[Zope3-dev] randid()

[Jeremy Hylton]

>>>>> "JF" == Jim Fulton <jim@zope.com> writes:

  JF> Jeremy Hylton wrote:
  >>
  JF> ...
  >> Is there any reason we can't replace its use in ObjectHub with a
  >> simple persistence counter?

  JF> What is a simple persistence counter?  I can't know whether the
  JF> current approach should be changed without knowing more about
  JF> your proposal.

  JF> How does a persistence counter work? Is it simply a counter
  JF> implemented as a persistent object? If so, then it would become
  JF> a hot spot, which would be bad.

I think we've talked offline about persistent counters before.  One
relatively simple approaches is to use manage a collection of counters
selected via threadid.  The amount of contention is limited by
selecting a range of ids for a thread id and then consuming the ids in
that range one-at-a-time.  Most conflicts are easily resolved;
occasionally conflicts would occur when two threads need to get new
ranges of ids.

But if randid() really just returns a random number, and the caller is
responsible for guaranteeing uniqueness, then this seems like the
simplest approach:

   random.randrange(1, 2**30)

This is much simpler than the current randid() function, which has
three default arguments, two calls to random functions, and a
multiply.  My question about randid() started because that code seemed
to be doing a lot of work for reasons that weren't very clear.

Jeremy