Re: [Gnu-arch-users] hardlinked pristine trees

[Andrea Arcangeli]

On Fri, Oct 03, 2003 at 01:11:40PM +0200, Pau Aliagas wrote:
> 
> I'm thinking about adding another optional optimization to arch that would 
> consist of hardlinking pristine trees to revision libraries, the same that 
> I've done for get and build-config.
> 
> I agree with some of the expressed complaints that working with hard links 
> is inherently dangerous... in working directories. Of course if you choose 
> this way it's up to to to be careful til some validation code is added to 
> cached revisions (it'll come some day).
> 
> But (and that's a big but), I don't see any danger in hardlinking pristine
> trees. The danger is the same than if you corrupt a local pristine, be it
> hardlinked or not, but the benefits are obvious: space saving, full speed
> gets, etc. Pristine trees are neeed, for instance, to compute
> what-changed.
> 
> There are quite a bunch of files to modify:
> 
> archive-cache.c build-revision.c cmd-add-pristine.c cmd-buildcfg.c
> cmd-cachedrevs.c cmd-cacherev.c cmd-deltapatch.c cmd-find-pristine.c
> cmd-getrev.c cmd-join-branch.c cmd-lock-pristine.c cmd-ls-pristines.c
> cmd-replay.c cmd-revdelta.c cmds.c cmd-uncacherev.c cmd-undo-changes.c
> cmd-what-changed.c commit.c configs.c import.c local-cache.c pristines.c
> tag.c)
> 
> so that I won't undertake it unless there's some consensus about it and 
> some hope to get it integrated in mainstream. I'm really busy now :/
> 
> Does anybody have an opinion about it?

makes perfect sense to me.

arch should just pick the nearest revlib available, cp -al from it, go
forward and backwards with the patchesets, and diff against the working
dir.

After this it will fly since we'll have the working dir sharing the same
inodes of the revlib and the pristine tree, so it'll be sooo fast ;).

It will fly.

I doubt cvs or anything else will be remotely comparable to the speed of
arch with these new boosting features ;)

Thank you very much for writing all these great features!

Andrea - If you prefer relying on open source software, check these links:
            rsync.kernel.org::pub/scm/linux/kernel/bkcvs/linux-2.[45]/
            http://www.cobite.com/cvsps/