dash/src/fs.cpp
Wladimir J. van der Laan 2be36d4db5 Merge #13159: Don't close old debug log file handle prematurely when trying to re-open (on SIGHUP)
75ea00f391b742e435c650aae3e827aad913d552 Remove unused fsbridge::freopen (practicalswift)
cceedbc4bf1056db17e0adf76d0db45b94777671 Don't close old debug log file handle prematurely when trying to re-open (on SIGHUP) (practicalswift)

Pull request description:

  Don't close old debug log file handle prematurely when trying to re-open (on `SIGHUP`).

  Context: https://github.com/bitcoin/bitcoin/pull/13148#issuecomment-386288606

  Thanks @ajtowns!

Tree-SHA512: c436b4286f00fc428b60269b6d6321f435c72c7ccec3c15b2194aac71196529b30f32c2384b418ffe3ed67ba7ee8ec51f4c9c5748e65945697c0437eafcdacd1

# Conflicts:
#	src/logging.cpp
2021-07-02 11:39:23 -04:00

219 lines
6.0 KiB
C++

#include <fs.h>
#ifndef WIN32
#include <fcntl.h>
#else
#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, 0, 0, &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();
}
}
void ifstream::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) {
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