[Zope-dev] RFC 2616, side effects, and idempotence (was: Last-Modified....)

[R. David Murray]

On Tue, 18 Jun 2002, Oliver Bleutgen wrote:
> First, your quoting is wrong, I didn't write that - talk about
> precisionist *g*.

Check the number of >s.  I don't know who lost the attribution
of the inner part, but I just replied to your message and
cut off everything after the last line quoted.  The joys of
email <grin>.

> But, there's also the attribute safe, which is described in 9.1.1:
[...]
> Which is IMO exactly what we were talking about in that thread.

Good point.

> Perhaps it is. I don't know the areas of the code where you have seen
> that, but it might be inspired not by the problem of idempotence, but of
> "safeness"

It's not in the one example I could quote you, in Z3 (some hoops
Casey jumped through to try to get the first call to look up a
non-existent annotation in an AttributeAnnotatable from causing
a ZODB write).  But in other cases it might well be.

In light of the hit counter use case, safety probably is much more
important than idempotence.

--RDM