Code review comment for lp://qastaging/~franxesk/gallery-app/duplicates-feature

When starting gallery on a Galaxy Nexus with about 270 photos in the ~/Pictures the UI is blocked for several seconds (like 10-20) before showing the first thumbnails. We need to show something like "Upgrading the database" to the user during that time.

But this not only happens the first time when upgrading the DB, but all the time at the startup. I guess there is a bug somewhere ...

When upgrading the DB, the new DB was not written properly for me (might be that's because I wasn't able to close gallery properly. You could sync the DB to disc directly after the upgrade.

void GalleryManager::onMediaItemAdded(QString file, bool lookForDuplicates) is running the the main (UI) thread. And as calculating the md5sum is expensive, it block's the UI thread for quite a while.
Can we for example calculate the md5sum in the MediaMonitor already, and pass it to that function in addition (optionally). So the md5sum is calculated in the separate thread.

In general please use at least 1000 photos on the desktop, to easily see performance issues (I would suggest to even use 10.000 - to have a comparable speed to the phone).