Re: [Mldonkey-users] feature suggestion: forward error correction

[Ignacy Gawedzki]

On Thu, Sep 05, 2002 at 02:45:45AM +0200, thus spake Christian Brandt:
>  Uncompletable Files are uncompletable because there is no longer a 
> complete Copy of the file available. You can't remove that fact by using 
> FEC, you would rather need an upload-technique which speeds up sending of 
> rare chunks. But even then you couldn't avoid incomplete files.
> 
>  To implement an "everything is complete" one must force the operator of a 
> client to keep data on his drive. But drivespace is a limited resource and 
> I think its not a donkeys mission to occupie other people resources based 
> on complicated assumptions which haven't to do much with "the real thing": 
> Bandwidth-Utilization.

I have one idea about solving the incomplete file problem.

There need not necessarily be some complete copy available on some host
in order to avoid the problem. In fact the union of all the chunks
available must be the complete file.

Then we must rather concentrate on how to spread the file so that this
condition holds as soon as possible. This could be achieved by letting
the uploader decide what chunk to send to a downloader based on a
latter's list of missing chunks. I must confess that I haven't looked at
the protocol yet, so I dunno how it is actually done. An alternative
solution seems to be that the downloader picks the chunks to ask for
more randomly.

In this way, the availability of chunks should be uniform and there
should not be any "rare" chunks anymore.

Ignacy Gawedzki

-- 
Life is like a penis: sometimes it is hard... but it's always way too short.