[Twisted-Python] run queries in deffered, but not in transaction
petshmidt at googlemail.com
Wed Sep 16 12:18:41 EDT 2009
On Tue, Sep 15, 2009 at 6:21 PM, Pet <petshmidt at googlemail.com> wrote:
> On Tue, Sep 15, 2009 at 5:19 PM, Mark Visser <markv at lumierevfx.com> wrote:
>> exarkun at twistedmatrix.com wrote:
>>> On 10:37 am, petshmidt at googlemail.com wrote:
>>>> I'd like to run several queries in background, some of them may fail.
>>> If you have a function along the lines of this one:
>>> def someInteractions(db):
>>> interactions = [
>>> Then a failure in one shouldn't affect two or three; likewise for any
>>> other failure or combination of failures. They are naturally (ugh, not
>>> a good word, but I can't think of a better one) independent. You have
>>> to go out of your way to associate them somehow.
>> I think he might mean he wants them to run sequentially, even if one fails.
>> You can do that explicitly via @inlineCallbacks like this:
>> def someInteractions(db):
>> yield db.runInteraction(one)
>> yield db.runInteraction(two)
>> yield db.runInteraction(three)
>> Or with callback/errbacks, like this:
>> def someInteractions(db)
>> d = db.runInteraction(one).addBoth(db.runInteraction,
>> two).addBoth(db.runInteraction, three)
I've tried to do following:
def logRequest(self, *arg, **kw):
obj = copy.deepcopy(kw['obj'])
d = self.db.runInteraction(obj.first)
d.addCallback(self.db.runInteraction, obj.second, param1, param2)
unfortunately it doesn't work in that way, because I suppose, obj is
destroyed if second or third interaction starts.
Is there a way to solve this?
> Hi Mark!
> Yes, I'd like run them sequentially, it was not clear for me, how to
> do it in one deferred.
> I will try your suggestions out.
> Thanks for help!
>> addBoth is a convenience method that adds the same function as a
>> callback and an errback:
>> Mark Visser, Software Director
>> Lumière VFX
>> Email: markv at lumierevfx.com
>> Phone: +1-514-316-1080 x3030
>> Twisted-Python mailing list
>> Twisted-Python at twistedmatrix.com
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