[ZODB-Dev] RFC: Pre-commit hooks

[Jim Fulton]

Julien Anguenot wrote:
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> Jim Fulton wrote:
> 
>>Julien Anguenot wrote:
>>
>>
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>>>I implemented a pre-commit hook on transaction supporting subscribers
>>>within CPS for our indexation use case. (for ZODB-3.2.x on
>>>Zope-2.7.x)
>>
>>
>>Cool
>>
>>
>>>if you're interested to take a look at it :
>>>
>>>http://lists.nuxeo.com/pipermail/cps-devel/2005-April/001357.html
>>
>>
>>I get a traceback from viewcvs when I try to view the patch.
>>
> 
> 
> this one ? :
> 
> http://cvs.nuxeo.org/cgi-bin/viewcvs.cgi/CPS3/CPSCore/PatchZODB.py?rev=1.1&view=auto
>

No, the one given in

   http://lists.nuxeo.com/pipermail/cps-devel/2005-April/001357.html

which is:

   http://cvs.nuxeo.org/cgi-bin/viewcvs.cgi/CPS3/CPSCore/PatchZODB.py

:)

> 
>>>The difference I can see with your proposal is the abort() hook facility
>>>that can be a good thing especially if the subscriber code has to
>>>communicate with external programs for rollback purpose.
>>
>>
>>I suggest that if you are going to "communicate with external
>>programs for rollback purpose", it would be much better to
>>participate as a data manager.
>>
> 
> 
> in ZODB-3.2 ? Can you explain ?

In other words, implementing the interface that transactions
expect of things like adtabase connections.  Unfortunately,
this wasn't documented until recently.  In ZODB 3.3,
transaction.interfaces has IDataManagerOriginal which attempts
to document the ZODB 3.2 transaction-manager interface.

Unfortunately, the data manager interface for ZODB 3.3 isn't
accurately documented yet.  (There's even a bonus inacurate
interface. ;) Tim and I intend to fix this this week.

>>I would say that the main difference is that with the simple hook
>>facility I proposed, you can just register simple callables. You
>>don't have to create a class.
> 
> 
> ok for this. My idea is to control what people are going to register. So
> I'm adding constraints by providing an interface they need to implement
> for their own subscribers. That's mostly the point.

Are you saying that you don't want people to use this facility
and you want to make them work harder in order to discourage them?

;)

Jim


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