1 files changed, 206 insertions, 2 deletions
diff --git a/src/fs.cpp b/src/fs.cpp
index 570ed3e2ee..3c8f4c0247 100644
--- a/src/fs.cpp
+++ b/src/fs.cpp
@@ -1,15 +1,219 @@
 #include <fs.h>
 
+#ifndef WIN32
+#include <fcntl.h>
+#else
+#define NOMINMAX
+#include <codecvt>
+#include <windows.h>
+#endif
+
 namespace fsbridge {
 
 FILE *fopen(const fs::path& p, const char *mode)
 {
+#ifndef WIN32
     return ::fopen(p.string().c_str(), mode);
+#else
+    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>,wchar_t> utf8_cvt;
+    return ::_wfopen(p.wstring().c_str(), utf8_cvt.from_bytes(mode).c_str());
+#endif
+}
+
+#ifndef WIN32
+
+static std::string GetErrorReason() {
+    return std::strerror(errno);
+}
+
+FileLock::FileLock(const fs::path& file)
+{
+    fd = open(file.string().c_str(), O_RDWR);
+    if (fd == -1) {
+        reason = GetErrorReason();
+    }
+}
+
+FileLock::~FileLock()
+{
+    if (fd != -1) {
+        close(fd);
+    }
+}
+
+bool FileLock::TryLock()
+{
+    if (fd == -1) {
+        return false;
+    }
+    struct flock lock;
+    lock.l_type = F_WRLCK;
+    lock.l_whence = SEEK_SET;
+    lock.l_start = 0;
+    lock.l_len = 0;
+    if (fcntl(fd, F_SETLK, &lock) == -1) {
+        reason = GetErrorReason();
+        return false;
+    }
+    return true;
+}
+#else
+
+static std::string GetErrorReason() {
+    wchar_t* err;
+    FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+        nullptr, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), reinterpret_cast<WCHAR*>(&err), 0, nullptr);
+    std::wstring err_str(err);
+    LocalFree(err);
+    return std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>>().to_bytes(err_str);
+}
+
+FileLock::FileLock(const fs::path& file)
+{
+    hFile = CreateFileW(file.wstring().c_str(),  GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+        nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+    if (hFile == INVALID_HANDLE_VALUE) {
+        reason = GetErrorReason();
+    }
+}
+
+FileLock::~FileLock()
+{
+    if (hFile != INVALID_HANDLE_VALUE) {
+        CloseHandle(hFile);
+    }
+}
+
+bool FileLock::TryLock()
+{
+    if (hFile == INVALID_HANDLE_VALUE) {
+        return false;
+    }
+    _OVERLAPPED overlapped = {0};
+    if (!LockFileEx(hFile, LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY, 0, std::numeric_limits<DWORD>::max(), std::numeric_limits<DWORD>::max(), &overlapped)) {
+        reason = GetErrorReason();
+        return false;
+    }
+    return true;
+}
+#endif
+
+std::string get_filesystem_error_message(const fs::filesystem_error& e)
+{
+#ifndef WIN32
+    return e.what();
+#else
+    // Convert from Multi Byte to utf-16
+    std::string mb_string(e.what());
+    int size = MultiByteToWideChar(CP_ACP, 0, mb_string.c_str(), mb_string.size(), nullptr, 0);
+
+    std::wstring utf16_string(size, L'\0');
+    MultiByteToWideChar(CP_ACP, 0, mb_string.c_str(), mb_string.size(), &*utf16_string.begin(), size);
+    // Convert from utf-16 to utf-8
+    return std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>, wchar_t>().to_bytes(utf16_string);
+#endif
+}
+
+#ifdef WIN32
+#ifdef __GLIBCXX__
+
+// reference: https://github.com/gcc-mirror/gcc/blob/gcc-7_3_0-release/libstdc%2B%2B-v3/include/std/fstream#L270
+
+static std::string openmodeToStr(std::ios_base::openmode mode)
+{
+    switch (mode & ~std::ios_base::ate) {
+    case std::ios_base::out:
+    case std::ios_base::out | std::ios_base::trunc:
+        return "w";
+    case std::ios_base::out | std::ios_base::app:
+    case std::ios_base::app:
+        return "a";
+    case std::ios_base::in:
+        return "r";
+    case std::ios_base::in | std::ios_base::out:
+        return "r+";
+    case std::ios_base::in | std::ios_base::out | std::ios_base::trunc:
+        return "w+";
+    case std::ios_base::in | std::ios_base::out | std::ios_base::app:
+    case std::ios_base::in | std::ios_base::app:
+        return "a+";
+    case std::ios_base::out | std::ios_base::binary:
+    case std::ios_base::out | std::ios_base::trunc | std::ios_base::binary:
+        return "wb";
+    case std::ios_base::out | std::ios_base::app | std::ios_base::binary:
+    case std::ios_base::app | std::ios_base::binary:
+        return "ab";
+    case std::ios_base::in | std::ios_base::binary:
+        return "rb";
+    case std::ios_base::in | std::ios_base::out | std::ios_base::binary:
+        return "r+b";
+    case std::ios_base::in | std::ios_base::out | std::ios_base::trunc | std::ios_base::binary:
+        return "w+b";
+    case std::ios_base::in | std::ios_base::out | std::ios_base::app | std::ios_base::binary:
+    case std::ios_base::in | std::ios_base::app | std::ios_base::binary:
+        return "a+b";
+    default:
+        return std::string();
+    }
 }
 
-FILE *freopen(const fs::path& p, const char *mode, FILE *stream)
+void ifstream::open(const fs::path& p, std::ios_base::openmode mode)
 {
-    return ::freopen(p.string().c_str(), mode, stream);
+    close();
+    m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str());
+    if (m_file == nullptr) {
+        return;
+    }
+    m_filebuf = __gnu_cxx::stdio_filebuf<char>(m_file, mode);
+    rdbuf(&m_filebuf);
+    if (mode & std::ios_base::ate) {
+        seekg(0, std::ios_base::end);
+    }
 }
 
+void ifstream::close()
+{
+    if (m_file != nullptr) {
+        m_filebuf.close();
+        fclose(m_file);
+    }
+    m_file = nullptr;
+}
+
+void ofstream::open(const fs::path& p, std::ios_base::openmode mode)
+{
+    close();
+    m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str());
+    if (m_file == nullptr) {
+        return;
+    }
+    m_filebuf = __gnu_cxx::stdio_filebuf<char>(m_file, mode);
+    rdbuf(&m_filebuf);
+    if (mode & std::ios_base::ate) {
+        seekp(0, std::ios_base::end);
+    }
+}
+
+void ofstream::close()
+{
+    if (m_file != nullptr) {
+        m_filebuf.close();
+        fclose(m_file);
+    }
+    m_file = nullptr;
+}
+#else // __GLIBCXX__
+
+static_assert(sizeof(*fs::path().BOOST_FILESYSTEM_C_STR) == sizeof(wchar_t),
+    "Warning: This build is using boost::filesystem ofstream and ifstream "
+    "implementations which will fail to open paths containing multibyte "
+    "characters. You should delete this static_assert to ignore this warning, "
+    "or switch to a different C++ standard library like the Microsoft C++ "
+    "Standard Library (where boost uses non-standard extensions to construct "
+    "stream objects with wide filenames), or the GNU libstdc++ library (where "
+    "a more complicated workaround has been implemented above).");
+
+#endif // __GLIBCXX__
+#endif // WIN32
+
 } // fsbridge