Adjust max streams when remote settings change

[dunkmann00]

If the remote server sends a settings update for max_concurrent_streams, check and potentially update the max number of streams we will use for a connection.

This is related to encode/httpx#2416.

[dunkmann00]

Not sure where to put this so I'll just add it as another message. When I tested this against APNS, I was able to see the settings change come in. This is what the change in max concurrent streams specifically looked like:

First event:
ChangedSetting(setting=SettingCodes.MAX_CONCURRENT_STREAMS, original_value=None, new_value=1)
Second Event:
ChangedSetting(setting=SettingCodes.MAX_CONCURRENT_STREAMS, original_value=1, new_value=1000)

[dunkmann00]

Hello @tomchristie, just wanted to reach out to see if you or somebody from the encode team could review this? Thanks!

[lovelydinosaur]

Great stuff, thanks! 🎉

The CI reports a linting failure indicating that the async and sync versions don't match. You can resolve this locally by running scripts/unasync.

I'd suggest resolving that first.

Then you might want to take a look at https://github.com/encode/httpcore/blob/master/tests/_async/test_http2.py and see if you're able to add some test coverage for this.

[dunkmann00]

Okay I think this is good to go! Let me know if there are any other changes you would like me to make.

[dunkmann00]

Hey @tomchristie! Just checking in to see what you think of the recent commits with the added tests?

[lovelydinosaur]

Great work, thanks!

[lovelydinosaur]

Would be interesting to see this working together with our latest logging update...

https://www.encode.io/httpcore/logging/

[dunkmann00]

Thanks for the merge!

Would be interesting to see this working together with our latest logging update...

Are you planning on bumping the httpcore dep in httpx. I'm not in a hurry or anything, but it would be easier to try this out if it was in httpx.