Bug 436501

Summary: Cache mechanism in Dolphin is making it completely unreliable.
Product: [Applications] dolphin Reporter: Leinier Cruz Salfran <leiniercs>
Component: generalAssignee: Dolphin Bug Assignee <dolphin-bugs-null>
Status: REPORTED ---    
Severity: normal CC: gabriel.barrantes.dev, kde, kfm-devel, tagwerk19
Priority: NOR    
Version: 20.12.0   
Target Milestone: ---   
Platform: FreeBSD Ports   
OS: FreeBSD   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: The demonstration of the last bad thing I've detected on Dolphin

Description Leinier Cruz Salfran 2021-05-02 19:45:11 UTC 
SUMMARY

Hello Dolphin developers. You're doing a great work with Dolphin, I really like the user interface and the possibilities it gives me, besides it is the intrinsic files explorer of the desktop environment, so it is interconnected with other stuff of the ecosystem. But, and here I go, there is something that is making Dolphin completely unreliable and it is happening from some years ago when I detected for the first time a problem with a transfer of files I made. I didn't reported it at the time but now.

The source of that bad behavior is the "cache" system you've implemented in it.

Please, let me tell you that the "cache system" is badly coded (100%) and it is causing problems with the visualization and transfer of files between locations and visualization of disk information like free space, among other things I'm pretty sure it is happening, but I didn't see them yet. I've lost files because of wrong copies (files not copied) and about a week ago my cousin reported to me that he didn't find some music files he had in the flash memory he gave me to make an organizational operation (he had a lot of musics on the root directory and he wanted me to put those musics into several directories). The last bad thing I detected was on Apr-30-2021:
- I copied a first SVG image from one location to another.
- Dolphin showed me the preview of the first image correctly.
- I found a second image I liked more.
- I deleted the first image from the destination location.
- I transferred the second image to the destination location.
- Dolphin showed me the preview of the second image correctly.
- I changed the name of the second image to the name of the first image.
- The problem: Dolphin showed me the image of the first image instead of the second.

Dolphin is a critical piece of the KDE Desktop Environment. It job is to work directly with files and directories, those who are important to everybody, so, it have to do it work completely well and beyond (200%). Do you imagine that you loss some important files of a project of yours because Dolphin didn't copied them correctly to the backup device, or you loss your favorites music and films, or you get embarrassed in your school or work when it is your turn to do a presentation in front of an auditorium and the "thing" doesn't work because of the lack of files in the memory flash? That must not happen never.

I have a proposal and it would be great if you all take it very seriously:

- Eliminate completely the cache system in Dolphin and make Dolphin do the work it need every time it need to do it.
Comment 1 Leinier Cruz Salfran 2021-05-02 19:59:49 UTC 
Created attachment 138096 [details]
The demonstration of the last bad thing I've detected on Dolphin

Here is the video that demonstrate that the "cache" system you've implemented in Dolphin must be wiped completely.
Comment 2 Kai Uwe Broulik 2021-05-02 21:03:53 UTC 
Lowering severity as no data loss occurs, merely a display issue.
Comment 3 Leinier Cruz Salfran 2021-05-02 21:08:56 UTC 
It seems you didn’t read the part when I wrote “my cousin reported to me that he doesn’t find some music he had on his flash memory”. Did you read the entire report?

> On 2 May 2021, at 5:03 PM, Kai Uwe Broulik <bugzilla_noreply@kde.org> wrote:
> 
> https://bugs.kde.org/show_bug.cgi?id=436501
> 
> Kai Uwe Broulik <kde@privat.broulik.de> changed:
> 
>           What    |Removed                     |Added
> ----------------------------------------------------------------------------
>           Severity|critical                    |normal
>                 CC|                            |kde@privat.broulik.de
> 
> --- Comment #2 from Kai Uwe Broulik <kde@privat.broulik.de> ---
> Lowering severity as no data loss occurs, merely a display issue.
> 
> -- 
> You are receiving this mail because:
> You reported the bug.
Comment 4 Kai Uwe Broulik 2021-05-03 07:30:53 UTC 
Well, your video only demonstrated a mix up of thumbnails. Perhaps file a separate ticket then.
Comment 5 Leinier Cruz Salfran 2021-05-03 13:58:50 UTC 
Hello.

I made a compound of my bad experiences with Dolphin. I made emphasis on this because this is happening right now and I consider it is a serious thing because it is related to the files of the persons.

The video was just something I made in order to illustrate that I'm telling the truth about the bad decision of implement the cache system on Dolphin. That "cache" is the reason of the bad and serious things that is happening right now.

I'm sure that if you carefully read the report you then you will realize that we are talking about something that must not be taken lightly.

I make this question to you: Since how long are you receiving complains about things that is not working or working bad in which the "cache" is involved?

The first time I detected Dolphin didn't copied some files was several years ago, but I wasn't sure and I didn't pay serious attention to that at the time, but now, with what I showed in the video and the report of my cousin, I considered it is the time to do things correctly and that's why I made this report.

Please, take this seriously. REMOVE COMPLETELY the cache system from Dolphin. Let Dolphin execute all the actions he needs whenever he needs. Today's hard disks are fast enough and it will be no performance impact and Dolphin will be reliable and trustworthy.

I wrote enough. If you need further assistance then write to me, otherwise, you can close this ticket. I hope the Dolphin team evaluate this and take this seriously.
Comment 6 tagwerk19 2021-05-03 14:48:51 UTC 
(In reply to Leinier Cruz Salfran from comment #0)
> - I copied a first SVG image from one location to another.
> - Dolphin showed me the preview of the first image correctly.
> - I found a second image I liked more.
> - I deleted the first image from the destination location.
> - I transferred the second image to the destination location.
> - Dolphin showed me the preview of the second image correctly.
> - I changed the name of the second image to the name of the first image.
> - The problem: Dolphin showed me the image of the first image instead of the
> second.
What version of Dolphin are you using?

Have a look at Bug 433127 and there's a relatively recently fixed issue that appeared when the files had the same modification time (to within a second).

If your "first image" and "second image" have the same modification time, you might be seeing the same.
Comment 7 Leinier Cruz Salfran 2021-05-03 16:14:12 UTC 
Hello, tagwerk19.

SYSTEM INFORMATION

Operating System: FreeBSD 13.0
KDE Plasma Version: 5.20.4
KDE Frameworks Version: 5.77.0
Qt Version: 5.15.2
Kernel Version: 13.0-RELEASE
OS Type: 64-bit

tagwerk19, that shouldn't happen. I have the criteria that a software must do it job straightly:
- If I order to Dolphin to copy a file then copy it, or a folder then, capture every children "directly" and copy them. If the destination is the same, then simply add the elements to the list or reload the files list again.
- If I order to Dolphin to delete something, then delete it and remove it from the list.
- If I order to Dolphin to rename a file, then rename it.
- If after each delete or rename action, Dolphin has to check once again the free space or the kind of file (in case the user changed the extension) or update the preview once again, then do it "directly".

We need to keep in mind that today's hardware is fast enough and even old hardware is decent.

Do not rely on a cache, do not append more processes.

Thank you all the time you put on this.