Websocket sansio implementataion

[gourav-kandoria]

This PR provides the implementation of websocket protocol using websockets sansI/O layer.

task details - #1908

Checklist for @Kludex

• data_receive shouldn't be using Exception. What is the right exception there?
• Check if max_size is being tested, and if not, test it. EDIT: I've checked it - it's not being tested.
• Add WebSocketsSansIOProtocol test for max_size.
• Should we remove CONT and PONG related code?
• Add documentation.
• Increase the coverage number.
• Add --ws websockets-sansio.
• Check if Websocket sansio implementataion #2060 (comment) is true.
• Answer the following questions:
  • Should we deprecate websockets legacy version?
  • Should we add a UserWarning saying that it's experimental, and asking users to comment in a discussion X?

[Kludex]

If you make the pipeline green, I can review it.

[gourav-kandoria]

sure

[gourav-kandoria]

@Kludex Could you please review it. all checks are passing now

[Kludex]

I'll review on the weekend.

[Kludex]

I'm going to explain +- how is going to be my review process, so you can try to speed it up:

1. I'll run the test suite, and check the coverage, and then I'll try to understand why some lines are not covered.
2. I'll check the type hints, and make sure that they make sense.
3. There are some tests that only work for wsproto or for websockets. I'm going to make sure that we are also running this protocol implementation where it makes sense.

[valentin994]

I'm going to explain +- how is going to be my review process, so you can try to speed it up:

1. I'll run the test suite, and check the coverage, and then I'll try to understand why some lines are not covered.

2. I'll check the type hints, and make sure that they make sense.

3. There are some tests that only work for `wsproto` or for `websockets`. I'm going to make sure that we are also running this protocol implementation where it makes sense.

I was looking at this task as well, but as gourav-kandoria already did it I can help with pointing out few semantics or if I see something else. If you don't mind 😄

[valentin994]

https://websockets.readthedocs.io/en/stable/howto/sansio.html
if I'm following this right after receiving data you should call receive_eof()

[gourav-kandoria]

@valentin994 @Kludex we don't have to call receive_eof() after receiving data. Because, protocol ensures that (https://docs.python.org/3/library/asyncio-protocol.html#asyncio.Protocol.data_received) data_received will only be called only when the data is there. In case when eof is received from client side, the transport will close and connection_lost will be called.

[gourav-kandoria]

okay sure, got it. till then I will also go through the code at my end.

[Kludex]

FYI, if you want to speed up the review process here, I need the lines on the report for the added file to be covered, or to understand why they aren't.

I'll eventually come to this PR even if you don't do it, but it may take some time.

[gourav-kandoria]

This lines(117-119) are not being covered. Because, I guess in the test suite there not any test which after connection establishment sends data which causes receive_data to throw exception such as data which don't follow websocket spec.

[Kludex]

We still need to test it. It's unlikely that we want Exception there as well.

[Kludex]

Why?

[gourav-kandoria]

oh my bad. branch got deleted by mistake. Due to bandwidth issue, I won't be able to contribute on this. That's why closed the pr.
Although If you want to continue on this. You may refer this branch https://github.com/gourav-kandoria/uvicorn/tree/websocket-sansio-implementation-2. adding additional typing checks would be sufficient as the code in this branch is following complete websocket asgi specs and passing all test cases

[Kludex]

cc @aaugustin