From: Rogan Dawes Date: Tue, 17 Apr 2007 17:18:45 GMT Subject: Re: [PATCH 2/2] Add keyword unexpansion support to convert.c Message-ID: <46250175.4020300@dawes.za.net> In-Reply-To: Linus Torvalds wrote: > > On Tue, 17 Apr 2007, Andy Parkins wrote: >> Adding expansion is harder, as I have no clue which calls to make to find >> even the most basic information about an object; but I thought I'd get >> feedback before I expend that effort. > > Adding expansion is not just "harder". It's basically impossible to do > with any kind of performance. > > Think "git checkout newbranch". > > And think what we do about files (and whole subdirectories!) that haven't > even changed. And finally, think about how important that optimization is > in an SCM like git that supports branches. Well, if the only keyword we support is $BlobId:$, then if the tree/object hasn't changed, then we still don't need to touch the object. Not so? Rogan