[Yum-devel] External downloader

Zdenek Pavlas zpavlas at redhat.com
Mon Nov 21 09:57:11 UTC 2011


>  This still uses curl multi, again given the giant bugs we've had
>  with basic curl downloading I don't want to introduce this for 1.0 ...
>  it's just asking for everything to not work properly.

Ok, I'm going to implement multiple downloader processes, and their 
management and polling in the parent.

> > [PATCH 10/10] Optional/throttled progress reporting
>  This last one isn't the correct solution, you can't just drop
>  updates.

Why not?  The size reported is cumulative, and when download finishes 
it's sent unconditionally.  Do we have users relying on faster than 
0.3s updates?  Do we have to 1:1 match write() and update()?

I've noticed curl (both multi and single) processes data in 1348-byte
chunks and easily does few hundred updates/s.

> Doesn't it matter a lot to fix this for 1.0? If so then the better
> solution would be to work out why we are doing a lot of small reads
> +writes and try to merge them at that layer.

I believe urlgrabber users never see individual reads and writes
(there's no download-to-fileobject API), so merging is not necessary.

>  You have access to push now? Can you remove the curl multi bits and
>  the last patch and push to a branch?

Yes, but avoiding curl multi is not trivial, as it complicates
the ExternalDownloader class.

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