RE: RE: [Plone-developers] Plone 1.1 - TODO

See responses below...

> Attempting to use time as anything other than the *seed* of a 
> random number 
> generator is a futile exercise. No matter what floating-point 
> precision you 
> use, you're assigning numbers based on a pattern that repeats 
> every second. 
> In a system where the assignment of an ID can take a fraction of a 
> millisecond, this is obviously going to cause problems.

The current system uses time and the id; with the exception of index_html as
an id, the chance of a collision is pretty low in a well-designed CMS
deployment. 

> The immediate answer (based on fewest lines of code) is to 
> use the actual 
> output of time.time() (floating point representation of seconds since 
> epoch), which should prevent any ID conflicts unless you're 
> assigning at a 
> rate faster than the precision of time.time() (which is to 6 
> decimal places 
> on my kit, but could be only to 3 DP on systems with low-resolution 
> counters). Again, this is totally CPU dependent and is a 
> situation that may 
> occur...

I think one naming scheme could likely involve the thread-id of the creating
thread.  When the UID is created, the id of the thread that creates it gets
the first few part of the UID string, followed by a dash, followed by the
results from time.time() - which would prevent the possibility of UID name
collision between multiple threads, and also increase thread/bucket affinity
in a refs BTree, at least in the creation of objects (which is likely
biggest potential source of conflict-errors).

Sean


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