dash/src/fs.h
Wladimir J. van der Laan de5d8af15d Merge #14768: revert removal of fstream.hpp header in fs.h
e816b341ab794fb84d89efb90b8c0f369d34d6ca revert removal of fstream.hpp header in fs.h (Karl-Johan Alm)

Pull request description:

  We cannot (yet) remove the EXPECTED_BOOST_INCLUDES entry as this header is still needed in `fs.h` (see #14763).

  Partially reverts #14718.

Tree-SHA512: e94d8d6208bee14af20a7a529e60a4898358ec8c070a8bf0701e589a2ae33df1305deac83cee619f103c24be0eb3c12a2f490209c125b247acf21561c7de456e
2021-08-10 20:24:28 -04:00

96 lines
3.2 KiB
C++

// Copyright (c) 2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_FS_H
#define BITCOIN_FS_H
#include <stdio.h>
#include <string>
#if defined WIN32 && defined __GLIBCXX__
#include <ext/stdio_filebuf.h>
#endif
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
/** Filesystem operations and types */
namespace fs = boost::filesystem;
/** Bridge operations to C stdio */
namespace fsbridge {
FILE *fopen(const fs::path& p, const char *mode);
class FileLock
{
public:
FileLock() = delete;
FileLock(const FileLock&) = delete;
FileLock(FileLock&&) = delete;
explicit FileLock(const fs::path& file);
~FileLock();
bool TryLock();
std::string GetReason() { return reason; }
private:
std::string reason;
#ifndef WIN32
int fd = -1;
#else
void* hFile = (void*)-1; // INVALID_HANDLE_VALUE
#endif
};
std::string get_filesystem_error_message(const fs::filesystem_error& e);
// GNU libstdc++ specific workaround for opening UTF-8 paths on Windows.
//
// On Windows, it is only possible to reliably access multibyte file paths through
// `wchar_t` APIs, not `char` APIs. But because the C++ standard doesn't
// require ifstream/ofstream `wchar_t` constructors, and the GNU library doesn't
// provide them (in contrast to the Microsoft C++ library, see
// https://stackoverflow.com/questions/821873/how-to-open-an-stdfstream-ofstream-or-ifstream-with-a-unicode-filename/822032#822032),
// Boost is forced to fall back to `char` constructors which may not work properly.
//
// Work around this issue by creating stream objects with `_wfopen` in
// combination with `__gnu_cxx::stdio_filebuf`. This workaround can be removed
// with an upgrade to C++17, where streams can be constructed directly from
// `std::filesystem::path` objects.
#if defined WIN32 && defined __GLIBCXX__
class ifstream : public std::istream
{
public:
ifstream() = default;
explicit ifstream(const fs::path& p, std::ios_base::openmode mode = std::ios_base::in) { open(p, mode); }
~ifstream() { close(); }
void open(const fs::path& p, std::ios_base::openmode mode = std::ios_base::in);
bool is_open() { return m_filebuf.is_open(); }
void close();
private:
__gnu_cxx::stdio_filebuf<char> m_filebuf;
FILE* m_file = nullptr;
};
class ofstream : public std::ostream
{
public:
ofstream() = default;
explicit ofstream(const fs::path& p, std::ios_base::openmode mode = std::ios_base::out) { open(p, mode); }
~ofstream() { close(); }
void open(const fs::path& p, std::ios_base::openmode mode = std::ios_base::out);
bool is_open() { return m_filebuf.is_open(); }
void close();
private:
__gnu_cxx::stdio_filebuf<char> m_filebuf;
FILE* m_file = nullptr;
};
#else // !(WIN32 && __GLIBCXX__)
typedef fs::ifstream ifstream;
typedef fs::ofstream ofstream;
#endif // WIN32 && __GLIBCXX__
};
#endif // BITCOIN_FS_H