Open "lock" files for the same folder only once

PR #20414.
Closes #12203.
This commit is contained in:
Vladimir Golovnev 2024-02-15 08:42:44 +03:00 committed by GitHub
parent e31b553807
commit f04edd555f
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2 changed files with 50 additions and 18 deletions

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@ -1,6 +1,6 @@
/*
* Bittorrent Client using Qt and libtorrent.
* Copyright (C) 2017 Vladimir Golovnev <glassez@yandex.ru>
* Copyright (C) 2017-2024 Vladimir Golovnev <glassez@yandex.ru>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@ -34,31 +34,56 @@
#include "base/utils/fs.h"
#include "base/utils/io.h"
QHash<Path, std::weak_ptr<QFile>> AsyncFileStorage::m_reservedPaths;
QReadWriteLock AsyncFileStorage::m_reservedPathsLock;
AsyncFileStorage::AsyncFileStorage(const Path &storageFolderPath, QObject *parent)
: QObject(parent)
, m_storageDir(storageFolderPath)
, m_lockFile((m_storageDir / Path(u"storage.lock"_s)).data())
{
Q_ASSERT(m_storageDir.isAbsolute());
if (!Utils::Fs::mkpath(m_storageDir))
throw AsyncFileStorageError(tr("Could not create directory '%1'.").arg(m_storageDir.toString()));
const Path lockFilePath = m_storageDir / Path(u"storage.lock"_s);
// TODO: This folder locking approach does not work for UNIX systems. Implement it.
if (!m_lockFile.open(QFile::WriteOnly))
throw AsyncFileStorageError(m_lockFile.errorString());
{
const QReadLocker readLocker {&m_reservedPathsLock};
m_lockFile = m_reservedPaths.value(lockFilePath).lock();
}
if (!m_lockFile)
{
const QWriteLocker writeLocker {&m_reservedPathsLock};
if (std::weak_ptr<QFile> &lockFile = m_reservedPaths[lockFilePath]; lockFile.expired()) [[likely]]
{
if (!Utils::Fs::mkpath(m_storageDir))
throw AsyncFileStorageError(tr("Could not create directory '%1'.").arg(m_storageDir.toString()));
auto lockFileDeleter = [](QFile *file)
{
file->close();
file->remove();
delete file;
};
m_lockFile = std::shared_ptr<QFile>(new QFile(lockFilePath.data()), std::move(lockFileDeleter));
// TODO: This folder locking approach does not work for UNIX systems. Implement it.
if (!m_lockFile->open(QFile::WriteOnly))
throw AsyncFileStorageError(m_lockFile->errorString());
lockFile = m_lockFile;
}
else
{
m_lockFile = lockFile.lock();
}
}
}
AsyncFileStorage::~AsyncFileStorage()
{
m_lockFile.close();
m_lockFile.remove();
}
AsyncFileStorage::~AsyncFileStorage() = default;
void AsyncFileStorage::store(const Path &filePath, const QByteArray &data)
{
QMetaObject::invokeMethod(this, [this, data, filePath]() { store_impl(filePath, data); }
, Qt::QueuedConnection);
QMetaObject::invokeMethod(this, [this, data, filePath] { store_impl(filePath, data); }, Qt::QueuedConnection);
}
Path AsyncFileStorage::storageDir() const

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@ -1,6 +1,6 @@
/*
* Bittorrent Client using Qt and libtorrent.
* Copyright (C) 2017 Vladimir Golovnev <glassez@yandex.ru>
* Copyright (C) 2017-2024 Vladimir Golovnev <glassez@yandex.ru>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@ -28,19 +28,23 @@
#pragma once
#include <memory>
#include <QFile>
#include <QHash>
#include <QObject>
#include <QReadWriteLock>
#include "base/exceptions.h"
#include "base/path.h"
class AsyncFileStorageError : public RuntimeError
class AsyncFileStorageError final : public RuntimeError
{
public:
using RuntimeError::RuntimeError;
};
class AsyncFileStorage : public QObject
class AsyncFileStorage final : public QObject
{
Q_OBJECT
Q_DISABLE_COPY_MOVE(AsyncFileStorage)
@ -60,5 +64,8 @@ private:
Q_INVOKABLE void store_impl(const Path &fileName, const QByteArray &data);
Path m_storageDir;
QFile m_lockFile;
std::shared_ptr<QFile> m_lockFile;
static QHash<Path, std::weak_ptr<QFile>> m_reservedPaths;
static QReadWriteLock m_reservedPathsLock;
};