/* * Bittorrent Client using Qt and libtorrent. * Copyright (C) 2016 Vladimir Golovnev * Copyright (C) 2014 sledgehammer999 * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * In addition, as a special exception, the copyright holders give permission to * link this program with the OpenSSL project's "OpenSSL" library (or with * modified versions of it that use the same license as the "OpenSSL" library), * and distribute the linked executables. You must obey the GNU General Public * License in all respects for all of the code used other than "OpenSSL". If you * modify file(s), you may extend this exception to your version of the file(s), * but you are not obligated to do so. If you do not wish to do so, delete this * exception statement from your version. */ #include "settingsstorage.h" #include #include #include #include "global.h" #include "logger.h" #include "path.h" #include "profile.h" #include "utils/fs.h" namespace { // Encapsulates serialization of settings in "atomic" way. // write() does not leave half-written files, // read() has a workaround for a case of power loss during a previous serialization class TransactionalSettings { public: explicit TransactionalSettings(const QString &name) : m_name(name) { } QVariantHash read() const; bool write(const QVariantHash &data) const; private: // we return actual file names used by QSettings because // there is no other way to get that name except // actually create a QSettings object. // if serialization operation was not successful we return empty string Path deserialize(const QString &name, QVariantHash &data) const; Path serialize(const QString &name, const QVariantHash &data) const; const QString m_name; }; } SettingsStorage *SettingsStorage::m_instance = nullptr; SettingsStorage::SettingsStorage() : m_data {TransactionalSettings(u"qBittorrent"_qs).read()} { m_timer.setSingleShot(true); m_timer.setInterval(5 * 1000); connect(&m_timer, &QTimer::timeout, this, &SettingsStorage::save); } SettingsStorage::~SettingsStorage() { save(); } void SettingsStorage::initInstance() { if (!m_instance) m_instance = new SettingsStorage; } void SettingsStorage::freeInstance() { delete m_instance; m_instance = nullptr; } SettingsStorage *SettingsStorage::instance() { return m_instance; } bool SettingsStorage::save() { const QWriteLocker locker(&m_lock); // guard for `m_dirty` too if (!m_dirty) return true; const TransactionalSettings settings(u"qBittorrent"_qs); if (!settings.write(m_data)) { m_timer.start(); return false; } m_dirty = false; return true; } QVariant SettingsStorage::loadValueImpl(const QString &key, const QVariant &defaultValue) const { const QReadLocker locker(&m_lock); return m_data.value(key, defaultValue); } void SettingsStorage::storeValueImpl(const QString &key, const QVariant &value) { const QWriteLocker locker(&m_lock); QVariant ¤tValue = m_data[key]; if (currentValue != value) { m_dirty = true; currentValue = value; m_timer.start(); } } void SettingsStorage::removeValue(const QString &key) { const QWriteLocker locker(&m_lock); #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)) if (m_data.remove(key)) #else if (m_data.remove(key) > 0) #endif { m_dirty = true; m_timer.start(); } } bool SettingsStorage::hasKey(const QString &key) const { const QReadLocker locker {&m_lock}; return m_data.contains(key); } QVariantHash TransactionalSettings::read() const { QVariantHash res; const Path newPath = deserialize(m_name + u"_new", res); if (!newPath.isEmpty()) { // "_new" file is NOT empty // This means that the PC closed either due to power outage // or because the disk was full. In any case the settings weren't transferred // in their final position. So assume that qbittorrent_new.ini/qbittorrent_new.conf // contains the most recent settings. Logger::instance()->addMessage(QObject::tr("Detected unclean program exit. Using fallback file to restore settings: %1") .arg(newPath.toString()) , Log::WARNING); QString finalPathStr = newPath.data(); const int index = finalPathStr.lastIndexOf(u"_new", -1, Qt::CaseInsensitive); finalPathStr.remove(index, 4); const Path finalPath {finalPathStr}; Utils::Fs::removeFile(finalPath); Utils::Fs::renameFile(newPath, finalPath); } else { deserialize(m_name, res); } return res; } bool TransactionalSettings::write(const QVariantHash &data) const { // QSettings deletes the file before writing it out. This can result in problems // if the disk is full or a power outage occurs. Those events might occur // between deleting the file and recreating it. This is a safety measure. // Write everything to qBittorrent_new.ini/qBittorrent_new.conf and if it succeeds // replace qBittorrent.ini/qBittorrent.conf with it. const Path newPath = serialize(m_name + u"_new", data); if (newPath.isEmpty()) { Utils::Fs::removeFile(newPath); return false; } QString finalPathStr = newPath.data(); const int index = finalPathStr.lastIndexOf(u"_new", -1, Qt::CaseInsensitive); finalPathStr.remove(index, 4); const Path finalPath {finalPathStr}; Utils::Fs::removeFile(finalPath); return Utils::Fs::renameFile(newPath, finalPath); } Path TransactionalSettings::deserialize(const QString &name, QVariantHash &data) const { SettingsPtr settings = Profile::instance()->applicationSettings(name); if (settings->allKeys().isEmpty()) return {}; // Copy everything into memory. This means even keys inserted in the file manually // or that we don't touch directly in this code (eg disabled by ifdef). This ensures // that they will be copied over when save our settings to disk. for (const QString &key : asConst(settings->allKeys())) { const QVariant value = settings->value(key); if (value.isValid()) data[key] = value; } return Path(settings->fileName()); } Path TransactionalSettings::serialize(const QString &name, const QVariantHash &data) const { SettingsPtr settings = Profile::instance()->applicationSettings(name); for (auto i = data.begin(); i != data.end(); ++i) settings->setValue(i.key(), i.value()); settings->sync(); // Important to get error status switch (settings->status()) { case QSettings::NoError: return Path(settings->fileName()); case QSettings::AccessError: Logger::instance()->addMessage(QObject::tr("An access error occurred while trying to write the configuration file."), Log::CRITICAL); break; case QSettings::FormatError: Logger::instance()->addMessage(QObject::tr("A format error occurred while trying to write the configuration file."), Log::CRITICAL); break; default: Logger::instance()->addMessage(QObject::tr("An unknown error occurred while trying to write the configuration file."), Log::CRITICAL); break; } return {}; }