RE: Re: Query Hit bitprint

> -----Message d'origine-----
> De : [email protected] [mailto:[email protected]] De la part
> de Sam Berlin
> Envoyé : mercredi 12 septembre 2007 17:25
> À : [email protected]
> Objet : Re: [the_gdf] Re: Query Hit bitprint
> 
> Your knowledge of LimeWire's download verification appears to be a
> little outdated, Philippe.
> 
> LimeWire currently does everything you are describing, including
> verifying pieces of the file as it downloads.
> 
> (The only thing it does not do is know the tiger tree ahead of time,
> but that isn't necessary for any of the other steps.  Swarmed
> downloads can make an intelligent guess about the tree size and then
> change their guess once the actual size is discovered.)

Sam, what is LimeWire doing when a file download completes? It displays :
"verifying file" which takes some time.

Doesn't this mean that the downloads are NOT checked duing the long period
of time when the content is being downloaded (and worse, LimeWire will still
share the existing fragments without being sure they are correct).

From what I have seen, LimeWire still downloads files linearily, even when
there are multiple sources serving their data at different speed.

I am still amazed to see that there are files shared sometimes by 50-200
users for which none of them is responding, or just one from time to time,
despite there are are tons of users waiting for that file and that could
help distributing the work load securely. I've checked this many times, and
these many sources were NOT spamming sources.

My opinion is that as soon as the THEX data is available and usable for the
fragments we have already downloaded, they should be checked immediately
against that data, and then the validated fragments shared immediately, and
the other fragments dropped and looked for from other sources. This will
remain true, even if we find more finely grained THEX, but the most basic
THEX data will contain the hashes for at least 100 fragments of the file,
much enough to verify every source long before the download completes.

If we still depend on the final verification, we are still wasting bandwidth
and time, locally and remotely.