libcruft-util/io_posix.hpp
Danny Robson f6056153e3 rename root namespace from util to cruft
This places, at long last, the core library code into the same namespace
as the extended library code.
2018-08-05 14:42:02 +10:00

87 lines
2.7 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2010-2016 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_IO_POSIX_HPP
#define __UTIL_IO_POSIX_HPP
#include "posix/fd.hpp"
#include "view.hpp"
#include <type_traits>
#include <experimental/filesystem>
#include <sys/mman.h>
#include <fcntl.h>
namespace cruft {
namespace detail::posix {
// represents a memory mapped file.
//
// the data pointer may be null in the case of a zero length file. it
// is expected that the user will take measures to avoid dereferencing
// such a pointer.
class mapped_file {
public:
using value_type = uint8_t;
using reference = value_type&;
using const_reference = const value_type&;
using iterator = value_type*;
using const_iterator = const value_type*;
using difference_type = std::iterator_traits<iterator>::difference_type;
using size_type = size_t;
mapped_file (const std::experimental::filesystem::path&,
int fflags = O_RDONLY | O_BINARY,
int mflags = PROT_READ);
mapped_file (const cruft::posix::fd&,
int mflags = PROT_READ);
mapped_file (const mapped_file&) = delete;
mapped_file& operator= (const mapped_file&) = delete;
mapped_file (const mapped_file&&) noexcept;
mapped_file& operator= (mapped_file&&) noexcept;
~mapped_file ();
bool empty (void) const;
/// returns the total allocated mapped region in bytes.
///
/// result is typed size_t (rather than the native signed type)
/// because we often use this in conjunction with sizeof and
/// packed structure.
///
/// it is greatly simpler to cast to signed where it's actually
/// required rather than the other way around.
size_type size (void) const;
const_iterator data (void) const &;
iterator data (void) &;
iterator begin (void) &;
iterator end (void) &;
const_iterator begin (void) const &;
const_iterator end (void) const &;
const_iterator cbegin (void) const &;
const_iterator cend (void) const &;
private:
uint8_t *m_data;
size_t m_size;
};
}
typedef detail::posix::mapped_file mapped_file;
}
#endif