Re: [boost] Adobe Source Libraries, GIL, and Boost

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-07-03 15:21:34

Sean Parent wrote:

>>> ZUIDs <http://opensource.adobe.com/classadobe_1_1zuid__t.html>
>>
>> Hmm, I guess I would think zuid should be its own little library.
>> There is
>> already a GUID in the vault which again might benefit from
>> collaboration here:
>>
>> http://www.boost-consulting.com/vault/index.php -- guid_v3.zip
> Interesting - this is not quite a conforming GUID (deviates in many
> of the same ways that ZUIDs do from the specification but I try to be
> honest and not call them GUIDs...
>
> <http://www.uddi.org/pubs/draft-leach-uuids-guids-01.txt>
>
> AFAICT the node ID in the boost code is purely dependent on the clock
> - this makes the entire ID uniqueness of the ID a function of time
> (making for a fairly high probability of collision). The ZUID code
> includes machine specific and process specific information in the
> node generation and has code to synchronize threads to avoid
> collisions from requesting IDs from separate threads at the same time.

Most people don't even bother with proper GUIDs nowadays, they just generate 
a cryptographic quality random number. The probability of a collision is 
"sufficiently low for most practical uses".