Add option for hashing_threads, use 10 asyc IO threads

Add option for setting lt::settings_pack::hashing_threads
introduced by libtorrent 2.0. It has no effect for earlier
libtorrent versions.
Use 10 async IO threads, as per #11461.
Closes #11461.

src/base/bittorrent/session.cpp

@@ -329,7 +329,8 @@ Session::Session(QObject *parent)
     , m_IPFilterFile(BITTORRENT_SESSION_KEY("IPFilter"))
     , m_announceToAllTrackers(BITTORRENT_SESSION_KEY("AnnounceToAllTrackers"), false)
     , m_announceToAllTiers(BITTORRENT_SESSION_KEY("AnnounceToAllTiers"), true)
-    , m_asyncIOThreads(BITTORRENT_SESSION_KEY("AsyncIOThreadsCount"), 4)
+    , m_asyncIOThreads(BITTORRENT_SESSION_KEY("AsyncIOThreadsCount"), 10)
+    , m_hashingThreads(BITTORRENT_SESSION_KEY("HashingThreadsCount"), 2)
     , m_filePoolSize(BITTORRENT_SESSION_KEY("FilePoolSize"), 40)
     , m_checkingMemUsage(BITTORRENT_SESSION_KEY("CheckingMemUsageSize"), 32)
 #if (LIBTORRENT_VERSION_NUM >= 10206)
@@ -1269,6 +1270,9 @@ void Session::loadLTSettings(lt::settings_pack &settingsPack)
     settingsPack.set_int(lt::settings_pack::peer_turnover_interval, peerTurnoverInterval());
 
     settingsPack.set_int(lt::settings_pack::aio_threads, asyncIOThreads());
+#if (LIBTORRENT_VERSION_NUM >= 20000)
+    settingsPack.set_int(lt::settings_pack::hashing_threads, hashingThreads());
+#endif
     settingsPack.set_int(lt::settings_pack::file_pool_size, filePoolSize());
 
     const int checkingMemUsageSize = checkingMemUsage() * 64;
@@ -3030,6 +3034,20 @@ void Session::setAsyncIOThreads(const int num)
     configureDeferred();
 }
 
+int Session::hashingThreads() const
+{
+    return qBound(1, m_hashingThreads.value(), 1024);
+}
+
+void Session::setHashingThreads(const int num)
+{
+    if (num == m_hashingThreads)
+        return;
+
+    m_hashingThreads = num;
+    configureDeferred();
+}
+
 int Session::filePoolSize() const
 {
     return m_filePoolSize;

src/base/bittorrent/session.h

@@ -342,6 +342,8 @@ namespace BitTorrent
         void setPeerTurnoverInterval(int num);
         int asyncIOThreads() const;
         void setAsyncIOThreads(int num);
+        int hashingThreads() const;
+        void setHashingThreads(int num);
         int filePoolSize() const;
         void setFilePoolSize(int size);
         int checkingMemUsage() const;
@@ -651,6 +653,7 @@ namespace BitTorrent
         CachedSettingValue<bool> m_announceToAllTrackers;
         CachedSettingValue<bool> m_announceToAllTiers;
         CachedSettingValue<int> m_asyncIOThreads;
+        CachedSettingValue<int> m_hashingThreads;
         CachedSettingValue<int> m_filePoolSize;
         CachedSettingValue<int> m_checkingMemUsage;
         CachedSettingValue<int> m_diskCacheSize;

src/gui/advancedsettings.cpp

@@ -85,6 +85,9 @@ namespace
         // libtorrent section
         LIBTORRENT_HEADER,
         ASYNC_IO_THREADS,
+#if (LIBTORRENT_VERSION_NUM >= 20000)
+        HASHING_THREADS,
+#endif
         FILE_POOL_SIZE,
         CHECKING_MEM_USAGE,
 #if (LIBTORRENT_VERSION_NUM < 20000)
@@ -187,6 +190,10 @@ void AdvancedSettings::saveAdvancedSettings()
 #endif
     // Async IO threads
     session->setAsyncIOThreads(m_spinBoxAsyncIOThreads.value());
+#if (LIBTORRENT_VERSION_NUM >= 20000)
+    // Hashing threads
+    session->setHashingThreads(m_spinBoxHashingThreads.value());
+#endif
     // File pool size
     session->setFilePoolSize(m_spinBoxFilePoolSize.value());
     // Checking Memory Usage
@@ -409,6 +416,16 @@ void AdvancedSettings::loadAdvancedSettings()
     m_spinBoxAsyncIOThreads.setValue(session->asyncIOThreads());
     addRow(ASYNC_IO_THREADS, (tr("Asynchronous I/O threads") + ' ' + makeLink("https://www.libtorrent.org/reference-Settings.html#aio_threads", "(?)"))
             , &m_spinBoxAsyncIOThreads);
+
+#if (LIBTORRENT_VERSION_NUM >= 20000)
+    // Hashing threads
+    m_spinBoxHashingThreads.setMinimum(1);
+    m_spinBoxHashingThreads.setMaximum(1024);
+    m_spinBoxHashingThreads.setValue(session->hashingThreads());
+    addRow(HASHING_THREADS, (tr("Hashing threads") + ' ' + makeLink("https://www.libtorrent.org/reference-Settings.html#hashing_threads", "(?)"))
+            , &m_spinBoxHashingThreads);
+#endif
+
     // File pool size
     m_spinBoxFilePoolSize.setMinimum(1);
     m_spinBoxFilePoolSize.setMaximum(std::numeric_limits<int>::max());

src/gui/advancedsettings.h

@@ -77,6 +77,8 @@ private:
 #if (LIBTORRENT_VERSION_NUM < 20000)
     QSpinBox m_spinBoxCache, m_spinBoxCacheTTL;
     QCheckBox m_checkBoxCoalesceRW;
+#else
+    QSpinBox m_spinBoxHashingThreads;
 #endif
 
     // OS dependent settings

src/webui/api/appcontroller.cpp

@@ -277,6 +277,8 @@ void AppController::preferencesAction()
     // libtorrent preferences
     // Async IO threads
     data["async_io_threads"] = session->asyncIOThreads();
+    // Hashing threads
+    data["hashing_threads"] = session->hashingThreads();
     // File pool size
     data["file_pool_size"] = session->filePoolSize();
     // Checking memory usage
@@ -701,6 +703,9 @@ void AppController::setPreferencesAction()
     // Async IO threads
     if (hasKey("async_io_threads"))
         session->setAsyncIOThreads(it.value().toInt());
+    // Hashing threads
+    if (hasKey("hashing_threads"))
+        session->setHashingThreads(it.value().toInt());
     // File pool size
     if (hasKey("file_pool_size"))
         session->setFilePoolSize(it.value().toInt());

src/webui/www/private/views/preferences.html

@@ -943,6 +943,14 @@
                     <input type="text" id="asyncIOThreads" style="width: 15em;" />
                 </td>
             </tr>
+            <tr>
+                <td>
+                    <label for="hashingThreads">QBT_TR(Hashing threads (requires libtorrent >= 2.0):)QBT_TR[CONTEXT=OptionsDialog]&nbsp;<a href="https://www.libtorrent.org/reference-Settings.html#hashing_threads" target="_blank">(?)</a></label>
+                </td>
+                <td>
+                    <input type="text" id="hashingThreads" style="width: 15em;" />
+                </td>
+            </tr>
             <tr>
                 <td>
                     <label for="filePoolSize">QBT_TR(File pool size:)QBT_TR[CONTEXT=OptionsDialog]&nbsp;<a href="https://www.libtorrent.org/reference-Settings.html#file_pool_size" target="_blank">(?)</a></label>
@@ -1871,6 +1879,7 @@
                         $('resolvePeerCountries').setProperty('checked', pref.resolve_peer_countries);
                         // libtorrent section
                         $('asyncIOThreads').setProperty('value', pref.async_io_threads);
+                        $('hashingThreads').setProperty('value', pref.hashing_threads);
                         $('filePoolSize').setProperty('value', pref.file_pool_size);
                         $('outstandMemoryWhenCheckingTorrents').setProperty('value', pref.checking_memory_use);
                         $('diskCache').setProperty('value', pref.disk_cache);
@@ -2257,6 +2266,7 @@
 
             // libtorrent section
             settings.set('async_io_threads', $('asyncIOThreads').getProperty('value'));
+            settings.set('hashing_threads', $('hashingThreads').getProperty('value'));
             settings.set('file_pool_size', $('filePoolSize').getProperty('value'));
             settings.set('checking_memory_use', $('outstandMemoryWhenCheckingTorrents').getProperty('value'));
             settings.set('disk_cache', $('diskCache').getProperty('value'));