Re: CAREFUL! No more delta object support!

From: Linus Torvalds <torvalds@osdl.org>
Date: Jun 29, 2005, 03:53 UTC
Message-ID: <Pine.LNX.4.58.0506282041360.19755@ppc970.osdl.org>
In-Reply-To: <Pine.LNX.4.58.0506281111480.19755@ppc970.osdl.org>

On Tue, 28 Jun 2005, Linus Torvalds wrote:

Show 8 quoted lines

> 
> >						 I'm not sure I
> > want to write the "parse incoming pack-file" thing, but git-unpack-objects
> > comes _reasonably_ close (but right now it seeks around using the index
> > file to resolve deltas, instead of keeping them in memory and resolving
> > them when possible).
> 
> I'm still thinking about this one. I think I'll just do it.

Ok, done. I had to basically rewrite that unpacking logic, but the end result is actually slightly smaller and cleaner, and it can now unpack from a stream. That stream reading logic that uncompresses directly from the stream buffer might be considered a bit too subtle (and somebody should really double-check it), but hey, it works for me.

In fact, I just did this:

	#
	# Create empty git archive "~/unpack"	
	#
	mkdir ~/unpack
	cd ~/unpack
	git-init-db

	#
	# Copy the git archive there over a pipe
	#
	cd ~/git
	git-rev-list --objects HEAD | git-pack-objects --depth=50 --window=50 --stdout | (cd ~/unpack ; git-unpack-objects)

	#
	# Go to new archive, set up the head, and fsck to verify
	#
	cd ~/unpack
	cat ~/git/.git/HEAD > .git/HEAD 
	git-fsck-cache --unreachable

Now, the above is a silly example, since I _could_ just have moved the pack file into .git/objects/pack, but that was not the point of this whole thing. The point was to do what a "git-ssh-push" would basically boil down to.

I'd like somebody who knows zlib intimately to take a look at how I do the streaming input thing (in particular, the "use(len - stream.avail_in);" part in the inflate loop in the "get_data()" function).

			Linus