fmtlegacy/include/fmt/chrono.h
2019-03-14 18:01:03 -07:00

505 lines
15 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
namespace internal {
template <typename Period> FMT_CONSTEXPR const char* get_units() {
return FMT_NULL;
}
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 {
void report_no_date() { FMT_THROW(format_error("no date")); }
template <typename Char> void on_text(const Char*, const Char*) {}
void on_abbr_weekday() { report_no_date(); }
void on_full_weekday() { report_no_date(); }
void on_dec0_weekday(numeric_system) { report_no_date(); }
void on_dec1_weekday(numeric_system) { report_no_date(); }
void on_abbr_month() { report_no_date(); }
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) {}
void on_datetime(numeric_system) { report_no_date(); }
void on_loc_date(numeric_system) { report_no_date(); }
void on_loc_time(numeric_system) { report_no_date(); }
void on_us_date() { report_no_date(); }
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() {}
void on_utc_offset() { report_no_date(); }
void on_tz_name() { report_no_date(); }
};
template <typename Int> inline int to_int(Int value) {
FMT_ASSERT(value >= (std::numeric_limits<int>::min)() &&
value <= (std::numeric_limits<int>::max)(),
"invalid value");
return static_cast<int>(value);
}
template <typename Rep, typename OutputIt>
OutputIt static format_chrono_duration_value(OutputIt out, Rep val,
int precision) {
if (precision < 0) {
return format_to(out, std::is_floating_point<Rep>::value ? "{:g}" : "{}",
val);
}
return format_to(out, "{:.{}f}", val, precision);
}
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);
else if (Period::den == 1)
return format_to(out, "[{}]s", Period::num);
else
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 val;
typedef std::chrono::duration<Rep, std::milli> milliseconds;
std::chrono::seconds s;
milliseconds ms;
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()),
s(std::chrono::duration_cast<std::chrono::seconds>(d)),
ms(std::chrono::duration_cast<milliseconds>(d - s)) {}
int hour() const { return to_int((s.count() / 3600) % 24); }
int hour12() const {
auto hour = to_int((s.count() / 3600) % 12);
return hour > 0 ? hour : 12;
}
int minute() const { return to_int((s.count() / 60) % 60); }
int second() const { return to_int(s.count() % 60); }
std::tm time() const {
auto time = std::tm();
time.tm_hour = hour();
time.tm_min = minute();
time.tm_sec = second();
return time;
}
void write(int value, int width) {
typedef typename int_traits<int>::main_type main_type;
main_type n = to_unsigned(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 format_localized(const tm& time, const char* format) {
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 = 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 = hour();
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);
if (ms != std::chrono::milliseconds(0)) {
*out++ = '.';
write(to_int(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() {
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);
}
};
public:
formatter() : spec(), precision(-1) {}
FMT_CONSTEXPR auto parse(basic_parse_context<Char>& ctx)
-> decltype(ctx.begin()) {
auto begin = ctx.begin(), end = ctx.end();
if (begin == end) return begin;
spec_handler handler{*this, ctx, format_str};
begin = internal::parse_align(begin, end, handler);
if (begin == end) return begin;
begin = internal::parse_width(begin, end, handler);
if (begin == end) return 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());
format_str =
basic_string_view<Char>(&*begin, internal::to_unsigned(end - begin));
return 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_