51999 - Compressed Cache

Status: VERIFIED INVALID

(Core :: Networking: Cache, enhancement, P3)

Description

[Brian 'netdragon' Bober]

It might slow things down a little, but I think people should have the option of 
having their cache stored on disk in compressed form.

Comment 1

[Gilles Durys]

Since one of the goals of a cache is to speed up things, I don't think it would
be reasonable nor useful (compressing html and css is  ok but compressing jpgs
and gifs is out of question)

Comment 2

[Doron Rosenberg (IBM)]

--> networking cache, even though I doubt this is a valid rfe.

Comment 3

[Brian 'netdragon' Bober]

Hmmm - then that would make it virtually useless. RLEing the documents wouldn't 
slow things down much but documents aren't very big. 

It would be an option for people with low disk space. Speed is not an issue. 

Comment 4

[Boris Zbarsky [:bzbarsky]]

Compressing gifs and jpegs is unlikely to yield much improvement anyway....

Comment 5

[Brian 'netdragon' Bober]

Of course zipping it wouldn't do much - but there must be a compression tecnique 
that would work.

Comment 6

[Boris Zbarsky [:bzbarsky]]

What makes you think so?

Compression techniques basically work by taking the actual information contained
in the file and expressing it in a smaller number of bits, paying the cost of
having a higher average entropy per bit.

Now at some point you start averaging an entropy of 1 per bit, at which point
further lossless compression is essentially impossible.  Gifs and Jpegs are
already compressed with rather decent algorigthms, so compressing them further
is hard both practically and theoretically.

In any case, unless you have a compression techinque to suggest that will work
well on jpegs and gifs, I suggest this bug be marked invalid....

Comment 7

[Brian 'netdragon' Bober]

The only algorithms that would work in my opinion would probably take too much 
time. There are many algorithms that would do the job, but with our current 
computing abilities - they are way to complicated for todays computers. 
Therefore, the only things that could be compressed in the cache are text - 
which would be practically worthless.

Comment 8

[Boris Zbarsky [:bzbarsky]]

Brian,

If you think that cache compression would be "practically worthless" until
computing technology improves significantly, why did you open this bug?

Comment 9

[Brian 'netdragon' Bober]

I was hoping someone knew of a compression algorithm I wasn't aware of that 
would work.

The thing is that Outlook Express compresses the headers. I took that to think 
that it compressed the images too. Then after I submitted the bug, I tried 
zipping, etc. images to no avail. Now I realize it can't be done with today's 
computers ( I found some techniques that would work but need hardware 
acceleration).

Please confirm as invalid. Sorry about the bug.

Comment 10

[Dan Nunn]

vrfy invalid