blob: fe798916f18289fb94d5d5950e412b0221812b91 [file] [log] [blame]
// Formatting library for C++ - time formatting
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_TIME_H_
#define FMT_TIME_H_
#include "format.h"
#include <ctime>
#include <locale>
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 != FMT_NULL; }
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 != FMT_NULL;
}
#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 != FMT_NULL; }
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 != FMT_NULL;
}
#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);
}
}
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;
};
FMT_END_NAMESPACE
#endif // FMT_TIME_H_