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Re: A look at some alternative PACK file encodings

From
A Large Angry SCM <gitzilla@gmail.com>
Date
Sep 7, 2006, 17:22 UTC
Message-ID
<4500556E.7070803@gmail.com>
In-Reply-To
<9e4733910609070557jd8cfc57nd4f7a8973b69f6ed@mail.gmail.com>
Jon Smirl wrote:
Show 21 quoted lines
> On 7 Sep 2006 05:07:56 -0400, linux@horizon.com <linux@horizon.com> wrote:
>> > Support for 'thin' packs would pretty much require mixing IDs and
>> > (relative) offsets in the same pack file.
>>
>> An alternative would be to create a small "placeholder" object that
>> just gives an ID, then refer to it by offset.
>>
>> That would avoid the need for an id/offset bit with every offset,
>> and possibly save more space if the same object was referenced
>> multiple times.
>>
>> And it just seems simpler.
> 
> There are 2 million objects in the Mozilla pack. This table would take:
> 2M *  (20b (sha)  + 10b(object index/overhead) = 60MB
> This 60MB is pretty much incompressible and increases download time.
> 
> Much better if storage of the sha1s can be totally eliminated and
> replaced by something smaller. Alternatively this map could be
> stripped for transmission and rebuilt locally.
> 
You've lost me. What are you attempting to do again?
Previous: Junio C HamanoNext: Nicolas Pitre
Message 8 of 10 in “Re: A look at some alternative PACK file encodings”
  1. linux@horizon.comSep 7, 2006
  2. Jon SmirlSep 7, 2006
  3. linux@horizon.comSep 7, 2006
  4. Jon SmirlSep 7, 2006
  5. linux@horizon.comSep 7, 2006
  6. Richard CurnowSep 7, 2006
  7. Junio C HamanoSep 7, 2006
  8. A Large Angry SCMSep 7, 2006
  9. Nicolas PitreSep 7, 2006
  10. linux@horizon.comSep 7, 2006

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