From: Andreas Ericsson <ae@op5.se>
Date: Tue, 24 Apr 2007 15:18:18 GMT
Subject: Re: Why SHA are 40 bytes? (aka looking for flames)
Message-ID: <462E1FBA.9020109@op5.se>
In-Reply-To: <alpine.LFD.0.98.0704241058490.12375@xanadu.home>

Nicolas Pitre wrote:
> On Tue, 24 Apr 2007, Andreas Ericsson wrote:
> 
>> Using a more efficient compression algorithm for the objects 
>> themselves (bzip2, anyone?) will most likely reduce storage size an 
>> order of magnitude more than reducing the size of the hash, although 
>> at the expense of CPU-efficiency.
> 
> An order of magnitude I really doubt it.  Maybe 20% could be a really 
> optimistic prediction.  But if bzip2 could reduce the repo by 20%, it 
> will slow runtime usage of that repo by maybe 100%.  That is not worth 
> it.
> 
> This is also the reason why we changed the default zlib compression 
> level from "best" to "default".
> 

... order of magnitude *more than reducing the size of the hash*.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231