Emacs: opening any file in a large repo

What I need

a fast/performant way to open any file under a large (git) repo (~9.8k files).

Context

I have tried various solutions, like Textmate.el and find-file-in-repository. I found these solutions via previous SO questions like this and this and through the LocateFilesAnywhere EmacsWiki.

While both solutions work wonderfully for small-to-mdeium repos, in this case they are practically unusable. When I start typing a filename, there's a delay of several seconds before I see any result. And changing any part of the search is very laggy too.

I think the main problem is that on typing any character, emacs/find-file-in-repository starts a shell command (git ls-files...). I really only need to do that when I have stopped typing.

Questions

is there a better library out there for this use-case?
if not, how can I introduce a delay into the command when I'm typing? i.e. while I'm in find-file-in-repository, I want the find-command to be invoked only when I stop typing (let's say a gap of 300ms).

emacs

Edit Report

1 Answer

Summary

After I received the three answers I tried them out (also answering my own question as none of the above solutions worked for me). I finally settled for helm-ls-git. Here's a comparison from my point-of-view:

Projectile

took around 30 minutes to index the repo. Since projectile is not aware of .gitignore, the actual number of files is more like 52k.
can be customized but something that just works (i.e. understands git) is preferable
may need to invalidate cache re-index time to time. That would be costly and frequent since new files are added everyday to the repo.

helm-cmd-t

looked good from the description and the source.
hard to install since it's not published in melpa/marmalade etc. More details in this issue I opened up.

GNU Global

Didn't try as it's likely to have the same problems as Projectile (git-unaware, needs it's own "index" that may need to be maintained time to time)

event-jr's answer however opened up some more options: I was unaware of helm till now. Looking at melpa for helm related plugins I found the following:

`helm-git`

This looked really promising
Was easy to install with package.el since it's in melpa
I also use an

answered 2013-01-16T06:34:50.377