Re: Compression and dictionaries

From: David Lang <dlang@digitalinsight.com>
Date: Aug 14, 2006, 17:34 UTC
Message-ID: <Pine.LNX.4.63.0608141033080.14796@qynat.qvtvafvgr.pbz>
In-Reply-To: <44E0AFCB.10908@garzik.org>

On Mon, 14 Aug 2006, Jeff Garzik wrote:

Show 17 quoted lines

> Date: Mon, 14 Aug 2006 13:15:55 -0400
> From: Jeff Garzik <jeff@garzik.org>
> To: Jakub Narebski <jnareb@gmail.com>
> Cc: git@vger.kernel.org
> Subject: Re: Compression and dictionaries
> 
> Jakub Narebski wrote:
>> David Lang wrote:
>> 
>>> the other factor that was mentioned was that a single-bit corruption in 
>>> the dictionary would make the entire pack file useless. if this is really 
>>> a concern then just store multiple copies of the dictionary. on a pack 
>>> with lots of files in it it can still be a significant win.
>> 
>> Or use some error-correcting code for storing dictionary.
>
> Error-correcting code?  We have sha1 hash to determine validity...

that would only tell you that what you have is garbage (and you need to restore from backup(, useing a ECC costs some space, but lets you recover from some errors without having to resort to backups.

David Lang