Parallel Fetch

[nightkhaos]

FEATURES="parallel-fetch" is ignored by pkgcore.

This is a very usage feature of portage and should be implemented into pkgcore, ideally by default.

[ferringb]

Will be added by default, but I'll be doing it a bit differently this time around in comparison to how I implemented it in portage originally- mainly is dependant upon ticket #7.

Rough complaints about portage's version:

1. Current implementation in portage has no decent feedback mechanism for when the background fetcher is being waited on- just a "waiting on blah lock". That sucks.
2. It's not able to do multiple in parallel (more then one fetcher thread). Personally, this is a feature I want, others may not- having the option is nice.
3. portage implementation is forking rather then threading- result of this is that chksums are redone twice, and original exit codes are lost (may be useful).

So... intending upon making it a fair bit more integrated (same level of integration parallel building requires), thus the delay.

[brot]

Beeing able to do multiple fetches in paralell is really a nice feature to have, just think about the following scenario:

I am bored and so decide to install ut. It needs to fetch both the addons: "ut2004megapack-linux.tar.bz2" and the patch for that game itself. Now since both files are downloaded from slow (read 3dgamers) servers, both downloads are slow. Instead of using the otherwise wasted bandiwth, portage waits until both are ready.

So i think an option to enable not only prefetch (downloading while merging) but paralellfetch(multiple downloads while merging) would be a really nice thing to have.