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Re: Packfile can't be mapped

From
Jon Smirl <jonsmirl@gmail.com>
Date
Aug 28, 2006, 15:44 UTC
Message-ID
<9e4733910608280844q41ea1a61r33c3eadc3e942604@mail.gmail.com>
In-Reply-To
<Pine.LNX.4.64.0608281026110.3683@localhost.localdomain>
On 8/28/06, Nicolas Pitre <nico@cam.org> wrote:
Show 9 quoted lines
> > Of course the major problem with pack-local, stream global
> > dictionaries is it voids the ability to reuse that zlib'd content
> > from that pack in another pack without wholesale copying the
> > dictionary as well.  This is an issue for servers which want to
> > copy out the pack entry without recompressing it but also want the
> > storage savings from the global dictionaries.
>
> Why would copying the dictionary as well be a problem?  How large might
> it be?  Can it be stored deflated itself?

The dictionaries are only 4KB. But they have to match up with the objects compressed using them. If you bring an object straight down out of a dictionary based pack and make it standalone you won't be able to read it. You need the dictionary to decode it. What if the local and remote packs have been packed using two different dictionaries? You can't directly move objects between them.

-- 
Jon Smirl
jonsmirl@gmail.com
Previous: Nicolas PitreNext: Nicolas Pitre
Message 8 of 16 in “Packfile can't be mapped”
  1. Jon SmirlAug 28, 2006
  2. Shawn PearceAug 28, 2006
  3. Nicolas PitreAug 28, 2006
  4. Linus TorvaldsAug 28, 2006
  5. Shawn PearceAug 28, 2006
  6. Jon SmirlAug 28, 2006
  7. Nicolas PitreAug 28, 2006
  8. Jon SmirlAug 28, 2006
  9. Nicolas PitreAug 28, 2006
  10. Shawn PearceAug 28, 2006
  11. Nicolas PitreAug 28, 2006
  12. Shawn PearceAug 28, 2006
  13. Shawn PearceAug 28, 2006
  14. Nicolas PitreAug 28, 2006
  15. Shawn PearceAug 29, 2006
  16. Shawn PearceAug 29, 2006

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