-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Tim Peters wrote: > [Julien Anguenot] > >>... >>To make it clear the idea is if you got this and if we call it "order". >> >>Callback Ca order 0 >>Callback Cb order 999999 >>Callback Cc order -999999 >> >>The order of execution will be Cc Ca and then Cb. >> >>Note the ones with a default order (e.g : 0) will be executed in the >>order of the regitration as it is currently. > > > Isn't it also true that if, e.g., Cd were added last with `order` 999999, > then it's guaranteed that Cb is invoked before Cd? That is, is there > something unique about 0 wrt "equal orders fire in registration order"? I > hope not.
It will have the same behavior as 0, of course. I badly took 0 as an example... > > >>You ok with this ? > > > Yup. Does it end here? Or is this an ever-growing subsystem, also > "needing" ways to query the `order` value associated with callbacks already > registered, ways to change their associated `order` values, ...? It's enough for us right now. > Note that > it would be incompatible if getBeforeCommitHooks() changed to return the > `order` values too. > right. > >>Note, the wording 'order' comes from Jim's implementation within Zope3 >>that I wanted to follow for consistency. >> >> > > http://svn.zope.org/Zope3/trunk/src/zope/configuration/interfaces.py?rev=375 > 52&view=auto > >>IConfigurationContext.action() for instance. an action with order 9999999 >>will be invoked after the other ones. > > > That may be the case, but the interface docstring there doesn't explain > anything about the effect of action's `order` argument. I would, of course, > like an accurate docstring in ZODB. I'll add this to do doctest right now on Zope3. > > >>And, of course, if it's called a priority then the execution will be be >>the opposite : Cb, Ca, Cc >> >>Now, it's probably better to use "order" to keep consistency with Zope3. > > > Well, Gary thought "priority" would give the same ordering as "order", so > "priority" instead sure isn't winning on universal obviousness <wink>. ;) Let's go for order then. > "order" is fine with me, and everyone so far guessed its intended meaning. > > cool >>>It's certainly easy to implement. The Collector will remain open all >>>weekend for patches <wink>. > > >>Well, I'd rather do a branch including the modifications and the tests >>that we could merge after. For you and for me it will be easier. Except >>if the ZODB sub-area of the Zope.org repository is a resticted one ? > > > Fine idea! Since it's a new feature, it would need to be done on a branch > off of ZODB/trunk (current 3.5 development). ZODB is not restricted (well, > no more than Zope or Zope3 are restricted -- you need zope.org commit > privileges to fiddle with any of them). then it's fine. > > Note that it's specifically allowed to register additional hooks _while_ > before-commit hooks are being invoked, so it's likely easiest to maintain > the _before_commit list in sorted order all along (via bisect.insort(), and > including a unique index number in the tuple inserted to resolve `order` > ties in registration order), or to use a BTree-based container instead. ok I'll check this. > > It's tricky to implement this in a way that scales efficiently to a "large > number" of hooks. I assume that's not a problem, because the current > implementation doesn't scale efficiently either (it's quadratic-time in the > number of hooks), and nobody has complained about that. It's not currently a problem for us with CPS. J. - -- Julien Anguenot | Nuxeo R&D (Paris, France) CPS Platform : http://www.cps-project.org Zope3 / ECM : http://www.z3lab.org mail: anguenot at nuxeo.com; tel: +33 (0) 6 72 57 57 66 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFC9y26GhoG8MxZ/pIRAv5UAJ42T5CX1cy8FMBewUDKVS6KcldAlwCeLBB5 ISAD/pZKuhHY2YT7CsIzyQY= =b5tB -----END PGP SIGNATURE----- _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
