Restore BitTorrent session asynchronously

Reduce the total startup time of the application and maintain sufficient responsiveness of the UI during startup due to the following:
1. Load resume data from disk asynchronously in separate thread;
2. Split handling of loaded resume data in chunks;
3. Reduce the number of emitting signals.

PR #16840.

src/app/application.cpp

@@ -309,10 +309,18 @@ void Application::setFileLoggerAgeType(const int value)
 
 void Application::processMessage(const QString &message)
 {
-    const QStringList params = message.split(PARAMS_SEPARATOR, Qt::SkipEmptyParts);
-    // If Application is not running (i.e., other
-    // components are not ready) store params
-    if (m_running)
+#ifndef DISABLE_GUI
+    if (message.isEmpty())
+    {
+        m_window->activate(); // show UI
+        return;
+    }
+#endif
+
+    const AddTorrentParams params = parseParams(message.split(PARAMS_SEPARATOR, Qt::SkipEmptyParts));
+    // If Application is not allowed to process params immediately
+    // (i.e., other components are not ready) store params
+    if (m_isProcessingParamsAllowed)
         processParams(params);
     else
         m_paramsQueue.append(params);
@@ -516,21 +524,10 @@ bool Application::sendParams(const QStringList &params)
     return m_instanceManager->sendMessage(params.join(PARAMS_SEPARATOR));
 }
 
-// As program parameters, we can get paths or urls.
-// This function parse the parameters and call
-// the right addTorrent function, considering
-// the parameter type.
-void Application::processParams(const QStringList &params)
+Application::AddTorrentParams Application::parseParams(const QStringList &params) const
 {
-#ifndef DISABLE_GUI
-    if (params.isEmpty())
-    {
-        m_window->activate(); // show UI
-        return;
-    }
-#endif
-    BitTorrent::AddTorrentParams torrentParams;
-    std::optional<bool> skipTorrentDialog;
+    AddTorrentParams parsedParams;
+    BitTorrent::AddTorrentParams &torrentParams = parsedParams.torrentParams;
 
     for (QString param : params)
     {
@@ -576,23 +573,31 @@ void Application::processParams(const QStringList &params)
 
         if (param.startsWith(u"@skipDialog="))
         {
-            skipTorrentDialog = (QStringView(param).mid(12).toInt() != 0);
+            parsedParams.skipTorrentDialog = (QStringView(param).mid(12).toInt() != 0);
             continue;
         }
 
+        parsedParams.torrentSource = param;
+        break;
+    }
+
+    return parsedParams;
+}
+
+void Application::processParams(const AddTorrentParams &params)
+{
 #ifndef DISABLE_GUI
     // There are two circumstances in which we want to show the torrent
     // dialog. One is when the application settings specify that it should
     // be shown and skipTorrentDialog is undefined. The other is when
     // skipTorrentDialog is false, meaning that the application setting
     // should be overridden.
-        const bool showDialogForThisTorrent = !skipTorrentDialog.value_or(!AddNewTorrentDialog::isEnabled());
+    const bool showDialogForThisTorrent = !params.skipTorrentDialog.value_or(!AddNewTorrentDialog::isEnabled());
     if (showDialogForThisTorrent)
-            AddNewTorrentDialog::show(param, torrentParams, m_window);
+        AddNewTorrentDialog::show(params.torrentSource, params.torrentParams, m_window);
     else
 #endif
-            BitTorrent::Session::instance()->addTorrent(param, torrentParams);
-    }
+        BitTorrent::Session::instance()->addTorrent(params.torrentSource, params.torrentParams);
 }
 
 int Application::exec(const QStringList &params)
@@ -612,21 +617,28 @@ int Application::exec(const QStringList &params)
     try
     {
         BitTorrent::Session::initInstance();
-        connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentFinished, this, &Application::torrentFinished);
-        connect(BitTorrent::Session::instance(), &BitTorrent::Session::allTorrentsFinished, this, &Application::allTorrentsFinished, Qt::QueuedConnection);
-
-        Net::GeoIPManager::initInstance();
-        TorrentFilesWatcher::initInstance();
-
+        connect(BitTorrent::Session::instance(), &BitTorrent::Session::restored, this, [this]()
+        {
 #ifndef DISABLE_WEBUI
             m_webui = new WebUI(this);
 #ifdef DISABLE_GUI
             if (m_webui->isErrored())
-            return 1;
+                QCoreApplication::exit(1);
             connect(m_webui, &WebUI::fatalError, this, []() { QCoreApplication::exit(1); });
 #endif // DISABLE_GUI
 #endif // DISABLE_WEBUI
 
+            m_isProcessingParamsAllowed = true;
+            for (const AddTorrentParams &params : m_paramsQueue)
+                processParams(params);
+            m_paramsQueue.clear();
+        });
+        connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentFinished, this, &Application::torrentFinished);
+        connect(BitTorrent::Session::instance(), &BitTorrent::Session::allTorrentsFinished, this, &Application::allTorrentsFinished, Qt::QueuedConnection);
+
+        Net::GeoIPManager::initInstance();
+        TorrentFilesWatcher::initInstance();
+
         new RSS::Session; // create RSS::Session singleton
         new RSS::AutoDownloader; // create RSS::AutoDownloader singleton
     }
@@ -669,17 +681,9 @@ int Application::exec(const QStringList &params)
     m_window = new MainWindow(this);
 #endif // DISABLE_GUI
 
-    m_running = true;
+    if (!params.isEmpty())
+        m_paramsQueue.append(parseParams(params));
 
-    // Now UI is ready to process signals from Session
-    BitTorrent::Session::instance()->startUpTorrents();
-
-    m_paramsQueue = params + m_paramsQueue;
-    if (!m_paramsQueue.isEmpty())
-    {
-        processParams(m_paramsQueue);
-        m_paramsQueue.clear();
-    }
     return BaseApplication::exec();
 }
 
@@ -699,16 +703,19 @@ bool Application::event(QEvent *ev)
             // Get the url instead
             path = static_cast<QFileOpenEvent *>(ev)->url().toString();
         qDebug("Received a mac file open event: %s", qUtf8Printable(path));
-        if (m_running)
-            processParams(QStringList(path));
+
+        const AddTorrentParams params = parseParams({path});
+        // If Application is not allowed to process params immediately
+        // (i.e., other components are not ready) store params
+        if (m_isProcessingParamsAllowed)
+            processParams(params);
         else
-            m_paramsQueue.append(path);
+            m_paramsQueue.append(params);
+
         return true;
     }
-    else
-    {
+
     return BaseApplication::event(ev);
-    }
 }
 #endif // Q_OS_MACOS
 #endif // DISABLE_GUI

src/app/application.h

@@ -41,6 +41,7 @@
 #include <QApplication>
 #endif
 
+#include "base/bittorrent/addtorrentparams.h"
 #include "base/interfaces/iapplication.h"
 #include "base/path.h"
 #include "base/settingvalue.h"
@@ -132,8 +133,16 @@ private slots:
 #endif
 
 private:
+    struct AddTorrentParams
+    {
+        QString torrentSource;
+        BitTorrent::AddTorrentParams torrentParams;
+        std::optional<bool> skipTorrentDialog;
+    };
+
     void initializeTranslation();
-    void processParams(const QStringList &params);
+    AddTorrentParams parseParams(const QStringList &params) const;
+    void processParams(const AddTorrentParams &params);
     void runExternalProgram(const BitTorrent::Torrent *torrent) const;
     void sendNotificationEmail(const BitTorrent::Torrent *torrent);
 
@@ -152,8 +161,8 @@ private:
 #endif
 
     ApplicationInstanceManager *m_instanceManager = nullptr;
-    bool m_running = false;
     QAtomicInt m_isCleanupRun;
+    bool m_isProcessingParamsAllowed = false;
     ShutdownDialogAction m_shutdownAct;
     QBtCommandLineParameters m_commandLineArgs;
 
@@ -162,7 +171,8 @@ private:
 
     QTranslator m_qtTranslator;
     QTranslator m_translator;
-    QStringList m_paramsQueue;
+
+    QList<AddTorrentParams> m_paramsQueue;
 
     SettingValue<bool> m_storeFileLoggerEnabled;
     SettingValue<bool> m_storeFileLoggerBackup;

src/base/CMakeLists.txt

@@ -124,6 +124,7 @@ add_library(qbt_base STATIC
     bittorrent/peeraddress.cpp
     bittorrent/peerinfo.cpp
     bittorrent/portforwarderimpl.cpp
+    bittorrent/resumedatastorage.cpp
     bittorrent/session.cpp
     bittorrent/speedmonitor.cpp
     bittorrent/statistics.cpp

src/base/base.pri

@@ -124,6 +124,7 @@ SOURCES += \
     $$PWD/bittorrent/peeraddress.cpp \
     $$PWD/bittorrent/peerinfo.cpp \
     $$PWD/bittorrent/portforwarderimpl.cpp \
+    $$PWD/bittorrent/resumedatastorage.cpp \
     $$PWD/bittorrent/session.cpp \
     $$PWD/bittorrent/speedmonitor.cpp \
     $$PWD/bittorrent/statistics.cpp \

src/base/bittorrent/bencoderesumedatastorage.cpp

@@ -90,21 +90,20 @@ namespace
 }
 
 BitTorrent::BencodeResumeDataStorage::BencodeResumeDataStorage(const Path &path, QObject *parent)
-    : ResumeDataStorage {parent}
-    , m_resumeDataPath {path}
-    , m_ioThread {new QThread {this}}
-    , m_asyncWorker {new Worker(m_resumeDataPath)}
+    : ResumeDataStorage(path, parent)
+    , m_ioThread {new QThread(this)}
+    , m_asyncWorker {new Worker(path)}
 {
     Q_ASSERT(path.isAbsolute());
 
-    if (!m_resumeDataPath.exists() && !Utils::Fs::mkpath(m_resumeDataPath))
+    if (!path.exists() && !Utils::Fs::mkpath(path))
     {
         throw RuntimeError(tr("Cannot create torrent resume folder: \"%1\"")
-                    .arg(m_resumeDataPath.toString()));
+                    .arg(path.toString()));
     }
 
     const QRegularExpression filenamePattern {u"^([A-Fa-f0-9]{40})\\.fastresume$"_qs};
-    const QStringList filenames = QDir(m_resumeDataPath.data()).entryList(QStringList(u"*.fastresume"_qs), QDir::Files, QDir::Unsorted);
+    const QStringList filenames = QDir(path.data()).entryList(QStringList(u"*.fastresume"_qs), QDir::Files, QDir::Unsorted);
 
     m_registeredTorrents.reserve(filenames.size());
     for (const QString &filename : filenames)
@@ -114,7 +113,7 @@ BitTorrent::BencodeResumeDataStorage::BencodeResumeDataStorage(const Path &path,
              m_registeredTorrents.append(TorrentID::fromString(rxMatch.captured(1)));
     }
 
-    loadQueue(m_resumeDataPath / Path(u"queue"_qs));
+    loadQueue(path / Path(u"queue"_qs));
 
     qDebug() << "Registered torrents count: " << m_registeredTorrents.size();
 
@@ -134,25 +133,19 @@ QVector<BitTorrent::TorrentID> BitTorrent::BencodeResumeDataStorage::registeredT
     return m_registeredTorrents;
 }
 
-std::optional<BitTorrent::LoadTorrentParams> BitTorrent::BencodeResumeDataStorage::load(const TorrentID &id) const
+BitTorrent::LoadResumeDataResult BitTorrent::BencodeResumeDataStorage::load(const TorrentID &id) const
 {
     const QString idString = id.toString();
-    const Path fastresumePath = m_resumeDataPath / Path(idString + u".fastresume");
-    const Path torrentFilePath = m_resumeDataPath / Path(idString + u".torrent");
+    const Path fastresumePath = path() / Path(idString + u".fastresume");
+    const Path torrentFilePath = path() / Path(idString + u".torrent");
 
     QFile resumeDataFile {fastresumePath.data()};
     if (!resumeDataFile.open(QIODevice::ReadOnly))
-    {
-        LogMsg(tr("Cannot read file %1: %2").arg(fastresumePath.toString(), resumeDataFile.errorString()), Log::WARNING);
-        return std::nullopt;
-    }
+        return nonstd::make_unexpected(tr("Cannot read file %1: %2").arg(fastresumePath.toString(), resumeDataFile.errorString()));
 
     QFile metadataFile {torrentFilePath.data()};
     if (metadataFile.exists() && !metadataFile.open(QIODevice::ReadOnly))
-    {
-        LogMsg(tr("Cannot read file %1: %2").arg(torrentFilePath.toString(), metadataFile.errorString()), Log::WARNING);
-        return std::nullopt;
-    }
+        return nonstd::make_unexpected(tr("Cannot read file %1: %2").arg(torrentFilePath.toString(), metadataFile.errorString()));
 
     const QByteArray data = resumeDataFile.readAll();
     const QByteArray metadata = (metadataFile.isOpen() ? metadataFile.readAll() : "");
@@ -160,16 +153,64 @@ std::optional<BitTorrent::LoadTorrentParams> BitTorrent::BencodeResumeDataStorag
     return loadTorrentResumeData(data, metadata);
 }
 
-std::optional<BitTorrent::LoadTorrentParams> BitTorrent::BencodeResumeDataStorage::loadTorrentResumeData(
-        const QByteArray &data, const QByteArray &metadata) const
+void BitTorrent::BencodeResumeDataStorage::doLoadAll() const
+{
+    qDebug() << "Loading torrents count: " << m_registeredTorrents.size();
+
+    emit const_cast<BencodeResumeDataStorage *>(this)->loadStarted(m_registeredTorrents);
+
+    for (const TorrentID &torrentID : asConst(m_registeredTorrents))
+        onResumeDataLoaded(torrentID, load(torrentID));
+
+    emit const_cast<BencodeResumeDataStorage *>(this)->loadFinished();
+}
+
+void BitTorrent::BencodeResumeDataStorage::loadQueue(const Path &queueFilename)
+{
+    QFile queueFile {queueFilename.data()};
+    if (!queueFile.exists())
+        return;
+
+    if (!queueFile.open(QFile::ReadOnly))
+    {
+        LogMsg(tr("Couldn't load torrents queue: %1").arg(queueFile.errorString()), Log::WARNING);
+        return;
+    }
+
+    const QRegularExpression hashPattern {u"^([A-Fa-f0-9]{40})$"_qs};
+    int start = 0;
+    while (true)
+    {
+        const auto line = QString::fromLatin1(queueFile.readLine().trimmed());
+        if (line.isEmpty())
+            break;
+
+        const QRegularExpressionMatch rxMatch = hashPattern.match(line);
+        if (rxMatch.hasMatch())
+        {
+            const auto torrentID = BitTorrent::TorrentID::fromString(rxMatch.captured(1));
+            const int pos = m_registeredTorrents.indexOf(torrentID, start);
+            if (pos != -1)
+            {
+                std::swap(m_registeredTorrents[start], m_registeredTorrents[pos]);
+                ++start;
+            }
+        }
+    }
+}
+
+BitTorrent::LoadResumeDataResult BitTorrent::BencodeResumeDataStorage::loadTorrentResumeData(const QByteArray &data, const QByteArray &metadata) const
 {
     const QByteArray allData = ((metadata.isEmpty() || data.isEmpty())
                                 ? data : (data.chopped(1) + metadata.mid(1)));
 
     lt::error_code ec;
     const lt::bdecode_node root = lt::bdecode(allData, ec);
-    if (ec || (root.type() != lt::bdecode_node::dict_t))
-        return std::nullopt;
+    if (ec)
+        return nonstd::make_unexpected(tr("Cannot parse resume data: %1").arg(QString::fromStdString(ec.message())));
+
+    if (root.type() != lt::bdecode_node::dict_t)
+        return nonstd::make_unexpected(tr("Cannot parse resume data: invalid foormat"));
 
     LoadTorrentParams torrentParams;
     torrentParams.restored = true;
@@ -247,7 +288,7 @@ std::optional<BitTorrent::LoadTorrentParams> BitTorrent::BencodeResumeDataStorag
 
     const bool hasMetadata = (p.ti && p.ti->is_valid());
     if (!hasMetadata && !root.dict_find("info-hash"))
-        return std::nullopt;
+        return nonstd::make_unexpected(tr("Resume data is invalid: neither metadata nor info-hash was found"));
 
     return torrentParams;
 }
@@ -276,39 +317,6 @@ void BitTorrent::BencodeResumeDataStorage::storeQueue(const QVector<TorrentID> &
     });
 }
 
-void BitTorrent::BencodeResumeDataStorage::loadQueue(const Path &queueFilename)
-{
-    QFile queueFile {queueFilename.data()};
-    if (!queueFile.exists())
-        return;
-
-    if (queueFile.open(QFile::ReadOnly))
-    {
-        const QRegularExpression hashPattern {u"^([A-Fa-f0-9]{40})$"_qs};
-        QString line;
-        int start = 0;
-        while (!(line = QString::fromLatin1(queueFile.readLine().trimmed())).isEmpty())
-        {
-            const QRegularExpressionMatch rxMatch = hashPattern.match(line);
-            if (rxMatch.hasMatch())
-            {
-                const auto torrentID = TorrentID::fromString(rxMatch.captured(1));
-                const int pos = m_registeredTorrents.indexOf(torrentID, start);
-                if (pos != -1)
-                {
-                    std::swap(m_registeredTorrents[start], m_registeredTorrents[pos]);
-                    ++start;
-                }
-            }
-        }
-    }
-    else
-    {
-        LogMsg(tr("Couldn't load torrents queue from '%1'. Error: %2")
-               .arg(queueFile.fileName(), queueFile.errorString()), Log::WARNING);
-    }
-}
-
 BitTorrent::BencodeResumeDataStorage::Worker::Worker(const Path &resumeDataDir)
     : m_resumeDataDir {resumeDataDir}
 {

src/base/bittorrent/bencoderesumedatastorage.h

@@ -31,7 +31,7 @@
 #include <QDir>
 #include <QVector>
 
-#include "base/path.h"
+#include "base/pathfwd.h"
 #include "resumedatastorage.h"
 
 class QByteArray;
@@ -49,16 +49,16 @@ namespace BitTorrent
         ~BencodeResumeDataStorage() override;
 
         QVector<TorrentID> registeredTorrents() const override;
-        std::optional<LoadTorrentParams> load(const TorrentID &id) const override;
+        LoadResumeDataResult load(const TorrentID &id) const override;
         void store(const TorrentID &id, const LoadTorrentParams &resumeData) const override;
         void remove(const TorrentID &id) const override;
         void storeQueue(const QVector<TorrentID> &queue) const override;
 
     private:
+        void doLoadAll() const override;
         void loadQueue(const Path &queueFilename);
-        std::optional<LoadTorrentParams> loadTorrentResumeData(const QByteArray &data, const QByteArray &metadata) const;
+        LoadResumeDataResult loadTorrentResumeData(const QByteArray &data, const QByteArray &metadata) const;
 
-        const Path m_resumeDataPath;
         QVector<TorrentID> m_registeredTorrents;
         QThread *m_ioThread = nullptr;
 

src/base/bittorrent/dbresumedatastorage.cpp

@@ -175,7 +175,7 @@ namespace BitTorrent
         Q_DISABLE_COPY_MOVE(Worker)
 
     public:
-        Worker(const Path &dbPath, const QString &dbConnectionName);
+        Worker(const Path &dbPath, const QString &dbConnectionName, QReadWriteLock &dbLock);
 
         void openDatabase() const;
         void closeDatabase() const;
@@ -187,11 +187,64 @@ namespace BitTorrent
     private:
         const Path m_path;
         const QString m_connectionName;
+        QReadWriteLock &m_dbLock;
     };
+
+    namespace
+    {
+        LoadTorrentParams parseQueryResultRow(const QSqlQuery &query)
+        {
+            LoadTorrentParams resumeData;
+            resumeData.restored = true;
+            resumeData.name = query.value(DB_COLUMN_NAME.name).toString();
+            resumeData.category = query.value(DB_COLUMN_CATEGORY.name).toString();
+            const QString tagsData = query.value(DB_COLUMN_TAGS.name).toString();
+            if (!tagsData.isEmpty())
+            {
+                const QStringList tagList = tagsData.split(u',');
+                resumeData.tags.insert(tagList.cbegin(), tagList.cend());
+            }
+            resumeData.hasSeedStatus = query.value(DB_COLUMN_HAS_SEED_STATUS.name).toBool();
+            resumeData.firstLastPiecePriority = query.value(DB_COLUMN_HAS_OUTER_PIECES_PRIORITY.name).toBool();
+            resumeData.ratioLimit = query.value(DB_COLUMN_RATIO_LIMIT.name).toInt() / 1000.0;
+            resumeData.seedingTimeLimit = query.value(DB_COLUMN_SEEDING_TIME_LIMIT.name).toInt();
+            resumeData.contentLayout = Utils::String::toEnum<TorrentContentLayout>(
+                        query.value(DB_COLUMN_CONTENT_LAYOUT.name).toString(), TorrentContentLayout::Original);
+            resumeData.operatingMode = Utils::String::toEnum<TorrentOperatingMode>(
+                        query.value(DB_COLUMN_OPERATING_MODE.name).toString(), TorrentOperatingMode::AutoManaged);
+            resumeData.stopped = query.value(DB_COLUMN_STOPPED.name).toBool();
+
+            resumeData.savePath = Profile::instance()->fromPortablePath(
+                        Path(query.value(DB_COLUMN_TARGET_SAVE_PATH.name).toString()));
+            resumeData.useAutoTMM = resumeData.savePath.isEmpty();
+            if (!resumeData.useAutoTMM)
+            {
+                resumeData.downloadPath = Profile::instance()->fromPortablePath(
+                            Path(query.value(DB_COLUMN_DOWNLOAD_PATH.name).toString()));
+            }
+
+            const QByteArray bencodedResumeData = query.value(DB_COLUMN_RESUMEDATA.name).toByteArray();
+            const QByteArray bencodedMetadata = query.value(DB_COLUMN_METADATA.name).toByteArray();
+            const QByteArray allData = ((bencodedMetadata.isEmpty() || bencodedResumeData.isEmpty())
+                                        ? bencodedResumeData
+                                        : (bencodedResumeData.chopped(1) + bencodedMetadata.mid(1)));
+
+            lt::error_code ec;
+            const lt::bdecode_node root = lt::bdecode(allData, ec);
+
+            lt::add_torrent_params &p = resumeData.ltAddTorrentParams;
+
+            p = lt::read_resume_data(root, ec);
+            p.save_path = Profile::instance()->fromPortablePath(Path(fromLTString(p.save_path)))
+                    .toString().toStdString();
+
+            return resumeData;
+        }
+    }
 }
 
 BitTorrent::DBResumeDataStorage::DBResumeDataStorage(const Path &dbPath, QObject *parent)
-    : ResumeDataStorage {parent}
+    : ResumeDataStorage(dbPath, parent)
     , m_ioThread {new QThread(this)}
 {
     const bool needCreateDB = !dbPath.exists();
@@ -212,7 +265,7 @@ BitTorrent::DBResumeDataStorage::DBResumeDataStorage(const Path &dbPath, QObject
             updateDBFromVersion1();
     }
 
-    m_asyncWorker = new Worker(dbPath, u"ResumeDataStorageWorker"_qs);
+    m_asyncWorker = new Worker(dbPath, u"ResumeDataStorageWorker"_qs, m_dbLock);
     m_asyncWorker->moveToThread(m_ioThread);
     connect(m_ioThread, &QThread::finished, m_asyncWorker, &QObject::deleteLater);
     m_ioThread->start();
@@ -262,7 +315,7 @@ QVector<BitTorrent::TorrentID> BitTorrent::DBResumeDataStorage::registeredTorren
     return registeredTorrents;
 }
 
-std::optional<BitTorrent::LoadTorrentParams> BitTorrent::DBResumeDataStorage::load(const TorrentID &id) const
+BitTorrent::LoadResumeDataResult BitTorrent::DBResumeDataStorage::load(const TorrentID &id) const
 {
     const QString selectTorrentStatement = u"SELECT * FROM %1 WHERE %2 = %3;"_qs
         .arg(quoted(DB_TABLE_TORRENTS), quoted(DB_COLUMN_TORRENT_ID.name), DB_COLUMN_TORRENT_ID.placeholder);
@@ -283,56 +336,11 @@ std::optional<BitTorrent::LoadTorrentParams> BitTorrent::DBResumeDataStorage::lo
     }
     catch (const RuntimeError &err)
     {
-        LogMsg(tr("Couldn't load resume data of torrent '%1'. Error: %2")
-            .arg(id.toString(), err.message()), Log::CRITICAL);
-        return std::nullopt;
+        return nonstd::make_unexpected(tr("Couldn't load resume data of torrent '%1'. Error: %2")
+            .arg(id.toString(), err.message()));
     }
 
-    LoadTorrentParams resumeData;
-    resumeData.restored = true;
-    resumeData.name = query.value(DB_COLUMN_NAME.name).toString();
-    resumeData.category = query.value(DB_COLUMN_CATEGORY.name).toString();
-    const QString tagsData = query.value(DB_COLUMN_TAGS.name).toString();
-    if (!tagsData.isEmpty())
-    {
-        const QStringList tagList = tagsData.split(u',');
-        resumeData.tags.insert(tagList.cbegin(), tagList.cend());
-    }
-    resumeData.hasSeedStatus = query.value(DB_COLUMN_HAS_SEED_STATUS.name).toBool();
-    resumeData.firstLastPiecePriority = query.value(DB_COLUMN_HAS_OUTER_PIECES_PRIORITY.name).toBool();
-    resumeData.ratioLimit = query.value(DB_COLUMN_RATIO_LIMIT.name).toInt() / 1000.0;
-    resumeData.seedingTimeLimit = query.value(DB_COLUMN_SEEDING_TIME_LIMIT.name).toInt();
-    resumeData.contentLayout = Utils::String::toEnum<TorrentContentLayout>(
-                query.value(DB_COLUMN_CONTENT_LAYOUT.name).toString(), TorrentContentLayout::Original);
-    resumeData.operatingMode = Utils::String::toEnum<TorrentOperatingMode>(
-                query.value(DB_COLUMN_OPERATING_MODE.name).toString(), TorrentOperatingMode::AutoManaged);
-    resumeData.stopped = query.value(DB_COLUMN_STOPPED.name).toBool();
-
-    resumeData.savePath = Profile::instance()->fromPortablePath(
-                Path(query.value(DB_COLUMN_TARGET_SAVE_PATH.name).toString()));
-    resumeData.useAutoTMM = resumeData.savePath.isEmpty();
-    if (!resumeData.useAutoTMM)
-    {
-        resumeData.downloadPath = Profile::instance()->fromPortablePath(
-                    Path(query.value(DB_COLUMN_DOWNLOAD_PATH.name).toString()));
-    }
-
-    const QByteArray bencodedResumeData = query.value(DB_COLUMN_RESUMEDATA.name).toByteArray();
-    const QByteArray bencodedMetadata = query.value(DB_COLUMN_METADATA.name).toByteArray();
-    const QByteArray allData = ((bencodedMetadata.isEmpty() || bencodedResumeData.isEmpty())
-                                ? bencodedResumeData
-                                : (bencodedResumeData.chopped(1) + bencodedMetadata.mid(1)));
-
-    lt::error_code ec;
-    const lt::bdecode_node root = lt::bdecode(allData, ec);
-
-    lt::add_torrent_params &p = resumeData.ltAddTorrentParams;
-
-    p = lt::read_resume_data(root, ec);
-    p.save_path = Profile::instance()->fromPortablePath(Path(fromLTString(p.save_path)))
-            .toString().toStdString();
-
-    return resumeData;
+    return parseQueryResultRow(query);
 }
 
 void BitTorrent::DBResumeDataStorage::store(const TorrentID &id, const LoadTorrentParams &resumeData) const
@@ -359,6 +367,49 @@ void BitTorrent::DBResumeDataStorage::storeQueue(const QVector<TorrentID> &queue
     });
 }
 
+void BitTorrent::DBResumeDataStorage::doLoadAll() const
+{
+    const QString connectionName = u"ResumeDataStorageLoadAll"_qs;
+
+    {
+        auto db = QSqlDatabase::addDatabase(u"QSQLITE"_qs, connectionName);
+        db.setDatabaseName(path().data());
+        if (!db.open())
+            throw RuntimeError(db.lastError().text());
+
+        QSqlQuery query {db};
+
+        const auto selectTorrentIDStatement = u"SELECT %1 FROM %2 ORDER BY %3;"_qs
+                .arg(quoted(DB_COLUMN_TORRENT_ID.name), quoted(DB_TABLE_TORRENTS), quoted(DB_COLUMN_QUEUE_POSITION.name));
+
+        const QReadLocker locker {&m_dbLock};
+
+        if (!query.exec(selectTorrentIDStatement))
+            throw RuntimeError(query.lastError().text());
+
+        QVector<TorrentID> registeredTorrents;
+        registeredTorrents.reserve(query.size());
+        while (query.next())
+            registeredTorrents.append(TorrentID::fromString(query.value(0).toString()));
+
+        emit const_cast<DBResumeDataStorage *>(this)->loadStarted(registeredTorrents);
+
+        const auto selectStatement = u"SELECT * FROM %1 ORDER BY %2;"_qs.arg(quoted(DB_TABLE_TORRENTS), quoted(DB_COLUMN_QUEUE_POSITION.name));
+        if (!query.exec(selectStatement))
+            throw RuntimeError(query.lastError().text());
+
+        while (query.next())
+        {
+            const auto torrentID = TorrentID::fromString(query.value(DB_COLUMN_TORRENT_ID.name).toString());
+            onResumeDataLoaded(torrentID, parseQueryResultRow(query));
+        }
+    }
+
+    emit const_cast<DBResumeDataStorage *>(this)->loadFinished();
+
+    QSqlDatabase::removeDatabase(connectionName);
+}
+
 int BitTorrent::DBResumeDataStorage::currentDBVersion() const
 {
     const auto selectDBVersionStatement = u"SELECT %1 FROM %2 WHERE %3 = %4;"_qs
@@ -372,6 +423,8 @@ int BitTorrent::DBResumeDataStorage::currentDBVersion() const
 
     query.bindValue(DB_COLUMN_NAME.placeholder, META_VERSION);
 
+    const QReadLocker locker {&m_dbLock};
+
     if (!query.exec())
         throw RuntimeError(query.lastError().text());
 
@@ -390,6 +443,8 @@ void BitTorrent::DBResumeDataStorage::createDB() const
 {
     auto db = QSqlDatabase::database(DB_CONNECTION_NAME);
 
+    const QWriteLocker locker {&m_dbLock};
+
     if (!db.transaction())
         throw RuntimeError(db.lastError().text());
 
@@ -453,6 +508,8 @@ void BitTorrent::DBResumeDataStorage::updateDBFromVersion1() const
 {
     auto db = QSqlDatabase::database(DB_CONNECTION_NAME);
 
+    const QWriteLocker locker {&m_dbLock};
+
     if (!db.transaction())
         throw RuntimeError(db.lastError().text());
 
@@ -485,9 +542,10 @@ void BitTorrent::DBResumeDataStorage::updateDBFromVersion1() const
     }
 }
 
-BitTorrent::DBResumeDataStorage::Worker::Worker(const Path &dbPath, const QString &dbConnectionName)
+BitTorrent::DBResumeDataStorage::Worker::Worker(const Path &dbPath, const QString &dbConnectionName, QReadWriteLock &dbLock)
     : m_path {dbPath}
     , m_connectionName {dbConnectionName}
+    , m_dbLock {dbLock}
 {
 }
 
@@ -612,6 +670,7 @@ void BitTorrent::DBResumeDataStorage::Worker::store(const TorrentID &id, const L
         if (!bencodedMetadata.isEmpty())
             query.bindValue(DB_COLUMN_METADATA.placeholder, bencodedMetadata);
 
+        const QWriteLocker locker {&m_dbLock};
         if (!query.exec())
             throw RuntimeError(query.lastError().text());
     }
@@ -636,6 +695,8 @@ void BitTorrent::DBResumeDataStorage::Worker::remove(const TorrentID &id) const
             throw RuntimeError(query.lastError().text());
 
         query.bindValue(DB_COLUMN_TORRENT_ID.placeholder, id.toString());
+
+        const QWriteLocker locker {&m_dbLock};
         if (!query.exec())
             throw RuntimeError(query.lastError().text());
     }
@@ -656,6 +717,8 @@ void BitTorrent::DBResumeDataStorage::Worker::storeQueue(const QVector<TorrentID
 
     try
     {
+        const QWriteLocker locker {&m_dbLock};
+
         if (!db.transaction())
             throw RuntimeError(db.lastError().text());
 

src/base/bittorrent/dbresumedatastorage.h

@@ -28,6 +28,8 @@
 
 #pragma once
 
+#include <QReadWriteLock>
+
 #include "base/pathfwd.h"
 #include "resumedatastorage.h"
 
@@ -45,12 +47,14 @@ namespace BitTorrent
         ~DBResumeDataStorage() override;
 
         QVector<TorrentID> registeredTorrents() const override;
-        std::optional<LoadTorrentParams> load(const TorrentID &id) const override;
+        LoadResumeDataResult load(const TorrentID &id) const override;
+
         void store(const TorrentID &id, const LoadTorrentParams &resumeData) const override;
         void remove(const TorrentID &id) const override;
         void storeQueue(const QVector<TorrentID> &queue) const override;
 
     private:
+        void doLoadAll() const override;
         int currentDBVersion() const;
         void createDB() const;
         void updateDBFromVersion1() const;
@@ -59,5 +63,7 @@ namespace BitTorrent
 
         class Worker;
         Worker *m_asyncWorker = nullptr;
+
+        mutable QReadWriteLock m_dbLock;
     };
 }

src/base/bittorrent/resumedatastorage.cpp

@@ -0,0 +1,76 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2015-2022  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
+ * 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 "resumedatastorage.h"
+
+#include <utility>
+
+#include <QMetaObject>
+#include <QMutexLocker>
+#include <QThread>
+
+const int TORRENTIDLIST_TYPEID = qRegisterMetaType<QVector<BitTorrent::TorrentID>>();
+
+BitTorrent::ResumeDataStorage::ResumeDataStorage(const Path &path, QObject *parent)
+    : QObject(parent)
+    , m_path {path}
+{
+}
+
+Path BitTorrent::ResumeDataStorage::path() const
+{
+    return m_path;
+}
+
+void BitTorrent::ResumeDataStorage::loadAll() const
+{
+    m_loadedResumeData.reserve(1024);
+
+    auto *loadingThread = QThread::create([this]()
+    {
+        doLoadAll();
+    });
+    connect(loadingThread, &QThread::finished, loadingThread, &QObject::deleteLater);
+    loadingThread->start();
+}
+
+QVector<BitTorrent::LoadedResumeData> BitTorrent::ResumeDataStorage::fetchLoadedResumeData() const
+{
+    const QMutexLocker locker {&m_loadedResumeDataMutex};
+
+    const QVector<BitTorrent::LoadedResumeData> loadedResumeData = m_loadedResumeData;
+    m_loadedResumeData.clear();
+
+    return loadedResumeData;
+}
+
+void BitTorrent::ResumeDataStorage::onResumeDataLoaded(const TorrentID &torrentID, const LoadResumeDataResult &loadResumeDataResult) const
+{
+    const QMutexLocker locker {&m_loadedResumeDataMutex};
+    m_loadedResumeData.append({torrentID, loadResumeDataResult});
+}

src/base/bittorrent/resumedatastorage.h

@@ -1,6 +1,6 @@
 /*
  * Bittorrent Client using Qt and libtorrent.
- * Copyright (C) 2015, 2018  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2015-2022  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
@@ -28,15 +28,25 @@
 
 #pragma once
 
-#include <optional>
-
 #include <QtContainerFwd>
+#include <QMutex>
 #include <QObject>
+#include <QVector>
+
+#include "base/3rdparty/expected.hpp"
+#include "base/path.h"
+#include "infohash.h"
+#include "loadtorrentparams.h"
 
 namespace BitTorrent
 {
-    class TorrentID;
-    struct LoadTorrentParams;
+    using LoadResumeDataResult = nonstd::expected<LoadTorrentParams, QString>;
+
+    struct LoadedResumeData
+    {
+        TorrentID torrentID;
+        LoadResumeDataResult result;
+    };
 
     class ResumeDataStorage : public QObject
     {
@@ -44,12 +54,31 @@ namespace BitTorrent
         Q_DISABLE_COPY_MOVE(ResumeDataStorage)
 
     public:
-        using QObject::QObject;
+        explicit ResumeDataStorage(const Path &path, QObject *parent = nullptr);
+
+        Path path() const;
 
         virtual QVector<TorrentID> registeredTorrents() const = 0;
-        virtual std::optional<LoadTorrentParams> load(const TorrentID &id) const = 0;
+        virtual LoadResumeDataResult load(const TorrentID &id) const = 0;
         virtual void store(const TorrentID &id, const LoadTorrentParams &resumeData) const = 0;
         virtual void remove(const TorrentID &id) const = 0;
         virtual void storeQueue(const QVector<TorrentID> &queue) const = 0;
+
+        void loadAll() const;
+        QVector<LoadedResumeData> fetchLoadedResumeData() const;
+
+    signals:
+        void loadStarted(const QVector<BitTorrent::TorrentID> &torrents);
+        void loadFinished();
+
+    protected:
+        void onResumeDataLoaded(const TorrentID &torrentID, const LoadResumeDataResult &loadResumeDataResult) const;
+
+    private:
+        virtual void doLoadAll() const = 0;
+
+        const Path m_path;
+        mutable QVector<LoadedResumeData> m_loadedResumeData;
+        mutable QMutex m_loadedResumeDataMutex;
     };
 }

src/base/bittorrent/session.cpp

@@ -104,6 +104,7 @@
 #include "magneturi.h"
 #include "nativesessionextension.h"
 #include "portforwarderimpl.h"
+#include "resumedatastorage.h"
 #include "statistics.h"
 #include "torrentimpl.h"
 #include "tracker.h"
@@ -112,6 +113,7 @@ using namespace std::chrono_literals;
 using namespace BitTorrent;
 
 const Path CATEGORIES_FILE_NAME {u"categories.json"_qs};
+const int MAX_PROCESSING_RESUMEDATA_COUNT = 50;
 
 namespace
 {
@@ -297,6 +299,23 @@ namespace
 #endif
 }
 
+struct BitTorrent::Session::ResumeSessionContext final : public QObject
+{
+    using QObject::QObject;
+
+    ResumeDataStorage *startupStorage = nullptr;
+    ResumeDataStorageType currentStorageType = ResumeDataStorageType::Legacy;
+    QVector<LoadedResumeData> loadedResumeData;
+    int processingResumeDataCount = 0;
+    bool isLoadFinished = false;
+    bool isLoadedResumeDataHandlingEnqueued = false;
+    QSet<QString> recoveredCategories;
+#ifdef QBT_USES_LIBTORRENT2
+    QSet<TorrentID> indexedTorrents;
+    QSet<TorrentID> skippedIDs;
+#endif
+};
+
 const int addTorrentParamsId = qRegisterMetaType<AddTorrentParams>();
 
 // Session
@@ -467,7 +486,6 @@ Session::Session(QObject *parent)
     const QStringList storedTags = m_storedTags.get();
     m_tags = {storedTags.cbegin(), storedTags.cend()};
 
-    enqueueRefresh();
     updateSeedingLimitTimer();
     populateAdditionalTrackers();
     if (isExcludedFileNamesEnabled())
@@ -494,19 +512,12 @@ Session::Session(QObject *parent)
 
     m_ioThread->start();
 
-    // Regular saving of fastresume data
-    connect(m_resumeDataTimer, &QTimer::timeout, this, [this]() { generateResumeData(); });
-    const int saveInterval = saveResumeDataInterval();
-    if (saveInterval > 0)
-    {
-        m_resumeDataTimer->setInterval(std::chrono::minutes(saveInterval));
-        m_resumeDataTimer->start();
-    }
-
     // initialize PortForwarder instance
-    new PortForwarderImpl {m_nativeSession};
+    new PortForwarderImpl(m_nativeSession);
 
     initMetrics();
+
+    prepareStartup();
 }
 
 bool Session::isDHTEnabled() const
@@ -1062,6 +1073,285 @@ void Session::configureComponents()
 #endif
 }
 
+void Session::prepareStartup()
+{
+    qDebug("Initializing torrents resume data storage...");
+
+    const Path dbPath = specialFolderLocation(SpecialFolder::Data) / Path(u"torrents.db"_qs);
+    const bool dbStorageExists = dbPath.exists();
+
+    auto *context = new ResumeSessionContext(this);
+    context->currentStorageType = resumeDataStorageType();
+
+    if (context->currentStorageType == ResumeDataStorageType::SQLite)
+    {
+        m_resumeDataStorage = new DBResumeDataStorage(dbPath, this);
+
+        if (!dbStorageExists)
+        {
+            const Path dataPath = specialFolderLocation(SpecialFolder::Data) / Path(u"BT_backup"_qs);
+            context->startupStorage = new BencodeResumeDataStorage(dataPath, this);
+        }
+    }
+    else
+    {
+        const Path dataPath = specialFolderLocation(SpecialFolder::Data) / Path(u"BT_backup"_qs);
+        m_resumeDataStorage = new BencodeResumeDataStorage(dataPath, this);
+
+        if (dbStorageExists)
+            context->startupStorage = new DBResumeDataStorage(dbPath, this);
+    }
+
+    if (!context->startupStorage)
+        context->startupStorage = m_resumeDataStorage;
+
+    connect(context->startupStorage, &ResumeDataStorage::loadStarted, context
+            , [this, context](const QVector<TorrentID> &torrents)
+    {
+#ifdef QBT_USES_LIBTORRENT2
+        context->indexedTorrents = QSet<TorrentID>(torrents.cbegin(), torrents.cend());
+#endif
+
+        handleLoadedResumeData(context);
+    });
+
+    connect(context->startupStorage, &ResumeDataStorage::loadFinished, context, [context]()
+    {
+        context->isLoadFinished = true;
+    });
+
+    connect(this, &Session::torrentsLoaded, context, [this, context](const QVector<Torrent *> &torrents)
+    {
+        context->processingResumeDataCount -= torrents.count();
+        if (!context->isLoadedResumeDataHandlingEnqueued)
+        {
+            QMetaObject::invokeMethod(this, [this, context]() { handleLoadedResumeData(context); }, Qt::QueuedConnection);
+            context->isLoadedResumeDataHandlingEnqueued = true;
+        }
+        m_nativeSession->post_torrent_updates();
+        m_refreshEnqueued = true;
+    });
+
+    context->startupStorage->loadAll();
+}
+
+void Session::handleLoadedResumeData(ResumeSessionContext *context)
+{
+    context->isLoadedResumeDataHandlingEnqueued = false;
+
+    while (context->processingResumeDataCount < MAX_PROCESSING_RESUMEDATA_COUNT)
+    {
+        if (context->loadedResumeData.isEmpty())
+            context->loadedResumeData = context->startupStorage->fetchLoadedResumeData();
+
+        if (context->loadedResumeData.isEmpty())
+        {
+            if (context->processingResumeDataCount == 0)
+            {
+                if (context->isLoadFinished)
+                {
+                    endStartup(context);
+                }
+                else if (!context->isLoadedResumeDataHandlingEnqueued)
+                {
+                    QMetaObject::invokeMethod(this, [this, context]() { handleLoadedResumeData(context); }, Qt::QueuedConnection);
+                    context->isLoadedResumeDataHandlingEnqueued = true;
+                }
+            }
+
+            break;
+        }
+
+        processNextResumeData(context);
+    }
+}
+
+void Session::processNextResumeData(ResumeSessionContext *context)
+{
+    const LoadedResumeData loadedResumeDataItem = context->loadedResumeData.takeFirst();
+
+    TorrentID torrentID = loadedResumeDataItem.torrentID;
+#ifdef QBT_USES_LIBTORRENT2
+    if (context->skippedIDs.contains(torrentID))
+        return;
+#endif
+
+    const nonstd::expected<LoadTorrentParams, QString> &loadResumeDataResult = loadedResumeDataItem.result;
+    if (!loadResumeDataResult)
+    {
+        LogMsg(tr("Failed to resume torrent. Torrent: \"%1\". Reason: \"%2\"")
+               .arg(torrentID.toString(), loadResumeDataResult.error()), Log::CRITICAL);
+        return;
+    }
+
+    LoadTorrentParams resumeData = *loadResumeDataResult;
+    bool needStore = false;
+
+#ifdef QBT_USES_LIBTORRENT2
+    const lt::info_hash_t infoHash = (resumeData.ltAddTorrentParams.ti
+                                      ? resumeData.ltAddTorrentParams.ti->info_hashes()
+                                      : resumeData.ltAddTorrentParams.info_hashes);
+    const bool isHybrid = infoHash.has_v1() && infoHash.has_v2();
+    const auto torrentIDv2 = TorrentID::fromInfoHash(infoHash);
+    const auto torrentIDv1 = TorrentID::fromInfoHash(lt::info_hash_t(infoHash.v1));
+    if (torrentID == torrentIDv2)
+    {
+        if (isHybrid && context->indexedTorrents.contains(torrentIDv1))
+        {
+            // if we don't have metadata, try to find it in alternative "resume data"
+            if (!resumeData.ltAddTorrentParams.ti)
+            {
+                const nonstd::expected<LoadTorrentParams, QString> loadAltResumeDataResult = context->startupStorage->load(torrentIDv1);
+                if (loadAltResumeDataResult)
+                    resumeData.ltAddTorrentParams.ti = loadAltResumeDataResult->ltAddTorrentParams.ti;
+            }
+
+            // remove alternative "resume data" and skip the attempt to load it
+            m_resumeDataStorage->remove(torrentIDv1);
+            context->skippedIDs.insert(torrentIDv1);
+        }
+    }
+    else if (torrentID == torrentIDv1)
+    {
+        torrentID = torrentIDv2;
+        needStore = true;
+        m_resumeDataStorage->remove(torrentIDv1);
+
+        if (context->indexedTorrents.contains(torrentID))
+        {
+            context->skippedIDs.insert(torrentID);
+
+            const nonstd::expected<LoadTorrentParams, QString> loadPreferredResumeDataResult = context->startupStorage->load(torrentID);
+            if (loadPreferredResumeDataResult)
+            {
+                std::shared_ptr<lt::torrent_info> ti = resumeData.ltAddTorrentParams.ti;
+                resumeData = *loadPreferredResumeDataResult;
+                if (!resumeData.ltAddTorrentParams.ti)
+                    resumeData.ltAddTorrentParams.ti = ti;
+            }
+        }
+    }
+    else
+    {
+        LogMsg(tr("Failed to resume torrent: inconsistent torrent ID is detected. Torrent: \"%1\"")
+               .arg(torrentID.toString()), Log::WARNING);
+        return;
+    }
+#else
+    const lt::sha1_hash infoHash = (resumeData.ltAddTorrentParams.ti
+                                      ? resumeData.ltAddTorrentParams.ti->info_hash()
+                                      : resumeData.ltAddTorrentParams.info_hash);
+    if (torrentID != TorrentID::fromInfoHash(infoHash))
+    {
+        LogMsg(tr("Failed to resume torrent: inconsistent torrent ID is detected. Torrent: \"%1\"")
+               .arg(torrentID.toString()), Log::WARNING);
+        return;
+    }
+#endif
+
+    if (m_resumeDataStorage != context->startupStorage)
+       needStore = true;
+
+    // TODO: Remove the following upgrade code in v4.6
+    // == BEGIN UPGRADE CODE ==
+    if (!needStore)
+    {
+        if (m_needUpgradeDownloadPath && isDownloadPathEnabled() && !resumeData.useAutoTMM)
+        {
+            resumeData.downloadPath = downloadPath();
+            needStore = true;
+        }
+    }
+    // == END UPGRADE CODE ==
+
+    if (needStore)
+         m_resumeDataStorage->store(torrentID, resumeData);
+
+    const QString category = resumeData.category;
+    bool isCategoryRecovered = context->recoveredCategories.contains(category);
+    if (!category.isEmpty() && (isCategoryRecovered || !m_categories.contains(category)))
+    {
+        if (!isCategoryRecovered)
+        {
+            if (addCategory(category))
+            {
+                context->recoveredCategories.insert(category);
+                isCategoryRecovered = true;
+                LogMsg(tr("Detected inconsistent data: category is missing from the configuration file."
+                          " Category will be recovered but its settings will be reset to default."
+                          " Torrent: \"%1\". Category: \"%2\"").arg(torrentID.toString(), category), Log::WARNING);
+            }
+            else
+            {
+                resumeData.category.clear();
+                LogMsg(tr("Detected inconsistent data: invalid category. Torrent: \"%1\". Category: \"%2\"")
+                       .arg(torrentID.toString(), category), Log::WARNING);
+            }
+        }
+
+        // We should check isCategoryRecovered again since the category
+        // can be just recovered by the code above
+        if (isCategoryRecovered && resumeData.useAutoTMM)
+        {
+            const Path storageLocation {resumeData.ltAddTorrentParams.save_path};
+            if ((storageLocation != categorySavePath(resumeData.category)) && (storageLocation != categoryDownloadPath(resumeData.category)))
+            {
+                resumeData.useAutoTMM = false;
+                resumeData.savePath = storageLocation;
+                resumeData.downloadPath = {};
+                LogMsg(tr("Detected mismatch between the save paths of the recovered category and the current save path of the torrent."
+                          " Torrent is now switched to Manual mode."
+                          " Torrent: \"%1\". Category: \"%2\"").arg(torrentID.toString(), category), Log::WARNING);
+            }
+        }
+    }
+
+    resumeData.ltAddTorrentParams.userdata = LTClientData(new ExtensionData);
+#ifndef QBT_USES_LIBTORRENT2
+    resumeData.ltAddTorrentParams.storage = customStorageConstructor;
+#endif
+
+    qDebug() << "Starting up torrent" << torrentID.toString() << "...";
+    m_loadingTorrents.insert(torrentID, resumeData);
+    m_nativeSession->async_add_torrent(resumeData.ltAddTorrentParams);
+    ++context->processingResumeDataCount;
+}
+
+void Session::endStartup(ResumeSessionContext *context)
+{
+    if (m_resumeDataStorage != context->startupStorage)
+    {
+        if (isQueueingSystemEnabled())
+            saveTorrentsQueue();
+
+        const Path dbPath = context->startupStorage->path();
+        delete context->startupStorage;
+
+        if (context->currentStorageType == ResumeDataStorageType::Legacy)
+            Utils::Fs::removeFile(dbPath);
+    }
+
+    context->deleteLater();
+
+    m_nativeSession->resume();
+    if (m_refreshEnqueued)
+        m_refreshEnqueued = false;
+    else
+        enqueueRefresh();
+
+    // Regular saving of fastresume data
+    connect(m_resumeDataTimer, &QTimer::timeout, this, &Session::generateResumeData);
+    const int saveInterval = saveResumeDataInterval();
+    if (saveInterval > 0)
+    {
+        m_resumeDataTimer->setInterval(std::chrono::minutes(saveInterval));
+        m_resumeDataTimer->start();
+    }
+
+    m_isRestored = true;
+    emit restored();
+}
+
 void Session::initializeNativeSession()
 {
     const std::string peerId = lt::generate_fingerprint(PEER_ID, QBT_VERSION_MAJOR, QBT_VERSION_MINOR, QBT_VERSION_BUGFIX, QBT_VERSION_BUILD);
@@ -1100,7 +1390,7 @@ void Session::initializeNativeSession()
         break;
     }
 #endif
-    m_nativeSession = new lt::session {sessionParams};
+    m_nativeSession = new lt::session(sessionParams, lt::session::paused);
 
     LogMsg(tr("Peer ID: \"%1\"").arg(QString::fromStdString(peerId)), Log::INFO);
     LogMsg(tr("HTTP User-Agent: \"%1\"").arg(USER_AGENT), Log::INFO);
@@ -1764,9 +2054,7 @@ void Session::fileSearchFinished(const TorrentID &id, const Path &savePath, cons
     const auto loadingTorrentsIter = m_loadingTorrents.find(id);
     if (loadingTorrentsIter != m_loadingTorrents.end())
     {
-        LoadTorrentParams params = loadingTorrentsIter.value();
-        m_loadingTorrents.erase(loadingTorrentsIter);
-
+        LoadTorrentParams &params = loadingTorrentsIter.value();
         lt::add_torrent_params &p = params.ltAddTorrentParams;
 
         p.save_path = savePath.toString().toStdString();
@@ -1775,7 +2063,7 @@ void Session::fileSearchFinished(const TorrentID &id, const Path &savePath, cons
         for (int i = 0; i < fileNames.size(); ++i)
             p.renamed_files[nativeIndexes[i]] = fileNames[i].toString().toStdString();
 
-        loadTorrent(params);
+        m_nativeSession->async_add_torrent(p);
     }
 }
 
@@ -2054,6 +2342,9 @@ bool Session::addTorrent(const QString &source, const AddTorrentParams &params)
 {
     // `source`: .torrent file path/url or magnet uri
 
+    if (!isRestored())
+        return false;
+
     if (Net::DownloadManager::hasSupportedScheme(source))
     {
         LogMsg(tr("Downloading torrent, please wait... Source: \"%1\"").arg(source));
@@ -2083,13 +2374,20 @@ bool Session::addTorrent(const QString &source, const AddTorrentParams &params)
 
 bool Session::addTorrent(const MagnetUri &magnetUri, const AddTorrentParams &params)
 {
-    if (!magnetUri.isValid()) return false;
+    if (!isRestored())
+        return false;
+
+    if (!magnetUri.isValid())
+        return false;
 
     return addTorrent_impl(magnetUri, params);
 }
 
 bool Session::addTorrent(const TorrentInfo &torrentInfo, const AddTorrentParams &params)
 {
+    if (!isRestored())
+        return false;
+
     return addTorrent_impl(torrentInfo, params);
 }
 
@@ -2152,6 +2450,8 @@ LoadTorrentParams Session::initLoadTorrentParams(const AddTorrentParams &addTorr
 // Add a torrent to the BitTorrent session
 bool Session::addTorrent_impl(const std::variant<MagnetUri, TorrentInfo> &source, const AddTorrentParams &addTorrentParams)
 {
+    Q_ASSERT(isRestored());
+
     const bool hasMetadata = std::holds_alternative<TorrentInfo>(source);
     const auto id = TorrentID::fromInfoHash(hasMetadata ? std::get<TorrentInfo>(source).infoHash() : std::get<MagnetUri>(source).infoHash());
 
@@ -2332,35 +2632,17 @@ bool Session::addTorrent_impl(const std::variant<MagnetUri, TorrentInfo> &source
 
     p.added_time = std::time(nullptr);
 
-    if (!isFindingIncompleteFiles)
-        return loadTorrent(loadTorrentParams);
-
-    m_loadingTorrents.insert(id, loadTorrentParams);
-    return true;
-}
-
-// Add a torrent to the BitTorrent session
-bool Session::loadTorrent(LoadTorrentParams params)
-{
-    lt::add_torrent_params &p = params.ltAddTorrentParams;
-
-    p.userdata = LTClientData(new ExtensionData);
-#ifndef QBT_USES_LIBTORRENT2
-    p.storage = customStorageConstructor;
-#endif
     // Limits
     p.max_connections = maxConnectionsPerTorrent();
     p.max_uploads = maxUploadsPerTorrent();
 
-    const bool hasMetadata = (p.ti && p.ti->is_valid());
-#ifdef QBT_USES_LIBTORRENT2
-    const auto id = TorrentID::fromInfoHash(hasMetadata ? p.ti->info_hashes() : p.info_hashes);
-#else
-    const auto id = TorrentID::fromInfoHash(hasMetadata ? p.ti->info_hash() : p.info_hash);
+    p.userdata = LTClientData(new ExtensionData);
+#ifndef QBT_USES_LIBTORRENT2
+    p.storage = customStorageConstructor;
 #endif
-    m_loadingTorrents.insert(id, params);
 
-    // Adding torrent to BitTorrent session
+    m_loadingTorrents.insert(id, loadTorrentParams);
+    if (!isFindingIncompleteFiles)
         m_nativeSession->async_add_torrent(p);
 
     return true;
@@ -3207,6 +3489,11 @@ QStringList Session::bannedIPs() const
     return m_bannedIPs;
 }
 
+bool Session::isRestored() const
+{
+    return m_isRestored;
+}
+
 #if defined(Q_OS_WIN)
 OSMemoryPriority Session::getOSMemoryPriority() const
 {
@@ -4537,206 +4824,6 @@ const CacheStatus &Session::cacheStatus() const
     return m_cacheStatus;
 }
 
-void Session::startUpTorrents()
-{
-    qDebug("Initializing torrents resume data storage...");
-
-    const Path dbPath = specialFolderLocation(SpecialFolder::Data) / Path(u"torrents.db"_qs);
-    const bool dbStorageExists = dbPath.exists();
-
-    ResumeDataStorage *startupStorage = nullptr;
-    if (resumeDataStorageType() == ResumeDataStorageType::SQLite)
-    {
-        m_resumeDataStorage = new DBResumeDataStorage(dbPath, this);
-
-        if (!dbStorageExists)
-        {
-            const Path dataPath = specialFolderLocation(SpecialFolder::Data) / Path(u"BT_backup"_qs);
-            startupStorage = new BencodeResumeDataStorage(dataPath, this);
-        }
-    }
-    else
-    {
-        const Path dataPath = specialFolderLocation(SpecialFolder::Data) / Path(u"BT_backup"_qs);
-        m_resumeDataStorage = new BencodeResumeDataStorage(dataPath, this);
-
-        if (dbStorageExists)
-            startupStorage = new DBResumeDataStorage(dbPath, this);
-    }
-
-    if (!startupStorage)
-        startupStorage = m_resumeDataStorage;
-
-    qDebug("Starting up torrents...");
-
-    const QVector<TorrentID> torrents = startupStorage->registeredTorrents();
-    int resumedTorrentsCount = 0;
-    QVector<TorrentID> queue;
-    QSet<QString> recoveredCategories;
-#ifdef QBT_USES_LIBTORRENT2
-    const QSet<TorrentID> indexedTorrents {torrents.cbegin(), torrents.cend()};
-    QSet<TorrentID> skippedIDs;
-#endif
-    for (TorrentID torrentID : torrents)
-    {
-#ifdef QBT_USES_LIBTORRENT2
-        if (skippedIDs.contains(torrentID))
-            continue;
-#endif
-
-        const std::optional<LoadTorrentParams> loadResumeDataResult = startupStorage->load(torrentID);
-        if (!loadResumeDataResult)
-        {
-            LogMsg(tr("Failed to resume torrent. Torrent: \"%1\"").arg(torrentID.toString()), Log::CRITICAL);
-            continue;
-        }
-
-        LoadTorrentParams resumeData = *loadResumeDataResult;
-        bool needStore = false;
-
-#ifdef QBT_USES_LIBTORRENT2
-        const lt::info_hash_t infoHash = (resumeData.ltAddTorrentParams.ti
-                                          ? resumeData.ltAddTorrentParams.ti->info_hashes()
-                                          : resumeData.ltAddTorrentParams.info_hashes);
-        const bool isHybrid = infoHash.has_v1() && infoHash.has_v2();
-        const auto torrentIDv2 = TorrentID::fromInfoHash(infoHash);
-        const auto torrentIDv1 = TorrentID::fromInfoHash(lt::info_hash_t(infoHash.v1));
-        if (torrentID == torrentIDv2)
-        {
-            if (isHybrid && indexedTorrents.contains(torrentIDv1))
-            {
-                // if we don't have metadata, try to find it in alternative "resume data"
-                if (!resumeData.ltAddTorrentParams.ti)
-                {
-                    const std::optional<LoadTorrentParams> loadAltResumeDataResult = startupStorage->load(torrentIDv1);
-                    if (loadAltResumeDataResult)
-                        resumeData.ltAddTorrentParams.ti = loadAltResumeDataResult->ltAddTorrentParams.ti;
-                }
-
-                // remove alternative "resume data" and skip the attempt to load it
-                m_resumeDataStorage->remove(torrentIDv1);
-                skippedIDs.insert(torrentIDv1);
-            }
-        }
-        else if (torrentID == torrentIDv1)
-        {
-            torrentID = torrentIDv2;
-            needStore = true;
-            m_resumeDataStorage->remove(torrentIDv1);
-
-            if (indexedTorrents.contains(torrentID))
-            {
-                skippedIDs.insert(torrentID);
-
-                const std::optional<LoadTorrentParams> loadPreferredResumeDataResult = startupStorage->load(torrentID);
-                if (loadPreferredResumeDataResult)
-                {
-                    std::shared_ptr<lt::torrent_info> ti = resumeData.ltAddTorrentParams.ti;
-                    resumeData = *loadPreferredResumeDataResult;
-                    if (!resumeData.ltAddTorrentParams.ti)
-                        resumeData.ltAddTorrentParams.ti = ti;
-                }
-            }
-        }
-        else
-        {
-            LogMsg(tr("Failed to resume torrent: inconsistent torrent ID is detected. Torrent: \"%1\"")
-                   .arg(torrentID.toString()), Log::WARNING);
-            continue;
-        }
-#else
-        const lt::sha1_hash infoHash = (resumeData.ltAddTorrentParams.ti
-                                          ? resumeData.ltAddTorrentParams.ti->info_hash()
-                                          : resumeData.ltAddTorrentParams.info_hash);
-        if (torrentID != TorrentID::fromInfoHash(infoHash))
-        {
-            LogMsg(tr("Failed to resume torrent: inconsistent torrent ID is detected. Torrent: \"%1\"")
-                   .arg(torrentID.toString()), Log::WARNING);
-            continue;
-        }
-#endif
-
-        if (m_resumeDataStorage != startupStorage)
-        {
-           needStore = true;
-           if (isQueueingSystemEnabled() && !resumeData.hasSeedStatus)
-                queue.append(torrentID);
-        }
-
-        // TODO: Remove the following upgrade code in v4.6
-        // == BEGIN UPGRADE CODE ==
-        if (m_needUpgradeDownloadPath && isDownloadPathEnabled())
-        {
-            if (!resumeData.useAutoTMM)
-            {
-                resumeData.downloadPath = downloadPath();
-                needStore = true;
-            }
-        }
-        // == END UPGRADE CODE ==
-
-        if (needStore)
-             m_resumeDataStorage->store(torrentID, resumeData);
-
-        const QString category = resumeData.category;
-        bool isCategoryRecovered = recoveredCategories.contains(category);
-        if (!category.isEmpty() && (isCategoryRecovered || !m_categories.contains(category)))
-        {
-            if (!isCategoryRecovered)
-            {
-                if (addCategory(category))
-                {
-                    recoveredCategories.insert(category);
-                    isCategoryRecovered = true;
-                    LogMsg(tr("Detected inconsistent data: category is missing from the configuration file."
-                              " Category will be recovered but its settings will be reset to default."
-                              " Torrent: \"%1\". Category: \"%2\"").arg(torrentID.toString(), category), Log::WARNING);
-                }
-                else
-                {
-                    resumeData.category.clear();
-                    LogMsg(tr("Detected inconsistent data: invalid category. Torrent: \"%1\". Category: \"%2\"")
-                           .arg(torrentID.toString(), category), Log::WARNING);
-                }
-            }
-
-            // We should check isCategoryRecovered again since the category
-            // can be just recovered by the code above
-            if (isCategoryRecovered && resumeData.useAutoTMM)
-            {
-                const Path storageLocation {resumeData.ltAddTorrentParams.save_path};
-                if ((storageLocation != categorySavePath(resumeData.category)) && (storageLocation != categoryDownloadPath(resumeData.category)))
-                {
-                    resumeData.useAutoTMM = false;
-                    resumeData.savePath = storageLocation;
-                    resumeData.downloadPath = {};
-                    LogMsg(tr("Detected mismatch between the save paths of the recovered category and the current save path of the torrent."
-                              " Torrent is now switched to Manual mode."
-                              " Torrent: \"%1\". Category: \"%2\"").arg(torrentID.toString(), category), Log::WARNING);
-                }
-            }
-        }
-
-        qDebug() << "Starting up torrent" << torrentID.toString() << "...";
-        if (!loadTorrent(resumeData))
-            LogMsg(tr("Failed to resume torrent. Torrent: \"%1\"").arg(torrentID.toString()), Log::CRITICAL);
-
-        // process add torrent messages before message queue overflow
-        if ((resumedTorrentsCount % 100) == 0) readAlerts();
-
-        ++resumedTorrentsCount;
-    }
-
-    if (m_resumeDataStorage != startupStorage)
-    {
-        delete startupStorage;
-        if (resumeDataStorageType() == ResumeDataStorageType::Legacy)
-            Utils::Fs::removeFile(dbPath);
-
-        if (isQueueingSystemEnabled())
-            m_resumeDataStorage->storeQueue(queue);
-    }
-}
 
 qint64 Session::getAlltimeDL() const
 {
@@ -4807,12 +4894,63 @@ void Session::setTorrentContentLayout(const TorrentContentLayout value)
 void Session::readAlerts()
 {
     const std::vector<lt::alert *> alerts = getPendingAlerts();
+    handleAddTorrentAlerts(alerts);
     for (const lt::alert *a : alerts)
         handleAlert(a);
 
     processTrackerStatuses();
 }
 
+void Session::handleAddTorrentAlerts(const std::vector<lt::alert *> &alerts)
+{
+    QVector<Torrent *> loadedTorrents;
+    if (!isRestored())
+        loadedTorrents.reserve(MAX_PROCESSING_RESUMEDATA_COUNT);
+
+    for (const lt::alert *a : alerts)
+    {
+        if (a->type() != lt::add_torrent_alert::alert_type)
+            continue;
+
+        auto alert = static_cast<const lt::add_torrent_alert *>(a);
+        if (alert->error)
+        {
+            const QString msg = QString::fromStdString(alert->message());
+            LogMsg(tr("Failed to load torrent. Reason: \"%1\"").arg(msg), Log::WARNING);
+            emit loadTorrentFailed(msg);
+
+            const lt::add_torrent_params &params = alert->params;
+            const bool hasMetadata = (params.ti && params.ti->is_valid());
+#ifdef QBT_USES_LIBTORRENT2
+            const auto torrentID = TorrentID::fromInfoHash(hasMetadata ? params.ti->info_hashes() : params.info_hashes);
+#else
+            const auto torrentID = TorrentID::fromInfoHash(hasMetadata ? params.ti->info_hash() : params.info_hash);
+#endif
+            m_loadingTorrents.remove(torrentID);
+
+            return;
+        }
+
+#ifdef QBT_USES_LIBTORRENT2
+        const auto torrentID = TorrentID::fromInfoHash(alert->handle.info_hashes());
+#else
+        const auto torrentID = TorrentID::fromInfoHash(alert->handle.info_hash());
+#endif
+        const auto loadingTorrentsIter = m_loadingTorrents.find(torrentID);
+        if (loadingTorrentsIter != m_loadingTorrents.end())
+        {
+            LoadTorrentParams params = loadingTorrentsIter.value();
+            m_loadingTorrents.erase(loadingTorrentsIter);
+
+            Torrent *torrent = createTorrent(alert->handle, params);
+            loadedTorrents.append(torrent);
+        }
+    }
+
+    if (!loadedTorrents.isEmpty())
+        emit torrentsLoaded(loadedTorrents);
+}
+
 void Session::handleAlert(const lt::alert *a)
 {
     try
@@ -4852,7 +4990,7 @@ void Session::handleAlert(const lt::alert *a)
             handleFileErrorAlert(static_cast<const lt::file_error_alert*>(a));
             break;
         case lt::add_torrent_alert::alert_type:
-            handleAddTorrentAlert(static_cast<const lt::add_torrent_alert*>(a));
+            // handled separately
             break;
         case lt::torrent_removed_alert::alert_type:
             handleTorrentRemovedAlert(static_cast<const lt::torrent_removed_alert*>(a));
@@ -4924,7 +5062,7 @@ void Session::dispatchTorrentAlert(const lt::alert *a)
     }
 }
 
-void Session::createTorrent(const lt::torrent_handle &nativeHandle)
+TorrentImpl *Session::createTorrent(const lt::torrent_handle &nativeHandle, const LoadTorrentParams &params)
 {
 #ifdef QBT_USES_LIBTORRENT2
     const auto torrentID = TorrentID::fromInfoHash(nativeHandle.info_hashes());
@@ -4932,21 +5070,15 @@ void Session::createTorrent(const lt::torrent_handle &nativeHandle)
     const auto torrentID = TorrentID::fromInfoHash(nativeHandle.info_hash());
 #endif
 
-    Q_ASSERT(m_loadingTorrents.contains(torrentID));
-
-    const LoadTorrentParams params = m_loadingTorrents.take(torrentID);
-
     auto *const torrent = new TorrentImpl(this, m_nativeSession, nativeHandle, params);
     m_torrents.insert(torrent->id(), torrent);
 
-    const bool hasMetadata = torrent->hasMetadata();
-
     if (!params.restored)
     {
         m_resumeDataStorage->store(torrent->id(), params);
 
         // The following is useless for newly added magnet
-        if (hasMetadata)
+        if (torrent->hasMetadata())
         {
             if (!torrentExportDirectory().isEmpty())
                 exportTorrentFile(torrent, torrentExportDirectory());
@@ -4959,9 +5091,6 @@ void Session::createTorrent(const lt::torrent_handle &nativeHandle)
         m_seedingLimitTimer->start();
     }
 
-    // Send torrent addition signal
-    emit torrentLoaded(torrent);
-    // Send new torrent signal
     if (params.restored)
     {
         LogMsg(tr("Restored torrent. Torrent: \"%1\"").arg(torrent->name()));
@@ -4975,29 +5104,8 @@ void Session::createTorrent(const lt::torrent_handle &nativeHandle)
     // Torrent could have error just after adding to libtorrent
     if (torrent->hasError())
         LogMsg(tr("Torrent errored. Torrent: \"%1\". Error: \"%2\"").arg(torrent->name(), torrent->error()), Log::WARNING);
-}
-
-void Session::handleAddTorrentAlert(const lt::add_torrent_alert *p)
-{
-    if (p->error)
-    {
-        const QString msg = QString::fromStdString(p->message());
-        LogMsg(tr("Failed to load torrent. Reason: \"%1\"").arg(msg), Log::WARNING);
-        emit loadTorrentFailed(msg);
 
-        const lt::add_torrent_params &params = p->params;
-        const bool hasMetadata = (params.ti && params.ti->is_valid());
-#ifdef QBT_USES_LIBTORRENT2
-        const auto id = TorrentID::fromInfoHash(hasMetadata ? params.ti->info_hashes() : params.info_hashes);
-#else
-        const auto id = TorrentID::fromInfoHash(hasMetadata ? params.ti->info_hash() : params.info_hash);
-#endif
-        m_loadingTorrents.remove(id);
-    }
-    else if (m_loadingTorrents.contains(p->handle.info_hash()))
-    {
-        createTorrent(p->handle);
-    }
+    return torrent;
 }
 
 void Session::handleTorrentRemovedAlert(const lt::torrent_removed_alert *p)

src/base/bittorrent/session.h

@@ -469,7 +469,8 @@ namespace BitTorrent
         void setOSMemoryPriority(OSMemoryPriority priority);
 #endif
 
-        void startUpTorrents();
+        bool isRestored() const;
+
         Torrent *findTorrent(const TorrentID &id) const;
         QVector<Torrent *> torrents() const;
         qsizetype torrentsCount() const;
@@ -539,6 +540,7 @@ namespace BitTorrent
         void loadTorrentFailed(const QString &error);
         void metadataDownloaded(const TorrentInfo &info);
         void recursiveTorrentDownloadPossible(Torrent *torrent);
+        void restored();
         void speedLimitModeChanged(bool alternative);
         void statsUpdated();
         void subcategoriesSupportChanged();
@@ -549,12 +551,12 @@ namespace BitTorrent
         void torrentCategoryChanged(Torrent *torrent, const QString &oldCategory);
         void torrentFinished(Torrent *torrent);
         void torrentFinishedChecking(Torrent *torrent);
-        void torrentLoaded(Torrent *torrent);
         void torrentMetadataReceived(Torrent *torrent);
         void torrentPaused(Torrent *torrent);
         void torrentResumed(Torrent *torrent);
         void torrentSavePathChanged(Torrent *torrent);
         void torrentSavingModeChanged(Torrent *torrent);
+        void torrentsLoaded(const QVector<Torrent *> &torrents);
         void torrentsUpdated(const QVector<Torrent *> &torrents);
         void torrentTagAdded(Torrent *torrent, const QString &tag);
         void torrentTagRemoved(Torrent *torrent, const QString &tag);
@@ -585,6 +587,8 @@ namespace BitTorrent
 #endif
 
     private:
+        struct ResumeSessionContext;
+
         struct MoveStorageJob
         {
             lt::torrent_handle torrentHandle;
@@ -630,8 +634,11 @@ namespace BitTorrent
 #endif
         void processTrackerStatuses();
         void populateExcludedFileNamesRegExpList();
+        void prepareStartup();
+        void handleLoadedResumeData(ResumeSessionContext *context);
+        void processNextResumeData(ResumeSessionContext *context);
+        void endStartup(ResumeSessionContext *context);
 
-        bool loadTorrent(LoadTorrentParams params);
         LoadTorrentParams initLoadTorrentParams(const AddTorrentParams &addTorrentParams);
         bool addTorrent_impl(const std::variant<MagnetUri, TorrentInfo> &source, const AddTorrentParams &addTorrentParams);
 
@@ -639,8 +646,8 @@ namespace BitTorrent
         void exportTorrentFile(const Torrent *torrent, const Path &folderPath);
 
         void handleAlert(const lt::alert *a);
+        void handleAddTorrentAlerts(const std::vector<lt::alert *> &alerts);
         void dispatchTorrentAlert(const lt::alert *a);
-        void handleAddTorrentAlert(const lt::add_torrent_alert *p);
         void handleStateUpdateAlert(const lt::state_update_alert *p);
         void handleMetadataReceivedAlert(const lt::metadata_received_alert *p);
         void handleFileErrorAlert(const lt::file_error_alert *p);
@@ -662,7 +669,7 @@ namespace BitTorrent
         void handleSocks5Alert(const lt::socks5_alert *p) const;
         void handleTrackerAlert(const lt::tracker_alert *a);
 
-        void createTorrent(const lt::torrent_handle &nativeHandle);
+        TorrentImpl *createTorrent(const lt::torrent_handle &nativeHandle, const LoadTorrentParams &params);
 
         void saveResumeData();
         void saveTorrentsQueue() const;
@@ -792,6 +799,8 @@ namespace BitTorrent
         CachedSettingValue<OSMemoryPriority> m_OSMemoryPriority;
 #endif
 
+        bool m_isRestored = false;
+
         // Order is important. This needs to be declared after its CachedSettingsValue
         // counterpart, because it uses it for initialization in the constructor
         // initialization list.

src/base/rss/rss_autodownloader.cpp

@@ -138,8 +138,20 @@ AutoDownloader::AutoDownloader()
     m_processingTimer->setSingleShot(true);
     connect(m_processingTimer, &QTimer::timeout, this, &AutoDownloader::process);
 
+    const auto *btSession = BitTorrent::Session::instance();
+    if (btSession->isRestored())
+    {
         if (isProcessingEnabled())
             startProcessing();
+    }
+    else
+    {
+        connect(btSession, &BitTorrent::Session::restored, this, [this]()
+        {
+            if (isProcessingEnabled())
+                startProcessing();
+        });
+    }
 }
 
 AutoDownloader::~AutoDownloader()
@@ -506,6 +518,7 @@ void AutoDownloader::setProcessingEnabled(const bool enabled)
         m_storeProcessingEnabled = enabled;
         if (enabled)
         {
+            if (BitTorrent::Session::instance()->isRestored())
                 startProcessing();
         }
         else

src/base/torrentfileswatcher.cpp

@@ -255,13 +255,12 @@ TorrentFilesWatcher *TorrentFilesWatcher::instance()
 TorrentFilesWatcher::TorrentFilesWatcher(QObject *parent)
     : QObject {parent}
     , m_ioThread {new QThread(this)}
-    , m_asyncWorker {new TorrentFilesWatcher::Worker}
 {
-    connect(m_asyncWorker, &TorrentFilesWatcher::Worker::magnetFound, this, &TorrentFilesWatcher::onMagnetFound);
-    connect(m_asyncWorker, &TorrentFilesWatcher::Worker::torrentFound, this, &TorrentFilesWatcher::onTorrentFound);
-
-    m_asyncWorker->moveToThread(m_ioThread);
-    m_ioThread->start();
+    const auto *btSession = BitTorrent::Session::instance();
+    if (btSession->isRestored())
+        initWorker();
+    else
+        connect(btSession, &BitTorrent::Session::restored, this, &TorrentFilesWatcher::initWorker);
 
     load();
 }
@@ -273,6 +272,27 @@ TorrentFilesWatcher::~TorrentFilesWatcher()
     delete m_asyncWorker;
 }
 
+void TorrentFilesWatcher::initWorker()
+{
+    Q_ASSERT(!m_asyncWorker);
+
+    m_asyncWorker = new TorrentFilesWatcher::Worker;
+
+    connect(m_asyncWorker, &TorrentFilesWatcher::Worker::magnetFound, this, &TorrentFilesWatcher::onMagnetFound);
+    connect(m_asyncWorker, &TorrentFilesWatcher::Worker::torrentFound, this, &TorrentFilesWatcher::onTorrentFound);
+
+    m_asyncWorker->moveToThread(m_ioThread);
+    m_ioThread->start();
+
+    for (auto it = m_watchedFolders.cbegin(); it != m_watchedFolders.cend(); ++it)
+    {
+        QMetaObject::invokeMethod(m_asyncWorker, [this, path = it.key(), options = it.value()]()
+        {
+            m_asyncWorker->setWatchedFolder(path, options);
+        });
+    }
+}
+
 void TorrentFilesWatcher::load()
 {
     QFile confFile {(specialFolderLocation(SpecialFolder::Config) / Path(CONF_FILE_NAME)).data()};
@@ -399,10 +419,13 @@ void TorrentFilesWatcher::doSetWatchedFolder(const Path &path, const WatchedFold
 
     m_watchedFolders[path] = options;
 
+    if (m_asyncWorker)
+    {
         QMetaObject::invokeMethod(m_asyncWorker, [this, path, options]()
         {
             m_asyncWorker->setWatchedFolder(path, options);
         });
+    }
 
     emit watchedFolderSet(path, options);
 }
@@ -410,11 +433,14 @@ void TorrentFilesWatcher::doSetWatchedFolder(const Path &path, const WatchedFold
 void TorrentFilesWatcher::removeWatchedFolder(const Path &path)
 {
     if (m_watchedFolders.remove(path))
+    {
+        if (m_asyncWorker)
         {
             QMetaObject::invokeMethod(m_asyncWorker, [this, path]()
             {
                 m_asyncWorker->removeWatchedFolder(path);
             });
+        }
 
         emit watchedFolderRemoved(path);
 

src/base/torrentfileswatcher.h

@@ -78,6 +78,7 @@ private:
     explicit TorrentFilesWatcher(QObject *parent = nullptr);
     ~TorrentFilesWatcher() override;
 
+    void initWorker();
     void load();
     void loadLegacy();
     void store() const;

src/gui/categoryfiltermodel.cpp

@@ -32,7 +32,6 @@
 #include <QIcon>
 
 #include "base/bittorrent/session.h"
-#include "base/bittorrent/torrent.h"
 #include "base/global.h"
 #include "uithememanager.h"
 
@@ -181,7 +180,7 @@ CategoryFilterModel::CategoryFilterModel(QObject *parent)
     connect(session, &Session::categoryRemoved, this, &CategoryFilterModel::categoryRemoved);
     connect(session, &Session::torrentCategoryChanged, this, &CategoryFilterModel::torrentCategoryChanged);
     connect(session, &Session::subcategoriesSupportChanged, this, &CategoryFilterModel::subcategoriesSupportChanged);
-    connect(session, &Session::torrentLoaded, this, &CategoryFilterModel::torrentAdded);
+    connect(session, &Session::torrentsLoaded, this, &CategoryFilterModel::torrentsLoaded);
     connect(session, &Session::torrentAboutToBeRemoved, this, &CategoryFilterModel::torrentAboutToBeRemoved);
 
     populate();
@@ -333,13 +332,16 @@ void CategoryFilterModel::categoryRemoved(const QString &categoryName)
     }
 }
 
-void CategoryFilterModel::torrentAdded(BitTorrent::Torrent *const torrent)
+void CategoryFilterModel::torrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents)
 {
+    for (const BitTorrent::Torrent *torrent : torrents)
+    {
         CategoryModelItem *item = findItem(torrent->category());
         Q_ASSERT(item);
 
         item->increaseTorrentsCount();
         m_rootItem->childAt(0)->increaseTorrentsCount();
+    }
 }
 
 void CategoryFilterModel::torrentAboutToBeRemoved(BitTorrent::Torrent *const torrent)

src/gui/categoryfiltermodel.h

@@ -28,17 +28,15 @@
 
 #pragma once
 
+#include <QtContainerFwd>
 #include <QAbstractItemModel>
 
+#include "base/bittorrent/torrent.h"
+
 class QModelIndex;
 
 class CategoryModelItem;
 
-namespace BitTorrent
-{
-    class Torrent;
-}
-
 class CategoryFilterModel final : public QAbstractItemModel
 {
     Q_OBJECT
@@ -64,7 +62,7 @@ public:
 private slots:
     void categoryAdded(const QString &categoryName);
     void categoryRemoved(const QString &categoryName);
-    void torrentAdded(BitTorrent::Torrent *const torrent);
+    void torrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents);
     void torrentAboutToBeRemoved(BitTorrent::Torrent *const torrent);
     void torrentCategoryChanged(BitTorrent::Torrent *const torrent, const QString &oldCategory);
     void subcategoriesSupportChanged();

src/gui/mainwindow.cpp

@@ -1205,12 +1205,12 @@ void MainWindow::keyPressEvent(QKeyEvent *event)
 {
     if (event->matches(QKeySequence::Paste))
     {
-        const QMimeData *mimeData {QGuiApplication::clipboard()->mimeData()};
+        const QMimeData *mimeData = QGuiApplication::clipboard()->mimeData();
 
         if (mimeData->hasText())
         {
-            const bool useTorrentAdditionDialog {AddNewTorrentDialog::isEnabled()};
-            const QStringList lines {mimeData->text().split(u'\n', Qt::SkipEmptyParts)};
+            const bool useTorrentAdditionDialog = AddNewTorrentDialog::isEnabled();
+            const QStringList lines = mimeData->text().split(u'\n', Qt::SkipEmptyParts);
 
             for (QString line : lines)
             {
@@ -1438,6 +1438,7 @@ void MainWindow::dragEnterEvent(QDragEnterEvent *event)
 {
     for (const QString &mime : asConst(event->mimeData()->formats()))
         qDebug("mimeData: %s", mime.toLocal8Bit().data());
+
     if (event->mimeData()->hasFormat(u"text/plain"_qs) || event->mimeData()->hasFormat(u"text/uri-list"_qs))
         event->acceptProposedAction();
 }

src/gui/search/searchjobwidget.cpp

@@ -208,7 +208,7 @@ void SearchJobWidget::cancelSearch()
 
 void SearchJobWidget::downloadTorrents(const AddTorrentOption option)
 {
-    const QModelIndexList rows {m_ui->resultsBrowser->selectionModel()->selectedRows()};
+    const QModelIndexList rows = m_ui->resultsBrowser->selectionModel()->selectedRows();
     for (const QModelIndex &rowIndex : rows)
         downloadTorrent(rowIndex, option);
 }
@@ -390,10 +390,10 @@ void SearchJobWidget::contextMenuEvent(QContextMenuEvent *event)
     auto *menu = new QMenu(this);
     menu->setAttribute(Qt::WA_DeleteOnClose);
 
-    menu->addAction(UIThemeManager::instance()->getIcon(u"kt-set-max-download-speed"_qs), tr("Open download window")
-        , this, [this]() { downloadTorrents(AddTorrentOption::ShowDialog); });
-    menu->addAction(UIThemeManager::instance()->getIcon(u"downloading"_qs), tr("Download")
-        , this, [this]() { downloadTorrents(AddTorrentOption::SkipDialog); });
+    menu->addAction(UIThemeManager::instance()->getIcon(u"kt-set-max-download-speed"_qs)
+        , tr("Open download window"), this, [this]() { downloadTorrents(AddTorrentOption::ShowDialog); });
+    menu->addAction(UIThemeManager::instance()->getIcon(u"downloading"_qs)
+        , tr("Download"), this, [this]() { downloadTorrents(AddTorrentOption::SkipDialog); });
     menu->addSeparator();
     menu->addAction(UIThemeManager::instance()->getIcon(u"application-x-mswinurl"_qs), tr("Open description page")
         , this, &SearchJobWidget::openTorrentPages);

src/gui/tagfiltermodel.cpp

@@ -33,7 +33,6 @@
 #include <QVector>
 
 #include "base/bittorrent/session.h"
-#include "base/bittorrent/torrent.h"
 #include "base/global.h"
 #include "uithememanager.h"
 
@@ -99,7 +98,7 @@ TagFilterModel::TagFilterModel(QObject *parent)
     connect(session, &Session::tagRemoved, this, &TagFilterModel::tagRemoved);
     connect(session, &Session::torrentTagAdded, this, &TagFilterModel::torrentTagAdded);
     connect(session, &Session::torrentTagRemoved, this, &TagFilterModel::torrentTagRemoved);
-    connect(session, &Session::torrentLoaded, this, &TagFilterModel::torrentAdded);
+    connect(session, &Session::torrentsLoaded, this, &TagFilterModel::torrentsLoaded);
     connect(session, &Session::torrentAboutToBeRemoved, this, &TagFilterModel::torrentAboutToBeRemoved);
     populate();
 }
@@ -230,8 +229,10 @@ void TagFilterModel::torrentTagRemoved(BitTorrent::Torrent *const torrent, const
     emit dataChanged(i, i);
 }
 
-void TagFilterModel::torrentAdded(BitTorrent::Torrent *const torrent)
+void TagFilterModel::torrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents)
 {
+    for (const BitTorrent::Torrent *torrent : torrents)
+    {
         allTagsItem()->increaseTorrentsCount();
 
         const QVector<TagModelItem *> items = findItems(torrent->tags());
@@ -240,6 +241,7 @@ void TagFilterModel::torrentAdded(BitTorrent::Torrent *const torrent)
 
         for (TagModelItem *item : items)
             item->increaseTorrentsCount();
+    }
 }
 
 void TagFilterModel::torrentAboutToBeRemoved(BitTorrent::Torrent *const torrent)

src/gui/tagfiltermodel.h

@@ -28,20 +28,16 @@
 
 #pragma once
 
-#include <QAbstractListModel>
 #include <QtContainerFwd>
+#include <QAbstractItemModel>
 
+#include "base/bittorrent/torrent.h"
 #include "base/tagset.h"
 
 class QModelIndex;
 
 class TagModelItem;
 
-namespace BitTorrent
-{
-    class Torrent;
-}
-
 class TagFilterModel final : public QAbstractListModel
 {
     Q_OBJECT
@@ -67,7 +63,7 @@ private slots:
     void tagRemoved(const QString &tag);
     void torrentTagAdded(BitTorrent::Torrent *const torrent, const QString &tag);
     void torrentTagRemoved(BitTorrent::Torrent *const, const QString &tag);
-    void torrentAdded(BitTorrent::Torrent *const torrent);
+    void torrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents);
     void torrentAboutToBeRemoved(BitTorrent::Torrent *const torrent);
 
 private:

src/gui/transferlistfilterswidget.cpp

@@ -134,8 +134,8 @@ BaseFilterWidget::BaseFilterWidget(QWidget *parent, TransferListWidget *transfer
     connect(this, &BaseFilterWidget::customContextMenuRequested, this, &BaseFilterWidget::showMenu);
     connect(this, &BaseFilterWidget::currentRowChanged, this, &BaseFilterWidget::applyFilter);
 
-    connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentLoaded
-            , this, &BaseFilterWidget::handleNewTorrent);
+    connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentsLoaded
+            , this, &BaseFilterWidget::handleTorrentsLoaded);
     connect(BitTorrent::Session::instance(), &BitTorrent::Session::torrentAboutToBeRemoved
             , this, &BaseFilterWidget::torrentAboutToBeDeleted);
 }
@@ -318,9 +318,11 @@ void StatusFilterWidget::applyFilter(int row)
     transferList->applyStatusFilter(row);
 }
 
-void StatusFilterWidget::handleNewTorrent(BitTorrent::Torrent *const torrent)
+void StatusFilterWidget::handleTorrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents)
 {
+    for (const BitTorrent::Torrent *torrent : torrents)
         updateTorrentStatus(torrent);
+
     updateTexts();
 }
 
@@ -376,6 +378,8 @@ TrackerFiltersList::TrackerFiltersList(QWidget *parent, TransferListWidget *tran
 
     m_trackers[NULL_HOST] = {{}, noTracker};
 
+    handleTorrentsLoaded(BitTorrent::Session::instance()->torrents());
+
     setCurrentRow(0, QItemSelectionModel::SelectCurrent);
     toggleFilter(Preferences::instance()->getTrackerFilterState());
 }
@@ -390,7 +394,7 @@ void TrackerFiltersList::addTrackers(const BitTorrent::Torrent *torrent, const Q
 {
     const BitTorrent::TorrentID torrentID = torrent->id();
     for (const BitTorrent::TrackerEntry &tracker : trackers)
-        addItem(tracker.url, torrentID);
+        addItems(tracker.url, {torrentID});
 }
 
 void TrackerFiltersList::removeTrackers(const BitTorrent::Torrent *torrent, const QStringList &trackers)
@@ -431,12 +435,12 @@ void TrackerFiltersList::refreshTrackers(const BitTorrent::Torrent *torrent)
     const bool isTrackerless = trackerEntries.isEmpty();
     if (isTrackerless)
     {
-        addItem(NULL_HOST, torrentID);
+        addItems(NULL_HOST, {torrentID});
     }
     else
     {
         for (const BitTorrent::TrackerEntry &trackerEntry : trackerEntries)
-            addItem(trackerEntry.url, torrentID);
+            addItems(trackerEntry.url, {torrentID});
     }
 
     updateGeometry();
@@ -445,23 +449,20 @@ void TrackerFiltersList::refreshTrackers(const BitTorrent::Torrent *torrent)
 void TrackerFiltersList::changeTrackerless(const BitTorrent::Torrent *torrent, const bool trackerless)
 {
     if (trackerless)
-        addItem(NULL_HOST, torrent->id());
+        addItems(NULL_HOST, {torrent->id()});
     else
         removeItem(NULL_HOST, torrent->id());
 }
 
-void TrackerFiltersList::addItem(const QString &tracker, const BitTorrent::TorrentID &id)
+void TrackerFiltersList::addItems(const QString &trackerURL, const QVector<BitTorrent::TorrentID> &torrents)
 {
-    const QString host = getHost(tracker);
+    const QString host = getHost(trackerURL);
     auto trackersIt = m_trackers.find(host);
     const bool exists = (trackersIt != m_trackers.end());
     QListWidgetItem *trackerItem = nullptr;
 
     if (exists)
     {
-        if (trackersIt->torrents.contains(id))
-            return;
-
         trackerItem = trackersIt->item;
     }
     else
@@ -469,17 +470,18 @@ void TrackerFiltersList::addItem(const QString &tracker, const BitTorrent::Torre
         trackerItem = new QListWidgetItem();
         trackerItem->setData(Qt::DecorationRole, UIThemeManager::instance()->getIcon(u"trackers"_qs));
 
-        TrackerData trackerData {{}, trackerItem};
+        const TrackerData trackerData {{}, trackerItem};
         trackersIt = m_trackers.insert(host, trackerData);
 
-        const QString scheme = getScheme(tracker);
+        const QString scheme = getScheme(trackerURL);
         downloadFavicon(u"%1://%2/favicon.ico"_qs.arg((scheme.startsWith(u"http") ? scheme : u"http"_qs), host));
     }
 
     Q_ASSERT(trackerItem);
 
     QSet<BitTorrent::TorrentID> &torrentIDs = trackersIt->torrents;
-    torrentIDs.insert(id);
+    for (const BitTorrent::TorrentID &torrentID : torrents)
+        torrentIDs.insert(torrentID);
 
     trackerItem->setText(u"%1 (%2)"_qs.arg(((host == NULL_HOST) ? tr("Trackerless") : host), QString::number(torrentIDs.size())));
     if (exists)
@@ -724,18 +726,30 @@ void TrackerFiltersList::applyFilter(const int row)
         transferList->applyTrackerFilter(getTorrentIDs(row));
 }
 
-void TrackerFiltersList::handleNewTorrent(BitTorrent::Torrent *const torrent)
+void TrackerFiltersList::handleTorrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents)
 {
+    QHash<QString, QVector<BitTorrent::TorrentID>> torrentsPerTracker;
+    for (const BitTorrent::Torrent *torrent : torrents)
+    {
         const BitTorrent::TorrentID torrentID = torrent->id();
         const QVector<BitTorrent::TrackerEntry> trackers = torrent->trackers();
         for (const BitTorrent::TrackerEntry &tracker : trackers)
-        addItem(tracker.url, torrentID);
+            torrentsPerTracker[tracker.url].append(torrentID);
 
         // Check for trackerless torrent
         if (trackers.isEmpty())
-        addItem(NULL_HOST, torrentID);
+            torrentsPerTracker[NULL_HOST].append(torrentID);
+    }
+
+    for (auto it = torrentsPerTracker.cbegin(); it != torrentsPerTracker.cend(); ++it)
+    {
+        const QString &trackerURL = it.key();
+        const QVector<BitTorrent::TorrentID> &torrents = it.value();
+        addItems(trackerURL, torrents);
+    }
 
-    item(ALL_ROW)->setText(tr("All (%1)", "this is for the tracker filter").arg(++m_totalTorrents));
+    m_totalTorrents += torrents.count();
+    item(ALL_ROW)->setText(tr("All (%1)", "this is for the tracker filter").arg(m_totalTorrents));
 }
 
 void TrackerFiltersList::torrentAboutToBeDeleted(BitTorrent::Torrent *const torrent)

src/gui/transferlistfilterswidget.h

@@ -71,7 +71,7 @@ protected:
 private slots:
     virtual void showMenu() = 0;
     virtual void applyFilter(int row) = 0;
-    virtual void handleNewTorrent(BitTorrent::Torrent *const) = 0;
+    virtual void handleTorrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents) = 0;
     virtual void torrentAboutToBeDeleted(BitTorrent::Torrent *const) = 0;
 };
 
@@ -92,7 +92,7 @@ private:
     // No need to redeclare them here as slots.
     void showMenu() override;
     void applyFilter(int row) override;
-    void handleNewTorrent(BitTorrent::Torrent *const) override;
+    void handleTorrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents) override;
     void torrentAboutToBeDeleted(BitTorrent::Torrent *const) override;
 
     void populate();
@@ -139,10 +139,10 @@ private:
     // No need to redeclare them here as slots.
     void showMenu() override;
     void applyFilter(int row) override;
-    void handleNewTorrent(BitTorrent::Torrent *const torrent) override;
+    void handleTorrentsLoaded(const QVector<BitTorrent::Torrent *> &torrents) override;
     void torrentAboutToBeDeleted(BitTorrent::Torrent *const torrent) override;
 
-    void addItem(const QString &tracker, const BitTorrent::TorrentID &id);
+    void addItems(const QString &trackerURL, const QVector<BitTorrent::TorrentID> &torrents);
     void removeItem(const QString &trackerURL, const BitTorrent::TorrentID &id);
     QString trackerFromRow(int row) const;
     int rowFromTracker(const QString &tracker) const;

src/gui/transferlistmodel.cpp

@@ -166,11 +166,10 @@ TransferListModel::TransferListModel(QObject *parent)
 
     // Load the torrents
     using namespace BitTorrent;
-    for (Torrent *const torrent : asConst(Session::instance()->torrents()))
-        addTorrent(torrent);
+    addTorrents(Session::instance()->torrents());
 
     // Listen for torrent changes
-    connect(Session::instance(), &Session::torrentLoaded, this, &TransferListModel::addTorrent);
+    connect(Session::instance(), &Session::torrentsLoaded, this, &TransferListModel::addTorrents);
     connect(Session::instance(), &Session::torrentAboutToBeRemoved, this, &TransferListModel::handleTorrentAboutToBeRemoved);
     connect(Session::instance(), &Session::torrentsUpdated, this, &TransferListModel::handleTorrentsUpdated);
 
@@ -599,15 +598,19 @@ bool TransferListModel::setData(const QModelIndex &index, const QVariant &value,
     return true;
 }
 
-void TransferListModel::addTorrent(BitTorrent::Torrent *const torrent)
+void TransferListModel::addTorrents(const QVector<BitTorrent::Torrent *> &torrents)
 {
+    int row = m_torrentList.size();
+    beginInsertRows({}, row, (row + torrents.size()));
+
+    for (BitTorrent::Torrent *torrent : torrents)
+    {
         Q_ASSERT(!m_torrentMap.contains(torrent));
 
-    const int row = m_torrentList.size();
+        m_torrentList.append(torrent);
+        m_torrentMap[torrent] = row++;
+    }
 
-    beginInsertRows({}, row, row);
-    m_torrentList << torrent;
-    m_torrentMap[torrent] = row;
     endInsertRows();
 }
 

src/gui/transferlistmodel.h

@@ -103,7 +103,7 @@ public:
     BitTorrent::Torrent *torrentHandle(const QModelIndex &index) const;
 
 private slots:
-    void addTorrent(BitTorrent::Torrent *const torrent);
+    void addTorrents(const QVector<BitTorrent::Torrent *> &torrents);
     void handleTorrentAboutToBeRemoved(BitTorrent::Torrent *const torrent);
     void handleTorrentStatusUpdated(BitTorrent::Torrent *const torrent);
     void handleTorrentsUpdated(const QVector<BitTorrent::Torrent *> &torrents);