On Tue, 20 Jul 2004 14:36:25 +0200, Bryan Ford wrote:

I'm soliciting feedback, discussion, and hopefully ultimately support for a very simple proposal that I've written up in preliminary form at this page:

http://www.brynosaurus.com/cachedir/

[...]

I don't yet know the best venue for discussion of this proposal (I realize Gimp-developer isn't it, since it's a highly cross-application issue that only slightly affects GIMP itself) - please E-mail me if you're interested and I'll point you to the appropriate forum once I find or create it. Or if you like the idea but just would like me to come back later when the proposal has been more widely peer reviewed by others, I'm happy with that too. :)

The best forum to discuss this proposal is probably the xdg-list. This is where things like the thumbnail managing standard (which you mentioned in your proposal) have been discussed. For more info about this list, see: http://www.freedesktop.org/Main/GettingInvolved If your proposal is adopted as a freedesktop standard, then it is likely that it will find its way into the GIMP and many other applications.

I have a few comments on your proposal. Not necessarily some things that should be changed, but maybe you could discuss the pros and cons in a rationale section or in the "alternative approaches" chapter: - Instead of a file containing a MD5 hash or some other signature, you could consider using an empty file or a symbolic link to ".". Neither of them is likely to conflict with normal files used by some application.
- If you want to have a non-empty file or symbolic link, what about using the full path to the file? If a cache directory is moved by the user (and not by the application that created it, because such an application would update the path) then maybe it should not be ignored anymore by the backup process. So comparing the path stored in the file or in the symbolic link with the current path of the file could be a good way to check if the directory is still a cache directory or if it is now a copy stored somewhere else by the user. - Some people don't like MixedCase for file names and prefer alllowercase or names_with_underscores.

-Raphaël

Hi,

Bryan Ford writes:

Dear GIMP developers,

I'm soliciting feedback, discussion, and hopefully ultimately support for a very simple proposal that I've written up in preliminary form at this page:

http://www.brynosaurus.com/cachedir/

I don't think the .thumbnails directory can be considered ephemeral or otherwise regenerable content. Regenerating all thumbnails can be very difficult and time-consuming. The original data might be on removable media and even if all the images are on disk you certainly don't want to go through the hassle of regenerating them all since you will most probably need a number of different applications to do that. I suggest that you change your proposal so that it explicitely states that the .thumbnails directory should _not_ be tagged as a cache directory.

Since GIMP doesn't put swap files into a dedicated directory your proposal will also not work for GIMP swap files (which are admittedly not worth to be archived).

Sven

Hi,

Raphaël Quinet writes:

- Some people don't like MixedCase for file names and prefer alllowercase or names_with_underscores.

Eeek, what about names-with-hyphens instead?

Sven

Hi,

Quoting Sven Neumann :

Bryan Ford writes:

I'm soliciting feedback, discussion, and hopefully ultimately support for a very simple proposal that I've written up in preliminary form at this page:

http://www.brynosaurus.com/cachedir/

Since GIMP doesn't put swap files into a dedicated directory your proposal will also not work for GIMP swap files (which are admittedly not worth to be archived).

If there were some way to tell that the tile cache was ephemeral data, then the proposal would work, wouldn't it?

Bryan, is there any demand for something like this in archiving programs?

Cheers, Dave.

--
Dave Neary
Lyon, France

Hi,

we should really move this discussion to xdg-list.

Bryan Ford writes:

While thumbnails aren't necessarily ephemeral, they certainly are automatically regenerable - it is the standard behavior for all applications I know of that use them to regenerate them automatically if they disappear for any reason. Sure, the original source material may be on removable media, so some of the thumbnails won't actually be _regenerated_ until the user inserts that particular CD-ROM and browses it again. But even if those thumbnails hadn't been lost, they wouldn't ever be used until that point anyway. Since the thumbnails are effectively useless until and unless the original content re-appears, and they can be regenerated from the original content once it does re-appear, I can't see how their storage matters beyond the performance penalty of having to re-compute the thumbnails from scratch. And that's the definition of a cache: if you lose it, you wait longer for stuff to load next time, but it's not disaster.

The point I was trying to make is that thumbnails are _not_ automatically regeneratable, at least not by the applications reading them. There are a couple of file formats that only certain applications understand (such as for example the GIMP XCF format). A file-manager doesn't know how to create a thumbnail for these file formats. It still can use the thumbnail that the application which created the file (GIMP in this expample) wrote to the .thumbnails directory. That's the whole point of the Thumbnail Managing Standard. If the .thumbnails directory is being deleted (or lost in a disk crash), vital information is lost which cannot easily be regenerated. I'd call that a disaster and thus vote for explicitely not tagging the .thumbnails directory as a cache directory. It simply isn't one.

Since GIMP doesn't put swap files into a dedicated directory your proposal will also not work for GIMP swap files (which are admittedly not worth to be archived).

I had thought that that was what the ~/.gimp-2.0/tmp directory was for, but on re-running the GIMP I see that I was mistaken. So you're right - in order to adopt the proposed convention for its tile cache, the GIMP would have to make an additional subdirectory and move its swap file into there.

We could very well do that but it is nevertheless a weak spot in your proposal and I suggest that you think about ways to tag individual files.

Sven