Handle tracker status updates asynchronously

* Add a helper for performing jobs in Session context
* Handle tracker status updates asynchronously

PR #18010.

src/base/bittorrent/session.h

@@ -468,6 +468,6 @@ namespace BitTorrent
         void trackersRemoved(Torrent *torrent, const QStringList &trackers);
         void trackerSuccess(Torrent *torrent, const QString &tracker);
         void trackerWarning(Torrent *torrent, const QString &tracker);
-        void trackerEntriesUpdated(const QHash<Torrent *, QSet<QString>> &updateInfos);
+        void trackerEntriesUpdated(Torrent *torrent, const QHash<QString, TrackerEntry> &updatedTrackerEntries);
     };
 }

src/base/bittorrent/sessionimpl.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>
  * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
  *
  * This program is free software; you can redistribute it and/or
@@ -35,7 +35,6 @@
 #include <ctime>
 #include <queue>
 #include <string>
-#include <utility>
 
 #ifdef Q_OS_WIN
 #include <Windows.h>
@@ -118,6 +117,24 @@ const Path CATEGORIES_FILE_NAME {u"categories.json"_qs};
 const int MAX_PROCESSING_RESUMEDATA_COUNT = 50;
 const int STATISTICS_SAVE_INTERVAL = std::chrono::milliseconds(15min).count();
 
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
+namespace std
+{
+    uint qHash(const std::string &key, uint seed = 0)
+    {
+        return qHash(QByteArray::fromRawData(key.data(), static_cast<int>(key.length())), seed);
+    }
+}
+
+namespace libtorrent
+{
+    uint qHash(const libtorrent::torrent_handle &key)
+    {
+        return static_cast<uint>(libtorrent::hash_value(key));
+    }
+}
+#endif
+
 namespace
 {
     const char PEER_ID[] = "qB";
@@ -5809,13 +5826,12 @@ void SessionImpl::handleTrackerAlert(const lt::tracker_alert *a)
     if (!torrent)
         return;
 
-    const auto trackerURL = QString::fromUtf8(a->tracker_url());
-    m_updatedTrackerEntries[torrent].insert(trackerURL);
+    QMap<TrackerEntry::Endpoint, int> &updateInfo = m_updatedTrackerEntries[torrent->nativeHandle()][std::string(a->tracker_url())];
 
     if (a->type() == lt::tracker_reply_alert::alert_type)
     {
         const int numPeers = static_cast<const lt::tracker_reply_alert *>(a)->num_peers;
-        torrent->updatePeerCount(trackerURL, a->local_endpoint, numPeers);
+        updateInfo.insert(a->local_endpoint, numPeers);
     }
 }
 
@@ -5869,20 +5885,50 @@ void SessionImpl::handleTorrentConflictAlert(const lt::torrent_conflict_alert *a
 
 void SessionImpl::processTrackerStatuses()
 {
+    if (m_updatedTrackerEntries.isEmpty())
+        return;
+
     for (auto it = m_updatedTrackerEntries.cbegin(); it != m_updatedTrackerEntries.cend(); ++it)
     {
-        auto torrent = static_cast<TorrentImpl *>(it.key());
-        const QSet<QString> &updatedTrackers = it.value();
+        invokeAsync([this, torrentHandle = it.key(), updatedTrackers = it.value()]() mutable
+        {
+            try
+            {
+                std::vector<lt::announce_entry> nativeTrackers = torrentHandle.trackers();
+                invoke([this, torrentHandle, nativeTrackers = std::move(nativeTrackers)
+                        , updatedTrackers = std::move(updatedTrackers)]
+                {
+                    TorrentImpl *torrent = m_torrents.value(torrentHandle.info_hash());
+                    if (!torrent)
+                        return;
 
-        for (const QString &trackerURL : updatedTrackers)
-            torrent->invalidateTrackerEntry(trackerURL);
+                    QHash<QString, TrackerEntry> updatedTrackerEntries;
+                    updatedTrackerEntries.reserve(updatedTrackers.size());
+                    for (const lt::announce_entry &announceEntry : nativeTrackers)
+                    {
+                        const auto updatedTrackersIter = updatedTrackers.find(announceEntry.url);
+                        if (updatedTrackersIter == updatedTrackers.end())
+                            continue;
+
+                        const QMap<TrackerEntry::Endpoint, int> &updateInfo = updatedTrackersIter.value();
+                        TrackerEntry trackerEntry = torrent->updateTrackerEntry(announceEntry, updateInfo);
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
+                        updatedTrackerEntries[trackerEntry.url] = std::move(trackerEntry);
+#else
+                        updatedTrackerEntries.emplace(trackerEntry.url, std::move(trackerEntry));
+#endif
                     }
 
-    if (!m_updatedTrackerEntries.isEmpty())
+                    emit trackerEntriesUpdated(torrent, updatedTrackerEntries);
+                });
+            }
+            catch (const std::exception &)
             {
-        emit trackerEntriesUpdated(m_updatedTrackerEntries);
-        m_updatedTrackerEntries.clear();
             }
+        });
+    }
+
+    m_updatedTrackerEntries.clear();
 }
 
 void SessionImpl::saveStatistics() const

src/base/bittorrent/sessionimpl.h

@@ -29,6 +29,7 @@
 
 #pragma once
 
+#include <utility>
 #include <variant>
 #include <vector>
 
@@ -36,11 +37,11 @@
 #include <libtorrent/portmap.hpp>
 #include <libtorrent/torrent_handle.hpp>
 
+#include <QtContainerFwd>
 #include <QElapsedTimer>
 #include <QHash>
 #include <QPointer>
 #include <QSet>
-#include <QtContainerFwd>
 #include <QVector>
 
 #include "base/path.h"
@@ -438,6 +439,12 @@ namespace BitTorrent
         void addMappedPorts(const QSet<quint16> &ports);
         void removeMappedPorts(const QSet<quint16> &ports);
 
+        template <typename Func>
+        void invoke(Func &&func)
+        {
+            QMetaObject::invokeMethod(this, std::forward<Func>(func));
+        }
+
         void invokeAsync(std::function<void ()> func);
 
     private slots:
@@ -719,7 +726,9 @@ namespace BitTorrent
         QMap<QString, CategoryOptions> m_categories;
         QSet<QString> m_tags;
 
-        QHash<Torrent *, QSet<QString>> m_updatedTrackerEntries;
+        // This field holds amounts of peers reported by trackers in their responses to announces
+        // (torrent.tracker_name.tracker_local_endpoint.num_peers)
+        QHash<lt::torrent_handle, QHash<std::string, QMap<TrackerEntry::Endpoint, int>>> m_updatedTrackerEntries;
 
         // I/O errored torrents
         QSet<TorrentID> m_recentErroredTorrents;

src/base/bittorrent/torrentimpl.cpp

@@ -522,9 +522,6 @@ void TorrentImpl::setAutoManaged(const bool enable)
 
 QVector<TrackerEntry> TorrentImpl::trackers() const
 {
-    if (!m_updatedTrackerEntries.isEmpty())
-        refreshTrackerEntries();
-
     return m_trackerEntries;
 }
 
@@ -1515,43 +1512,25 @@ void TorrentImpl::fileSearchFinished(const Path &savePath, const PathList &fileN
     endReceivedMetadataHandling(savePath, fileNames);
 }
 
-void TorrentImpl::updatePeerCount(const QString &trackerURL, const TrackerEntry::Endpoint &endpoint, const int count)
-{
-    m_updatedTrackerEntries[trackerURL][endpoint] = count;
-}
-
-void TorrentImpl::invalidateTrackerEntry(const QString &trackerURL)
+TrackerEntry TorrentImpl::updateTrackerEntry(const lt::announce_entry &announceEntry, const QMap<TrackerEntry::Endpoint, int> &updateInfo)
 {
-    std::ignore = m_updatedTrackerEntries[trackerURL];
-}
-
-void TorrentImpl::refreshTrackerEntries() const
-{
-    const std::vector<lt::announce_entry> nativeTrackers = m_nativeHandle.trackers();
-    Q_ASSERT(nativeTrackers.size() == m_trackerEntries.size());
-
-    for (TrackerEntry &trackerEntry : m_trackerEntries)
+    const auto it = std::find_if(m_trackerEntries.begin(), m_trackerEntries.end()
+            , [&announceEntry](const TrackerEntry &trackerEntry)
     {
-        const auto updatedTrackerIter = m_updatedTrackerEntries.find(trackerEntry.url);
-        if (updatedTrackerIter == m_updatedTrackerEntries.end())
-            continue;
-
-        const auto nativeTrackerIter = std::find_if(nativeTrackers.cbegin(), nativeTrackers.cend()
-                                    , [trackerURL = trackerEntry.url.toStdString()](const lt::announce_entry &announceEntry)
-        {
-            return (announceEntry.url == trackerURL);
+        return (trackerEntry.url == QString::fromStdString(announceEntry.url));
     });
-        Q_ASSERT(nativeTrackerIter != nativeTrackers.cend());
 
-        const lt::announce_entry &announceEntry = *nativeTrackerIter;
+    Q_ASSERT(it != m_trackerEntries.end());
+    // TODO: use [[unlikely]] in C++20
+    if (Q_UNLIKELY(it == m_trackerEntries.end()))
+        return {};
+
 #ifdef QBT_USES_LIBTORRENT2
-        updateTrackerEntry(trackerEntry, announceEntry, m_nativeHandle.info_hashes(), updatedTrackerIter.value());
+    ::updateTrackerEntry(*it, announceEntry, nativeHandle().info_hashes(), updateInfo);
 #else
-        updateTrackerEntry(trackerEntry, announceEntry, updatedTrackerIter.value());
+    ::updateTrackerEntry(*it, announceEntry, updateInfo);
 #endif
-    }
-
-    m_updatedTrackerEntries.clear();
+    return *it;
 }
 
 std::shared_ptr<const libtorrent::torrent_info> TorrentImpl::nativeTorrentInfo() const

src/base/bittorrent/torrentimpl.h

@@ -248,15 +248,13 @@ namespace BitTorrent
         void saveResumeData(lt::resume_data_flags_t flags = {});
         void handleMoveStorageJobFinished(const Path &path, bool hasOutstandingJob);
         void fileSearchFinished(const Path &savePath, const PathList &fileNames);
-        void updatePeerCount(const QString &trackerURL, const TrackerEntry::Endpoint &endpoint, int count);
-        void invalidateTrackerEntry(const QString &trackerURL);
+        TrackerEntry updateTrackerEntry(const lt::announce_entry &announceEntry, const QMap<TrackerEntry::Endpoint, int> &updateInfo);
 
     private:
         using EventTrigger = std::function<void ()>;
 
         std::shared_ptr<const lt::torrent_info> nativeTorrentInfo() const;
 
-        void refreshTrackerEntries() const;
         void updateStatus(const lt::torrent_status &nativeStatus);
         void updateState();
 
@@ -316,10 +314,7 @@ namespace BitTorrent
 
         MaintenanceJob m_maintenanceJob = MaintenanceJob::None;
 
-        // TODO: Use QHash<TrackerEntry::Endpoint, int> once Qt5 is dropped.
-        using TrackerEntryUpdateInfo = QMap<TrackerEntry::Endpoint, int>;
-        mutable QHash<QString, TrackerEntryUpdateInfo> m_updatedTrackerEntries;
-        mutable QVector<TrackerEntry> m_trackerEntries;
+        QVector<TrackerEntry> m_trackerEntries;
         FileErrorInfo m_lastFileError;
 
         // Persistent data

src/gui/transferlistfilterswidget.cpp

@@ -599,23 +599,16 @@ void TrackerFiltersList::setDownloadTrackerFavicon(bool value)
     }
 }
 
-void TrackerFiltersList::handleTrackerEntriesUpdated(const QHash<BitTorrent::Torrent *, QSet<QString>> &updateInfos)
+void TrackerFiltersList::handleTrackerEntriesUpdated(const BitTorrent::Torrent *torrent
+        , const QHash<QString, BitTorrent::TrackerEntry> &updatedTrackerEntries)
 {
-    for (auto torrentsIt = updateInfos.cbegin(); torrentsIt != updateInfos.cend(); ++torrentsIt)
-    {
-        const BitTorrent::Torrent *torrent = torrentsIt.key();
-        const QSet<QString> &trackerURLs = torrentsIt.value();
     const BitTorrent::TorrentID id = torrent->id();
 
     auto errorHashesIt = m_errors.find(id);
     auto warningHashesIt = m_warnings.find(id);
 
-        const QVector<BitTorrent::TrackerEntry> trackers = torrent->trackers();
-        for (const BitTorrent::TrackerEntry &trackerEntry : trackers)
+    for (const BitTorrent::TrackerEntry &trackerEntry : updatedTrackerEntries)
     {
-            if (!trackerURLs.contains(trackerEntry.url))
-                continue;
-
         if (trackerEntry.status == BitTorrent::TrackerEntry::Working)
         {
             if (errorHashesIt != m_errors.end())
@@ -651,7 +644,6 @@ void TrackerFiltersList::handleTrackerEntriesUpdated(const QHash<BitTorrent::Tor
         m_errors.erase(errorHashesIt);
     if ((warningHashesIt != m_warnings.end()) && warningHashesIt.value().isEmpty())
         m_warnings.erase(warningHashesIt);
-    }
 
     item(ERROR_ROW)->setText(tr("Error (%1)").arg(m_errors.size()));
     item(WARNING_ROW)->setText(tr("Warning (%1)").arg(m_warnings.size()));
@@ -920,9 +912,10 @@ void TransferListFiltersWidget::changeTrackerless(const BitTorrent::Torrent *tor
     m_trackerFilters->changeTrackerless(torrent, trackerless);
 }
 
-void TransferListFiltersWidget::trackerEntriesUpdated(const QHash<BitTorrent::Torrent *, QSet<QString>> &updateInfos)
+void TransferListFiltersWidget::trackerEntriesUpdated(const BitTorrent::Torrent *torrent
+        , const QHash<QString, BitTorrent::TrackerEntry> &updatedTrackerEntries)
 {
-    m_trackerFilters->handleTrackerEntriesUpdated(updateInfos);
+    m_trackerFilters->handleTrackerEntriesUpdated(torrent, updatedTrackerEntries);
 }
 
 void TransferListFiltersWidget::onCategoryFilterStateChanged(bool enabled)

src/gui/transferlistfilterswidget.h

@@ -131,7 +131,8 @@ public:
     void removeTrackers(const BitTorrent::Torrent *torrent, const QStringList &trackers);
     void refreshTrackers(const BitTorrent::Torrent *torrent);
     void changeTrackerless(const BitTorrent::Torrent *torrent, bool trackerless);
-    void handleTrackerEntriesUpdated(const QHash<BitTorrent::Torrent *, QSet<QString>> &updateInfos);
+    void handleTrackerEntriesUpdated(const BitTorrent::Torrent *torrent
+            , const QHash<QString, BitTorrent::TrackerEntry> &updatedTrackerEntries);
     void setDownloadTrackerFavicon(bool value);
 
 private slots:
@@ -180,7 +181,8 @@ public slots:
     void removeTrackers(const BitTorrent::Torrent *torrent, const QStringList &trackers);
     void refreshTrackers(const BitTorrent::Torrent *torrent);
     void changeTrackerless(const BitTorrent::Torrent *torrent, bool trackerless);
-    void trackerEntriesUpdated(const QHash<BitTorrent::Torrent *, QSet<QString>> &updateInfos);
+    void trackerEntriesUpdated(const BitTorrent::Torrent *torrent
+            , const QHash<QString, BitTorrent::TrackerEntry> &updatedTrackerEntries);
 
 private slots:
     void onCategoryFilterStateChanged(bool enabled);