[Zope-dev] more on stacked component registries

[Chris Withers]

Stephan Richter wrote:
> On Tuesday 15 January 2008, Chris Withers wrote:
>> For what I'm after, I need to have a more dynamic buildup of
>> registrations based on which objects have been traversed through.
> 
> Right. I think the component architecture is not really made for this.

Sure it is, I'm talking about what basically happens with nested site 
managers. The problem is that the current nesting implementation seems 
predicated on zodb-like persistence. I'm looking at storing all "data", 
including site managers, in a relational database. The actual folder 
structure should remain as static as it does with zodb...

> I think 
> it would be easier to turn on/off registrations by using dynamically directly 
> provided interfaces (via a proxy) or use security. 

Not sure what you mean by either of these...

>> - stack the registries up during travesal in some way. I guess this
>>    would be a variant of what's done now with current nested registries.
>>    Is this feasible? Will there be performance problems?
> 
> I think the performance would decrease, because caches cannot be built up. 
> Also, you then must be able to access this custom registry. Remember, this 
> must be all in memory, because of thread-safety!

Yeah, but this is what happens more static-ly with the existing site 
managers, right?

>> - use one global registry and add/remove registrations during traversal
>> as necessary. How fast is registration/unregistration of adapters and
>> the like? How many adapter adds/removes at a traversal node would it
>> take to really slow things down?
> 
> You cannot do this; it is not thread-safe.

Well okay, one registry per thread... would that work?

cheers,

Chris

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