[Twisted-Python] Problem with txampq_helper ampqFactory: closing connections

[exarkun at twistedmatrix.com]

On 29 Jan, 10:11 pm, andrewfr_ice at yahoo.com wrote:
>Hi Folks:
>
>I need to maintain a programme that uses txampq_helper library 
>ampqFactory. The current program does not close the connection to the 
>underlying rabbitmq (the code is a mess).
>
>Can I simple call theampqFactory.protocol.transport.loseConnection()?

Does this factory keep a reference to a connected protocol as its 
`protocol` attribute?  Most factories keep a reference to their protocol 
class there.

If it isn't keeping a reference to the instance then you won't be able 
to disconnect it this way, you'll have to find a reference to it some 
other way.

One easy way to do this is to wrap the factory with `WrappingFactory` 
from `twisted.protocols.policies`.  This factory keeps a `protocols` 
dictionary on itself tracking all of the currently-connected protocols 
it (and the wrapped factory) have been used to create.
>Do I need to unregisterProducer() first (in ampqFactory, i see stuff 
>like resumeProducing() so I assume it is a producer)

You do need to unregister, yes.  Alternatively, you can use 
`abortConnection` as long as the transport you're using has implemented 
that method (and as long as you don't care if some bytes in the send 
buffer get dropped).
Jean-Paul