Support message delivery tag

[annatisch]

First pass at exposing the binary data provided in the message delivery tag.
This is used by ServiceBus to provide the lock token.

[yunhaoling]

Hello @annatisch

Would it be better to let the message_receiver to assign delivery-tag of Transfer frame to each message instead of just storing the latest delivery-tag in a link?

• The delivery-tag seems to be related to each Transfer frame (which is equal to a message I think).
• If we only set the latest delivery-tag on the Link, then what about the following situation (I'm not sure whether it's the use case for ServiceBus):
  • Step1: receive the 1st msg
  • Step2: receive the 2rd msg
  • Step3: Now I want to lock the 1st msg (but the last delivery-tag of the receiver is from the 2rd message)

I found that the link will pass the handling of Transfer to the receiver.
How about handling Transfer and assigning the delivery-tag to the message created in the on_transfer_received of the message_receiver?

[annatisch]

Thanks @yunhaoling - yeah good call - I will refactor.

[luipir]

only @yunhaoling as possible reviewer?

[annatisch]

Hi @yunhaoling - I have reverted my debugging and this is now ready to review.

[annatisch]

@luipir - if you look at the builds you can download one of the test wheels to test out locally if you like:
https://dev.azure.com/azure-sdk/public/_build/results?buildId=118233

Just select your chosen platform flavor from the "Artifacts" drop down.

[annatisch]

Closing this in favour of PR #96 which includes some additional fixes.

[luipir]

@annatisch sorry I hadn't time to test yet ... I'll do (the new PR) as soon as I finish other code. Tnx for the (possible) fix.