Add/restore all torrents in "paused" state and then resume those
that need to be really "resumed" (added/restored in "resumed" state).
Keep torrents with missing files paused.
Force recheck torrent with missing files when it's resumed by the user.
During startup we can get above 1000 alerts at each pop even with only
30 torrents in the queue. This is because libtorrent will post
piece_finished_alert and file_completed_alert for each torrent. These
alerts push out of the way the ones we care about.
The alert queue will be grown to max only if needed. So we don't use
more memory. It will greatly depend on how many torrents a user has in
their session.
When getting fastresume_rejected_alert we need to act as fast as
possible in pausing it, otherwise there's a chance it will begin
downloading and writing to disk before we pause it.
Updating file priorities is an async operation in libtorrent, when we
just updated it and immediately query it, we might get the
old/wrong values, so we rely on `updatedFilePrio` in this case.
Don't post "torrent resumed" event when torrent starts in "resumed"
state.
Fix confusing names. Now "resumed torrent" means "unpaused torrent"
only. When we load previously added torrent it is called "restored
torrent".
Now it applies the setting to all files in torrent, no matter whether
the file is previewable or not.
Torrent client shouldn't be smart by deciding which file this
option will be applied to, i.e. it should just follow the user's decision.
When having big torrents, the rechecking might take a while to
complete. Users need some sort of feedback that progress is being made.
Also, I changed the float to qreal since that's the return type.
This is another indication to the user that something is happening
behind the scenes.
Uses the same icon/color as "Checking" status.
Torrents in the `Moving` state are considered as "Active". This should
prevent accidental program exit from the user and inhibit system sleep.
Libtorrent can recheck only unpaused torrents. We get around this by
unpausing the torrent, issuing the recheck and pausing again after we
get alerted by libtorrent that the recheck has finished. This alert is
asyncronous. There is a small time frame where the program might start
downloading and writing data to the file before we pause it. This can
lead to data corruption if the file on disk is totally different that
the one expected by the torrent AND the file on disk is a valid file on
its own. OR in case the user points the new torrent to the wrong
directory by mistake.
To get around this the torrent is placed in upload_mode and out of
automanagement.
