From 0d7c3673323f223bdc48a10f8d4c4dc2d65cc352 Mon Sep 17 00:00:00 2001
From: Vladimir Golovnev <glassez@yandex.ru>
Date: Fri, 6 Dec 2024 19:59:45 +0300
Subject: [PATCH] Avoid redundant requests of announce entries from libtorrent

PR #21949.
---
 src/base/bittorrent/sessionimpl.cpp | 25 ++++++++-----------------
 src/base/bittorrent/sessionimpl.h   |  3 +--
 2 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/src/base/bittorrent/sessionimpl.cpp b/src/base/bittorrent/sessionimpl.cpp
index 544ec7cea..26ae301b4 100644
--- a/src/base/bittorrent/sessionimpl.cpp
+++ b/src/base/bittorrent/sessionimpl.cpp
@@ -5526,8 +5526,6 @@ void SessionImpl::readAlerts()
 
     // Some torrents may become "finished" after different alerts handling.
     processPendingFinishedTorrents();
-
-    processTrackerStatuses();
 }
 
 void SessionImpl::handleAddTorrentAlert(const lt::add_torrent_alert *alert)
@@ -6203,7 +6201,10 @@ void SessionImpl::handleTrackerAlert(const lt::tracker_alert *alert)
     if (!torrent)
         return;
 
+    const auto prevSize = m_updatedTrackerStatuses.size();
     QMap<int, int> &updateInfo = m_updatedTrackerStatuses[torrent->nativeHandle()][std::string(alert->tracker_url())][alert->local_endpoint];
+    if (prevSize < m_updatedTrackerStatuses.size())
+        updateTrackerEntryStatuses(torrent->nativeHandle());
 
     if (alert->type() == lt::tracker_reply_alert::alert_type)
     {
@@ -6265,17 +6266,6 @@ void SessionImpl::handleTorrentConflictAlert(const lt::torrent_conflict_alert *a
 }
 #endif
 
-void SessionImpl::processTrackerStatuses()
-{
-    if (m_updatedTrackerStatuses.isEmpty())
-        return;
-
-    for (auto it = m_updatedTrackerStatuses.cbegin(); it != m_updatedTrackerStatuses.cend(); ++it)
-        updateTrackerEntryStatuses(it.key(), it.value());
-
-    m_updatedTrackerStatuses.clear();
-}
-
 void SessionImpl::saveStatistics() const
 {
     if (!m_isStatisticsDirty)
@@ -6300,20 +6290,21 @@ void SessionImpl::loadStatistics()
     m_previouslyUploaded = value[u"AlltimeUL"_s].toLongLong();
 }
 
-void SessionImpl::updateTrackerEntryStatuses(lt::torrent_handle torrentHandle, QHash<std::string, QHash<lt::tcp::endpoint, QMap<int, int>>> updatedTrackers)
+void SessionImpl::updateTrackerEntryStatuses(lt::torrent_handle torrentHandle)
 {
-    invokeAsync([this, torrentHandle = std::move(torrentHandle), updatedTrackers = std::move(updatedTrackers)]() mutable
+    invokeAsync([this, torrentHandle = std::move(torrentHandle)]() mutable
     {
         try
         {
             std::vector<lt::announce_entry> nativeTrackers = torrentHandle.trackers();
-            invoke([this, torrentHandle, nativeTrackers = std::move(nativeTrackers)
-                    , updatedTrackers = std::move(updatedTrackers)]
+            invoke([this, torrentHandle, nativeTrackers = std::move(nativeTrackers)]
             {
                 TorrentImpl *torrent = m_torrents.value(torrentHandle.info_hash());
                 if (!torrent || torrent->isStopped())
                     return;
 
+                QHash<std::string, QHash<lt::tcp::endpoint, QMap<int, int>>> updatedTrackers = m_updatedTrackerStatuses.take(torrentHandle);
+
                 QHash<QString, TrackerEntryStatus> trackers;
                 trackers.reserve(updatedTrackers.size());
                 for (const lt::announce_entry &announceEntry : nativeTrackers)
diff --git a/src/base/bittorrent/sessionimpl.h b/src/base/bittorrent/sessionimpl.h
index ef0c6b401..4f35c59c2 100644
--- a/src/base/bittorrent/sessionimpl.h
+++ b/src/base/bittorrent/sessionimpl.h
@@ -541,7 +541,6 @@ namespace BitTorrent
         void populateAdditionalTrackers();
         void enableIPFilter();
         void disableIPFilter();
-        void processTrackerStatuses();
         void processTorrentShareLimits(TorrentImpl *torrent);
         void populateExcludedFileNamesRegExpList();
         void prepareStartup();
@@ -605,7 +604,7 @@ namespace BitTorrent
         void saveStatistics() const;
         void loadStatistics();
 
-        void updateTrackerEntryStatuses(lt::torrent_handle torrentHandle, QHash<std::string, QHash<lt::tcp::endpoint, QMap<int, int>>> updatedTrackers);
+        void updateTrackerEntryStatuses(lt::torrent_handle torrentHandle);
 
         void handleRemovedTorrent(const TorrentID &torrentID, const QString &partfileRemoveError = {});