detail/windows/file_descriptor.hpp

0001 // Copyright (c) 2016 Klemens D. Morgenstern
0002 //
0003 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #ifndef BOOST_PROCESS_DETAIL_WINDOWS_FILE_DESCRIPTOR_HPP_
0007 #define BOOST_PROCESS_DETAIL_WINDOWS_FILE_DESCRIPTOR_HPP_
0008
0009 #include <boost/winapi/basic_types.hpp>
0010 #include <boost/winapi/handles.hpp>
0011 #include <boost/winapi/file_management.hpp>
0012 #include <string>
0013 #include <boost/process/filesystem.hpp>
0014 #include <boost/core/exchange.hpp>
0015
0016 namespace boost { namespace process { namespace detail { namespace windows {
0017
0018 struct file_descriptor
0019 {
0020     enum mode_t
0021     {
0022         read  = 1,
0023         write = 2,
0024         read_write = 3
0025     };
0026     static ::boost::winapi::DWORD_ desired_access(mode_t mode)
0027     {
0028         switch(mode)
0029         {
0030         case read:
0031             return ::boost::winapi::GENERIC_READ_;
0032         case write:
0033             return ::boost::winapi::GENERIC_WRITE_;
0034         case read_write:
0035             return ::boost::winapi::GENERIC_READ_
0036                  | ::boost::winapi::GENERIC_WRITE_;
0037         default:
0038             return 0u;
0039         }
0040     }
0041
0042     file_descriptor() = default;
0043     file_descriptor(const boost::process::filesystem::path& p, mode_t mode = read_write)
0044         : file_descriptor(p.native(), mode)
0045     {
0046     }
0047
0048     file_descriptor(const std::string & path , mode_t mode = read_write)
0049 #if defined(BOOST_NO_ANSI_APIS)
0050         : file_descriptor(::boost::process::detail::convert(path), mode)
0051 #else
0052         : file_descriptor(path.c_str(), mode)
0053 #endif
0054     {}
0055     file_descriptor(const std::wstring & path, mode_t mode = read_write)
0056         : file_descriptor(path.c_str(), mode) {}
0057
0058     file_descriptor(const char*    path, mode_t mode = read_write)
0059 #if defined(BOOST_NO_ANSI_APIS)
0060         : file_descriptor(std::string(path), mode)
0061 #else
0062         : _handle(
0063                 ::boost::winapi::create_file(
0064                         path,
0065                         desired_access(mode),
0066                         ::boost::winapi::FILE_SHARE_READ_ |
0067                         ::boost::winapi::FILE_SHARE_WRITE_,
0068                         nullptr,
0069                         ::boost::winapi::OPEN_ALWAYS_,
0070
0071                         ::boost::winapi::FILE_ATTRIBUTE_NORMAL_,
0072                         nullptr
0073                 ))
0074 #endif
0075     {
0076     }
0077     file_descriptor(const wchar_t * path, mode_t mode = read_write)
0078         : _handle(
0079             ::boost::winapi::create_file(
0080                     path,
0081                     desired_access(mode),
0082                     ::boost::winapi::FILE_SHARE_READ_ |
0083                     ::boost::winapi::FILE_SHARE_WRITE_,
0084                     nullptr,
0085                     ::boost::winapi::OPEN_ALWAYS_,
0086
0087                     ::boost::winapi::FILE_ATTRIBUTE_NORMAL_,
0088                     nullptr
0089             ))
0090 {
0091
0092 }
0093     file_descriptor(const file_descriptor & ) = delete;
0094     file_descriptor(file_descriptor &&other)
0095         : _handle( boost::exchange(other._handle, ::boost::winapi::INVALID_HANDLE_VALUE_) )
0096     {
0097     }
0098
0099     file_descriptor& operator=(const file_descriptor & ) = delete;
0100     file_descriptor& operator=(file_descriptor &&other)
0101     {
0102         if (_handle != ::boost::winapi::INVALID_HANDLE_VALUE_)
0103             ::boost::winapi::CloseHandle(_handle);
0104         _handle = boost::exchange(other._handle, ::boost::winapi::INVALID_HANDLE_VALUE_);
0105         return *this;
0106     }
0107
0108     ~file_descriptor()
0109     {
0110         if (_handle != ::boost::winapi::INVALID_HANDLE_VALUE_)
0111             ::boost::winapi::CloseHandle(_handle);
0112     }
0113
0114     ::boost::winapi::HANDLE_ handle() const { return _handle;}
0115
0116 private:
0117     ::boost::winapi::HANDLE_ _handle = ::boost::winapi::INVALID_HANDLE_VALUE_;
0118 };
0119
0120 }}}}
0121
0122 #endif /* BOOST_PROCESS_DETAIL_WINDOWS_FILE_DESCRIPTOR_HPP_ */