From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 17 Feb 2012 22:25:25 GMT
Subject: Re: git status: small difference between stating whole repository and small subdirectory
Message-ID: <7vaa4hrtbe.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20120217203755.GA30114@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> That being said, we do have an index extension to store the tree sha1 of
> whole directories (i.e., we populate it when we write a whole tree or
> subtree into the index from the object db, and it becomes invalidated
> when a file becomes modified). This optimization is used by things like
> "git commit" to avoid having to recreate the same sub-trees over and
> over when creating tree objects from the index. But we could also use it
> here to avoid having to even read the sub-tree objects from the object
> db.

Like b65982b (Optimize "diff-index --cached" using cache-tree, 2009-05-20)
perhaps?