libcruft-util/win32/file.cpp

131 lines
3.5 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 2019 Danny Robson <danny@nerdcruft.net>
*/
#include "file.hpp"
#include "except.hpp"
#include "../cast.hpp"
using cruft::win32::file;
///////////////////////////////////////////////////////////////////////////////
file::file ()
: m_handle (INVALID_HANDLE_VALUE)
{ ; }
//-----------------------------------------------------------------------------
file::file (std::filesystem::path const &src, DWORD access, DWORD share, DWORD create, DWORD flags)
: m_handle (
error::try_call (
CreateFileW,
src.c_str (),
access,
share,
nullptr, // security
create,
flags,
nullptr // template
)
)
{ ; }
//-----------------------------------------------------------------------------
file::file (file &&src) noexcept
: m_handle (std::move (src.m_handle))
{ ; }
//-----------------------------------------------------------------------------
file::file (handle &&src) noexcept
: m_handle (std::move (src))
{ ; }
//-----------------------------------------------------------------------------
file& file::operator= (file &&rhs) noexcept
{
std::swap (m_handle, rhs.m_handle);
return *this;
}
//-----------------------------------------------------------------------------
file::file (posix::fd &&src)
: file (handle (std::move (src)))
{ ; }
///////////////////////////////////////////////////////////////////////////////
DWORD
file::read(void *buf, size_t available)
{
DWORD total_read;
error::try_call (ReadFile, m_handle, buf, available, &total_read, nullptr);
return total_read;
}
//-----------------------------------------------------------------------------
DWORD
file::write (void *buf, size_t available)
{
DWORD total_written;
error::try_call (WriteFile, m_handle, buf, available, &total_written, nullptr);
return total_written;
}
///////////////////////////////////////////////////////////////////////////////
DWORD
file::read(void *buf, size_t available, OVERLAPPED &overlapped)
{
DWORD total_read;
auto const res = ReadFile (m_handle, buf, available, &total_read, &overlapped);
// If we're performing async IO then a value of FALSE is always returned.
if (!overlapped.hEvent && res == FALSE)
error::throw_code();
return total_read;
}
//-----------------------------------------------------------------------------
DWORD
file::write (void *buf, size_t available, OVERLAPPED &overlapped)
{
DWORD total_written;
auto const res = WriteFile (m_handle, buf, available, &total_written, &overlapped);
// If we're performing async IO then a value of FALSE is always returned.
if (!overlapped.hEvent && res == FALSE)
error::throw_code();
return total_written;
}
///////////////////////////////////////////////////////////////////////////////
u64
file::set_pointer(u64 request, DWORD method)
{
LONG const lo = request & 0xffffffff;
LONG hi = request >> 32u;
auto result = SetFilePointer (m_handle, lo, &hi, method);
if (result == INVALID_SET_FILE_POINTER)
error::throw_code();
u64 offset = cruft::cast::lossless<u64> (result) | cruft::cast::lossless<u64> (hi) << 32;
return offset;
}