[KPhotoAlbum] Thumbnail Performance & Compatibility: ImageManager vs KIO

[Johannes Zarl]

On Sunday 30 June 2013 18:49:49 Robert Krawitz wrote:
> > Actually, it roughly doubles the storage required. After all you have
> > one copy of the slightly less efficiently stored thumbnails, used by
> > almost all other applications, plus one copy of the slightly more
> > efficiently stored thumbnails, used by KPA.
> 
> Since I typically don't use a lot of other applications on the large
> majority of my image files, this isn't an issue (I currently have 1777
> thumbnails in my .thumbnails, vs. something over 70,000 in KPA).  And
> the storage is still small change compared to the image files
> themselves.  At least for my purposes, a good tradeoff.  In terms of
> actual storage, my KPA thumbnails consume about 450 MB; my entire image
> directory is close to 700 GB.  The non-KPA thumbnails consume about 50
> MB (in the .thumbnails/normal directory).

Ok, that's valuable input for me. I don't want to change something just to 
realise afterwards that for most people(*) it's a non-issue or maybe even 
detrimental.


> > If we already store the thumbnails twice, we could at least generate
> > them only once. By using PreviewJob to create the thumbnail that we
> > put into out thumbnailcache, we would effectively half the time spent
> > on thumbnail generation.
> 
> Well, it would have to convert them into the canonical format, and do
> the extra I/O to write them out.

Well, yes. But if that's the only issue I'd say it's worth trying it out to 
see if it really is a problem.


  Johannes



(*) Actually I had hoped that more people would comment on my original mail. 
After all, the suggestion "throw out ImageManager completely" should have 
triggered *some* response.