libs/iostreams/src/file_descriptor.cpp
// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2003-2007 Jonathan Turkanis
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
// See http://www.boost.org/libs/iostreams for documentation.
// Inspired by fdstream.hpp, (C) Copyright Nicolai M. Josuttis 2001,
// available at http://www.josuttis.com/cppcode/fdstream.html.
// Define BOOST_IOSTREAMS_SOURCE so that <boost/iostreams/detail/config.hpp>
// knows that we are building the library (possibly exporting code), rather
// than using it (possibly importing code).
#define BOOST_IOSTREAMS_SOURCE
#include <cassert>
#include <cerrno>
#include <cstdio> // SEEK_SET, etc.
#include <boost/config.hpp> // BOOST_JOIN
#include <boost/iostreams/detail/error.hpp>
#include <boost/iostreams/detail/config/dyn_link.hpp>
#include <boost/iostreams/detail/config/rtl.hpp> // BOOST_IOSTREAMS_FD_XXX
#include <boost/iostreams/detail/config/windows_posix.hpp>
#include <boost/iostreams/detail/ios.hpp> // openmodes, failure.
#include <boost/iostreams/device/file_descriptor.hpp>
#include <boost/integer_traits.hpp>
// OS-specific headers for low-level i/o.
#include <fcntl.h> // file opening flags.
#include <sys/stat.h> // file access permissions.
#ifdef BOOST_IOSTREAMS_WINDOWS
# include <io.h> // low-level file i/o.
# define WINDOWS_LEAN_AND_MEAN
# include <windows.h>
# ifndef INVALID_SET_FILE_POINTER
# define INVALID_SET_FILE_POINTER ((DWORD)-1)
# endif
#else
# include <sys/types.h> // mode_t.
# include <unistd.h> // low-level file i/o.
#endif
namespace boost { namespace iostreams {
//------------------Implementation of file_descriptor-------------------------//
file_descriptor::file_descriptor() : pimpl_(new impl) { }
file_descriptor::file_descriptor(handle_type fd, bool close_on_exit)
: pimpl_(new impl(fd, close_on_exit))
{ }
#ifdef BOOST_IOSTREAMS_WINDOWS
file_descriptor::file_descriptor(int fd, bool close_on_exit)
: pimpl_(new impl(int_to_handle(fd), close_on_exit))
{ }
#endif
file_descriptor::file_descriptor( const char* path,
BOOST_IOS::openmode mode,
BOOST_IOS::openmode base_mode )
: pimpl_(new impl)
{ open(std::string(path), mode, base_mode); }
file_descriptor::file_descriptor( const std::string& path,
BOOST_IOS::openmode mode,
BOOST_IOS::openmode base_mode )
: pimpl_(new impl)
{ open(path, mode, base_mode); }
void file_descriptor::open
( const std::string& path, BOOST_IOS::openmode m,
BOOST_IOS::openmode base )
{
using namespace std;
m |= base;
#ifdef BOOST_IOSTREAMS_WINDOWS //---------------------------------------------//
DWORD dwDesiredAccess;
DWORD dwCreationDisposition;
if ( (m & (BOOST_IOS::in | BOOST_IOS::out))
==
(BOOST_IOS::in | BOOST_IOS::out) )
{
if (m & BOOST_IOS::app)
throw BOOST_IOSTREAMS_FAILURE("bad open mode");
dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
dwCreationDisposition =
(m & BOOST_IOS::trunc) ?
OPEN_ALWAYS :
OPEN_EXISTING;
} else if (m & BOOST_IOS::in) {
if (m & (BOOST_IOS::app |BOOST_IOS::trunc))
throw BOOST_IOSTREAMS_FAILURE("bad open mode");
dwDesiredAccess = GENERIC_READ;
dwCreationDisposition = OPEN_EXISTING;
} else if (m & BOOST_IOS::out) {
dwDesiredAccess = GENERIC_WRITE;
dwCreationDisposition = OPEN_ALWAYS;
if (m & BOOST_IOS::app)
pimpl_->flags_ |= impl::append;
} else {
throw BOOST_IOSTREAMS_FAILURE("bad open mode");
}
HANDLE handle =
::CreateFileA( path.c_str(),
dwDesiredAccess,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL, // lpSecurityAttributes
dwCreationDisposition,
FILE_ATTRIBUTE_NORMAL,
NULL ); // hTemplateFile
if (handle != INVALID_HANDLE_VALUE) {
pimpl_->handle_ = handle;
pimpl_->flags_ |= impl::close_on_exit;
} else {
pimpl_->flags_ = 0;
throw BOOST_IOSTREAMS_FAILURE("bad open");
}
#else // #ifdef BOOST_IOSTREAMS_WINDOWS //------------------------------------//
// Calculate oflag argument to open.
int oflag = 0;
if ( (m & (BOOST_IOS::in | BOOST_IOS::out))
==
(BOOST_IOS::in | BOOST_IOS::out) )
{
assert(!(m & BOOST_IOS::app));
oflag |= O_RDWR;
} else if (m & BOOST_IOS::in) {
assert(!(m & (BOOST_IOS::app |BOOST_IOS::trunc)));
oflag |= O_RDONLY;
} else if (m & BOOST_IOS::out) {
oflag |= O_WRONLY;
m |= BOOST_IOS::trunc;
if (m & BOOST_IOS::app)
oflag |= O_APPEND;
}
if (m & BOOST_IOS::trunc)
oflag |= O_CREAT;
#ifdef _LARGEFILE64_SOURCE
oflag |= O_LARGEFILE;
#endif
// Calculate pmode argument to open.
mode_t pmode = S_IRUSR | S_IWUSR |
S_IRGRP | S_IWGRP |
S_IROTH | S_IWOTH;
// Open file.
int fd = BOOST_IOSTREAMS_FD_OPEN(path.c_str(), oflag, pmode);
if (fd == -1) {
throw BOOST_IOSTREAMS_FAILURE("bad open");
} else {
pimpl_->handle_ = fd;
pimpl_->flags_ = impl::close_on_exit;
}
#endif // #ifndef BOOST_IOSTREAMS_WINDOWS //----------------------------------//
}
void file_descriptor::open
( const char* path, BOOST_IOS::openmode m,
BOOST_IOS::openmode base )
{ open(std::string(path), m, base); }
std::streamsize file_descriptor::read(char_type* s, std::streamsize n)
{
#ifdef BOOST_IOSTREAMS_WINDOWS
DWORD result;
if (!::ReadFile(pimpl_->handle_, s, n, &result, NULL))
throw detail::bad_read();
return result == 0 ? -1 : static_cast<std::streamsize>(result);
#else // #ifdef BOOST_IOSTREAMS_WINDOWS
errno = 0;
std::streamsize result = BOOST_IOSTREAMS_FD_READ(pimpl_->handle_, s, n);
if (errno != 0)
throw detail::bad_read();
return result == 0 ? -1 : result;
#endif // #ifdef BOOST_IOSTREAMS_WINDOWS
}
std::streamsize file_descriptor::write(const char_type* s, std::streamsize n)
{
#ifdef BOOST_IOSTREAMS_WINDOWS
if (pimpl_->flags_ & impl::append) {
DWORD const dwResult =
::SetFilePointer(pimpl_->handle_, 0, NULL, FILE_END);
if ( dwResult == INVALID_SET_FILE_POINTER &&
::GetLastError() != NO_ERROR )
{
throw detail::bad_seek();
}
}
DWORD ignore;
if (!::WriteFile(pimpl_->handle_, s, n, &ignore, NULL))
throw detail::bad_write();
return n;
#else // #ifdef BOOST_IOSTREAMS_WINDOWS
int amt = BOOST_IOSTREAMS_FD_WRITE(pimpl_->handle_, s, n);
if (amt < n)
throw detail::bad_write(); // Handles blocking fd's only.
return n;
#endif // #ifdef BOOST_IOSTREAMS_WINDOWS
}
std::streampos file_descriptor::seek
(stream_offset off, BOOST_IOS::seekdir way)
{
using namespace std;
#ifdef BOOST_IOSTREAMS_WINDOWS
LONG lDistanceToMove = static_cast<LONG>(off & 0xffffffff);
LONG lDistanceToMoveHigh = static_cast<LONG>(off >> 32);
DWORD dwResultLow =
::SetFilePointer( pimpl_->handle_,
lDistanceToMove,
&lDistanceToMoveHigh,
way == BOOST_IOS::beg ?
FILE_BEGIN :
way == BOOST_IOS::cur ?
FILE_CURRENT :
FILE_END );
if ( dwResultLow == INVALID_SET_FILE_POINTER &&
::GetLastError() != NO_ERROR )
{
throw detail::bad_seek();
} else {
return offset_to_position(
(stream_offset(lDistanceToMoveHigh) << 32) + dwResultLow
);
}
#else // #ifdef BOOST_IOSTREAMS_WINDOWS
if ( off > integer_traits<BOOST_IOSTREAMS_FD_OFFSET>::const_max ||
off < integer_traits<BOOST_IOSTREAMS_FD_OFFSET>::const_min )
{
throw BOOST_IOSTREAMS_FAILURE("bad offset");
}
stream_offset result =
BOOST_IOSTREAMS_FD_SEEK(
pimpl_->handle_,
static_cast<BOOST_IOSTREAMS_FD_OFFSET>(off),
( way == BOOST_IOS::beg ?
SEEK_SET :
way == BOOST_IOS::cur ?
SEEK_CUR :
SEEK_END )
);
if (result == -1)
throw detail::bad_seek();
return offset_to_position(result);
#endif // #ifdef BOOST_IOSTREAMS_WINDOWS
}
void file_descriptor::close() { close_impl(*pimpl_); }
void file_descriptor::close_impl(impl& i)
{
#ifdef BOOST_IOSTREAMS_WINDOWS
if (i.handle_ != reinterpret_cast<handle_type>(-1)) {
if (!::CloseHandle(i.handle_))
throw BOOST_IOSTREAMS_FAILURE("bad close");
i.handle_ = reinterpret_cast<handle_type>(-1);
i.flags_ = 0;
return;
}
#else // #ifdef BOOST_IOSTREAMS_WINDOWS
if (i.handle_ != -1) {
if (BOOST_IOSTREAMS_FD_CLOSE(i.handle_) == -1)
throw BOOST_IOSTREAMS_FAILURE("bad close");
i.handle_ = -1;
i.flags_ = 0;
}
#endif // #ifdef BOOST_IOSTREAMS_WINDOWS
}
#ifdef BOOST_IOSTREAMS_WINDOWS
file_descriptor::handle_type file_descriptor::int_to_handle(int fd)
{
return reinterpret_cast<handle_type>(_get_osfhandle(fd));
}
#endif
} } // End namespaces iostreams, boost.