[Event Hubs] Implement PartitionManager methods

[ShivangiReja]

One of the required parameters to the EventProcessor constructor is partitionManager.

PartitionManager is an interface that describes 3 methods. Created a class called InMemoryPartitionManager which implements PartitionManager methods. Internally InMemoryPartitionManager class maintains a map to store partitionOwnerships.

• listOwnerships: Accepts an eventHubName and consumerGroupName and returns a list of PartitionOwnership
• claimOwnerships: Accepts a list of PartitionOwnership, check partitionOwnership in the map if it's not present then adds partitionOwnership into the map and returns the same list of PartitionOwnership.
• updateCheckpoint: Updates the checkpoint

[chradek]

Very minor nits

[conniey]

Is this something all languages are exposing? I don't remember seeing it in our API design, that close() takes a reason. 🤔

[ShivangiReja]

Proposed API for javascript, here it takes CloseReason.

[chradek]

@conniey We brought that up on Monday too, because we were curious how Java would know why the subscription was closed.

[conniey]

Yeah, I also wonder what the user could do differently with that reason (ie. user shutdown vs stolen)? I mean, we log it in the EventConsumer but it is not propagated out.

[chradek]

In theory if it was a shutdown they could checkpoint one last time, whereas if it were stolen they wouldn’t be able to update the checkpoint.