[KPhotoAlbum] Fwd: Re: Breaking changes in file layout

[Johannes Zarl-Zierl]

Hi Andreas,

Am Montag, 6. April 2020, 18:47:53 CEST schrieb Andreas Schleth:
> Right now, I manually fix the file permissions on the various thumbnails
> with chmod -R ug+rw to allow access for different members of the family.
> Our common database resides on NFS and is accessed via different
> computers with different screen resolutions.
> As for now, this has worked with only occasional hiccups that can be
> fixed by cleaning up the permissions.
> 
> With our current setup I have around 4,5 GB worth of thumbnails and
> videoThumbnails laying around. That would at least double and clog my
> backups. Also it takes a several hours to regenerate all these
> thumbnails. Especially the video thumbnails take a while.
> 
> As you know, thumbnail generation is one of my sore points ever since
> the switch was made from the system generated thumbnails to custom
> thumbnails many years back.
> I have accidentally triggered thumbnail regeneration a few times to my
> dismay ...
> 
> 
> So, If you all could come up with a solution that avoids duplication of
> the thumbnails, I would be quite relieved.

A good point. I see two separate issues involved here:

1. Keeping thumbnails on the image storage.
If we adopt the proposal as-is, you can still have this, with minor effort on 
your side: You just have to move the cache directory to your shared location 
and add a symlink.
Would that be an acceptable solution?

2. thumbnail consistency
We could include the thumbnail size with the thumbnail database itself. This 
would prevent any future inconsistencies from happening.
The required change in the thumbnail file format can be implemented without a 
need to regenerate the thumbnail data.

How does that sound?

Cheers,
Johannes