Throttle folder status updates in general

changelog/unreleased/9919

@@ -0,0 +1,3 @@
+Enhancement: Reduce CPU load during discovery
+
+https://github.com/owncloud/client/pull/9919

src/gui/folder.cpp

@@ -127,7 +127,9 @@ Folder::Folder(const FolderDefinition &definition,
 
         connect(_engine.data(), &SyncEngine::aboutToRemoveAllFiles,
             this, &Folder::slotAboutToRemoveAllFiles);
-        connect(_engine.data(), &SyncEngine::transmissionProgress, this, &Folder::slotTransmissionProgress);
+        connect(_engine.data(), &SyncEngine::transmissionProgress, this, [this](const ProgressInfo &pi) {
+            emit ProgressDispatcher::instance()->progressInfo(this, pi);
+        });
         connect(_engine.data(), &SyncEngine::itemCompleted,
             this, &Folder::slotItemCompleted);
         connect(_engine.data(), &SyncEngine::newBigFolder,
@@ -1125,14 +1127,6 @@ void Folder::slotEmitFinishedDelayed()
     }
 }
 
-// the progress comes without a folder and the valid path set. Add that here
-// and hand the result over to the progress dispatcher.
-void Folder::slotTransmissionProgress(const ProgressInfo &pi)
-{
-    emit progressInfo(pi);
-    emit ProgressDispatcher::instance()->progressInfo(this, pi);
-}
-
 // a item is completed: count the errors and forward to the ProgressDispatcher
 void Folder::slotItemCompleted(const SyncFileItemPtr &item)
 {

src/gui/folder.h

@@ -367,7 +367,6 @@ class Folder : public QObject
     void syncStateChange();
     void syncStarted();
     void syncFinished(const SyncResult &result);
-    void progressInfo(const ProgressInfo &progress);
     void newBigFolderDiscovered(const QString &); // A new folder bigger than the threshold was discovered
     void syncPausedChanged(Folder *, bool paused);
     void canSyncChanged();
@@ -448,7 +447,6 @@ private slots:
      */
     void slotSyncError(const QString &message, ErrorCategory category = ErrorCategory::Normal);
 
-    void slotTransmissionProgress(const ProgressInfo &pi);
     void slotItemCompleted(const SyncFileItemPtr &);
 
     void etagRetreived(const QByteArray &, const QDateTime &tp);

src/gui/folderstatusmodel.cpp

@@ -93,8 +93,10 @@ void FolderStatusModel::setAccountState(AccountStatePtr accountState)
         info._checked = Qt::PartiallyChecked;
         _folders << info;
 
-        connect(f, &Folder::progressInfo, this, [f, this](const ProgressInfo &info) {
-            slotSetProgress(info, f);
+        connect(ProgressDispatcher::instance(), &ProgressDispatcher::progressInfo, this, [f, this](Folder *folder, const ProgressInfo &progress) {
+            if (folder == f) {
+                slotSetProgress(progress, f);
+            }
         });
 
         connect(f, &Folder::newBigFolderDiscovered, this, &FolderStatusModel::slotNewBigFolder, Qt::UniqueConnection);
@@ -895,38 +897,36 @@ void FolderStatusModel::slotSetProgress(const ProgressInfo &progress, Folder *f)
 
     auto *pi = &folder._progress;
 
-    const QVector<int> roles = { FolderStatusDelegate::SyncProgressItemString, FolderStatusDelegate::WarningCount, Qt::ToolTipRole };
-
-    switch (progress.status()) {
-    case ProgressInfo::None:
-        Q_UNREACHABLE();
-    case ProgressInfo::Discovery:
-        if (!progress._currentDiscoveredRemoteFolder.isEmpty()) {
-            pi->_overallSyncString = tr("Checking for changes in remote '%1'").arg(progress._currentDiscoveredRemoteFolder);
-            emit dataChanged(index(folderIndex), index(folderIndex), roles);
-        } else if (!progress._currentDiscoveredLocalFolder.isEmpty()) {
-            pi->_overallSyncString = tr("Checking for changes in local '%1'").arg(progress._currentDiscoveredLocalFolder);
-            emit dataChanged(index(folderIndex), index(folderIndex), roles);
-        }
-        break;
-    case ProgressInfo::Reconcile:
-        pi->_overallSyncString = tr("Reconciling changes");
-        emit dataChanged(index(folderIndex), index(folderIndex), roles);
-        break;
-    case ProgressInfo::Propagation:
-        Q_FALLTHROUGH();
-    case ProgressInfo::Done:
-        if (!progress._lastCompletedItem.isEmpty()
-            && Progress::isWarningKind(progress._lastCompletedItem._status)) {
-            pi->_warningCount++;
-        }
+    if (progress.status() == ProgressInfo::Done && !progress._lastCompletedItem.isEmpty()
+        && Progress::isWarningKind(progress._lastCompletedItem._status)) {
+        pi->_warningCount++;
+    }
+    // depending on the use of virtual files or small files this slot might be called very often.
+    // throttle the model updates to prevent an needlessly high cpu usage used on ui updates.
+    if (std::chrono::steady_clock::now() - folder._lastProgressUpdated > progressUpdateTimeOutC) {
+        const QVector<int> roles = { FolderStatusDelegate::SyncProgressItemString, FolderStatusDelegate::WarningCount, Qt::ToolTipRole };
 
-        // progress updates are expensive, throtle them
-        if (std::chrono::steady_clock::now() - folder._lastProgressUpdated > progressUpdateTimeOutC) {
+        switch (progress.status()) {
+        case ProgressInfo::None:
+            Q_UNREACHABLE();
+            break;
+        case ProgressInfo::Discovery:
+            if (!progress._currentDiscoveredRemoteFolder.isEmpty()) {
+                pi->_overallSyncString = tr("Checking for changes in remote '%1'").arg(progress._currentDiscoveredRemoteFolder);
+            } else if (!progress._currentDiscoveredLocalFolder.isEmpty()) {
+                pi->_overallSyncString = tr("Checking for changes in local '%1'").arg(progress._currentDiscoveredLocalFolder);
+            }
+            break;
+        case ProgressInfo::Reconcile:
+            pi->_overallSyncString = tr("Reconciling changes");
+            break;
+        case ProgressInfo::Propagation:
+            Q_FALLTHROUGH();
+        case ProgressInfo::Done:
             computeProgress(progress, pi);
-            folder._lastProgressUpdated = std::chrono::steady_clock::now();
-            emit dataChanged(index(folderIndex), index(folderIndex), roles);
         }
+        emit dataChanged(index(folderIndex), index(folderIndex), roles);
+        folder._lastProgressUpdated = std::chrono::steady_clock::now();
     }
 }