fmtlegacy/include/fmt/posix.h
2019-11-17 08:29:08 -08:00

322 lines
8.8 KiB
C++

// A C++ interface to POSIX functions.
//
// Copyright (c) 2012 - 2016, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_POSIX_H_
#define FMT_POSIX_H_
#if defined(__MINGW32__) || defined(__CYGWIN__)
// Workaround MinGW bug https://sourceforge.net/p/mingw/bugs/2024/.
# undef __STRICT_ANSI__
#endif
#include <cerrno>
#include <clocale> // for locale_t
#include <cstdio>
#include <cstdlib> // for strtod_l
#include <cstddef>
#if defined __APPLE__ || defined(__FreeBSD__)
# include <xlocale.h> // for LC_NUMERIC_MASK on OS X
#endif
#include "format.h"
// UWP doesn't provide _pipe.
#if FMT_HAS_INCLUDE("winapifamily.h")
# include <winapifamily.h>
#endif
#if FMT_HAS_INCLUDE("fcntl.h") && \
(!defined(WINAPI_FAMILY) || (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
# include <fcntl.h> // for O_RDONLY
# define FMT_USE_FCNTL 1
#else
# define FMT_USE_FCNTL 0
#endif
#ifndef FMT_POSIX
# if defined(_WIN32) && !defined(__MINGW32__)
// Fix warnings about deprecated symbols.
# define FMT_POSIX(call) _##call
# else
# define FMT_POSIX(call) call
# endif
#endif
// Calls to system functions are wrapped in FMT_SYSTEM for testability.
#ifdef FMT_SYSTEM
# define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
#else
# define FMT_SYSTEM(call) call
# ifdef _WIN32
// Fix warnings about deprecated symbols.
# define FMT_POSIX_CALL(call) ::_##call
# else
# define FMT_POSIX_CALL(call) ::call
# endif
#endif
// Retries the expression while it evaluates to error_result and errno
// equals to EINTR.
#ifndef _WIN32
# define FMT_RETRY_VAL(result, expression, error_result) \
do { \
(result) = (expression); \
} while ((result) == (error_result) && errno == EINTR)
#else
# define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
#endif
#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
FMT_BEGIN_NAMESPACE
/**
\rst
A reference to a null-terminated string. It can be constructed from a C
string or ``std::string``.
You can use one of the following type aliases for common character types:
+---------------+-----------------------------+
| Type | Definition |
+===============+=============================+
| cstring_view | basic_cstring_view<char> |
+---------------+-----------------------------+
| wcstring_view | basic_cstring_view<wchar_t> |
+---------------+-----------------------------+
This class is most useful as a parameter type to allow passing
different types of strings to a function, for example::
template <typename... Args>
std::string format(cstring_view format_str, const Args & ... args);
format("{}", 42);
format(std::string("{}"), 42);
\endrst
*/
template <typename Char> class basic_cstring_view {
private:
const Char* data_;
public:
/** Constructs a string reference object from a C string. */
basic_cstring_view(const Char* s) : data_(s) {}
/**
\rst
Constructs a string reference from an ``std::string`` object.
\endrst
*/
basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
/** Returns the pointer to a C string. */
const Char* c_str() const { return data_; }
};
using cstring_view = basic_cstring_view<char>;
using wcstring_view = basic_cstring_view<wchar_t>;
// An error code.
class error_code {
private:
int value_;
public:
explicit error_code(int value = 0) FMT_NOEXCEPT : value_(value) {}
int get() const FMT_NOEXCEPT { return value_; }
};
// A buffered file.
class buffered_file {
private:
FILE* file_;
friend class file;
explicit buffered_file(FILE* f) : file_(f) {}
public:
buffered_file(const buffered_file&) = delete;
void operator=(const buffered_file&) = delete;
// Constructs a buffered_file object which doesn't represent any file.
buffered_file() FMT_NOEXCEPT : file_(nullptr) {}
// Destroys the object closing the file it represents if any.
FMT_API ~buffered_file() FMT_NOEXCEPT;
public:
buffered_file(buffered_file&& other) FMT_NOEXCEPT : file_(other.file_) {
other.file_ = nullptr;
}
buffered_file& operator=(buffered_file&& other) FMT_NOEXCEPT {
close();
file_ = other.file_;
other.file_ = nullptr;
return *this;
}
// Opens a file.
FMT_API buffered_file(cstring_view filename, cstring_view mode);
// Closes the file.
FMT_API void close();
// Returns the pointer to a FILE object representing this file.
FILE* get() const FMT_NOEXCEPT { return file_; }
// We place parentheses around fileno to workaround a bug in some versions
// of MinGW that define fileno as a macro.
FMT_API int(fileno)() const;
void vprint(string_view format_str, format_args args) {
fmt::vprint(file_, format_str, args);
}
template <typename... Args>
inline void print(string_view format_str, const Args&... args) {
vprint(format_str, make_format_args(args...));
}
};
#if FMT_USE_FCNTL
// A file. Closed file is represented by a file object with descriptor -1.
// Methods that are not declared with FMT_NOEXCEPT may throw
// fmt::system_error in case of failure. Note that some errors such as
// closing the file multiple times will cause a crash on Windows rather
// than an exception. You can get standard behavior by overriding the
// invalid parameter handler with _set_invalid_parameter_handler.
class file {
private:
int fd_; // File descriptor.
// Constructs a file object with a given descriptor.
explicit file(int fd) : fd_(fd) {}
public:
// Possible values for the oflag argument to the constructor.
enum {
RDONLY = FMT_POSIX(O_RDONLY), // Open for reading only.
WRONLY = FMT_POSIX(O_WRONLY), // Open for writing only.
RDWR = FMT_POSIX(O_RDWR) // Open for reading and writing.
};
// Constructs a file object which doesn't represent any file.
file() FMT_NOEXCEPT : fd_(-1) {}
// Opens a file and constructs a file object representing this file.
FMT_API file(cstring_view path, int oflag);
public:
file(const file&) = delete;
void operator=(const file&) = delete;
file(file&& other) FMT_NOEXCEPT : fd_(other.fd_) { other.fd_ = -1; }
file& operator=(file&& other) FMT_NOEXCEPT {
close();
fd_ = other.fd_;
other.fd_ = -1;
return *this;
}
// Destroys the object closing the file it represents if any.
FMT_API ~file() FMT_NOEXCEPT;
// Returns the file descriptor.
int descriptor() const FMT_NOEXCEPT { return fd_; }
// Closes the file.
FMT_API void close();
// Returns the file size. The size has signed type for consistency with
// stat::st_size.
FMT_API long long size() const;
// Attempts to read count bytes from the file into the specified buffer.
FMT_API std::size_t read(void* buffer, std::size_t count);
// Attempts to write count bytes from the specified buffer to the file.
FMT_API std::size_t write(const void* buffer, std::size_t count);
// Duplicates a file descriptor with the dup function and returns
// the duplicate as a file object.
FMT_API static file dup(int fd);
// Makes fd be the copy of this file descriptor, closing fd first if
// necessary.
FMT_API void dup2(int fd);
// Makes fd be the copy of this file descriptor, closing fd first if
// necessary.
FMT_API void dup2(int fd, error_code& ec) FMT_NOEXCEPT;
// Creates a pipe setting up read_end and write_end file objects for reading
// and writing respectively.
FMT_API static void pipe(file& read_end, file& write_end);
// Creates a buffered_file object associated with this file and detaches
// this file object from the file.
FMT_API buffered_file fdopen(const char* mode);
};
// Returns the memory page size.
long getpagesize();
#endif // FMT_USE_FCNTL
#ifdef FMT_LOCALE
// A "C" numeric locale.
class Locale {
private:
# ifdef _WIN32
using locale_t = _locale_t;
enum { LC_NUMERIC_MASK = LC_NUMERIC };
static locale_t newlocale(int category_mask, const char* locale, locale_t) {
return _create_locale(category_mask, locale);
}
static void freelocale(locale_t locale) { _free_locale(locale); }
static double strtod_l(const char* nptr, char** endptr, _locale_t locale) {
return _strtod_l(nptr, endptr, locale);
}
# endif
locale_t locale_;
public:
using type = locale_t;
Locale(const Locale&) = delete;
void operator=(const Locale&) = delete;
Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
if (!locale_) FMT_THROW(system_error(errno, "cannot create locale"));
}
~Locale() { freelocale(locale_); }
type get() const { return locale_; }
// Converts string to floating-point number and advances str past the end
// of the parsed input.
double strtod(const char*& str) const {
char* end = nullptr;
double result = strtod_l(str, &end, locale_);
str = end;
return result;
}
};
#endif // FMT_LOCALE
FMT_END_NAMESPACE
#endif // FMT_POSIX_H_