Re: storing images thumbnails as pseudo files?

[David Masover <ninja@slaphack.com>]

Pysiak Satriani wrote:
> Hello,
> 
> suppose pseudo files, file-as-directory are on my r4 partition and are usuable.
> 
> Does namesys' vision allow things like storing image thumbnails "inside the file
> itself" ?

Ultimately, yes.  Currently, I don't know.

The most common use of pseudofiles, for instance, is to access metadata 
we already have.  For instance, Reiser4 stores file permissions the same 
way as anyone else, but you can access foo/..pseudo/rwx.

That's an example.  I haven't been in this community for a year or more, 
so I have no idea what the delimiter is.

For now, I don't think you can have arbitrary normal files within files, 
just metadata that has a plugin already.  You might try something like 
this, though:


$ mkdir -p .thumbs/test.jpg

// create 150px thumbnail
$ jpgtn -s 150 -H test.jpg

// move the thumbnail "into" the file
$ mv tn_test .thumbs/test.jpg/150px

// the same but a 100px thumbnail
$ jpgtn -s 100 -H test.jpg
$ mv tn_test .thumbs/test.jpg/100px


Ultimately, the Namesys vision would allow for something like this to 
happen:

$ cp /mnt/camera/test.jpg .

Then your link would look something like this:

<a href="test.jpg"><img src="test.jpg/.../thumbs/150px.png" /></a>

The thumbnail would be generated by the FS (probably by calling jpgtn or 
a similar tool) the first time it was accessed, then cached until disk 
space is needed for something else.

The rest of the kernel development list seems to believe that such 
functionality would be better achieved by hacking glibc or Apache to 
emulate that, rather than having it be a feature of the filesystem itself.

Disclaimer:  I don't speak for Namesys, and I don't work here.  While 
I'm pretty confident I understand their vision, the final word on 
anything Reiser is always from Hans Reiser.