[zeromq-dev] XPub welcome message and manual subscriptions

[Michael Haberler]

Hi Doron,

a question on ZMQ_XPUB_MANUAL and ZMQ_SUBSCRIBE:

> Am 26.11.2014 um 14:30 schrieb Doron Somech <somdoron at gmail.com>:
> 
> Hi All,
> 
> Just want to let you know and have a discussion on two features (two solutions to problems) that I have just added to zeromq:
> 
> Manual Subscriptions:
> Publisher can be configured to manual mode, with manual mode subscriptions send from the client are not added automatically (nor unsubscriptions) and user must call set socket option with ZMQ_SUBSCRIBE on the publisher side to confirm them. 
> 
> The idea is that now subscriptions can be confirmed according to credentials, another use is to actually use a token for the subscription and the publisher will translate the token to one or more topics. For the second use the subscriber side must be of type xsub to avoid filtering messages on the client side.
> 
> You can take a look at the test for usage: https://github.com/zeromq/libzmq/blob/master/tests/test_xpub_manual.cpp.

the subscription is a subscriber socket property, but the ZMQ_SUBSCRIBE confirming the subscription with the actual topic works on the publisher socket

It's not clear on how the ZMQ_SUBSCRIBE is associated with the subscriber; is it just confirming "the last pending subscribe" ?

- Michael