You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
spdlog/include/spdlog/details/fmt_helper.h

117 lines
3.6 KiB
C++

// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)
#pragma once
#include <chrono>
#include <iterator>
#include <type_traits>
#include "../common.h"
// Some fmt helpers to efficiently format and pad ints and strings
namespace spdlog {
namespace details {
namespace fmt_helper {
inline void append_string_view(spdlog::string_view_t view, memory_buf_t &dest) {
const auto *buf_ptr = view.data();
dest.append(buf_ptr, buf_ptr + view.size());
}
template <typename T>
void append_int(T n, memory_buf_t &dest) {
fmt::format_int i(n);
dest.append(i.data(), i.data() + i.size());
}
template <typename T>
constexpr unsigned int count_digits_fallback(T n) {
// taken from fmt: https://github.com/fmtlib/fmt/blob/8.0.1/include/fmt/format.h#L899-L912
unsigned int count = 1;
for (;;) {
// Integer division is slow so do it for a group of four digits instead
// of for every digit. The idea comes from the talk by Alexandrescu
// "Three Optimization Tips for C++". See speed-test for a comparison.
if (n < 10) return count;
if (n < 100) return count + 1;
if (n < 1000) return count + 2;
if (n < 10000) return count + 3;
n /= 10000U;
count += 4;
}
}
template <typename T>
inline unsigned int count_digits(T n) {
using count_type = std::conditional_t<(sizeof(T) > sizeof(uint32_t)), uint64_t, uint32_t>;
return static_cast<unsigned int>(fmt::
// fmt 7.0.0 renamed the internal namespace to detail.
// See: https://github.com/fmtlib/fmt/issues/1538
#if FMT_VERSION < 70000
internal
#else
detail
#endif
::count_digits(static_cast<count_type>(n)));
}
inline void pad2(int n, memory_buf_t &dest) {
if (n >= 0 && n < 100) // 0-99
{
dest.push_back(static_cast<char>('0' + (n / 10)));
dest.push_back(static_cast<char>('0' + (n % 10)));
} else // unlikely, but just in case, let fmt deal with it
{
fmt_lib::format_to(std::back_inserter(dest), SPDLOG_FMT_STRING("{:02}"), n);
}
}
template <typename T>
inline void pad_uint(T n, unsigned int width, memory_buf_t &dest) {
static_assert(std::is_unsigned_v<T>, "pad_uint must get unsigned T");
for (auto digits = count_digits(n); digits < width; ++digits) {
dest.push_back('0');
}
append_int(n, dest);
}
template <typename T>
void pad3(T n, memory_buf_t &dest) {
static_assert(std::is_unsigned_v<T>, "pad3 must get unsigned T");
if (n < 1000) {
dest.push_back(static_cast<char>((n / 100) + '0'));
n = n % 100;
dest.push_back(static_cast<char>((n / 10) + '0'));
dest.push_back(static_cast<char>((n % 10) + '0'));
} else {
append_int(n, dest);
}
}
template <typename T>
void pad6(T n, memory_buf_t &dest) {
pad_uint(n, 6, dest);
}
template <typename T>
void pad9(T n, memory_buf_t &dest) {
pad_uint(n, 9, dest);
}
// return fraction of a second of the given time_point.
// e.g.
// fraction<std::milliseconds>(tp) -> will return the millis part of the second
template <typename ToDuration>
ToDuration time_fraction(log_clock::time_point tp) {
using std::chrono::duration_cast;
using std::chrono::seconds;
auto duration = tp.time_since_epoch();
auto secs = duration_cast<seconds>(duration);
return duration_cast<ToDuration>(duration) - duration_cast<ToDuration>(secs);
}
} // namespace fmt_helper
} // namespace details
} // namespace spdlog