From: Petr Baudis Date: Mon, 09 May 2005 21:28:42 GMT Subject: Re: Darcs-git: a few notes for Git hackers Message-ID: <20050509212842.GC15712@pasky.ji.cz> In-Reply-To: <7ihdhc5le2.fsf@lanthane.pps.jussieu.fr> Dear diary, on Mon, May 09, 2005 at 08:01:25PM CEST, I got a letter where Juliusz Chroboczek told me that... > 1. Darcs-git uses the fact that Git updates are atomic when reading > from a Git repository. Darcs-git almost writes to Git repositories > atomically, with one exception: it performs a non-atomic > read/update/write cycle on .git/HEAD. > > For that reason, I'm taking a high-level lock on .git repositories > whenever I write them. The lockfile is ``.git/lock''. I haven't > thought about whether Darcs can be easily coerced into accessing Git > repos atomically; have people writing Git wrappers found the need for > a global lock? FWIW, Cogito does not lock at all yet - this is one of the things which should be fixed soon. > - there's no way to have multiple simultaneous caches, short of > hacking at the values of Git's global variables by hand. See the Brad Robert's patches of Apr 21. I've decided not to apply them since it appears a lot has changed since then and it would be some pain; but they may be a worthy starting point for a more up-to-date patch. -- Petr "Pasky" Baudis Stuff: http://pasky.or.cz/ C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor