Re: update-index --assume-unchanged doesn't make things go fast

> On 6/27/08, Jakub Narebski <jnareb@gmail.com> wrote:
>> "Avery Pennarun" <apenwarr@gmail.com> writes:
>> > On 6/26/08, Stephen R. van den Berg <srb@cuci.nl> wrote:
>>  >> Avery Pennarun wrote:
>>  >>> 1) What's a sensible way to tell git to *not* opendir() specific
>>  >>> directories to look for unexpected files in "git status"?  (I don't
>>  >>> think I know enough to implement this myself.)
>>  >>
>>  >> Would checking the mtime on the directory itself help?
>>  >
>>  > I'm guessing it would help somewhat (although not as much as not
>>  > checking anything at all).  However, we'd still have to check the
>>  > mtime *against* something, and I don't think the index stores
>>  > information about directories themselves.
>>
>> By the way, from time to time there on this mailing list is idea
>>  to add entries for directories in the index.  This could help situation
>>  like yours, tracking emty directories, faster operations when some trees
>>  are unchanged, subtree <-> subproject changes.
>>
>>  But it always comes back to: 1.) no proposed implementation, 2.) "git
>>  tracks contents"...
>
> Yes, I've seen the occasional discussions about this.
>
> I might volunteer to help solve (1) except that I have a feeling that
> changing the index format would mangle all sorts of things beyond my
> current understanding.  Attaining that understanding might not be so
> bad, except for (2), which seems like any proposed changes will
> probably be rejected anyhow.
>
> So naturally I was hoping for a magical alternative suggestion for my
> current problem instead :)  One option I'm thinking about is to have
> my proposed daemon keep its own "index", which tracks *all* the files
> on the filesystem, not just the ones that have been
> git-update-index'd.  Then anything that needs to compare against the
> filesystem can choose to compare against the contents of this file
> instead if it exists (and/or the right option is set, etc).  Does that
> sound sane?