[Zope-dev] Globally unique id's in Zope in a new way

[Sam Gendler]

> For example, it would actually be nice if Zope provided an implementation
> of UUID (called GUID by Microsoft).  A UUID is a guaranteed unique 64-bit
> value.  It's used in COM, CORBA and other systems which need to have
> automatically generated guaranteed unique values.  The nice thing about
> UUID's is that they are guaranteed to be unique network wide.  In other
> words, you (supposedly) can't generate a UUID which would ever conflict
> with a UUID that I generated.  It does this by an algorithm which takes
> into account things like time-of-date, network card address, etc.  I don't
> have the details on the algorithm but I know it is publically
> available.  It would probably best be implemented at the C level.

I just generated something like this for a product, in python.  In order
to guarantee uniqueness across a cluster of servers, I use the last
octet of the ip address (assuming the cluster is all on the same
subnet), the time, a call to randint(1,10000).  If you really want to
make things interesting, run that through the sha algorithm, and you get
a nice 160 bit key rendered in hex.

In obfuscated code, it looks like:

sha(split(gethostbyname(gethostname()),'.')[3]+str(int(time.time()-900000000))+str(randint(1,1000))).hexdigest()

but you would do well to make it multiple lines of code... ;-)

--sam


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Sam Gendler
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