Bug 379937

Summary: Sorting is slow for 'type' column
Product: [Applications] dolphin Reporter: Brennan Kinney <polarathene-signup>
Component: view-engine: generalAssignee: Dolphin Bug Assignee <dolphin-bugs-null>
Status: REPORTED ---    
Severity: wishlist CC: popov895
Priority: NOR    
Version First Reported In: 17.04.0   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Brennan Kinney 2017-05-17 12:38:18 UTC 
15 folders 14k files directory. Sorted by 'filename' is reasonably quick, by 'type' initial time until display is about 5 seconds, navigations to the directory without a refresh are 2 seconds delay before displaying anything.

This indicates some sort of caching might be in place, yet is still much slower than a default filename sort? 

This is with a details view on an SSD, i5-6500 CPU, 32GB RAM, Nvidia 1070 non-free drivers. Distro is Manjaro(no idea why it's missing on the platform list considering popularity?)
Comment 1 Christoph Feck 2017-05-17 13:11:44 UTC 
Sorting by type needs to check the MIME type, which means it needs to load the file contents.
Comment 2 Brennan Kinney 2017-05-17 13:22:43 UTC 
(In reply to Christoph Feck from comment #1)
> Sorting by type needs to check the MIME type, which means it needs to load
> the file contents.

Is there no way to cache the sorted result the next time the directory is accessed with the type column for sorting? If nothing has changed within the directory, such as navigate up/back and then to the directory again...why does the directory contents need to be sorted again?

Is memoization not an option? Or in my case an extension column to sort would probably work just as well without requiring to load file contents?
Comment 3 popov895 2022-04-19 20:37:05 UTC 
(In reply to Christoph Feck from comment #1)
> Sorting by type needs to check the MIME type, which means it needs to load
> the file contents.

Why not to sort by file extension?