fmtlegacy/include/fmt/chrono.h
2019-06-04 18:50:30 -07:00

715 lines
22 KiB
C++

// Formatting library for C++ - chrono support
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_CHRONO_H_
#define FMT_CHRONO_H_
#include "format.h"
#include "locale.h"
#include <chrono>
#include <ctime>
#include <locale>
#include <sstream>
FMT_BEGIN_NAMESPACE
// Prevents expansion of a preceding token as a function-style macro.
// Usage: f FMT_NOMACRO()
#define FMT_NOMACRO
namespace internal {
inline null<> localtime_r FMT_NOMACRO(...) { return null<>(); }
inline null<> localtime_s(...) { return null<>(); }
inline null<> gmtime_r(...) { return null<>(); }
inline null<> gmtime_s(...) { return null<>(); }
} // namespace internal
// Thread-safe replacement for std::localtime
inline std::tm localtime(std::time_t time) {
struct dispatcher {
std::time_t time_;
std::tm tm_;
dispatcher(std::time_t t) : time_(t) {}
bool run() {
using namespace fmt::internal;
return handle(localtime_r(&time_, &tm_));
}
bool handle(std::tm* tm) { return tm != nullptr; }
bool handle(internal::null<>) {
using namespace fmt::internal;
return fallback(localtime_s(&tm_, &time_));
}
bool fallback(int res) { return res == 0; }
#if !FMT_MSC_VER
bool fallback(internal::null<>) {
using namespace fmt::internal;
std::tm* tm = std::localtime(&time_);
if (tm) tm_ = *tm;
return tm != nullptr;
}
#endif
};
dispatcher lt(time);
// Too big time values may be unsupported.
if (!lt.run()) FMT_THROW(format_error("time_t value out of range"));
return lt.tm_;
}
// Thread-safe replacement for std::gmtime
inline std::tm gmtime(std::time_t time) {
struct dispatcher {
std::time_t time_;
std::tm tm_;
dispatcher(std::time_t t) : time_(t) {}
bool run() {
using namespace fmt::internal;
return handle(gmtime_r(&time_, &tm_));
}
bool handle(std::tm* tm) { return tm != nullptr; }
bool handle(internal::null<>) {
using namespace fmt::internal;
return fallback(gmtime_s(&tm_, &time_));
}
bool fallback(int res) { return res == 0; }
#if !FMT_MSC_VER
bool fallback(internal::null<>) {
std::tm* tm = std::gmtime(&time_);
if (tm) tm_ = *tm;
return tm != nullptr;
}
#endif
};
dispatcher gt(time);
// Too big time values may be unsupported.
if (!gt.run()) FMT_THROW(format_error("time_t value out of range"));
return gt.tm_;
}
namespace internal {
inline std::size_t strftime(char* str, std::size_t count, const char* format,
const std::tm* time) {
return std::strftime(str, count, format, time);
}
inline std::size_t strftime(wchar_t* str, std::size_t count,
const wchar_t* format, const std::tm* time) {
return std::wcsftime(str, count, format, time);
}
} // namespace internal
template <typename Char> struct formatter<std::tm, Char> {
template <typename ParseContext>
auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
auto it = ctx.begin();
if (it != ctx.end() && *it == ':') ++it;
auto end = it;
while (end != ctx.end() && *end != '}') ++end;
tm_format.reserve(internal::to_unsigned(end - it + 1));
tm_format.append(it, end);
tm_format.push_back('\0');
return end;
}
template <typename FormatContext>
auto format(const std::tm& tm, FormatContext& ctx) -> decltype(ctx.out()) {
basic_memory_buffer<Char> buf;
std::size_t start = buf.size();
for (;;) {
std::size_t size = buf.capacity() - start;
std::size_t count =
internal::strftime(&buf[start], size, &tm_format[0], &tm);
if (count != 0) {
buf.resize(start + count);
break;
}
if (size >= tm_format.size() * 256) {
// If the buffer is 256 times larger than the format string, assume
// that `strftime` gives an empty result. There doesn't seem to be a
// better way to distinguish the two cases:
// https://github.com/fmtlib/fmt/issues/367
break;
}
const std::size_t MIN_GROWTH = 10;
buf.reserve(buf.capacity() + (size > MIN_GROWTH ? size : MIN_GROWTH));
}
return std::copy(buf.begin(), buf.end(), ctx.out());
}
basic_memory_buffer<Char> tm_format;
};
namespace internal {
template <typename Period> FMT_CONSTEXPR const char* get_units() {
return nullptr;
}
template <> FMT_CONSTEXPR const char* get_units<std::atto>() { return "as"; }
template <> FMT_CONSTEXPR const char* get_units<std::femto>() { return "fs"; }
template <> FMT_CONSTEXPR const char* get_units<std::pico>() { return "ps"; }
template <> FMT_CONSTEXPR const char* get_units<std::nano>() { return "ns"; }
template <> FMT_CONSTEXPR const char* get_units<std::micro>() { return "µs"; }
template <> FMT_CONSTEXPR const char* get_units<std::milli>() { return "ms"; }
template <> FMT_CONSTEXPR const char* get_units<std::centi>() { return "cs"; }
template <> FMT_CONSTEXPR const char* get_units<std::deci>() { return "ds"; }
template <> FMT_CONSTEXPR const char* get_units<std::ratio<1>>() { return "s"; }
template <> FMT_CONSTEXPR const char* get_units<std::deca>() { return "das"; }
template <> FMT_CONSTEXPR const char* get_units<std::hecto>() { return "hs"; }
template <> FMT_CONSTEXPR const char* get_units<std::kilo>() { return "ks"; }
template <> FMT_CONSTEXPR const char* get_units<std::mega>() { return "Ms"; }
template <> FMT_CONSTEXPR const char* get_units<std::giga>() { return "Gs"; }
template <> FMT_CONSTEXPR const char* get_units<std::tera>() { return "Ts"; }
template <> FMT_CONSTEXPR const char* get_units<std::peta>() { return "Ps"; }
template <> FMT_CONSTEXPR const char* get_units<std::exa>() { return "Es"; }
template <> FMT_CONSTEXPR const char* get_units<std::ratio<60>>() {
return "m";
}
template <> FMT_CONSTEXPR const char* get_units<std::ratio<3600>>() {
return "h";
}
enum class numeric_system {
standard,
// Alternative numeric system, e.g. 十二 instead of 12 in ja_JP locale.
alternative
};
// Parses a put_time-like format string and invokes handler actions.
template <typename Char, typename Handler>
FMT_CONSTEXPR const Char* parse_chrono_format(const Char* begin,
const Char* end,
Handler&& handler) {
auto ptr = begin;
while (ptr != end) {
auto c = *ptr;
if (c == '}') break;
if (c != '%') {
++ptr;
continue;
}
if (begin != ptr) handler.on_text(begin, ptr);
++ptr; // consume '%'
if (ptr == end) FMT_THROW(format_error("invalid format"));
c = *ptr++;
switch (c) {
case '%':
handler.on_text(ptr - 1, ptr);
break;
case 'n': {
const char newline[] = "\n";
handler.on_text(newline, newline + 1);
break;
}
case 't': {
const char tab[] = "\t";
handler.on_text(tab, tab + 1);
break;
}
// Day of the week:
case 'a':
handler.on_abbr_weekday();
break;
case 'A':
handler.on_full_weekday();
break;
case 'w':
handler.on_dec0_weekday(numeric_system::standard);
break;
case 'u':
handler.on_dec1_weekday(numeric_system::standard);
break;
// Month:
case 'b':
handler.on_abbr_month();
break;
case 'B':
handler.on_full_month();
break;
// Hour, minute, second:
case 'H':
handler.on_24_hour(numeric_system::standard);
break;
case 'I':
handler.on_12_hour(numeric_system::standard);
break;
case 'M':
handler.on_minute(numeric_system::standard);
break;
case 'S':
handler.on_second(numeric_system::standard);
break;
// Other:
case 'c':
handler.on_datetime(numeric_system::standard);
break;
case 'x':
handler.on_loc_date(numeric_system::standard);
break;
case 'X':
handler.on_loc_time(numeric_system::standard);
break;
case 'D':
handler.on_us_date();
break;
case 'F':
handler.on_iso_date();
break;
case 'r':
handler.on_12_hour_time();
break;
case 'R':
handler.on_24_hour_time();
break;
case 'T':
handler.on_iso_time();
break;
case 'p':
handler.on_am_pm();
break;
case 'Q':
handler.on_duration_value();
break;
case 'q':
handler.on_duration_unit();
break;
case 'z':
handler.on_utc_offset();
break;
case 'Z':
handler.on_tz_name();
break;
// Alternative representation:
case 'E': {
if (ptr == end) FMT_THROW(format_error("invalid format"));
c = *ptr++;
switch (c) {
case 'c':
handler.on_datetime(numeric_system::alternative);
break;
case 'x':
handler.on_loc_date(numeric_system::alternative);
break;
case 'X':
handler.on_loc_time(numeric_system::alternative);
break;
default:
FMT_THROW(format_error("invalid format"));
}
break;
}
case 'O':
if (ptr == end) FMT_THROW(format_error("invalid format"));
c = *ptr++;
switch (c) {
case 'w':
handler.on_dec0_weekday(numeric_system::alternative);
break;
case 'u':
handler.on_dec1_weekday(numeric_system::alternative);
break;
case 'H':
handler.on_24_hour(numeric_system::alternative);
break;
case 'I':
handler.on_12_hour(numeric_system::alternative);
break;
case 'M':
handler.on_minute(numeric_system::alternative);
break;
case 'S':
handler.on_second(numeric_system::alternative);
break;
default:
FMT_THROW(format_error("invalid format"));
}
break;
default:
FMT_THROW(format_error("invalid format"));
}
begin = ptr;
}
if (begin != ptr) handler.on_text(begin, ptr);
return ptr;
}
struct chrono_format_checker {
FMT_NORETURN void report_no_date() { FMT_THROW(format_error("no date")); }
template <typename Char> void on_text(const Char*, const Char*) {}
FMT_NORETURN void on_abbr_weekday() { report_no_date(); }
FMT_NORETURN void on_full_weekday() { report_no_date(); }
FMT_NORETURN void on_dec0_weekday(numeric_system) { report_no_date(); }
FMT_NORETURN void on_dec1_weekday(numeric_system) { report_no_date(); }
FMT_NORETURN void on_abbr_month() { report_no_date(); }
FMT_NORETURN void on_full_month() { report_no_date(); }
void on_24_hour(numeric_system) {}
void on_12_hour(numeric_system) {}
void on_minute(numeric_system) {}
void on_second(numeric_system) {}
FMT_NORETURN void on_datetime(numeric_system) { report_no_date(); }
FMT_NORETURN void on_loc_date(numeric_system) { report_no_date(); }
FMT_NORETURN void on_loc_time(numeric_system) { report_no_date(); }
FMT_NORETURN void on_us_date() { report_no_date(); }
FMT_NORETURN void on_iso_date() { report_no_date(); }
void on_12_hour_time() {}
void on_24_hour_time() {}
void on_iso_time() {}
void on_am_pm() {}
void on_duration_value() {}
void on_duration_unit() {}
FMT_NORETURN void on_utc_offset() { report_no_date(); }
FMT_NORETURN void on_tz_name() { report_no_date(); }
};
template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
inline bool isnan(T) {
return false;
}
template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
inline bool isnan(T value) {
return std::isnan(value);
}
template <typename T> inline int to_int(T value) {
FMT_ASSERT(isnan(value) || (value >= (std::numeric_limits<int>::min)() &&
value <= (std::numeric_limits<int>::max)()),
"invalid value");
return static_cast<int>(value);
}
template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
inline T mod(T x, int y) {
return x % y;
}
template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
inline T mod(T x, int y) {
return std::fmod(x, y);
}
// If T is an integral type, maps T to its unsigned counterpart, otherwise
// leaves it unchanged (unlike std::make_unsigned).
template <typename T, bool INTEGRAL = std::is_integral<T>::value>
struct make_unsigned_or_unchanged {
using type = T;
};
template <typename T> struct make_unsigned_or_unchanged<T, true> {
using type = typename std::make_unsigned<T>::type;
};
template <typename Rep, typename Period,
typename std::enable_if<std::is_integral<Rep>::value, int>::type = 0>
inline std::chrono::duration<Rep, std::milli> get_milliseconds(
std::chrono::duration<Rep, Period> d) {
auto s = std::chrono::duration_cast<std::chrono::seconds>(d);
return std::chrono::duration_cast<std::chrono::milliseconds>(d - s);
}
template <
typename Rep, typename Period,
typename std::enable_if<std::is_floating_point<Rep>::value, int>::type = 0>
inline std::chrono::duration<Rep, std::milli> get_milliseconds(
std::chrono::duration<Rep, Period> d) {
return std::chrono::duration<Rep, std::milli>(
mod(d.count() * Period::num / Period::den * 1000, 1000));
}
template <typename Rep, typename OutputIt>
OutputIt format_chrono_duration_value(OutputIt out, Rep val, int precision) {
if (precision >= 0) return format_to(out, "{:.{}f}", val, precision);
return format_to(out, std::is_floating_point<Rep>::value ? "{:g}" : "{}",
val);
}
template <typename Period, typename OutputIt>
static OutputIt format_chrono_duration_unit(OutputIt out) {
if (const char* unit = get_units<Period>()) return format_to(out, "{}", unit);
if (Period::den == 1) return format_to(out, "[{}]s", Period::num);
return format_to(out, "[{}/{}]s", Period::num, Period::den);
}
template <typename FormatContext, typename OutputIt, typename Rep,
typename Period>
struct chrono_formatter {
FormatContext& context;
OutputIt out;
int precision;
// rep is unsigned to avoid overflow.
using rep =
conditional_t<std::is_integral<Rep>::value && sizeof(Rep) < sizeof(int),
unsigned, typename make_unsigned_or_unchanged<Rep>::type>;
rep val;
typedef std::chrono::duration<rep> seconds;
seconds s;
typedef std::chrono::duration<rep, std::milli> milliseconds;
bool negative;
typedef typename FormatContext::char_type char_type;
explicit chrono_formatter(FormatContext& ctx, OutputIt o,
std::chrono::duration<Rep, Period> d)
: context(ctx), out(o), val(d.count()), negative(false) {
if (d.count() < 0) {
val = -val;
negative = true;
}
s = std::chrono::duration_cast<seconds>(
std::chrono::duration<rep, Period>(val));
}
Rep hour() const { return mod((s.count() / 3600), 24); }
Rep hour12() const {
Rep hour = mod((s.count() / 3600), 12);
return hour <= 0 ? 12 : hour;
}
Rep minute() const { return mod((s.count() / 60), 60); }
Rep second() const { return mod(s.count(), 60); }
std::tm time() const {
auto time = std::tm();
time.tm_hour = to_int(hour());
time.tm_min = to_int(minute());
time.tm_sec = to_int(second());
return time;
}
void write_sign() {
if (negative) {
*out++ = '-';
negative = false;
}
}
void write(Rep value, int width) {
write_sign();
if (isnan(value)) return write_nan();
typedef typename int_traits<int>::main_type main_type;
main_type n = to_unsigned(to_int(value));
int num_digits = internal::count_digits(n);
if (width > num_digits) out = std::fill_n(out, width - num_digits, '0');
out = format_decimal<char_type>(out, n, num_digits);
}
void write_nan() { std::copy_n("nan", 3, out); }
void format_localized(const tm& time, const char* format) {
if (isnan(val)) return write_nan();
auto locale = context.locale().template get<std::locale>();
auto& facet = std::use_facet<std::time_put<char_type>>(locale);
std::basic_ostringstream<char_type> os;
os.imbue(locale);
facet.put(os, os, ' ', &time, format, format + std::strlen(format));
auto str = os.str();
std::copy(str.begin(), str.end(), out);
}
void on_text(const char_type* begin, const char_type* end) {
std::copy(begin, end, out);
}
// These are not implemented because durations don't have date information.
void on_abbr_weekday() {}
void on_full_weekday() {}
void on_dec0_weekday(numeric_system) {}
void on_dec1_weekday(numeric_system) {}
void on_abbr_month() {}
void on_full_month() {}
void on_datetime(numeric_system) {}
void on_loc_date(numeric_system) {}
void on_loc_time(numeric_system) {}
void on_us_date() {}
void on_iso_date() {}
void on_utc_offset() {}
void on_tz_name() {}
void on_24_hour(numeric_system ns) {
if (ns == numeric_system::standard) return write(hour(), 2);
auto time = tm();
time.tm_hour = to_int(hour());
format_localized(time, "%OH");
}
void on_12_hour(numeric_system ns) {
if (ns == numeric_system::standard) return write(hour12(), 2);
auto time = tm();
time.tm_hour = hour12();
format_localized(time, "%OI");
}
void on_minute(numeric_system ns) {
if (ns == numeric_system::standard) return write(minute(), 2);
auto time = tm();
time.tm_min = minute();
format_localized(time, "%OM");
}
void on_second(numeric_system ns) {
if (ns == numeric_system::standard) {
write(second(), 2);
auto ms = get_milliseconds(std::chrono::duration<Rep, Period>(val));
if (ms != std::chrono::milliseconds(0)) {
*out++ = '.';
write(ms.count(), 3);
}
return;
}
auto time = tm();
time.tm_sec = second();
format_localized(time, "%OS");
}
void on_12_hour_time() { format_localized(time(), "%r"); }
void on_24_hour_time() {
write(hour(), 2);
*out++ = ':';
write(minute(), 2);
}
void on_iso_time() {
on_24_hour_time();
*out++ = ':';
write(second(), 2);
}
void on_am_pm() { format_localized(time(), "%p"); }
void on_duration_value() {
write_sign();
out = format_chrono_duration_value(out, val, precision);
}
void on_duration_unit() { out = format_chrono_duration_unit<Period>(out); }
};
} // namespace internal
template <typename Rep, typename Period, typename Char>
struct formatter<std::chrono::duration<Rep, Period>, Char> {
private:
align_spec spec;
int precision;
typedef internal::arg_ref<Char> arg_ref_type;
arg_ref_type width_ref;
arg_ref_type precision_ref;
mutable basic_string_view<Char> format_str;
typedef std::chrono::duration<Rep, Period> duration;
struct spec_handler {
formatter& f;
basic_parse_context<Char>& context;
basic_string_view<Char> format_str;
template <typename Id> FMT_CONSTEXPR arg_ref_type make_arg_ref(Id arg_id) {
context.check_arg_id(arg_id);
return arg_ref_type(arg_id);
}
FMT_CONSTEXPR arg_ref_type make_arg_ref(basic_string_view<Char> arg_id) {
context.check_arg_id(arg_id);
const auto str_val = internal::string_view_metadata(format_str, arg_id);
return arg_ref_type(str_val);
}
FMT_CONSTEXPR arg_ref_type make_arg_ref(internal::auto_id) {
return arg_ref_type(context.next_arg_id());
}
void on_error(const char* msg) { FMT_THROW(format_error(msg)); }
void on_fill(Char fill) { f.spec.fill_ = fill; }
void on_align(alignment align) { f.spec.align_ = align; }
void on_width(unsigned width) { f.spec.width_ = width; }
void on_precision(unsigned precision) { f.precision = precision; }
void end_precision() {}
template <typename Id> void on_dynamic_width(Id arg_id) {
f.width_ref = make_arg_ref(arg_id);
}
template <typename Id> void on_dynamic_precision(Id arg_id) {
f.precision_ref = make_arg_ref(arg_id);
}
};
typedef typename basic_parse_context<Char>::iterator iterator;
struct parse_range {
iterator begin;
iterator end;
};
FMT_CONSTEXPR parse_range do_parse(basic_parse_context<Char>& ctx) {
auto begin = ctx.begin(), end = ctx.end();
if (begin == end || *begin == '}') return {begin, begin};
spec_handler handler{*this, ctx, format_str};
begin = internal::parse_align(begin, end, handler);
if (begin == end) return {begin, begin};
begin = internal::parse_width(begin, end, handler);
if (begin == end) return {begin, begin};
if (*begin == '.') {
if (std::is_floating_point<Rep>::value)
begin = internal::parse_precision(begin, end, handler);
else
handler.on_error("precision not allowed for this argument type");
}
end = parse_chrono_format(begin, end, internal::chrono_format_checker());
return {begin, end};
}
public:
formatter() : spec(), precision(-1) {}
FMT_CONSTEXPR auto parse(basic_parse_context<Char>& ctx)
-> decltype(ctx.begin()) {
auto range = do_parse(ctx);
format_str = basic_string_view<Char>(
&*range.begin, internal::to_unsigned(range.end - range.begin));
return range.end;
}
template <typename FormatContext>
auto format(const duration& d, FormatContext& ctx) -> decltype(ctx.out()) {
auto begin = format_str.begin(), end = format_str.end();
// As a possible future optimization, we could avoid extra copying if width
// is not specified.
basic_memory_buffer<Char> buf;
auto out = std::back_inserter(buf);
typedef output_range<decltype(ctx.out()), Char> range;
basic_writer<range> w(range(ctx.out()));
internal::handle_dynamic_spec<internal::width_checker>(
spec.width_, width_ref, ctx, format_str.begin());
internal::handle_dynamic_spec<internal::precision_checker>(
precision, precision_ref, ctx, format_str.begin());
if (begin == end || *begin == '}') {
out = internal::format_chrono_duration_value(out, d.count(), precision);
internal::format_chrono_duration_unit<Period>(out);
} else {
internal::chrono_formatter<FormatContext, decltype(out), Rep, Period> f(
ctx, out, d);
f.precision = precision;
parse_chrono_format(begin, end, f);
}
w.write(buf.data(), buf.size(), spec);
return w.out();
}
};
FMT_END_NAMESPACE
#endif // FMT_CHRONO_H_