Merge pull request #18034 from glassez/fetch-async

Fetch data asynchronously

src/base/bittorrent/peerinfo.cpp

@@ -1,6 +1,6 @@
 /*
  * Bittorrent Client using Qt and libtorrent.
- * Copyright (C) 2015  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
@@ -31,16 +31,15 @@
 #include <QBitArray>
 
 #include "base/bittorrent/ltqbitarray.h"
-#include "base/bittorrent/torrent.h"
 #include "base/net/geoipmanager.h"
 #include "base/unicodestrings.h"
 #include "peeraddress.h"
 
 using namespace BitTorrent;
 
-PeerInfo::PeerInfo(const Torrent *torrent, const lt::peer_info &nativeInfo)
+PeerInfo::PeerInfo(const lt::peer_info &nativeInfo, const QBitArray &allPieces)
     : m_nativeInfo(nativeInfo)
-    , m_relevance(calcRelevance(torrent))
+    , m_relevance(calcRelevance(allPieces))
 {
     determineFlags();
 }
@@ -246,9 +245,8 @@ QString PeerInfo::connectionType() const
         : u"Web"_qs;
 }
 
-qreal PeerInfo::calcRelevance(const Torrent *torrent) const
+qreal PeerInfo::calcRelevance(const QBitArray &allPieces) const
 {
-    const QBitArray allPieces = torrent->pieces();
     const int localMissing = allPieces.count(false);
     if (localMissing <= 0)
         return 0;

src/base/bittorrent/peerinfo.h

@@ -1,6 +1,6 @@
 /*
  * Bittorrent Client using Qt and libtorrent.
- * Copyright (C) 2015  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
@@ -36,7 +36,6 @@ class QBitArray;
 
 namespace BitTorrent
 {
-    class Torrent;
     struct PeerAddress;
 
     class PeerInfo
@@ -45,7 +44,7 @@ namespace BitTorrent
 
     public:
         PeerInfo() = default;
-        PeerInfo(const Torrent *torrent, const lt::peer_info &nativeInfo);
+        PeerInfo(const lt::peer_info &nativeInfo, const QBitArray &allPieces);
 
         bool fromDHT() const;
         bool fromPeX() const;
@@ -93,7 +92,7 @@ namespace BitTorrent
         int downloadingPieceIndex() const;
 
     private:
-        qreal calcRelevance(const Torrent *torrent) const;
+        qreal calcRelevance(const QBitArray &allPieces) const;
         void determineFlags();
 
         lt::peer_info m_nativeInfo = {};

src/base/bittorrent/sessionimpl.cpp

@@ -627,6 +627,8 @@ SessionImpl::~SessionImpl()
     // we delete lt::session
     delete Net::PortForwarder::instance();
 
+    // We must stop "async worker" only after deletion
+    // of all the components that could potentially use it
     m_asyncWorker->clear();
     m_asyncWorker->waitForDone();
 

src/base/bittorrent/sessionimpl.h

@@ -443,7 +443,7 @@ namespace BitTorrent
         template <typename Func>
         void invoke(Func &&func)
         {
-            QMetaObject::invokeMethod(this, std::forward<Func>(func));
+            QMetaObject::invokeMethod(this, std::forward<Func>(func), Qt::QueuedConnection);
         }
 
         void invokeAsync(std::function<void ()> func);

src/base/bittorrent/torrent.h

@@ -1,6 +1,6 @@
 /*
  * Bittorrent Client using Qt and libtorrent.
- * Copyright (C) 2015  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2015-2022  Vladimir Golovnev <glassez@yandex.ru>
  * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
  *
  * This program is free software; you can redistribute it and/or
@@ -106,9 +106,10 @@ namespace BitTorrent
     uint qHash(TorrentState key, uint seed = 0);
 #endif
 
-    class Torrent : public AbstractFileStorage
+    class Torrent : public QObject, public AbstractFileStorage
     {
-        Q_GADGET
+        Q_OBJECT
+        Q_DISABLE_COPY_MOVE(Torrent)
 
     public:
         enum class StopCondition
@@ -128,7 +129,7 @@ namespace BitTorrent
         static const qreal MAX_RATIO;
         static const int MAX_SEEDING_TIME;
 
-        virtual ~Torrent() = default;
+        using QObject::QObject;
 
         virtual InfoHash infoHash() const = 0;
         virtual QString name() const = 0;
@@ -309,7 +310,7 @@ namespace BitTorrent
         virtual void removeUrlSeeds(const QVector<QUrl> &urlSeeds) = 0;
         virtual bool connectPeer(const PeerAddress &peerAddress) = 0;
         virtual void clearPeers() = 0;
-        virtual bool setMetadata(const TorrentInfo &torrentInfo) = 0;
+        virtual void setMetadata(const TorrentInfo &torrentInfo) = 0;
 
         virtual StopCondition stopCondition() const = 0;
         virtual void setStopCondition(StopCondition stopCondition) = 0;
@@ -318,6 +319,19 @@ namespace BitTorrent
         virtual nonstd::expected<QByteArray, QString> exportToBuffer() const = 0;
         virtual nonstd::expected<void, QString> exportToFile(const Path &path) const = 0;
 
+        virtual void fetchPeerInfo(std::function<void (QVector<PeerInfo>)> resultHandler) const = 0;
+        virtual void fetchURLSeeds(std::function<void (QVector<QUrl>)> resultHandler) const = 0;
+        virtual void fetchFilesProgress(std::function<void (QVector<qreal>)> resultHandler) const = 0;
+        virtual void fetchPieceAvailability(std::function<void (QVector<int>)> resultHandler) const = 0;
+        virtual void fetchDownloadingPieces(std::function<void (QBitArray)> resultHandler) const = 0;
+        /**
+         * @brief fraction of file pieces that are available at least from one peer
+         *
+         * This is not the same as torrrent availability, it is just a fraction of pieces
+         * that can be downloaded right now. It varies between 0 to 1.
+         */
+        virtual void fetchAvailableFileFractions(std::function<void (QVector<qreal>)> resultHandler) const = 0;
+
         TorrentID id() const;
         bool isResumed() const;
         qlonglong remainingSize() const;

src/base/bittorrent/torrentimpl.cpp

@@ -48,6 +48,7 @@
 #include <QByteArray>
 #include <QDebug>
 #include <QFile>
+#include <QPointer>
 #include <QSet>
 #include <QStringList>
 #include <QUrl>
@@ -236,7 +237,7 @@ namespace
 
 TorrentImpl::TorrentImpl(SessionImpl *session, lt::session *nativeSession
                                      , const lt::torrent_handle &nativeHandle, const LoadTorrentParams &params)
-    : QObject(session)
+    : Torrent(session)
     , m_session(session)
     , m_nativeSession(nativeSession)
     , m_nativeHandle(nativeHandle)
@@ -620,50 +621,86 @@ QVector<QUrl> TorrentImpl::urlSeeds() const
 
 void TorrentImpl::addUrlSeeds(const QVector<QUrl> &urlSeeds)
 {
-    const std::set<std::string> currentSeeds = m_nativeHandle.url_seeds();
-
-    QVector<QUrl> addedUrlSeeds;
-    addedUrlSeeds.reserve(urlSeeds.size());
-
-    for (const QUrl &url : urlSeeds)
+    m_session->invokeAsync([urlSeeds, session = m_session
+                           , nativeHandle = m_nativeHandle
+                           , thisTorrent = QPointer<TorrentImpl>(this)]
     {
-        const std::string nativeUrl = url.toString().toStdString();
-        if (currentSeeds.find(nativeUrl) == currentSeeds.end())
+        try
         {
-            m_nativeHandle.add_url_seed(nativeUrl);
-            addedUrlSeeds << url;
-        }
-    }
+            const std::set<std::string> nativeSeeds = nativeHandle.url_seeds();
+            QVector<QUrl> currentSeeds;
+            currentSeeds.reserve(static_cast<decltype(currentSeeds)::size_type>(nativeSeeds.size()));
+            for (const std::string &urlSeed : nativeSeeds)
+                currentSeeds.append(QString::fromStdString(urlSeed));
 
-    if (!addedUrlSeeds.isEmpty())
-    {
-        m_session->handleTorrentNeedSaveResumeData(this);
-        m_session->handleTorrentUrlSeedsAdded(this, addedUrlSeeds);
-    }
+            QVector<QUrl> addedUrlSeeds;
+            addedUrlSeeds.reserve(urlSeeds.size());
+
+            for (const QUrl &url : urlSeeds)
+            {
+                if (!currentSeeds.contains(url))
+                {
+                    nativeHandle.add_url_seed(url.toString().toStdString());
+                    addedUrlSeeds.append(url);
+                }
+            }
+
+            session->invoke([session, thisTorrent, addedUrlSeeds]
+            {
+                if (!thisTorrent)
+                    return;
+
+                if (!addedUrlSeeds.isEmpty())
+                {
+                    session->handleTorrentNeedSaveResumeData(thisTorrent);
+                    session->handleTorrentUrlSeedsAdded(thisTorrent, addedUrlSeeds);
+                }
+            });
+        }
+        catch (const std::exception &) {}
+    });
 }
 
 void TorrentImpl::removeUrlSeeds(const QVector<QUrl> &urlSeeds)
 {
-    const std::set<std::string> currentSeeds = m_nativeHandle.url_seeds();
-
-    QVector<QUrl> removedUrlSeeds;
-    removedUrlSeeds.reserve(urlSeeds.size());
-
-    for (const QUrl &url : urlSeeds)
+    m_session->invokeAsync([urlSeeds, session = m_session
+                           , nativeHandle = m_nativeHandle
+                           , thisTorrent = QPointer<TorrentImpl>(this)]
     {
-        const std::string nativeUrl = url.toString().toStdString();
-        if (currentSeeds.find(nativeUrl) != currentSeeds.end())
+        try
         {
-            m_nativeHandle.remove_url_seed(nativeUrl);
-            removedUrlSeeds << url;
-        }
-    }
+            const std::set<std::string> nativeSeeds = nativeHandle.url_seeds();
+            QVector<QUrl> currentSeeds;
+            currentSeeds.reserve(static_cast<decltype(currentSeeds)::size_type>(nativeSeeds.size()));
+            for (const std::string &urlSeed : nativeSeeds)
+                currentSeeds.append(QString::fromStdString(urlSeed));
 
-    if (!removedUrlSeeds.isEmpty())
-    {
-        m_session->handleTorrentNeedSaveResumeData(this);
-        m_session->handleTorrentUrlSeedsRemoved(this, removedUrlSeeds);
-    }
+            QVector<QUrl> removedUrlSeeds;
+            removedUrlSeeds.reserve(urlSeeds.size());
+
+            for (const QUrl &url : urlSeeds)
+            {
+                if (currentSeeds.contains(url))
+                {
+                    nativeHandle.remove_url_seed(url.toString().toStdString());
+                    removedUrlSeeds.append(url);
+                }
+            }
+
+            session->invoke([session, thisTorrent, removedUrlSeeds]
+            {
+                if (!thisTorrent)
+                    return;
+
+                if (!removedUrlSeeds.isEmpty())
+                {
+                    session->handleTorrentNeedSaveResumeData(thisTorrent);
+                    session->handleTorrentUrlSeedsRemoved(thisTorrent, removedUrlSeeds);
+                }
+            });
+        }
+        catch (const std::exception &) {}
+    });
 }
 
 void TorrentImpl::clearPeers()
@@ -1282,7 +1319,7 @@ QVector<PeerInfo> TorrentImpl::peers() const
     peers.reserve(static_cast<decltype(peers)::size_type>(nativePeers.size()));
 
     for (const lt::peer_info &peer : nativePeers)
-        peers << PeerInfo(this, peer);
+        peers.append(PeerInfo(peer, pieces()));
 
     return peers;
 }
@@ -2025,7 +2062,7 @@ void TorrentImpl::handleFileCompletedAlert(const lt::file_completed_alert *p)
     const int fileIndex = m_indexMap.value(p->index, -1);
     Q_ASSERT(fileIndex >= 0);
 
-    m_completedFiles[fileIndex] = true;
+    m_completedFiles.setBit(fileIndex);
 
     if (m_session->isAppendExtensionEnabled())
     {
@@ -2185,17 +2222,24 @@ lt::torrent_handle TorrentImpl::nativeHandle() const
     return m_nativeHandle;
 }
 
-bool TorrentImpl::setMetadata(const TorrentInfo &torrentInfo)
+void TorrentImpl::setMetadata(const TorrentInfo &torrentInfo)
 {
     if (hasMetadata())
-        return false;
+        return;
 
+    m_session->invokeAsync([nativeHandle = m_nativeHandle, torrentInfo]
+    {
+        try
+        {
 #ifdef QBT_USES_LIBTORRENT2
-    return m_nativeHandle.set_metadata(torrentInfo.nativeInfo()->info_section());
+            nativeHandle.set_metadata(torrentInfo.nativeInfo()->info_section());
 #else
-    const std::shared_ptr<lt::torrent_info> nativeInfo = torrentInfo.nativeInfo();
-    return m_nativeHandle.set_metadata(lt::span<const char>(nativeInfo->metadata().get(), nativeInfo->metadata_size()));
+            const std::shared_ptr<lt::torrent_info> nativeInfo = torrentInfo.nativeInfo();
+            nativeHandle.set_metadata(lt::span<const char>(nativeInfo->metadata().get(), nativeInfo->metadata_size()));
 #endif
+        }
+        catch (const std::exception &) {}
+    });
 }
 
 Torrent::StopCondition TorrentImpl::stopCondition() const
@@ -2415,6 +2459,171 @@ nonstd::expected<void, QString> TorrentImpl::exportToFile(const Path &path) cons
     return {};
 }
 
+void TorrentImpl::fetchPeerInfo(std::function<void (QVector<PeerInfo>)> resultHandler) const
+{
+    invokeAsync([nativeHandle = m_nativeHandle, allPieces = pieces()]() -> QVector<PeerInfo>
+    {
+        try
+        {
+            std::vector<lt::peer_info> nativePeers;
+            nativeHandle.get_peer_info(nativePeers);
+            QVector<PeerInfo> peers;
+            peers.reserve(static_cast<decltype(peers)::size_type>(nativePeers.size()));
+            for (const lt::peer_info &peer : nativePeers)
+                peers.append(PeerInfo(peer, allPieces));
+            return peers;
+        }
+        catch (const std::exception &) {}
+
+        return {};
+    }
+    , std::move(resultHandler));
+}
+
+void TorrentImpl::fetchURLSeeds(std::function<void (QVector<QUrl>)> resultHandler) const
+{
+    invokeAsync([nativeHandle = m_nativeHandle]() -> QVector<QUrl>
+    {
+        try
+        {
+            const std::set<std::string> currentSeeds = nativeHandle.url_seeds();
+            QVector<QUrl> urlSeeds;
+            urlSeeds.reserve(static_cast<decltype(urlSeeds)::size_type>(currentSeeds.size()));
+            for (const std::string &urlSeed : currentSeeds)
+                urlSeeds.append(QString::fromStdString(urlSeed));
+            return urlSeeds;
+        }
+        catch (const std::exception &) {}
+
+        return {};
+    }
+    , std::move(resultHandler));
+}
+
+void TorrentImpl::fetchFilesProgress(std::function<void (QVector<qreal>)> resultHandler) const
+{
+    invokeAsync([nativeHandle = m_nativeHandle, torrentInfo = m_torrentInfo
+                , completedFiles = m_completedFiles]() -> QVector<qreal>
+    {
+        if (!torrentInfo.isValid())
+            return {};
+
+        const int filesCount = torrentInfo.filesCount();
+        if (completedFiles.count(true) == filesCount)
+            return QVector<qreal>(filesCount, 1);
+
+        try
+        {
+#ifdef QBT_USES_LIBTORRENT2
+            const std::vector<int64_t> fp = nativeHandle.file_progress(lt::torrent_handle::piece_granularity);
+#else
+            std::vector<int64_t> fp;
+            nativeHandle.file_progress(fp, lt::torrent_handle::piece_granularity);
+#endif
+
+            const auto nativeIndexes = torrentInfo.nativeIndexes();
+            QVector<qreal> result;
+            result.reserve(filesCount);
+            for (int i = 0; i < filesCount; ++i)
+            {
+                const int64_t progress = fp[LT::toUnderlyingType(nativeIndexes[i])];
+                const qlonglong size = torrentInfo.fileSize(i);
+                if ((size <= 0) || (progress == size))
+                    result.append(1);
+                else
+                    result.append(progress / static_cast<qreal>(size));
+            }
+            return result;
+        }
+        catch (const std::exception &) {}
+
+        return {};
+    }
+    , std::move(resultHandler));
+}
+
+void TorrentImpl::fetchPieceAvailability(std::function<void (QVector<int>)> resultHandler) const
+{
+    invokeAsync([nativeHandle = m_nativeHandle]() -> QVector<int>
+    {
+        try
+        {
+            std::vector<int> piecesAvailability;
+            nativeHandle.piece_availability(piecesAvailability);
+            return QVector<int>(piecesAvailability.cbegin(), piecesAvailability.cend());
+        }
+        catch (const std::exception &) {}
+
+        return {};
+    }
+    , std::move(resultHandler));
+}
+
+void TorrentImpl::fetchDownloadingPieces(std::function<void (QBitArray)> resultHandler) const
+{
+    invokeAsync([nativeHandle = m_nativeHandle, torrentInfo = m_torrentInfo]() -> QBitArray
+    {
+        try
+        {
+#ifdef QBT_USES_LIBTORRENT2
+            const std::vector<lt::partial_piece_info> queue = nativeHandle.get_download_queue();
+#else
+            std::vector<lt::partial_piece_info> queue;
+            nativeHandle.get_download_queue(queue);
+#endif
+            QBitArray result;
+            result.resize(torrentInfo.piecesCount());
+            for (const lt::partial_piece_info &info : queue)
+                result.setBit(LT::toUnderlyingType(info.piece_index));
+            return result;
+        }
+        catch (const std::exception &) {}
+
+        return {};
+    }
+    , std::move(resultHandler));
+}
+
+void TorrentImpl::fetchAvailableFileFractions(std::function<void (QVector<qreal>)> resultHandler) const
+{
+    invokeAsync([nativeHandle = m_nativeHandle, torrentInfo = m_torrentInfo]() -> QVector<qreal>
+    {
+        if (!torrentInfo.isValid() || (torrentInfo.filesCount() <= 0))
+            return {};
+
+        try
+        {
+            std::vector<int> piecesAvailability;
+            nativeHandle.piece_availability(piecesAvailability);
+            const int filesCount = torrentInfo.filesCount();
+            // libtorrent returns empty array for seeding only torrents
+            if (piecesAvailability.empty())
+                return QVector<qreal>(filesCount, -1);
+
+            QVector<qreal> result;
+            result.reserve(filesCount);
+            for (int i = 0; i < filesCount; ++i)
+            {
+                const TorrentInfo::PieceRange filePieces = torrentInfo.filePieces(i);
+
+                int availablePieces = 0;
+                for (const int piece : filePieces)
+                    availablePieces += (piecesAvailability[piece] > 0) ? 1 : 0;
+
+                const qreal availability = filePieces.isEmpty()
+                        ? 1  // the file has no pieces, so it is available by default
+                        : static_cast<qreal>(availablePieces) / filePieces.size();
+                result.append(availability);
+            }
+            return result;
+        }
+        catch (const std::exception &) {}
+
+        return {};
+    }
+    , std::move(resultHandler));
+}
+
 void TorrentImpl::prioritizeFiles(const QVector<DownloadPriority> &priorities)
 {
     if (!hasMetadata()) return;
@@ -2478,3 +2687,19 @@ QVector<qreal> TorrentImpl::availableFileFractions() const
     }
     return res;
 }
+
+template <typename Func, typename Callback>
+void TorrentImpl::invokeAsync(Func func, Callback resultHandler) const
+{
+    m_session->invokeAsync([session = m_session
+                           , func = std::move(func)
+                           , resultHandler = std::move(resultHandler)
+                           , thisTorrent = QPointer<const TorrentImpl>(this)]() mutable
+    {
+        session->invoke([result = func(), thisTorrent, resultHandler = std::move(resultHandler)]
+        {
+            if (thisTorrent)
+                resultHandler(result);
+        });
+    });
+}

src/base/bittorrent/torrentimpl.h

@@ -80,10 +80,10 @@ namespace BitTorrent
         lt::operation_t operation;
     };
 
-    class TorrentImpl final : public QObject, public Torrent
+    class TorrentImpl final : public Torrent
     {
+        Q_OBJECT
         Q_DISABLE_COPY_MOVE(TorrentImpl)
-        Q_DECLARE_TR_FUNCTIONS(BitTorrent::TorrentImpl)
 
     public:
         TorrentImpl(SessionImpl *session, lt::session *nativeSession
@@ -227,7 +227,7 @@ namespace BitTorrent
         void removeUrlSeeds(const QVector<QUrl> &urlSeeds) override;
         bool connectPeer(const PeerAddress &peerAddress) override;
         void clearPeers() override;
-        bool setMetadata(const TorrentInfo &torrentInfo) override;
+        void setMetadata(const TorrentInfo &torrentInfo) override;
 
         StopCondition stopCondition() const override;
         void setStopCondition(StopCondition stopCondition) override;
@@ -236,6 +236,13 @@ namespace BitTorrent
         nonstd::expected<QByteArray, QString> exportToBuffer() const override;
         nonstd::expected<void, QString> exportToFile(const Path &path) const override;
 
+        void fetchPeerInfo(std::function<void (QVector<PeerInfo>)> resultHandler) const override;
+        void fetchURLSeeds(std::function<void (QVector<QUrl>)> resultHandler) const override;
+        void fetchFilesProgress(std::function<void (QVector<qreal>)> resultHandler) const override;
+        void fetchPieceAvailability(std::function<void (QVector<int>)> resultHandler) const override;
+        void fetchDownloadingPieces(std::function<void (QBitArray)> resultHandler) const override;
+        void fetchAvailableFileFractions(std::function<void (QVector<qreal>)> resultHandler) const override;
+
         bool needSaveResumeData() const;
 
         // Session interface
@@ -292,6 +299,9 @@ namespace BitTorrent
 
         nonstd::expected<lt::entry, QString> exportTorrent() const;
 
+        template <typename Func, typename Callback>
+        void invokeAsync(Func func, Callback resultHandler) const;
+
         SessionImpl *const m_session = nullptr;
         lt::session *m_nativeSession = nullptr;
         lt::torrent_handle m_nativeHandle;

src/gui/properties/peerlistwidget.cpp

@@ -37,6 +37,7 @@
 #include <QHostAddress>
 #include <QMenu>
 #include <QMessageBox>
+#include <QPointer>
 #include <QSet>
 #include <QShortcut>
 #include <QSortFilterProxyModel>
@@ -392,38 +393,47 @@ void PeerListWidget::saveSettings() const
 
 void PeerListWidget::loadPeers(const BitTorrent::Torrent *torrent)
 {
-    if (!torrent) return;
-
-    const QVector<BitTorrent::PeerInfo> peers = torrent->peers();
-    QSet<PeerEndpoint> existingPeers;
-    for (auto i = m_peerItems.cbegin(); i != m_peerItems.cend(); ++i)
-        existingPeers << i.key();
+    if (!torrent)
+        return;
 
-    for (const BitTorrent::PeerInfo &peer : peers)
+    using TorrentPtr = QPointer<const BitTorrent::Torrent>;
+    torrent->fetchPeerInfo([this, torrent = TorrentPtr(torrent)](const QVector<BitTorrent::PeerInfo> &peers)
     {
-        if (peer.address().ip.isNull()) continue;
+        if (torrent != m_properties->getCurrentTorrent())
+            return;
 
-        bool isNewPeer = false;
-        updatePeer(torrent, peer, isNewPeer);
-        if (!isNewPeer)
+        QSet<PeerEndpoint> existingPeers;
+        existingPeers.reserve(m_peerItems.size());
+        for (auto i = m_peerItems.cbegin(); i != m_peerItems.cend(); ++i)
+            existingPeers.insert(i.key());
+
+        for (const BitTorrent::PeerInfo &peer : peers)
         {
-            const PeerEndpoint peerEndpoint {peer.address(), peer.connectionType()};
-            existingPeers.remove(peerEndpoint);
+            if (peer.address().ip.isNull())
+                continue;
+
+            bool isNewPeer = false;
+            updatePeer(torrent, peer, isNewPeer);
+            if (!isNewPeer)
+            {
+                const PeerEndpoint peerEndpoint {peer.address(), peer.connectionType()};
+                existingPeers.remove(peerEndpoint);
+            }
         }
-    }
 
-    // Remove peers that are gone
-    for (const PeerEndpoint &peerEndpoint : asConst(existingPeers))
-    {
-        QStandardItem *item = m_peerItems.take(peerEndpoint);
+        // Remove peers that are gone
+        for (const PeerEndpoint &peerEndpoint : asConst(existingPeers))
+        {
+            QStandardItem *item = m_peerItems.take(peerEndpoint);
 
-        QSet<QStandardItem *> &items = m_itemsByIP[peerEndpoint.address.ip];
-        items.remove(item);
-        if (items.isEmpty())
-            m_itemsByIP.remove(peerEndpoint.address.ip);
+            QSet<QStandardItem *> &items = m_itemsByIP[peerEndpoint.address.ip];
+            items.remove(item);
+            if (items.isEmpty())
+                m_itemsByIP.remove(peerEndpoint.address.ip);
 
-        m_listModel->removeRow(item->row());
-    }
+            m_listModel->removeRow(item->row());
+        }
+    });
 }
 
 void PeerListWidget::updatePeer(const BitTorrent::Torrent *torrent, const BitTorrent::PeerInfo &peer, bool &isNewPeer)
@@ -433,7 +443,7 @@ void PeerListWidget::updatePeer(const BitTorrent::Torrent *torrent, const BitTor
     const Qt::Alignment intDataTextAlignment = Qt::AlignRight | Qt::AlignVCenter;
 
     const auto setModelData =
-        [this] (const int row, const int column, const QString &displayData
+        [this](const int row, const int column, const QString &displayData
                 , const QVariant &underlyingData, const Qt::Alignment textAlignmentData = {}
                 , const QString &toolTip = {})
     {

src/gui/properties/propertieswidget.cpp

@@ -34,6 +34,7 @@
 #include <QHeaderView>
 #include <QListWidgetItem>
 #include <QMenu>
+#include <QPointer>
 #include <QSplitter>
 #include <QShortcut>
 #include <QStackedWidget>
@@ -498,13 +499,20 @@ void PropertiesWidget::loadDynamicData()
 
             if (m_torrent->hasMetadata())
             {
+                using TorrentPtr = QPointer<BitTorrent::Torrent>;
+
                 m_ui->labelTotalPiecesVal->setText(tr("%1 x %2 (have %3)", "(torrent pieces) eg 152 x 4MB (have 25)").arg(m_torrent->piecesCount()).arg(Utils::Misc::friendlyUnit(m_torrent->pieceLength())).arg(m_torrent->piecesHave()));
 
                 if (!m_torrent->isSeed() && !m_torrent->isPaused() && !m_torrent->isQueued() && !m_torrent->isChecking())
                 {
                     // Pieces availability
                     showPiecesAvailability(true);
-                    m_piecesAvailability->setAvailability(m_torrent->pieceAvailability());
+                    m_torrent->fetchPieceAvailability([this, torrent = TorrentPtr(m_torrent)](const QVector<int> &pieceAvailability)
+                    {
+                        if (torrent == m_torrent)
+                            m_piecesAvailability->setAvailability(pieceAvailability);
+                    });
+
                     m_ui->labelAverageAvailabilityVal->setText(Utils::String::fromDouble(m_torrent->distributedCopies(), 3));
                 }
                 else
@@ -515,7 +523,12 @@ void PropertiesWidget::loadDynamicData()
                 // Progress
                 qreal progress = m_torrent->progress() * 100.;
                 m_ui->labelProgressVal->setText(Utils::String::fromDouble(progress, 1) + u'%');
-                m_downloadedPieces->setProgress(m_torrent->pieces(), m_torrent->downloadingPieces());
+
+                m_torrent->fetchDownloadingPieces([this, torrent = TorrentPtr(m_torrent)](const QBitArray &downloadingPieces)
+                {
+                    if (torrent == m_torrent)
+                        m_downloadedPieces->setProgress(m_torrent->pieces(), downloadingPieces);
+                });
             }
             else
             {
@@ -538,6 +551,19 @@ void PropertiesWidget::loadDynamicData()
             qDebug("Updating priorities in files tab");
             m_ui->filesList->setUpdatesEnabled(false);
 
+            using TorrentPtr = QPointer<BitTorrent::Torrent>;
+            m_torrent->fetchFilesProgress([this, torrent = TorrentPtr(m_torrent)](const QVector<qreal> &filesProgress)
+            {
+                if (torrent == m_torrent)
+                    m_propListModel->model()->updateFilesProgress(filesProgress);
+            });
+
+            m_torrent->fetchAvailableFileFractions([this, torrent = TorrentPtr(m_torrent)](const QVector<qreal> &availableFileFractions)
+            {
+                if (torrent == m_torrent)
+                    m_propListModel->model()->updateFilesAvailability(availableFileFractions);
+            });
+
             // Load torrent content if not yet done so
             const bool isContentInitialized = m_propListModel->model()->hasIndex(0, 0);
             if (!isContentInitialized)
@@ -546,9 +572,6 @@ void PropertiesWidget::loadDynamicData()
                 m_propListModel->model()->setupModelData(*m_torrent);
                 // Load file priorities
                 m_propListModel->model()->updateFilesPriorities(m_torrent->filePriorities());
-                // Update file progress/availability
-                m_propListModel->model()->updateFilesProgress(m_torrent->filesProgress());
-                m_propListModel->model()->updateFilesAvailability(m_torrent->availableFileFractions());
 
                 // Expand single-item folders recursively.
                 // This will trigger sorting and filtering so do it after all relevant data is loaded.
@@ -563,8 +586,6 @@ void PropertiesWidget::loadDynamicData()
             {
                 // Torrent content was loaded already, only make some updates
 
-                m_propListModel->model()->updateFilesProgress(m_torrent->filesProgress());
-                m_propListModel->model()->updateFilesAvailability(m_torrent->availableFileFractions());
                 // XXX: We don't update file priorities regularly for performance
                 // reasons. This means that priorities will not be updated if
                 // set from the Web UI.
@@ -583,15 +604,21 @@ void PropertiesWidget::loadUrlSeeds()
     if (!m_torrent)
         return;
 
-    m_ui->listWebSeeds->clear();
-    qDebug("Loading URL seeds");
-    const QVector<QUrl> hcSeeds = m_torrent->urlSeeds();
-    // Add url seeds
-    for (const QUrl &hcSeed : hcSeeds)
+    using TorrentPtr = QPointer<BitTorrent::Torrent>;
+    m_torrent->fetchURLSeeds([this, torrent = TorrentPtr(m_torrent)](const QVector<QUrl> &urlSeeds)
     {
-        qDebug("Loading URL seed: %s", qUtf8Printable(hcSeed.toString()));
-        new QListWidgetItem(hcSeed.toString(), m_ui->listWebSeeds);
-    }
+        if (torrent != m_torrent)
+            return;
+
+        m_ui->listWebSeeds->clear();
+        qDebug("Loading URL seeds");
+        // Add url seeds
+        for (const QUrl &urlSeed : urlSeeds)
+        {
+            qDebug("Loading URL seed: %s", qUtf8Printable(urlSeed.toString()));
+            new QListWidgetItem(urlSeed.toString(), m_ui->listWebSeeds);
+        }
+    });
 }
 
 Path PropertiesWidget::getFullPath(const QModelIndex &index) const

src/gui/properties/trackerlistwidget.cpp

@@ -36,6 +36,7 @@
 #include <QHeaderView>
 #include <QMenu>
 #include <QMessageBox>
+#include <QPointer>
 #include <QShortcut>
 #include <QStringList>
 #include <QTreeWidgetItem>
@@ -310,42 +311,50 @@ void TrackerListWidget::loadStickyItems(const BitTorrent::Torrent *torrent)
         m_LSDItem->setText(COL_MSG, privateMsg);
     }
 
-    // XXX: libtorrent should provide this info...
-    // Count peers from DHT, PeX, LSD
-    uint seedsDHT = 0, seedsPeX = 0, seedsLSD = 0, peersDHT = 0, peersPeX = 0, peersLSD = 0;
-    for (const BitTorrent::PeerInfo &peer : asConst(torrent->peers()))
+    using TorrentPtr = QPointer<const BitTorrent::Torrent>;
+    torrent->fetchPeerInfo([this, torrent = TorrentPtr(torrent)](const QVector<BitTorrent::PeerInfo> &peers)
     {
-        if (peer.isConnecting()) continue;
+        if (torrent != m_properties->getCurrentTorrent())
+            return;
 
-        if (peer.fromDHT())
-        {
-            if (peer.isSeed())
-                ++seedsDHT;
-            else
-                ++peersDHT;
-        }
-        if (peer.fromPeX())
+        // XXX: libtorrent should provide this info...
+        // Count peers from DHT, PeX, LSD
+        uint seedsDHT = 0, seedsPeX = 0, seedsLSD = 0, peersDHT = 0, peersPeX = 0, peersLSD = 0;
+        for (const BitTorrent::PeerInfo &peer : peers)
         {
-            if (peer.isSeed())
-                ++seedsPeX;
-            else
-                ++peersPeX;
-        }
-        if (peer.fromLSD())
-        {
-            if (peer.isSeed())
-                ++seedsLSD;
-            else
-                ++peersLSD;
+            if (peer.isConnecting())
+                continue;
+
+            if (peer.fromDHT())
+            {
+                if (peer.isSeed())
+                    ++seedsDHT;
+                else
+                    ++peersDHT;
+            }
+            if (peer.fromPeX())
+            {
+                if (peer.isSeed())
+                    ++seedsPeX;
+                else
+                    ++peersPeX;
+            }
+            if (peer.fromLSD())
+            {
+                if (peer.isSeed())
+                    ++seedsLSD;
+                else
+                    ++peersLSD;
+            }
         }
-    }
 
-    m_DHTItem->setText(COL_SEEDS, QString::number(seedsDHT));
-    m_DHTItem->setText(COL_LEECHES, QString::number(peersDHT));
-    m_PEXItem->setText(COL_SEEDS, QString::number(seedsPeX));
-    m_PEXItem->setText(COL_LEECHES, QString::number(peersPeX));
-    m_LSDItem->setText(COL_SEEDS, QString::number(seedsLSD));
-    m_LSDItem->setText(COL_LEECHES, QString::number(peersLSD));
+        m_DHTItem->setText(COL_SEEDS, QString::number(seedsDHT));
+        m_DHTItem->setText(COL_LEECHES, QString::number(peersDHT));
+        m_PEXItem->setText(COL_SEEDS, QString::number(seedsPeX));
+        m_PEXItem->setText(COL_LEECHES, QString::number(peersPeX));
+        m_LSDItem->setText(COL_SEEDS, QString::number(seedsLSD));
+        m_LSDItem->setText(COL_LEECHES, QString::number(peersLSD));
+    });
 }
 
 void TrackerListWidget::loadTrackers()