Implement full async channel

[bollhals]

Proposed Changes

Implements the proposal (#970) except the wait for confirmation part (will be done later to keep this PR "smaller") and some smaller modification / renamings along the way.

Types of Changes

• [ ] Bug fix (non-breaking change which fixes issue #NNNN)
• [x] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• [x] Documentation improvements (corrections, new content, etc)
• [x] Cosmetic change (whitespace, formatting, etc)

Checklist

• [x] I have read the CONTRIBUTING.md document
• [x] I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• [x] All tests pass locally with my changes
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have added necessary documentation (if appropriate)
• [x] Any dependent changes have been merged and published in related repositories

Further Comments

• I've added xml documentation to all public API's
• I've made the Channel classes as well as the interface public. The interface is returned in methods but it can be casted if users want to be able to.
• I've extracted all channel 0 specific methods into the ConnectionChannel class, so the actual Channel is less crowded.
• The implementation itself isn't fully async yet, but this is more about the API itself, so we can modify the things below next.

Open questions

• Where should these types be saved in the source? (Current stored in "client/impl/channel")
• What namespace should these types have?

[bollhals]

Mind taking a look at this? @stebet @bording @michaelklishin (You were commenting on #970 )

[bollhals]

I can't yet request formal reviews, but I would like to start having a discussion about these changes as they should mark the direction of 8.0. @michaelklishin @stebet @danielmarbach @lukebakken

[stebet]

I can't yet request formal reviews, but I would like to start having a discussion about these changes as they should mark the direction of 8.0. @michaelklishin @stebet @danielmarbach @lukebakken

I'll take a look at this tomorrow :)

[bollhals]

Sorry wasn't able to finish the whole thing. I have limited time at my hands before christmas. Here are a few thoughts

Well it's a big change and any feedback is very much appreciated!

Regarding the questions about async in Consumer / Connection, as the PR was already quite huge, so I've tried to limit changes outside of the IModel/IChannel for a future PR. I think it's simple to do changes to full async all the way stepwise. But yes all of it should be modified!

[michaelklishin]

Sorry to drag you into resolving some non-trivial conflicts @bollhals. We decided to go ahead and merge https://github.com/rabbitmq/rabbitmq-dotnet-client/pull/1202 as it felt like the right thing to do since we require net6.0 now for 7.0. This obviously affects all pull requests in flight.

[lukebakken]

I will hopefully be able to bring this PR up-to-date once #1199 is merged.

[michaelklishin]

I reverted #1202 because it makes back and forward-porting impossible unless all maintained branches adopt file-scoped namespaces.

[lukebakken]

@bollhals now that I've merged #1264 would you like to rebase this on main? I can give it a try as well.

[bollhals]

I'm swamped with other stuff right now, so I do not have a lot of time to invest in this. So if you/someone can take over, that would be great.

[stebet]

~~Would it make sense to make several small PRs, starting simply with ConnectAsync and then gradually going through the operations?~~

I'll take a quick look to see how much work this is to merge and go through before suggesting we take an approach like splitting it up into smaller PRs

[lukebakken]

Thanks @stebet

[lukebakken]

@stebet I'm starting on porting these changes to main, beginning with the IModel -> IChannel and related renames.