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// Copyright (c) 2017 The Bitcoin Core developers
// Copyright (c) 2019 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <fs.h>
#ifndef WIN32
#include <cstring>
#include <fcntl.h>
#include <sys/file.h>
#include <sys/utsname.h>
#include <unistd.h>
#else
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <codecvt>
#include <windows.h>
#endif
namespace fsbridge {
FILE *fopen(const fs::path &p, const char *mode) {
#ifndef WIN32
return ::fopen(p.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.c_str(), O_RDWR);
if (fd == -1) {
reason = GetErrorReason();
}
}
FileLock::~FileLock() {
if (fd != -1) {
close(fd);
}
}
static bool IsWSL() {
struct utsname uname_data;
return uname(&uname_data) == 0 &&
std::string(uname_data.version).find("Microsoft") !=
std::string::npos;
}
bool FileLock::TryLock() {
if (fd == -1) {
return false;
}
// Exclusive file locking is broken on WSL using fcntl (issue #18622)
// This workaround can be removed once the bug on WSL is fixed
static const bool is_wsl = IsWSL();
if (is_wsl) {
if (flock(fd, LOCK_EX | LOCK_NB) == -1) {
reason = GetErrorReason();
return false;
}
} else {
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.data(),
mb_string.size(), nullptr, 0);
std::wstring utf16_string(size, L'\0');
MultiByteToWideChar(CP_ACP, 0, mb_string.data(), 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();
}
}
void ifstream::open(const fs::path &p, std::ios_base::openmode mode) {
close();
mode |= std::ios_base::in;
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();
mode |= std::ios_base::out;
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__
#if BOOST_VERSION >= 107700
static_assert(
sizeof(*BOOST_FILESYSTEM_C_STR(boost::filesystem::path())) ==
sizeof(wchar_t),
#else
static_assert(
sizeof(*boost::filesystem::path().BOOST_FILESYSTEM_C_STR) ==
sizeof(wchar_t),
#endif // BOOST_VERSION >= 107700
"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
} // namespace fsbridge

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Expires
Sat, Nov 23, 09:55 (1 d, 10 h)
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4522755
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fs.cpp (7 KB)

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