Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-11 Thread Dieter Maurer
Jim Fulton wrote at 2006-10-9 15:04 -0400: ... To make cache garbage collection as fast as possible, I have proposed to actually store the sticky information in the C object structure. I don't like the idea of adding that overhead to every persistent object just for this use case. OTOH, we

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-10 Thread Chris Withers
Jim Fulton wrote: Chris Withers wrote: Jim Fulton wrote: - I wonder if an argument could be made than we shouldn't implicitly deactivate an object that has been accessed in a a transaction while the transaction is still running. Would this prevent ZODB from ever promising not to use more

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-09 Thread Chris Withers
Jim Fulton wrote: - I wonder if an argument could be made than we shouldn't implicitly deactivate an object that has been accessed in a a transaction while the transaction is still running. Would this prevent ZODB from ever promising not to use more than a certain amount of memory? The

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-09 Thread Jim Fulton
Chris Withers wrote: Jim Fulton wrote: - I wonder if an argument could be made than we shouldn't implicitly deactivate an object that has been accessed in a a transaction while the transaction is still running. Would this prevent ZODB from ever promising not to use more than a certain

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-09 Thread Jim Fulton
Dieter Maurer wrote: Jim Fulton wrote at 2006-10-6 16:55 -0400: ... As explained in the proposal: We have 3 use cases for volatile attributes: I didn't ask why you use volatile attributes. I asked why _p_sticky needs to be stored on each instance, since it is set at the class level. It

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-09 Thread Dieter Maurer
Jim Fulton wrote at 2006-10-9 13:22 -0400: ... Hm, I don't why the use cases imply setting it only at the class level, but OK. I'll just take that as a given. So, since _p_sticky is set at the class level, why store it on the instances? Use case 2, set on class level; use case 3, set on

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-06 Thread Jim Fulton
Dieter Maurer wrote: I have put an enhancement proposal at http://www.zope.org/Wikis/ZODB/VolatileAttributeLifetimeGarantee It allows applications to declare that they need for some (so called sticky) objects a garanteed lifetime for their volatile attributes that extends until at least

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-06 Thread Dieter Maurer
Jim Fulton wrote at 2006-10-6 12:10 -0400: ... I'm a little uneasy about baking this policy so deeply into the infrastructure. I wonder if the use case can be handled another way. A persistent object can override _p_deactivate. For example: def _p_deactivate(self): pass

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-06 Thread Jim Fulton
Dieter Maurer wrote: Jim Fulton wrote at 2006-10-6 12:10 -0400: ... I'm a little uneasy about baking this policy so deeply into the infrastructure. I wonder if the use case can be handled another way. A persistent object can override _p_deactivate. For example: def _p_deactivate(self):

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-06 Thread Jim Fulton
Dieter Maurer wrote: Jim Fulton wrote at 2006-10-6 15:08 -0400: ... You could implement your sticky attribute at the application level: def _p_deactivate(self): if getattr(self, '_p_sticky', False): return Persistent._p_deactivate(self) You could provide any

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-06 Thread Dieter Maurer
Jim Fulton wrote at 2006-10-6 16:02 -0400: Dieter Maurer wrote: Jim Fulton wrote at 2006-10-6 15:08 -0400: ... You could implement your sticky attribute at the application level: def _p_deactivate(self): if getattr(self, '_p_sticky', False): return

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-10-06 Thread Jim Fulton
Dieter Maurer wrote: Jim Fulton wrote at 2006-10-6 16:02 -0400: Dieter Maurer wrote: Jim Fulton wrote at 2006-10-6 15:08 -0400: ... You could implement your sticky attribute at the application level: def _p_deactivate(self): if getattr(self, '_p_sticky', False):

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-09-29 Thread Sidnei da Silva
| Feedback is welcome -- either in the Wiki or here. I've seen an informal version of this by Dieter on a mailing list somewhere (might even have been this list) ages ago and even thought that it was already implemented. I really like the proposal, +1 on it. -- Sidnei da Silva Enfold Systems

Re: [ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

2006-09-29 Thread Dieter Maurer
Sidnei da Silva wrote at 2006-9-29 22:13 -0300: | Feedback is welcome -- either in the Wiki or here. I've seen an informal version of this by Dieter on a mailing list somewhere (might even have been this list) ages ago and even thought that it was already implemented. It is implemented in our