afb81b8278
Some checks failed
Docker. / Ubuntu (push) Has been cancelled
User-agent updater. / User-agent (push) Failing after 15s
Lock Threads / lock (push) Failing after 10s
Waiting for answer. / waiting-for-answer (push) Failing after 22s
Close stale issues and PRs / stale (push) Successful in 13s
Needs user action. / needs-user-action (push) Failing after 8s
Can't reproduce. / cant-reproduce (push) Failing after 8s
90 lines
1.9 KiB
C++
90 lines
1.9 KiB
C++
// This file is part of Desktop App Toolkit,
|
|
// a set of libraries for developing nice desktop applications.
|
|
//
|
|
// For license and copyright information please follow this link:
|
|
// https://github.com/desktop-app/legal/blob/master/LEGAL
|
|
//
|
|
#include "base/file_lock.h"
|
|
|
|
#include "base/platform/win/base_file_utilities_win.h"
|
|
|
|
#include <QtCore/QDir>
|
|
|
|
#include <windows.h>
|
|
#include <io.h>
|
|
#include <fileapi.h>
|
|
|
|
namespace base {
|
|
|
|
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 (Platform::CloseProcesses(file.fileName()));
|
|
|
|
return false;
|
|
}
|
|
|
|
bool FileLock::locked() const {
|
|
return (_lock != nullptr);
|
|
}
|
|
|
|
void FileLock::unlock() {
|
|
_lock = nullptr;
|
|
}
|
|
|
|
FileLock::~FileLock() = default;
|
|
|
|
} // namespace base
|