send_c_cancel example

[medihack]

I am having difficulties to understand send_c_cancel(msg_id, context_id) and can't find an easy example for it. From where do I get the context_id?

Let's say I want to cancel a send_c_get operation with multiple accepted contexts (e.g. by requesting `StoragePresentationContexts´). How do I know which context at the end is used, and how it's context_id is?

I found some usage in test_service_qr.py, but I don't understand it either. Why are there two calls directly after each other (assoc.send_c_cancel(1, 3), assoc.send_c_cancel(11142, 1)). And where do these context IDs come from?

And a last question ... I guess the canceling must always come from the same association (maybe from another thread). Is that right?

[scaramallion]

The context_id is the ID of the presentation context you're using for the C-GET operation. Hmm, I admit it's not straight forward to get, I'll probably make that a bit easier next version.

from pynetdicom.sop_class import PatientRootQueryRetrieveInformationModelGet
# assuming this is the query model you're using in `send_c_get()`
to_match = PatientRootQueryRetrieveInformationModelGet
cxs = [cx for cx in assoc.accepted_contexts if cx.abstract_syntax == to_match]
cx_id = cxs[0].context_id

Might need a bit of tweaking if you're requesting multiple contexts with the same abstract syntax.

Yeah, cancellation must come from the same association.

[medihack]

Thanks a lot, this makes it clear. I leave the issue open to track it for a possible enhancement.