Cached items in fsCachedData folder?

[R C-R]

On my iMac in the container folder for both AD & AP there is a folder named "fsCachedData." In each there are multiple files with filename like "88C94449-78EC-413E-BA92-FB6441D35C12" & no extension. Below are their full file paths:

~/Library/Containers/com.seriflabs.affinitydesigner/Data/Library/Caches/com.seriflabs.affinitydesigner/fsCachedData

~/Library/Containers/com.seriflabs.affinityphoto/Data/Library/Caches/com.seriflabs.affinityphoto/fsCachedData

Currently there are 245 files in the AD folder & 27 files in the AP one. Both apps were bought from the Mac App Store. APub was bought from the Affinity Store. It has no similar folder I can find in its ~/Library/Application Support/Affinity Publisher/ folder.

I want to know if it is normal for these two folders to contain files like these, what puts them there, & if it is OK to delete them.

More info: according to Finder & 'Get info' the default app set to open them is TextEdit, but oddly double-clicking on them opens them in Preview.app, AD, or AP (different apps depending on which one I double-click on). All are RGB or greyscale image files. Most are small thumbnail sized images around 150 × 84 px, but a few are as large as 1250 x 1000 px or so.

A few I recognize as images that have appeared in the Welcome screen of AD or AP. I cannot identify a source for most of the others, although some may be cached thumbnails from Pixabay.

[Old Bruce]

6 hours ago, R C-R said:

On my iMac in the container folder for both AD & AP there is a folder named "fsCachedData." In each there are multiple files with filename like "88C94449-78EC-413E-BA92-FB6441D35C12" & no extension.

Same here, oddly for Designer they are all dated for February 29 of this year and the ones for Photo are from up to a year ago.

[thomaso]

For Serif-Store purchases these cache files are stored in ~/Library/Caches.

You should be able to display the content of these files simply via macOS Quicklook (select file(s) + space key), or by adding an Affinity suffix.
In my cache folders these files contain irrelevant images which all seem to be stored for the "Welcome Screen" (which I have set to off in all 3 apps) or from the Stock-image Panel.

Cache files usually are user-related content which gets stored in the sake to speed up just in case they might get used. You can try and copy such a folder + delete its original to experience the difference. They will become re-stored automatically.

These cache folders in Affinity may appear quite small compared to those of your internet browser apps or of the Adobe RAW converter app for instance.

Library Cache folders get backuped by TimeMachine only for the 24hrs local snapshots – but not onto your actual backup volume (the folders simply don't exist there).

[R C-R]

10 minutes ago, Old Bruce said:

Same here, oddly for Designer they are all dated for February 29 of this year and the ones for Photo are from up to a year ago.

For AD, I have 11 dated February 29 with the rest dated either April 13 or 18. For AP, all of mine except 1 are from March or April of this year.

Also, I was wrong about none of them opening in TextEdit when I double-click on them -- a few do open in TextEdit by default. From browsing through them, they contain a collection of metadata (not images) about Pixabay files, I suppose from keyword searches I did in the Stock panel.

[R C-R]

1 hour ago, thomaso said:

For Serif-Store purchases these cache files are stored in ~/Library/Caches.

Thanks! I thought I looked in there but missed the com.seriflabs.affinitypublisher folder among all the others.

2 hours ago, thomaso said:

You should be able to display the content of these files simply via macOS Quicklook (select file(s) + space key), or by adding an Affinity suffix.

Quick Look works with most of them, but not for (I think) svg files, or for ones that are just Pixabay metadata -- QL just shows a generic document icon for them. I guess that is to be expected.

I know cache files are usually just there to improve rendering speed so unless they start using ridiculous amounts of disk space (which the Affinity ones as yet do not do) as a rule I leave them alone.

FWIW, in the past I have been advised by Apple Support to clear certain ones of them & their corresponding (SQLite?) database files to fix certain specific issues, like the wrong image being displayed or (more rarely) an app crashing for no obvious reason. IIRC, they said it was not a good idea to try to delete just individual cache files & not to delete all of them in a folder without also deleting the database files. I have the impression that they consider this a 'last resort' fix, something to try when nothing else does.

[thomaso]

On 5/14/2020 at 10:22 PM, R C-R said:

not a good idea to try to delete just individual cache files & not to delete all of them in a folder without also deleting the database files. I have the impression that they consider this a 'last resort' fix, something to try when nothing else does.

Agree. If you want to get rid of those files you should delete their parent (com.seriflabs. ...) folder which in this case appears to include the databases (.db).

Actually as a user I can't know how a file inside the Library folder, even inside my user folder, is organised by an app or the system. So, even if cache files inside the ~/Library/Caches folder aren't fundamentally essential and might get auto-replaced if needed, a manual manipulation might confuse a related process which naturally trusts to be informed any time correctly about these files, without having a reason to reckon with any user action at those hidden locations.

On the other hand since ~/Library/Caches/ isn't backuped by timemachine while I can reinstall my entire disk(s) from a backup, user library included, I, me as user, do also trust that an app or the system can cope with a manual deletion of such caches, even if possibly with some hiccups for a while (e.g. app wants to write into this folder > is missing the folder > has to recreate the folder > has to recreate the files).

And on another hand (are they limited?) I can't trust that a process really is aware what files it stores in such folders, or whether some may be useless, either now or at any later time and just forgotten to get deleted (or simply just not cared about). Like every improved bug-deleting program code does cause new, unexpected issues. "A computer is an instrument which supports us to solve problems we would not have without computers."

Edit: What sparked your interest in this folder, since it is not large and you initially could recognize / see / assign its content?