string r(3, ' ');
ws(in);
r[0] = static_cast<char>(in.get());
r[1] = static_cast<char>(in.get());
r[2] = static_cast<char>(in.get());
return r;
}
static
unsigned
parse_dow(std::istream& in)
{
const char*const dow_names[] =
{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
auto s = parse3(in);
auto dow = std::find(std::begin(dow_names), std::end(dow_names), s) - dow_names;
if (dow >= std::end(dow_names) - std::begin(dow_names))
throw std::runtime_error("oops: bad dow name: " + s);
return static_cast<unsigned>(dow);
}
static
unsigned
parse_month(std::istream& in)
{
const char*const month_names[] =
{"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
auto s = parse3(in);
auto m = std::find(std::begin(month_names), std::end(month_names), s) - month_names;
if (m >= std::end(month_names) - std::begin(month_names))
throw std::runtime_error("oops: bad month name: " + s);
return static_cast<unsigned>(++m);
}
static
std::chrono::seconds
parse_unsigned_time(std::istream& in)
{
using namespace std::chrono;
int x;
in >> x;
auto r = seconds{hours{x}};
if (!in.eof() && in.peek() == ':')
{
in.get();
in >> x;
r += minutes{x};
if (!in.eof() && in.peek() == ':')
{
in.get();
in >> x;
r += seconds{x};
}
}
return r;
}
static
std::chrono::seconds
parse_signed_time(std::istream& in)
{
ws(in);
auto sign = 1;
if (in.peek() == '-')
{
sign = -1;
in.get();
}
else if (in.peek() == '+')
in.get();
return sign * parse_unsigned_time(in);
}
// MonthDayTime
MonthDayTime::MonthDayTime(second_point tp, tz timezone)
: zone_(timezone)
{
using namespace date;
const auto dp = floor<days>(tp);
const auto hms = make_time(tp - dp);
const auto ymd = year_month_day(dp);
u = ymd.month() / ymd.day();
h_ = hms.hours();
m_ = hms.minutes();
s_ = hms.seconds();
}
MonthDayTime::MonthDayTime(const date::month_day& md, tz timezone)
: zone_(timezone)
{
u = md;
}
date::day
MonthDayTime::day() const
{
switch (type_)
{
case month_day:
return u.month_day_.day();
case month_last_dow:
return date::day{31};
case lteq:
case gteq:
break;
}
return u.month_day_weekday_.month_day_.day();
}
date::month
MonthDayTime::month() const
{
switch (type_)
{
case month_day:
return u.month_day_.month();
case month_last_dow:
return u.month_weekday_last_.month();
case lteq:
case gteq:
break;
}
return u.month_day_weekday_.month_day_.month();
}
int
MonthDayTime::compare(date::year y, const MonthDayTime& x, date::year yx,
std::chrono::seconds offset, std::chrono::minutes prev_save) const
{
if (zone_ != x.zone_)
{
auto dp0 = to_day_point(y);
auto dp1 = x.to_day_point(yx);
if (std::abs((dp0-dp1).count()) > 1)
return dp0 < dp1 ? -1 : 1;
if (zone_ == tz::local)
{
auto tp0 = to_time_point(y) - prev_save;
if (x.zone_ == tz::utc)
tp0 -= offset;
auto tp1 = x.to_time_point(yx);
return tp0 < tp1 ? -1 : tp0 == tp1 ? 0 : 1;
}
else if (zone_ == tz::standard)
{
auto tp0 = to_time_point(y);
auto tp1 = x.to_time_point(yx);
if (x.zone_ == tz::local)
tp1 -= prev_save;
else
tp0 -= offset;
return tp0 < tp1 ? -1 : tp0 == tp1 ? 0 : 1;
}
// zone_ == tz::utc
auto tp0 = to_time_point(y);
auto tp1 = x.to_time_point(yx);
if (x.zone_ == tz::local)
tp1 -= offset + prev_save;
else
tp1 -= offset;
return tp0 < tp1 ? -1 : tp0 == tp1 ? 0 : 1;
}
auto const t0 = to_time_point(y);
auto const t1 = x.to_time_point(yx);
return t0 < t1 ? -1 : t0 == t1 ? 0 : 1;
}
second_point
MonthDayTime::to_sys(date::year y, std::chrono::seconds offset,
std::chrono::seconds save) const
{
using namespace date;
using namespace std::chrono;
auto until_utc = to_time_point(y);
if (zone_ == tz::standard)
until_utc -= offset;
else if (zone_ == tz::local)
until_utc -= offset + save;
return until_utc;
}
MonthDayTime::U&
MonthDayTime::U::operator=(const date::month_day& x)
{
month_day_ = x;
return *this;
}
MonthDayTime::U&
MonthDayTime::U::operator=(const date::month_weekday_last& x)
{
month_weekday_last_ = x;
return *this;
}
MonthDayTime::U&
MonthDayTime::U::operator=(const pair& x)
{
month_day_weekday_ = x;
return *this;
}
date::day_point
MonthDayTime::to_day_point(date::year y) const
{
using namespace std::chrono;
using namespace date;
switch (type_)
{
case month_day:
return day_point(y/u.month_day_);
case month_last_dow:
return day_point(y/u.month_weekday_last_);
case lteq:
{
auto const x = y/u.month_day_weekday_.month_day_;
auto const wd1 = weekday(x);
auto const wd0 = u.month_day_weekday_.weekday_;
return day_point(x) - (wd1-wd0);
}
case gteq:
break;
}
auto const x = y/u.month_day_weekday_.month_day_;
auto const wd1 = u.month_day_weekday_.weekday_;
auto const wd0 = weekday(x);
return day_point(x) + (wd1-wd0);
}
second_point
MonthDayTime::to_time_point(date::year y) const
{
return to_day_point(y) + h_ + m_ + s_;
}
void
MonthDayTime::canonicalize(date::year y)
{
using namespace std::chrono;
using namespace date;
switch (type_)
{
case month_day:
return;
case month_last_dow:
{
auto const ymd = year_month_day(y/u.month_weekday_last_);
u.month_day_ = ymd.month()/ymd.day();
type_ = month_day;
return;
}
case lteq:
{
auto const x = y/u.month_day_weekday_.month_day_;
auto const wd1 = weekday(x);
auto const wd0 = u.month_day_weekday_.weekday_;
auto const ymd = year_month_day(day_point(x) - (wd1-wd0));
u.month_day_ = ymd.month()/ymd.day();
type_ = month_day;
return;
}
case gteq:
{
auto const x = y/u.month_day_weekday_.month_day_;
auto const wd1 = u.month_day_weekday_.weekday_;
auto const wd0 = weekday(x);
auto const ymd = year_month_day(day_point(x) + (wd1-wd0));
u.month_day_ = ymd.month()/ymd.day();
type_ = month_day;
return;
}
}
}
std::istream&
operator>>(std::istream& is, MonthDayTime& x)
{
using namespace date;
using namespace std::chrono;
x = MonthDayTime{};
if (!is.eof() && ws(is) && !is.eof() && is.peek() != '#')
{
auto m = parse_month(is);
if (!is.eof() && ws(is) && !is.eof() && is.peek() != '#')
{
if (is.peek() == 'l')
{
for (int i = 0; i < 4; ++i)
is.get();
auto dow = parse_dow(is);
x.type_ = MonthDayTime::month_last_dow;
x.u = date::month(m)/weekday(dow)[last];
}
else if (std::isalpha(is.peek()))
{
auto dow = parse_dow(is);
char c;
is >> c;
if (c == '<' || c == '>')
{
char c2;
is >> c2;
if (c2 != '=')
throw std::runtime_error(std::string("bad operator: ") + c + c2);
int d;
is >> d;
if (d < 1 || d > 31)
throw std::runtime_error(std::string("bad operator: ") + c + c2
+ std::to_string(d));
x.type_ = c == '<' ? MonthDayTime::lteq : MonthDayTime::gteq;
x.u = {date::month(m)/d, weekday(dow)};
}
else
throw std::runtime_error(std::string("bad operator: ") + c);
}
else // if (std::isdigit(is.peek())
{
int d;
is >> d;
if (d < 1 || d > 31)
throw std::runtime_error(std::string("day of month: ")
+ std::to_string(d));
x.type_ = MonthDayTime::month_day;
x.u = date::month(m)/d;
}
if (!is.eof() && ws(is) && !is.eof() && is.peek() != '#')
{
int t;
is >> t;
x.h_ = hours{t};
if (!is.eof() && is.peek() == ':')
{
is.get();
is >> t;
x.m_ = minutes{t};
if (!is.eof() && is.peek() == ':')
{
is.get();
is >> t;
x.s_ = seconds{t};
}
}
if (!is.eof() && std::isalpha(is.peek()))
{
char c;
is >> c;
switch (c)
{
case 's':
x.zone_ = tz::standard;
break;
case 'u':
x.zone_ = tz::utc;
break;
}
}
}
}
else
{
x.u = month{m}/1;
}
}
return is;
}
std::ostream&
operator<<(std::ostream& os, const MonthDayTime& x)
{
switch (x.type_)
{
case MonthDayTime::month_day:
os << x.u.month_day_ << " ";
break;
case MonthDayTime::month_last_dow:
os << x.u.month_weekday_last_ << " ";
break;
case MonthDayTime::lteq:
os << x.u.month_day_weekday_.weekday_ << " on or before "
<< x.u.month_day_weekday_.month_day_ << " ";
break;
case MonthDayTime::gteq:
if ((static_cast<unsigned>(x.day()) - 1) % 7 == 0)
{
os << (x.u.month_day_weekday_.month_day_.month() /
x.u.month_day_weekday_.weekday_[
(static_cast<unsigned>(x.day()) - 1)/7+1]) << " ";
}
else
{
os << x.u.month_day_weekday_.weekday_ << " on or after "
<< x.u.month_day_weekday_.month_day_ << " ";
}
break;
}
os << date::make_time(x.h_ + x.m_ + x.s_);
if (x.zone_ == tz::utc)
os << "UTC ";
else if (x.zone_ == tz::standard)
os << "STD ";
else
os << " ";
return os;
}
// Rule
Rule::Rule(const std::string& s)
{
try
{
using namespace date;
using namespace std::chrono;
std::istringstream in(s);
in.exceptions(std::ios::failbit | std::ios::badbit);
std::string word;
in >> word >> name_;
int x;
ws(in);
if (std::isalpha(in.peek()))
{
in >> word;
if (word == "min")
{
starting_year_ = year::min();
}
else
throw std::runtime_error("Didn't find expected word: " + word);
}
else
{
in >> x;
starting_year_ = year{x};
}
std::ws(in);
if (std::isalpha(in.peek()))
{
in >> word;
if (word == "only")
{
ending_year_ = starting_year_;
}
else if (word == "max")
{
ending_year_ = year::max();
}
else
throw std::runtime_error("Didn't find expected word: " + word);
}
else
{
in >> x;
ending_year_ = year{x};
}
in >> word; // TYPE (always "-")
assert(word == "-");
in >> starting_at_;
save_ = duration_cast<minutes>(parse_signed_time(in));
in >> abbrev_;
if (abbrev_ == "-")
abbrev_.clear();
assert(hours{0} <= save_ && save_ <= hours{2});
}
catch (...)
{
std::cerr << s << '\n';
std::cerr << *this << '\n';
throw;
}
}
Rule::Rule(const Rule& r, date::year starting_year, date::year ending_year)
: name_(r.name_)
, starting_year_(starting_year)
, ending_year_(ending_year)
, starting_at_(r.starting_at_)
, save_(r.save_)
, abbrev_(r.abbrev_)
{
}
bool
operator==(const Rule& x, const Rule& y)
{
if (std::tie(x.name_, x.save_, x.starting_year_, x.ending_year_) ==
std::tie(y.name_, y.save_, y.starting_year_, y.ending_year_))
return x.month() == y.month() && x.day() == y.day();
return false;
}
bool
operator<(const Rule& x, const Rule& y)
{
using namespace std::chrono;
auto const xm = x.month();
auto const ym = y.month();
if (std::tie(x.name_, x.starting_year_, xm, x.ending_year_) <
std::tie(y.name_, y.starting_year_, ym, y.ending_year_))
return true;
if (std::tie(x.name_, x.starting_year_, xm, x.ending_year_) >
std::tie(y.name_, y.starting_year_, ym, y.ending_year_))
return false;
return x.day() < y.day();
}
bool
operator==(const Rule& x, const date::year& y)
{
return x.starting_year_ <= y && y <= x.ending_year_;
}
bool
operator<(const Rule& x, const date::year& y)
{
return x.ending_year_ < y;
}
bool
operator==(const date::year& x, const Rule& y)
{
return y.starting_year_ <= x && x <= y.ending_year_;
}
bool
operator<(const date::year& x, const Rule& y)
{
return x < y.starting_year_;
}
bool
operator==(const Rule& x, const std::string& y)
{
return x.name() == y;
}
bool
operator<(const Rule& x, const std::string& y)
{
return x.name() < y;
}
bool
operator==(const std::string& x, const Rule& y)
{
return y.name() == x;
}
bool
operator<(const std::string& x, const Rule& y)
{
return x < y.name();
}
std::ostream&
operator<<(std::ostream& os, const Rule& r)
{
using namespace date;
using namespace std::chrono;
save_stream _(os);
os.fill(' ');
os.flags(std::ios::dec | std::ios::left);
os.width(15);
os << r.name_;
os << r.starting_year_ << " " << r.ending_year_ << " ";
os << r.starting_at_;
if (r.save_ >= minutes{0})
os << ' ';
os << date::make_time(r.save_) << " ";
os << r.abbrev_;
return os;
}
date::day
Rule::day() const
{
return starting_at_.day();
}
date::month
Rule::month() const
{
return starting_at_.month();
}
struct find_rule_by_name
{
bool operator()(const Rule& x, const std::string& nm) const
{
return x.name() < nm;
}
bool operator()(const std::string& nm, const Rule& x) const
{
return nm < x.name();
}
};
bool
Rule::overlaps(const Rule& x, const Rule& y)
{
// assume x.starting_year_ <= y.starting_year_;
if (!(x.starting_year_ <= y.starting_year_))
{
std::cerr << x << '\n';
std::cerr << y << '\n';
assert(x.starting_year_ <= y.starting_year_);
}
if (y.starting_year_ > x.ending_year_)
return false;
return !(x.starting_year_ == y.starting_year_ && x.ending_year_ == y.ending_year_);
}
void
Rule::split(std::vector<Rule>& rules, std::size_t i, std::size_t k, std::size_t& e)
{
using namespace date;
using difference_type = std::vector<Rule>::iterator::difference_type;
// rules[i].starting_year_ <= rules[k].starting_year_ &&
// rules[i].ending_year_ >= rules[k].starting_year_ &&
// (rules[i].starting_year_ != rules[k].starting_year_ ||
// rules[i].ending_year_ != rules[k].ending_year_)
assert(rules[i].starting_year_ <= rules[k].starting_year_ &&
rules[i].ending_year_ >= rules[k].starting_year_ &&
(rules[i].starting_year_ != rules[k].starting_year_ ||
rules[i].ending_year_ != rules[k].ending_year_));
if (rules[i].starting_year_ == rules[k].starting_year_)
{
if (rules[k].ending_year_ < rules[i].ending_year_)
{
rules.insert(rules.begin() + static_cast<difference_type>(k+1),
Rule(rules[i], rules[k].ending_year_ + years{1},
std::move(rules[i].ending_year_)));
++e;
rules[i].ending_year_ = rules[k].ending_year_;
}
else // rules[k].ending_year_ > rules[i].ending_year_
{
rules.insert(rules.begin() + static_cast<difference_type>(k+1),
Rule(rules[k], rules[i].ending_year_ + years{1},
std::move(rules[k].ending_year_)));
++e;
rules[k].ending_year_ = rules[i].ending_year_;
}
}
else // rules[i].starting_year_ < rules[k].starting_year_
{
if (rules[k].ending_year_ < rules[i].ending_year_)
{
rules.insert(rules.begin() + static_cast<difference_type>(k),
Rule(rules[i], rules[k].starting_year_, rules[k].ending_year_));
++k;
rules.insert(rules.begin() + static_cast<difference_type>(k+1),
Rule(rules[i], rules[k].ending_year_ + years{1},
std::move(rules[i].ending_year_)));
rules[i].ending_year_ = rules[k].starting_year_ - years{1};
e += 2;
}
else if (rules[k].ending_year_ > rules[i].ending_year_)
{
rules.insert(rules.begin() + static_cast<difference_type>(k),
Rule(rules[i], rules[k].starting_year_, rules[i].ending_year_));
++k;
rules.insert(rules.begin() + static_cast<difference_type>(k+1),
Rule(rules[k], rules[i].ending_year_ + years{1},
std::move(rules[k].ending_year_)));
e += 2;
rules[k].ending_year_ = std::move(rules[i].ending_year_);
rules[i].ending_year_ = rules[k].starting_year_ - years{1};
}
else // rules[k].ending_year_ == rules[i].ending_year_
{
rules.insert(rules.begin() + static_cast<difference_type>(k),
Rule(rules[i], rules[k].starting_year_,
std::move(rules[i].ending_year_)));
++k;
++e;
rules[i].ending_year_ = rules[k].starting_year_ - years{1};
}
}
}
void
Rule::split_overlaps(std::vector<Rule>& rules, std::size_t i, std::size_t& e)
{
using difference_type = std::vector<Rule>::iterator::difference_type;
auto j = i;
for (; i + 1 < e; ++i)
{
for (auto k = i + 1; k < e; ++k)
{
if (overlaps(rules[i], rules[k]))
{
split(rules, i, k, e);
std::sort(rules.begin() + static_cast<difference_type>(i),
rules.begin() + static_cast<difference_type>(e));
}
}
}
for (; j < e; ++j)
{
if (rules[j].starting_year() == rules[j].ending_year())
rules[j].starting_at_.canonicalize(rules[j].starting_year());
}
}
void
Rule::split_overlaps(std::vector<Rule>& rules)
{
using difference_type = std::vector<Rule>::iterator::difference_type;
for (std::size_t i = 0; i < rules.size();)
{
auto e = static_cast<std::size_t>(std::upper_bound(
rules.cbegin()+static_cast<difference_type>(i), rules.cend(), rules[i].name(),
[](const std::string& nm, const Rule& x)
{
return nm < x.name();
}) - rules.cbegin());
split_overlaps(rules, i, e);
auto first = rules.cbegin() + static_cast<difference_type>(i);
auto last = rules.cbegin() + static_cast<difference_type>(e);
auto t = std::lower_bound(first, last, min_year);
if (t > first+1)
{
if (t == last || t->starting_year() >= min_year)
--t;
auto d = static_cast<std::size_t>(t - first);
rules.erase(first, t);
e -= d;
}
first = rules.cbegin() + static_cast<difference_type>(i);
last = rules.cbegin() + static_cast<difference_type>(e);
t = std::upper_bound(first, last, max_year);
if (t != last)
{
auto d = static_cast<std::size_t>(last - t);
rules.erase(t, last);
e -= d;
}
i = e;
}
rules.shrink_to_fit();
}
// Zone
Zone::zonelet::~zonelet()
{
using minutes = std::chrono::minutes;
using string = std::string;
if (tag_ == has_save)
u.save_.~minutes();
else
u.rule_.~string();
}
Zone::zonelet::zonelet()
{
::new(&u.rule_) std::string();
}
Zone::zonelet::zonelet(const zonelet& i)
: gmtoff_(i.gmtoff_)
, tag_(i.tag_)
, format_(i.format_)
, until_year_(i.until_year_)
, until_date_(i.until_date_)
, until_utc_(i.until_utc_)
, until_std_(i.until_std_)
, until_loc_(i.until_loc_)
, initial_save_(i.initial_save_)
, initial_abbrev_(i.initial_abbrev_)
, first_rule_(i.first_rule_)
, last_rule_(i.last_rule_)
{
if (tag_ == has_save)
::new(&u.save_) std::chrono::minutes(i.u.save_);
else
::new(&u.rule_) std::string(i.u.rule_);
}
Zone::Zone(const std::string& s)
{
try
{
using namespace date;
std::istringstream in(s);
in.exceptions(std::ios::failbit | std::ios::badbit);
std::string word;
in >> word >> name_;
parse_info(in);
}
catch (...)
{
std::cerr << s << '\n';
std::cerr << *this << '\n';
zonelets_.pop_back();
throw;
}
}
void
Zone::add(const std::string& s)
{
try
{
std::istringstream in(s);
in.exceptions(std::ios::failbit | std::ios::badbit);
ws(in);
if (!in.eof() && in.peek() != '#')
parse_info(in);
}
catch (...)
{
std::cerr << s << '\n';
std::cerr << *this << '\n';
zonelets_.pop_back();
throw;
}
}
void
Zone::parse_info(std::istream& in)
{
using namespace date;
using namespace std::chrono;
zonelets_.emplace_back();
auto& zonelet = zonelets_.back();
zonelet.gmtoff_ = parse_signed_time(in);
in >> zonelet.u.rule_;
if (zonelet.u.rule_ == "-")
zonelet.u.rule_.clear();
in >> zonelet.format_;
if (!in.eof())
ws(in);
if (in.eof() || in.peek() == '#')
{
zonelet.until_year_ = year::max();
zonelet.until_date_ = MonthDayTime(boring_day, tz::utc);
}
else
{
int y;
in >> y;
zonelet.until_year_ = year{y};
in >> zonelet.until_date_;
zonelet.until_date_.canonicalize(zonelet.until_year_);
}
if ((zonelet.until_year_ < min_year) ||
(zonelets_.size() > 1 && zonelets_.end()[-2].until_year_ > max_year))
zonelets_.pop_back();
}
// Find the rule that comes chronologically before Rule r. For multi-year rules,
// y specifies which rules in r. For single year rules, y is assumed to be equal
// to the year specified by r.
// Returns a pointer to the chronologically previous rule, and the year within
// that rule. If there is no previous rule, returns nullptr and year::min().
// Preconditions:
// r->starting_year() <= y && y <= r->ending_year()
static
std::pair<const Rule*, date::year>
find_previous_rule(const Rule* r, date::year y)
{
using namespace date;
auto const& rules = get_tzdb().rules;
if (y == r->starting_year())
{
if (r == &rules.front() || r->name() != r[-1].name())
return {nullptr, year::min()};
--r;
if (y == r->starting_year())
return {r, y};
return {r, r->ending_year()};
}
if (r == &rules.front() || r->name() != r[-1].name() ||
r[-1].starting_year() < r->starting_year())
{
while (r < &rules.back() && r->name() == r[1].name() &&
r->starting_year() == r[1].starting_year())
++r;
return {r, --y};
}
--r;
return {r, y};
}
// Find the rule that comes chronologically after Rule r. For multi-year rules,
// y specifies which rules in r. For single year rules, y is assumed to be equal
// to the year specified by r.
// Returns a pointer to the chronologically next rule, and the year within
// that rule. If there is no next rule, return a pointer to a defaulted rule
// and y+1.
// Preconditions:
// first <= r && r < last && r->starting_year() <= y && y <= r->ending_year()
// [first, last) all have the same name
static
std::pair<const Rule*, date::year>
find_next_rule(const Rule* first, const Rule* last, const Rule* r, date::year y)
{
using namespace date;
if (y == r->ending_year())
{
if (r == last-1)
return {nullptr, year::max()};
++r;
if (y == r->ending_year())
return {r, y};
return {r, r->starting_year()};
}
if (r == last-1 || r->ending_year() < r[1].ending_year())
{
while (r > first && r->starting_year() == r[-1].starting_year())
--r;
return {r, ++y};
}
++r;
return {r, y};
}
// Find the rule that comes chronologically after Rule r. For multi-year rules,
// y specifies which rules in r. For single year rules, y is assumed to be equal
// to the year specified by r.
// Returns a pointer to the chronologically next rule, and the year within
// that rule. If there is no next rule, return nullptr and year::max().
// Preconditions:
// r->starting_year() <= y && y <= r->ending_year()
static
std::pair<const Rule*, date::year>
find_next_rule(const Rule* r, date::year y)
{
using namespace date;
auto const& rules = get_tzdb().rules;
if (y == r->ending_year())
{
if (r == &rules.back() || r->name() != r[1].name())
return {nullptr, year::max()};
++r;
if (y == r->ending_year())
return {r, y};
return {r, r->starting_year()};
}
if (r == &rules.back() || r->name() != r[1].name() ||
r->ending_year() < r[1].ending_year())
{
while (r > &rules.front() && r->name() == r[-1].name() &&
r->starting_year() == r[-1].starting_year())
--r;
return {r, ++y};
}
++r;
return {r, y};
}
static
const Rule*
find_first_std_rule(const std::pair<const Rule*, const Rule*>& eqr)
{
auto r = eqr.first;
auto ry = r->starting_year();
while (r->save() != std::chrono::minutes{0})
{
std::tie(r, ry) = find_next_rule(eqr.first, eqr.second, r, ry);
if (r == nullptr)
throw std::runtime_error("Could not find standard offset in rule "
+ eqr.first->name());
}
return r;
}
static
std::pair<const Rule*, date::year>
find_rule_for_zone(const std::pair<const Rule*, const Rule*>& eqr,
const date::year& y, const std::chrono::seconds& offset,
const MonthDayTime& mdt)
{
assert(eqr.first != nullptr);
assert(eqr.second != nullptr);
using namespace std::chrono;
using namespace date;
auto r = eqr.first;
auto ry = r->starting_year();
auto prev_save = minutes{0};
auto prev_year = year::min();
const Rule* prev_rule = nullptr;
while (r != nullptr)
{
if (mdt.compare(y, r->mdt(), ry, offset, prev_save) <= 0)
break;
prev_rule = r;
prev_year = ry;
prev_save = prev_rule->save();
std::tie(r, ry) = find_next_rule(eqr.first, eqr.second, r, ry);
}
return {prev_rule, prev_year};
}
static
std::pair<const Rule*, date::year>
find_rule_for_zone(const std::pair<const Rule*, const Rule*>& eqr,
const second_point& tp_utc, const second_point& tp_std,
const second_point& tp_loc)
{
using namespace std::chrono;
using namespace date;
auto r = eqr.first;
auto ry = r->starting_year();
auto prev_save = minutes{0};
auto prev_year = year::min();
const Rule* prev_rule = nullptr;
while (r != nullptr)
{
bool found;
switch (r->mdt().zone())
{
case tz::utc:
found = tp_utc < r->mdt().to_time_point(ry);
break;
case tz::standard:
found = tp_std < r->mdt().to_time_point(ry);
break;
case tz::local:
found = tp_loc < r->mdt().to_time_point(ry);
break;
default:
assert(false);
}
if (found)
break;
prev_rule = r;
prev_year = ry;
prev_save = prev_rule->save();
std::tie(r, ry) = find_next_rule(eqr.first, eqr.second, r, ry);
}
return {prev_rule, prev_year};
}
static
Info
find_rule(const std::pair<const Rule*, date::year>& first,
const std::pair<const Rule*, date::year>& last,
const date::year& y, const std::chrono::seconds& offset,
const MonthDayTime& mdt, const std::chrono::minutes& initial_save,
const std::string& initial_abbrev)
{
using namespace std::chrono;
using namespace date;
auto r = first.first;
auto ry = first.second;
Info x{day_point(year::min()/boring_day), day_point(year::max()/boring_day),
seconds{0}, initial_save, initial_abbrev};
while (r != nullptr)
{
auto tr = r->mdt().to_sys(ry, offset, x.save);
auto tx = mdt.to_sys(y, offset, x.save);
// Find last rule where tx >= tr
if (tx <= tr || (r == last.first && ry == last.second))
{
if (tx < tr && r == first.first && ry == first.second)
{
x.end = r->mdt().to_sys(ry, offset, x.save);
break;
}
if (tx < tr)
{
std::tie(r, ry) = find_previous_rule(r, ry); // can't return nullptr for r
assert(r != nullptr);
}
// r != nullptr && tx >= tr (if tr were to be recomputed)
auto prev_save = initial_save;
if (!(r == first.first && ry == first.second))
prev_save = find_previous_rule(r, ry).first->save();
x.begin = r->mdt().to_sys(ry, offset, prev_save);
x.save = r->save();
x.abbrev = r->abbrev();
if (!(r == last.first && ry == last.second))
{
std::tie(r, ry) = find_next_rule(r, ry); // can't return nullptr for r
assert(r != nullptr);
x.end = r->mdt().to_sys(ry, offset, x.save);
}
else
x.end = day_point(year::max()/boring_day);
break;
}
x.save = r->save();
std::tie(r, ry) = find_next_rule(r, ry); // Can't return nullptr for r
assert(r != nullptr);
}
return x;
}
void
Zone::adjust_infos(const std::vector<Rule>& rules)
{
using namespace std::chrono;
using namespace date;
const zonelet* prev_zonelet = nullptr;
for (auto& z : zonelets_)
{
// Classify info as rule-based, has save, or neither
if (!z.u.rule_.empty())
{
// Find out if this zonelet has a rule or a save
auto i = std::lower_bound(rules.begin(), rules.end(), z.u.rule_,
[](const Rule& r, const std::string& nm)
{
return r.name() < nm;
});
if (i == rules.end() || i->name() != z.u.rule_)
{
// The rule doesn't exist. Assume this is a save
try
{
using namespace std::chrono;
using string = std::string;
std::istringstream in(z.u.rule_);
in.exceptions(std::ios::failbit | std::ios::badbit);
auto tmp = duration_cast<minutes>(parse_signed_time(in));
z.u.rule_.~string();
z.tag_ = zonelet::has_save;
::new(&z.u.save_) minutes(tmp);
}
catch (...)
{
std::cerr << name_ << " : " << z.u.rule_ << '\n';
throw;
}
}
}
else
{
// This zone::zonelet has no rule and no save
z.tag_ = zonelet::is_empty;
}
std::pair<const Rule*, const Rule*> eqr{};
if (z.tag_ == zonelet::has_rule)
{
eqr = std::equal_range(rules.data(), rules.data() + rules.size(), z.u.rule_);
assert(eqr.first != eqr.second);
}
minutes final_save{0};
if (z.tag_ == zonelet::has_save)
{
final_save = z.u.save_;
}
else if (z.tag_ == zonelet::has_rule)
{
z.last_rule_ = find_rule_for_zone(eqr, z.until_year_, z.gmtoff_,
z.until_date_);
if (z.last_rule_.first != nullptr)
final_save = z.last_rule_.first->save();
}
z.until_utc_ = z.until_date_.to_sys(z.until_year_, z.gmtoff_, final_save);
z.until_std_ = z.until_utc_ + z.gmtoff_;
z.until_loc_ = z.until_std_ + final_save;
if (z.tag_ == zonelet::has_rule)
{
if (prev_zonelet != nullptr)
{
z.first_rule_ = find_rule_for_zone(eqr, prev_zonelet->until_utc_,
prev_zonelet->until_std_,
prev_zonelet->until_loc_);
if (z.first_rule_.first != nullptr)
{
z.initial_save_ = z.first_rule_.first->save();
z.initial_abbrev_ = z.first_rule_.first->abbrev();
if (z.first_rule_ != z.last_rule_)
{
z.first_rule_ = find_next_rule(eqr.first, eqr.second,
z.first_rule_.first,
z.first_rule_.second);
}
else
{
z.first_rule_ = std::make_pair(nullptr, year::min());
z.last_rule_ = std::make_pair(nullptr, year::max());
}
}
}
if (z.first_rule_.first == nullptr && z.last_rule_.first != nullptr)
{
z.first_rule_ = std::make_pair(eqr.first, eqr.first->starting_year());
z.initial_abbrev_ = find_first_std_rule(eqr)->abbrev();
}
}
#ifndef NDEBUG
if (z.first_rule_.first == nullptr)
{
assert(z.first_rule_.second == year::min());
assert(z.last_rule_.first == nullptr);
assert(z.last_rule_.second == year::max());
}
else
{
assert(z.last_rule_.first != nullptr);
}
#endif
prev_zonelet = &z;
}
}
static
std::string
format_abbrev(std::string format, const std::string& variable, std::chrono::seconds off,
std::chrono::minutes save)
{
using namespace std::chrono;
auto k = format.find("%s");
if (k != std::string::npos)
{
format.replace(k, 2, variable);
}
else
{
k = format.find('/');
if (k != std::string::npos)
{
if (save == minutes{0})
format.erase(k);
else
format.erase(0, k+1);
}
else
{
k = format.find("%z");
if (k != std::string::npos)
{
std::string temp;
if (off < seconds{0})
{
temp = '-';
off = -off;
}
else
temp = '+';
auto h = floor<hours>(off);
off -= h;
if (h < hours{10})
temp += '0';
temp += std::to_string(h.count());
if (off > seconds{0})
{
auto m = floor<minutes>(off);
off -= m;
if (m < minutes{10})
temp += '0';
temp += std::to_string(m.count());
if (off > seconds{0})
{
if (off < seconds{10})
temp += '0';
temp += std::to_string(off.count());
}
}
format.replace(k, 2, temp);
}
}
}
return format;
}
Info
Zone::get_info(std::chrono::system_clock::time_point tp, tz timezone) const
{
using namespace std::chrono;
using namespace date;
assert(timezone != tz::standard);
auto y = year_month_day(floor<days>(tp)).year();
if (y < min_year || y > max_year)
throw std::runtime_error("The year " + std::to_string(static_cast<int>(y)) +
" is out of range:[" + std::to_string(static_cast<int>(min_year)) + ", "
+ std::to_string(static_cast<int>(max_year)) + "]");
auto tps = floor<seconds>(tp);
auto i = std::upper_bound(zonelets_.begin(), zonelets_.end(), tps,
[timezone](second_point t, const zonelet& zl)
{
return timezone == tz::utc ? t < zl.until_utc_ : t < zl.until_loc_;
});
Info r{};
if (i != zonelets_.end())
{
if (i->tag_ == zonelet::has_save)
{
if (i != zonelets_.begin())
r.begin = i[-1].until_utc_;
else
r.begin = day_point(year::min()/boring_day);
r.end = i->until_utc_;
r.offset = i->gmtoff_ + i->u.save_;
r.save = i->u.save_;
}
else if (i->u.rule_.empty())
{
if (i != zonelets_.begin())
r.begin = i[-1].until_utc_;
else
r.begin = day_point(year::min()/boring_day);
r.end = i->until_utc_;
r.offset = i->gmtoff_;
}
else
{
r = find_rule(i->first_rule_, i->last_rule_, y, i->gmtoff_,
MonthDayTime(tps, timezone), i->initial_save_,
i->initial_abbrev_);
r.offset = i->gmtoff_ + r.save;
if (i != zonelets_.begin() && r.begin < i[-1].until_utc_)
r.begin = i[-1].until_utc_;
if (r.end > i->until_utc_)
r.end = i->until_utc_;
}
r.abbrev = format_abbrev(i->format_, r.abbrev, r.offset, r.save);
assert(r.begin < r.end);
}
return r;
}
std::ostream&
operator<<(std::ostream& os, const Zone& z)
{
using namespace date;
using namespace std::chrono;
save_stream _(os);
os.fill(' ');
os.flags(std::ios::dec | std::ios::left);
os.width(35);
os << z.name_;
std::string indent;
for (auto const& s : z.zonelets_)
{
os << indent;
if (s.gmtoff_ >= seconds{0})
os << ' ';
os << make_time(s.gmtoff_) << " ";
os.width(15);
if (s.tag_ != Zone::zonelet::has_save)
os << s.u.rule_;
else
{
std::ostringstream tmp;
tmp << make_time(s.u.save_);
os << tmp.str();
}
os.width(8);
os << s.format_ << " ";
os << s.until_year_ << ' ' << s.until_date_;
os << " " << s.until_utc_ << " UTC";
os << " " << s.until_std_ << " STD";
os << " " << s.until_loc_;
os << " " << make_time(s.initial_save_);
os << " " << s.initial_abbrev_;
if (s.first_rule_.first != nullptr)
os << " {" << *s.first_rule_.first << ", " << s.first_rule_.second << '}';
else
os << " {" << "nullptr" << ", " << s.first_rule_.second << '}';
if (s.last_rule_.first != nullptr)
os << " {" << *s.last_rule_.first << ", " << s.last_rule_.second << '}';
else
os << " {" << "nullptr" << ", " << s.last_rule_.second << '}';
os << '\n';
if (indent.empty())
indent = std::string(35, ' ');
}
return os;
}
// Link
Link::Link(const std::string& s)
{
using namespace date;
std::istringstream in(s);
in.exceptions(std::ios::failbit | std::ios::badbit);
std::string word;
in >> word >> target_ >> name_;
}
std::ostream&
operator<<(std::ostream& os, const Link& x)
{
using namespace date;
save_stream _(os);
os.fill(' ');
os.flags(std::ios::dec | std::ios::left);
os.width(35);
return os << x.name_ << " --> " << x.target_;
}
// Leap
Leap::Leap(const std::string& s)
{
using namespace date;
std::istringstream in(s);
in.exceptions(std::ios::failbit | std::ios::badbit);
std::string word;
int y;
MonthDayTime date;
in >> word >> y >> date;
date_ = date.to_time_point(year(y));
}
std::ostream&
operator<<(std::ostream& os, const Leap& x)
{
using namespace date;
return os << x.date_ << " +";
}
static
TZ_DB
init_tzdb()
{
using namespace date;
const std::string path = install + folder_delimiter;
std::string line;
bool continue_zone = false;
TZ_DB db;
for (const auto& filename : files)
{
std::ifstream infile(path + filename);
while (infile)
{
std::getline(infile, line);
if (!line.empty() && line[0] != '#')
{
std::istringstream in(line);
std::string word;
in >> word;
if (word == "Rule")
{
db.rules.push_back(Rule(line));
continue_zone = false;
}
else if (word == "Link")
{
db.links.push_back(Link(line));
continue_zone = false;
}
else if (word == "Leap")
{
db.leaps.push_back(Leap(line));
continue_zone = false;
}
else if (word == "Zone")
{
db.zones.push_back(Zone(line));
continue_zone = true;
}
else if (line[0] == '\t' && continue_zone)
{
db.zones.back().add(line);
}
else
{
std::cerr << line << '\n';
}
}
}
}
std::sort(db.rules.begin(), db.rules.end());
Rule::split_overlaps(db.rules);
std::sort(db.zones.begin(), db.zones.end());
for (auto& z : db.zones)
z.adjust_infos(db.rules);
db.zones.shrink_to_fit();
std::sort(db.links.begin(), db.links.end());
db.links.shrink_to_fit();
std::sort(db.leaps.begin(), db.leaps.end());
db.leaps.shrink_to_fit();
#if TIMEZONE_MAPPING
std::string mapping_file = path + "TimeZoneMappings.csv";
db.mappings = load_timezone_mappings_from_csv_file(mapping_file);
get_windows_timezone_info(db.native_zones);
#endif
return db;
}
static
TZ_DB&
access_tzdb()
{
static TZ_DB tz_db;
return tz_db;
}
const TZ_DB&
reload_tzdb()
{
return access_tzdb() = init_tzdb();
}
const TZ_DB&
reload_tzdb(const std::string& new_install)
{
install = new_install;
return access_tzdb() = init_tzdb();
}
const TZ_DB&
get_tzdb()
{
static const TZ_DB& ref = access_tzdb() = init_tzdb();
return ref;
}
const Zone*
locate_zone(const std::string& tz_name)
{
const auto& db = get_tzdb();
auto zi = std::lower_bound(db.zones.begin(), db.zones.end(), tz_name,
[](const Zone& z, const std::string& nm)
{
return z.name() < nm;
});
if (zi == db.zones.end() || zi->name() != tz_name)
{
auto li = std::lower_bound(db.links.begin(), db.links.end(), tz_name,
[](const Link& z, const std::string& nm)
{
return z.name() < nm;
});
if (li != db.links.end() && li->name() == tz_name)
{
zi = std::lower_bound(db.zones.begin(), db.zones.end(), li->target(),
[](const Zone& z, const std::string& nm)
{
return z.name() < nm;
});
if (zi != db.zones.end() && zi->name() == li->target())
return &*zi;
}
throw std::runtime_error(tz_name + " not found in timezone database");
}
return &*zi;
}
#ifdef TZ_TEST
#ifdef _WIN32
const Zone*
locate_native_zone(const std::string& native_tz_name)
{
std::string standard_tz_name;
if (!native_to_standard_timezone_name(native_tz_name, standard_tz_name))
{
std::string msg;
msg = "locate_native_zone() failed: A mapping from the Windows Time Zone id \"";
msg += native_tz_name;
msg += "\" was not found in the time zone mapping database.";
throw std::runtime_error(msg);
}
return locate_zone(standard_tz_name);
}
#endif
#endif
std::ostream&
operator<<(std::ostream& os, const TZ_DB& db)
{
std::string title("--------------------------------------------"
"--------------------------------------------\n"
"Name ""Start Y ""End Y "
"Beginning ""Offset "
"Designator\n"
"--------------------------------------------"
"--------------------------------------------\n");
int count = 0;
for (const auto& x : db.rules)
{
if (count++ % 50 == 0)
os << title;
os << x << '\n';
}
os << '\n';
title = std::string("---------------------------------------------------------"
"--------------------------------------------------------\n"
"Name ""Offset "
"Rule ""Abrev ""Until\n"
"---------------------------------------------------------"
"--------------------------------------------------------\n");
count = 0;
for (const auto& x : db.zones)
{
if (count++ % 10 == 0)
os << title;
os << x << '\n';
}
os << '\n';
title = std::string("---------------------------------------------------------"
"--------------------------------------------------------\n"
"Alias ""To\n"
"---------------------------------------------------------"
"--------------------------------------------------------\n");
count = 0;
for (const auto& x : db.links)
{
if (count++ % 45 == 0)
os << title;
os << x << '\n';
}
os << '\n';
title = std::string("---------------------------------------------------------"
"--------------------------------------------------------\n"
"Leap second on\n"
"---------------------------------------------------------"
"--------------------------------------------------------\n");
os << title;
for (const auto& x : db.leaps)
os << x << '\n';
return os;
}
// -----------------------
std::ostream&
operator<<(std::ostream& os, const Info& r)
{
using namespace date;
os << r.begin << '\n';
os << r.end << '\n';
os << make_time(r.offset) << "\n";
os << make_time(r.save) << "\n";
os << r.abbrev << '\n';
return os;
}
#ifdef _WIN32
const Zone*
current_zone()
{
#if TIMEZONE_MAPPING
TIME_ZONE_INFORMATION tzi{};
DWORD tz_result = ::GetTimeZoneInformation(&tzi);
if (tz_result == TIME_ZONE_ID_INVALID)
{
auto error_code = ::GetLastError(); // Store this quick before it gets overwritten.
throw std::runtime_error("GetTimeZoneInformation failed: " + get_win32_message(error_code));
}
std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;
std::string standard_name(converter.to_bytes(tzi.StandardName));
auto tz = find_native_timezone_by_standard_name(standard_name);
if (!tz)
{
std::string msg;
msg = "current_zone() failed: ";
msg += standard_name;
msg += " was not found in the Windows Time Zone registry";
throw std::runtime_error( msg );
}
std::string standard_tzid;
if (!native_to_standard_timezone_name(tz->timezone_id, standard_tzid))
{
std::string msg;
msg = "current_zone() failed: A mapping from the Windows Time Zone id \"";
msg += tz->timezone_id;
msg += "\" was not found in the time zone mapping database.";
throw std::runtime_error(msg);
}
return date::locate_zone(standard_tzid);
#else
// Currently Win32 requires mapping for this function to work.
throw std::runtime_error("current_zone not implemented.");
#endif
}
#else // ! WIN32
const Zone*
current_zone()
{
// On some versions of some linux distro's (e.g. Ubuntu),
// the current timezone might be in the first line of
// the /etc/timezone file. So we check that.
#if __linux
std::ifstream timezone_file("/etc/timezone");
if (timezone_file.is_open())
{
std::string line;
std::getline(timezone_file, line);
if (!line.empty())
return locate_zone(line);
// Fall through to try other means.
}
#endif
// On some OS's a file called /etc/localtime may
// exist and it may be either a real file
// containing time zone details or a symlink to such a file.
// On MacOS and BSD Unix if this file is a symlink it
// might resolve to a path like this:
// "/usr/share/zoneinfo/America/Los_Angeles"
// If it does, we try to determine the current
// timezone from the remainder of the path by removing the prefix
// and hoping the rest resolves to valid timezone.
// It may not always work though. If it doesn't then an
// exception will be thrown by local_timezone.
// The path may also take a relative form:
// "../usr/share/zoneinfo/America/Los_Angeles".
struct stat sb;
CONSTDATA auto timezone = "/etc/localtime";
if (lstat(timezone, &sb) == -1 || sb.st_size == 0)
throw std::runtime_error("Could not get lstat on /etc/localtime");
std::string result(sb.st_size, '\0');
while (true)
{
auto sz = readlink(timezone, &result.front(), result.size());
if (sz == -1)
throw std::runtime_error("readlink failure");
auto tmp = result.size();
result.resize(sz);
if (sz <= tmp)
break;
}
const char zonepath[] = "/usr/share/zoneinfo/";
const size_t zonepath_len = sizeof(zonepath)/sizeof(zonepath[0])-1;
const size_t pos = result.find(zonepath);
if (pos != result.npos)
result.erase(0, zonepath_len+pos);
return locate_zone(result);
}
#endif
} // namespace date
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