transmission/libtransmission/utils.h

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// This file Copyright © Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#pragma once
#include <algorithm> // for std::for_each()
#include <cctype>
#include <cstddef> // size_t
#include <cstdint> // uint8_t, uint32_t, uint64_t
#include <ctime> // time_t
#include <locale>
#include <memory>
#include <optional>
#include <string>
#include <string_view>
#include <type_traits>
#include <vector>
struct tr_error;
/**
* @addtogroup utils Utilities
* @{
*/
#if !defined(_)
#if defined(HAVE_GETTEXT) && !defined(__APPLE__)
#include <libintl.h>
#define _(a) gettext(a)
#else
#define _(a) (a)
#endif
#endif
#if defined(HAVE_NGETTEXT)
#define tr_ngettext ngettext
#else
#define tr_ngettext(singular, plural, count) ((count) == 1 ? (singular) : (plural))
#endif
/* #define DISABLE_GETTEXT */
#ifndef DISABLE_GETTEXT
#if defined(_WIN32)
#define DISABLE_GETTEXT
#endif
#endif
#ifdef DISABLE_GETTEXT
#undef _
#undef tr_ngettext
#define _(a) (a)
#define tr_ngettext(singular, plural, count) ((count) == 1 ? (singular) : (plural))
#endif
std::optional<std::locale> tr_locale_set_global(char const* locale_name) noexcept;
std::optional<std::locale> tr_locale_set_global(std::locale const& locale) noexcept;
// ---
[[nodiscard]] std::string_view tr_get_mime_type_for_filename(std::string_view filename);
bool tr_file_read(std::string_view filename, std::vector<char>& contents, tr_error* error = nullptr);
bool tr_file_move(std::string_view oldpath, std::string_view newpath, tr_error* error = nullptr);
bool tr_file_save(std::string_view filename, std::string_view contents, tr_error* error = nullptr);
template<typename ContiguousRange>
constexpr auto tr_file_save(std::string_view filename, ContiguousRange const& x, tr_error* error = nullptr)
{
return tr_file_save(filename, std::string_view{ std::data(x), std::size(x) }, error);
}
/** @brief return the current date in milliseconds */
[[nodiscard]] uint64_t tr_time_msec();
#ifdef _WIN32
[[nodiscard]] std::string tr_win32_format_message(uint32_t code);
[[nodiscard]] std::string tr_win32_native_to_utf8(std::wstring_view);
[[nodiscard]] std::wstring tr_win32_utf8_to_native(std::string_view);
int tr_main_win32(int argc, char** argv, int (*real_main)(int, char**));
#define tr_main(...) \
main_impl(__VA_ARGS__); \
int main(int argc, char* argv[]) \
{ \
return tr_main_win32(argc, argv, &main_impl); \
} \
int main_impl(__VA_ARGS__)
#else
#define tr_main main
#endif
// ---
/** @brief Convenience wrapper around `strerorr()` guaranteed to not return nullptr
@param errnum the error number to describe */
[[nodiscard]] char const* tr_strerror(int errnum);
template<typename T>
[[nodiscard]] std::string tr_strlower(T in)
{
auto out = std::string{ std::move(in) };
std::for_each(std::begin(out), std::end(out), [](char& ch) { ch = std::tolower(ch); });
return out;
}
template<typename T>
[[nodiscard]] std::string tr_strupper(T in)
{
auto out = std::string{ std::move(in) };
std::for_each(std::begin(out), std::end(out), [](char& ch) { ch = std::toupper(ch); });
return out;
}
// --- std::string_view utils
/**
* @brief Rich Salz's classic implementation of shell-style pattern matching for `?`, `\`, `[]`, and `*` characters.
* @return 1 if the pattern matches, 0 if it doesn't, or -1 if an error occurred
*/
[[nodiscard]] bool tr_wildmat(std::string_view text, std::string_view pattern);
template<typename T>
[[nodiscard]] constexpr bool tr_strv_contains(std::string_view sv, T key) noexcept // c++23
{
return sv.find(key) != std::string_view::npos;
}
[[nodiscard]] constexpr bool tr_strv_starts_with(std::string_view sv, char key) // c++20
{
return !std::empty(sv) && sv.front() == key;
}
[[nodiscard]] constexpr bool tr_strv_starts_with(std::string_view sv, std::string_view key) // c++20
{
return std::size(key) <= std::size(sv) && sv.substr(0, std::size(key)) == key;
}
[[nodiscard]] constexpr bool tr_strv_starts_with(std::wstring_view sv, std::wstring_view key) // c++20
{
return std::size(key) <= std::size(sv) && sv.substr(0, std::size(key)) == key;
}
[[nodiscard]] constexpr bool tr_strv_ends_with(std::string_view sv, std::string_view key) // c++20
{
return std::size(key) <= std::size(sv) && sv.substr(std::size(sv) - std::size(key)) == key;
}
[[nodiscard]] constexpr bool tr_strv_ends_with(std::string_view sv, char key) // c++20
{
return !std::empty(sv) && sv.back() == key;
}
template<typename T>
[[nodiscard]] constexpr int tr_compare_3way(T const& left, T const& right)
{
if (left < right)
{
return -1;
}
if (right < left)
{
return 1;
}
return 0;
}
constexpr std::string_view tr_strv_sep(std::string_view* sv, char delim)
{
auto pos = sv->find(delim);
auto const ret = sv->substr(0, pos);
sv->remove_prefix(pos != std::string_view::npos ? pos + 1 : std::size(*sv));
return ret;
}
constexpr bool tr_strv_sep(std::string_view* sv, std::string_view* token, char delim)
{
if (std::empty(*sv))
{
return false;
}
*token = tr_strv_sep(sv, delim);
return true;
}
[[nodiscard]] std::string_view tr_strv_strip(std::string_view str);
[[nodiscard]] std::string tr_strv_convert_utf8(std::string_view sv);
[[nodiscard]] std::string tr_strv_replace_invalid(std::string_view sv, uint32_t replacement = 0xFFFD /*<2A>*/);
/**
* @brief copies `src` into `buf`.
*
* - Always returns std::size(src).
* - `src` will be copied into `buf` iff `buflen >= std::size(src)`
* - `buf` will also be zero terminated iff `buflen >= std::size(src) + 1`.
*/
size_t tr_strv_to_buf(std::string_view src, char* buf, size_t buflen);
// ---
template<typename T, std::enable_if_t<std::is_integral_v<T>, bool> = true>
[[nodiscard]] std::optional<T> tr_num_parse(std::string_view str, std::string_view* setme_remainder = nullptr, int base = 10);
template<typename T, std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
[[nodiscard]] std::optional<T> tr_num_parse(std::string_view str, std::string_view* setme_remainder = nullptr);
/**
* @brief Given a string like "1-4" or "1-4,6,9,14-51", this returns a
* newly-allocated array of all the integers in the set.
* @return a vector of integers, which is empty if the string can't be parsed.
*
* For example, "5-8" will return [ 5, 6, 7, 8 ] and setmeCount will be 4.
*/
[[nodiscard]] std::vector<int> tr_num_parse_range(std::string_view str);
/**
* @brief truncate a double value at a given number of decimal places.
*
* this can be used to prevent a `printf()` call from rounding up:
* call with the `decimal_places` argument equal to the number of
* decimal places in the `printf()`'s precision:
*
* - printf("%.2f%%", 99.999) ==> "100.00%"
*
* - printf("%.2f%%", tr_truncd(99.999, 2)) ==> "99.99%"
* ^ ^
* | These should match |
* +------------------------+
*/
[[nodiscard]] double tr_truncd(double x, int decimal_places);
/* return a percent formatted string of either x.xx, xx.x or xxx */
[[nodiscard]] std::string tr_strpercent(double x);
/** @brief return `TR_RATIO_NA`, `TR_RATIO_INF`, or a number in [0..1]
@return `TR_RATIO_NA`, `TR_RATIO_INF`, or a number in [0..1] */
[[nodiscard]] double tr_getRatio(uint64_t numerator, uint64_t denominator);
/** @param ratio the ratio to convert to a string
@param infinity the string representation of "infinity" */
[[nodiscard]] std::string tr_strratio(double ratio, char const* infinity);
// ---
namespace libtransmission::detail::tr_time
{
extern time_t current_time;
}
/**
* @brief very inexpensive form of time(nullptr)
* @return the current epoch time in seconds
*
* This function returns a second counter that is updated once per second.
* If something blocks the libtransmission thread for more than a second,
* that counter may be thrown off, so this function is not guaranteed
* to always be accurate. However, it is *much* faster when 100% accuracy
* isn't needed
*/
[[nodiscard]] static inline time_t tr_time() noexcept
{
return libtransmission::detail::tr_time::current_time;
}
/** @brief Private libtransmission function to update `tr_time()`'s counter */
constexpr void tr_timeUpdate(time_t now) noexcept
{
libtransmission::detail::tr_time::current_time = now;
}
/** @brief Portability wrapper for `htonll()` that uses the system implementation if available */
[[nodiscard]] uint64_t tr_htonll(uint64_t hostlonglong);
/** @brief Portability wrapper for `ntohll()` that uses the system implementation if available */
[[nodiscard]] uint64_t tr_ntohll(uint64_t netlonglong);
// ---
/** @brief Check if environment variable exists. */
[[nodiscard]] bool tr_env_key_exists(char const* key);
/** @brief Get environment variable value as string. */
[[nodiscard]] std::string tr_env_get_string(std::string_view key, std::string_view default_value = {});
// ---
class tr_net_init_mgr
{
public:
~tr_net_init_mgr();
static std::unique_ptr<tr_net_init_mgr> create();
private:
tr_net_init_mgr();
tr_net_init_mgr(tr_net_init_mgr&&) = delete;
tr_net_init_mgr(tr_net_init_mgr const&) = delete;
tr_net_init_mgr& operator=(tr_net_init_mgr&&) = delete;
tr_net_init_mgr& operator=(tr_net_init_mgr const&) = delete;
static bool initialised;
};
/** @brief Initialise libtransmission for each app
* @return A manager object to be kept in scope of main() */
std::unique_ptr<tr_net_init_mgr> tr_lib_init();