fmtlegacy/fmt/time.h
2016-11-06 09:05:58 -08:00

144 lines
3.7 KiB
C++

/*
Formatting library for C++ - time formatting
Copyright (c) 2012 - 2016, 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>
#ifdef _MSC_VER
# pragma warning(push)
# pragma warning(disable: 4702) // unreachable code
# pragma warning(disable: 4996) // "deprecated" functions
#endif
namespace fmt {
template <typename ArgFormatter>
void format_arg(BasicFormatter<char, ArgFormatter> &f,
const char *&format_str, const std::tm &tm) {
if (*format_str == ':')
++format_str;
const char *end = format_str;
while (*end && *end != '}')
++end;
if (*end != '}')
FMT_THROW(FormatError("missing '}' in format string"));
internal::MemoryBuffer<char, internal::INLINE_BUFFER_SIZE> format;
format.append(format_str, end + 1);
format[format.size() - 1] = '\0';
Buffer<char> &buffer = f.writer().buffer();
std::size_t start = buffer.size();
for (;;) {
std::size_t size = buffer.capacity() - start;
std::size_t count = std::strftime(&buffer[start], size, &format[0], &tm);
if (count != 0) {
buffer.resize(start + count);
break;
}
if (size >= 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;
buffer.reserve(buffer.capacity() + (size > MIN_GROWTH ? size : MIN_GROWTH));
}
format_str = end + 1;
}
namespace internal{
inline Null<> localtime_r(...) { return Null<>(); }
inline Null<> localtime_s(...) { return Null<>(); }
inline Null<> gmtime_r(...) { return Null<>(); }
inline Null<> gmtime_s(...) { return Null<>(); }
}
// Thread-safe replacement for std::localtime
inline std::tm localtime(std::time_t time) {
struct LocalTime {
std::time_t time_;
std::tm tm_;
LocalTime(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; }
bool fallback(internal::Null<>) {
using namespace fmt::internal;
std::tm *tm = std::localtime(&time_);
if (tm) tm_ = *tm;
return tm != FMT_NULL;
}
};
LocalTime lt(time);
if (lt.run())
return lt.tm_;
// Too big time values may be unsupported.
FMT_THROW(fmt::FormatError("time_t value out of range"));
return std::tm();
}
// Thread-safe replacement for std::gmtime
inline std::tm gmtime(std::time_t time) {
struct GMTime {
std::time_t time_;
std::tm tm_;
GMTime(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; }
bool fallback(internal::Null<>) {
std::tm *tm = std::gmtime(&time_);
if (tm != FMT_NULL) tm_ = *tm;
return tm != FMT_NULL;
}
};
GMTime gt(time);
if (gt.run())
return gt.tm_;
// Too big time values may be unsupported.
FMT_THROW(fmt::FormatError("time_t value out of range"));
return std::tm();
}
} //namespace fmt
#ifdef _MSC_VER
# pragma warning(pop)
#endif
#endif // FMT_TIME_H_