What Happened?

On opening photos, it kicks off a Branch.reorder_all (https://github.com/elementary/photos/blob/master/src/sidebar/Branch.vala#L337), which takes on the order of minutes on my computer to complete. This makes Photos effectively unusable unless I go to make coffee between launching it and starting to use it.

At first, I thought photos was stuck, since it sat consuming 100% CPU on one core for so long and elementary OS launched the "Photos isn't responding" window, but after letting it sit, it eventually finishes.

Steps to Reproduce

1. Have a very large collection of photos (86GB) neatly organized into folders based on year/month/day/photo
2. Open photos

Expected Behavior

It should open in a reasonable amount of time

OS Version

6.x (Odin)

Software Version

Compiled from git

Log Output

There's no logs in the path that's taking the time

Hardware Info

Linux firestar 5.11.0-37-generic #41~20.04.2-Ubuntu SMP Fri Sep 24 09:06:38 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

01:00.0 VGA compatible controller: NVIDIA Corporation GP104 [GeForce GTX 1070] (rev a1)

nvidia-driver-470/focal,now 470.74-0ubuntu0.20.04.1 amd64 [installed]