On Thu, Dec 20, 2007 at 12:01:51PM +0000, Simon Marlow wrote: > David Roundy wrote: > >On Dec 18, 2007 4:58 AM, Simon Marlow <[EMAIL PROTECTED]> wrote: > >>Hmm, this worries me a bit. I typically have many GHC trees, and I > >>anticipate using a cache with darcs 2, so will this mean that whatsnew > >>will sometimes miss changes? Or will it just be slower? > > > >Well, using the file-modification-times optimization always means that > >whatsnew will sometimes miss changes, since it's always possible that > >the pristine cache will have the same timestamp as the working directory > >file, but this is unlikely (and no more likely when interacting with > >multiple repositories, it's actually in a single repository that you're > >more likely to modify a file in the working directory within a second of > >when a darcs record is performed). The main issue would be that it'd be > >slower. This shouldn't be a big issue, since whichever darcs repository > >you last recorded in (or pulled into, etc) will have a fast whatsnew. > > > >One other possibility would be that we could disable global caching of > >the pristine cache (bad confusion of the term "cache" here). > > Ok. Though it seems the right thing to do is to store the modification > times in a file under _darcs, the file just needs to contain a list of > (<file>,<time>) pairs that you read into a Data.Map (you're really just > using the filesystem as a Data.Map at the moment). The question is how > much hacking you'd have to do to make this fast enough... I don't know. It > shouldn't be too hard to beat stat() with Data.Map, but there's the > overhead of populating the Data.Map in the first place.
I mostly just don't like introducing yet more files under _darcs. Each file introduced involves creating a new file format that must be supported forever, and the less often we do this, the less often we make mistakes! :) > I guess this isn't a high priority now. But it would be good if it were > possible to disable globally caching the pristine copy, so we can get the > darcs1 behaviour. Perhaps have separate 'cache:' and 'cachepristine:'? I agree. Or maybe cache: and cachepatches: (the latter not caching pristine). -- David Roundy Department of Physics Oregon State University _______________________________________________ darcs-devel mailing list darcs-devel@darcs.net http://lists.osuosl.org/mailman/listinfo/darcs-devel
