From: Alex Riesen <raa.lkml@gmail.com>
Date: Fri, 08 Dec 2006 07:48:09 GMT
Subject: Re: cygwin, 44k files: how to commit only index?
Message-ID: <81b0412b0612072348q13faaab0s9ba7a235f7fd64dc@mail.gmail.com>
In-Reply-To: <7vhcw6n8iz.fsf@assigned-by-dhcp.cox.net>

On 12/8/06, Junio C Hamano <junkio@cox.net> wrote:
> >> The current code for "diff-index --cached" reads the whole tree
> >> into the index as stage #1 entries (diff-lib.c::run_diff_index),
> >> and then compares stage #0 (from the original index contents)
> >> and stage #1 (the tree parameter from the command line).  Even
> >> if you stop at the first mismatch, you would already have paid
> >> the overhead to open and read all tree objects before even
> >> starting the comparison.
> >
> > But I don't have to pay for the overhead of comparing all
> > entries, if I can stop at first mismatch and exit with non-0.
>
> Bench it if you doubt me.

I don't question that the overhead of comparing is very much
unnoticable. It just that it surely isn't zero, and it will grow with
the size of repo (linearly, right?)... And I am sure that this
repo will _only_ grow (typical corporate project).

> I'd bet that the time spent in comparison between stages inside
> index (and remember, you are not generating textual diff, only
> comparing the SHA-1) is dwarfed by the overhead of populating
> the stage #1 of the index with what is read from all the tree
> objects.

I already understood that. I just haven't found yet what can I do