143 lines
3.1 KiB
C++
143 lines
3.1 KiB
C++
/*
|
|
This file is part of Telegram Desktop,
|
|
the official desktop application for the Telegram messaging service.
|
|
|
|
For license and copyright information please follow this link:
|
|
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
|
|
*/
|
|
#include "storage/storage_file_lock.h"
|
|
|
|
#include "platform/win/windows_dlls.h"
|
|
#include "base/platform/win/base_windows_h.h"
|
|
|
|
#include <io.h>
|
|
#include <fileapi.h>
|
|
#include <RestartManager.h>
|
|
|
|
namespace Storage {
|
|
namespace {
|
|
|
|
bool CloseProcesses(const QString &filename) {
|
|
using namespace Platform;
|
|
|
|
if (!Dlls::RmStartSession
|
|
|| !Dlls::RmRegisterResources
|
|
|| !Dlls::RmGetList
|
|
|| !Dlls::RmShutdown
|
|
|| !Dlls::RmEndSession) {
|
|
return false;
|
|
}
|
|
auto result = BOOL(FALSE);
|
|
auto session = DWORD();
|
|
auto sessionKey = std::wstring(CCH_RM_SESSION_KEY + 1, wchar_t(0));
|
|
auto error = Dlls::RmStartSession(&session, 0, sessionKey.data());
|
|
if (error != ERROR_SUCCESS) {
|
|
return false;
|
|
}
|
|
const auto guard = gsl::finally([&] { Dlls::RmEndSession(session); });
|
|
|
|
const auto path = QDir::toNativeSeparators(filename).toStdWString();
|
|
auto nullterm = path.c_str();
|
|
error = Dlls::RmRegisterResources(
|
|
session,
|
|
1,
|
|
&nullterm,
|
|
0,
|
|
nullptr,
|
|
0,
|
|
nullptr);
|
|
if (error != ERROR_SUCCESS) {
|
|
return false;
|
|
}
|
|
|
|
auto processInfoNeeded = UINT(0);
|
|
auto processInfoCount = UINT(0);
|
|
auto reason = DWORD();
|
|
|
|
error = Dlls::RmGetList(
|
|
session,
|
|
&processInfoNeeded,
|
|
&processInfoCount,
|
|
nullptr,
|
|
&reason);
|
|
if (error != ERROR_SUCCESS && error != ERROR_MORE_DATA) {
|
|
return false;
|
|
} else if (processInfoNeeded <= 0) {
|
|
return true;
|
|
}
|
|
error = Dlls::RmShutdown(session, RmForceShutdown, NULL);
|
|
if (error != ERROR_SUCCESS) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
class FileLock::Lock {
|
|
public:
|
|
static int Acquire(const QFile &file);
|
|
|
|
explicit Lock(int descriptor);
|
|
~Lock();
|
|
|
|
private:
|
|
static constexpr auto offsetLow = DWORD(kLockOffset);
|
|
static constexpr auto offsetHigh = DWORD(0);
|
|
static constexpr auto limitLow = DWORD(kLockLimit);
|
|
static constexpr auto limitHigh = DWORD(0);
|
|
|
|
int _descriptor = 0;
|
|
|
|
};
|
|
|
|
int FileLock::Lock::Acquire(const QFile &file) {
|
|
const auto descriptor = file.handle();
|
|
if (!descriptor || !file.isOpen()) {
|
|
return false;
|
|
}
|
|
const auto handle = HANDLE(_get_osfhandle(descriptor));
|
|
if (!handle) {
|
|
return false;
|
|
}
|
|
return LockFile(handle, offsetLow, offsetHigh, limitLow, limitHigh)
|
|
? descriptor
|
|
: 0;
|
|
}
|
|
|
|
FileLock::Lock::Lock(int descriptor) : _descriptor(descriptor) {
|
|
}
|
|
|
|
FileLock::Lock::~Lock() {
|
|
if (const auto handle = HANDLE(_get_osfhandle(_descriptor))) {
|
|
UnlockFile(handle, offsetLow, offsetHigh, limitLow, limitHigh);
|
|
}
|
|
}
|
|
|
|
FileLock::FileLock() = default;
|
|
|
|
bool FileLock::lock(QFile &file, QIODevice::OpenMode mode) {
|
|
Expects(_lock == nullptr || file.isOpen());
|
|
|
|
unlock();
|
|
file.close();
|
|
do {
|
|
if (!file.open(mode)) {
|
|
return false;
|
|
} else if (const auto descriptor = Lock::Acquire(file)) {
|
|
_lock = std::make_unique<Lock>(descriptor);
|
|
return true;
|
|
}
|
|
file.close();
|
|
} while (CloseProcesses(file.fileName()));
|
|
|
|
return false;
|
|
}
|
|
|
|
void FileLock::unlock() {
|
|
_lock = nullptr;
|
|
}
|
|
|
|
FileLock::~FileLock() = default;
|
|
|
|
} // namespace Storage
|