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From: "Jon Smirl" <jonsmirl@gmail.com>
To: "Marco Costalba" <mcostalba@gmail.com>
Cc: "Git Mailing List" <git@vger.kernel.org>, "Nicolas Pitre" <nico@cam.org>
Subject: Re: Why SHA are 40 bytes? (aka looking for flames)
Date: Sat, 21 Apr 2007 13:59:24 -0400	[thread overview]
Message-ID: <9e4733910704211059h16c06e11k967d0bdd3e4970fc@mail.gmail.com> (raw)
In-Reply-To: <e5bfff550704211006t59cb49h179685d694a1d75a@mail.gmail.com>

On 4/21/07, Marco Costalba <mcostalba@gmail.com> wrote:
> On 4/21/07, Jon Smirl <jonsmirl@gmail.com> wrote:
> > On 4/21/07, Marco Costalba <mcostalba@gmail.com> wrote:
> > > Well, why to store always the full length SHA?
> >
> > When Shawn gets done with full compression the SHAs would get stored
> > in the packfile once  and then be replaced with a token generated from
> > the compression algorithm. Compression tokens are designed to use the
> > minimal number of bits depending on frequency of occurrence.
> >
>
> Currently in Lunux tree there are about 445.424 objects (git
> count-objects -v), if each object has his 40 bytes name it is about
> 20MB to store sha *once*, probably with no real disambiguate need to
> be that much.

You have to store the full SHAs at least once since they are the
signature against data corruption.

> Marco
>


-- 
Jon Smirl
jonsmirl@gmail.com

  reply	other threads:[~2007-04-21 17:59 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-21 13:35 Why SHA are 40 bytes? (aka looking for flames) Marco Costalba
2007-04-21 15:08 ` Andy Parkins
2007-04-21 16:53   ` Karl Hasselström
2007-04-21 17:09     ` Marco Costalba
2007-04-21 16:58   ` Marco Costalba
2007-04-21 15:37 ` Jon Smirl
2007-04-21 17:06   ` Marco Costalba
2007-04-21 17:59     ` Jon Smirl [this message]
2007-04-21 18:28       ` Marco Costalba
2007-04-21 19:36         ` Jon Smirl
2007-04-24 14:48         ` Andreas Ericsson
2007-04-24 15:04           ` Nicolas Pitre
2007-04-24 15:18             ` Andreas Ericsson
2007-04-24 16:19               ` Nicolas Pitre
2007-04-22 13:27     ` Nicolas Pitre
2007-04-24  0:46       ` H. Peter Anvin
2007-04-24  2:30         ` Shawn O. Pearce
2007-04-24  2:44         ` Nicolas Pitre

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