QFileSystemModelPrivate::_q_directoryChanged get executed too frenquently which result in the performance issue

In my application there is a file management feature. I use QFileSytemModel to map filesystem from windows, and QListView to display it on UI.

when copy 1000 elements(200 folders + 800 files) from one folder to another folder, there will be a big performance issue on QFileSytemModel. As long as one path is watched, even i do copy past on windows on this path, UI still get freezed. Thounds of _q_directoryChanged  are queued for executing and block the whole application.

i think the root cause are:

1. QFileInfoGatherer running on a separate thread, _q_directoryChanged  running on main thread. they are connected in the following way:q->connect(&fileInfoGatherer, SIGNAL(updates(QString,QVector<QPair<QString,QFileInfo> >)),
q, SLOT(_q_fileSystemChanged(QString,QVector<QPair<QString,QFileInfo> >)));

During the _q_directoryChanged  excuting, it will block the ui.

2. the updates signal was emit too frequent than expected during copy. QFileInfoGatherer::getFileInfos executes around every 200ms, but each time it may emit several updates signal