Re: [PATCH 3/3] Use struct tree in diff-tree

From: Daniel Barkalow <barkalow@iabervon.org>
Date: Jan 31, 2006, 21:49 UTC
Message-ID: <Pine.LNX.4.64.0601311626070.25300@iabervon.org>
In-Reply-To: <7virs0uma8.fsf@assigned-by-dhcp.cox.net>

On Tue, 31 Jan 2006, Junio C Hamano wrote:

Show 25 quoted lines

> Linus Torvalds <torvalds@osdl.org> writes:
> 
> > On Sun, 29 Jan 2006, Daniel Barkalow wrote:
> >>
> >> It had been open-coding a tree parser. This updates the programs that
> >> call diff_tree() to send it the struct tree instead of a buffer and
> >> size.
> >
> > Please don't.
> > ...
> > Junio, please don't apply this.
> >
> > 		Linus
> 
> I haven't, and I won't.  From my gut feeling I did not even
> place it in "pu".  After timing it myself and then looking at
> the code I agree with your analysis.
> 
> The one to git-tar-tree I've already applied, mostly because I
> was not careful enough and especially I did not care enough
> about performance of that program.  On my slow machine the tip
> of kernel before you came back takes 9.2 seconds wallclock as
> opposed to 8.7 seconds to tar up, so the patch degrades the
> performance by about 5%.  Maybe we would want to revert that one
> as well.

Probably a better solution is to move the tree parser from tree-diff.c into tree.c, provide a clear API in tree.h, and use that in tar-tree. There's definitely no need to have another parser beyond the one currently in tree-diff and the struct tree one.

I think I should be able to change the struct tree API slightly to make it an iterator instead of a linked list, and get the efficiency benefits of the tree-diff parser while still having a nice API.

	-Daniel
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