I'm experimenting with an event notification service based on a
publish-subscribe model for some projects I'm working on. When a
subscription comes in, a 'Subscription' object is made, that
basically looks like this:
class Subscription(Base):
def __init__(self, subscriber, eventType, filter=None):
self.subscriber = subscriber
self.eventType = eventType
self.filter = filter
def __hash__(self):
return hash(self.subscriber) & \
hash(self.eventType) & \
hash(self.filter)
'subscriber' is a reference to the subscribing object, and it's
very likely to be to an object in the ZODB. Is it wise to have
more than one persistent reference to a single persistent object?
I swear that I had once heard Jim say (vocally) that you could do
references like this in the ZODB now. I'm trying to avoid using
Paths because objects have a tendency to move around[*], and I have
performance concerns for a single event service object to have to
call 'unrestrictedTraverse' to every subscriber.
[*] (it's due to the annoyances with manage_beforeDelete() and
friends that
I'm writing this tool.)
Second question: If I use the hash of the Subscription as a key, is
there any advantages/disadvantages with using an IOBTree to hold
Subscription objects instead of a PersistentMapping?
Jeffrey P Shell, [EMAIL PROTECTED]
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