Added a new parameter for configuring socket connection.

[xydan83]

From #70 issue.

    # By default, in order to optimize the transmission of small data packets,
    # the send buffer size is set to 2048 bytes. To transfer large data packets (>50MB),
    # it is recommended to increase the buffer value.
    # It is also possible to set all possible socket settings.
    # See https://docs.python.org/3/library/socket.html#socket.socket.setsockopt for more information.
    # If the socket_options is None, then the system defaults are used.

[frederikaalund]

Thanks for the pull request. This is a really cool feature and a nice addition to asyncio-mqtt. 👍

I've reviewed the changes and I'd like some minor changes here and there. Let me know what you think. :)

[frederikaalund]

Good job with the initial typing here. 👍 I really like the details in the comment as well

I suggest that we drop the default SO_SNDBUF setting. Move it to the comment, though, as a nice example.

I also suggest that we expand on this, so that people can set multiple options using any of the three overloads of setsockopt. First, we define:

# See the overloads of `socket.setsockopt` for details.
SocketOption = Union[
    Tuple[int, int, Union[int, bytes]],
    Tuple[int, int, None, int],
]

Second, we accept an iterable of socket options in the Client.__init__.

socket_options: Iterable[SocketOption],

[xydan83]

Yes, is good idea!

[xydan83]

I found it worth adding one more thing so that there would be no compatibility issues with the new library version when upgrading.
If we do this: socket_options: Iterable[SocketOption], then we get an error
TypeError: init() missing 1 required keyword-only argument: 'socket_options', because we have no input parameter when constructing an object.

Maybe add a default value?
For example: socket_options: Optional[Iterable[SocketOption]] = ()

[xydan83]

Thank you! Great changes. Thus, the setting will be more flexible.

[frederikaalund]

Glad you like it. :) Let me know when you push the new changes. 👍

For now, there seems to be some merge conflicts. I recommend that you:

• Rebase on top of master git pull --rebase -i (the -i is for interactive mode)
• Force push your changes git push --force

That should also get rid of the "Added new parameter 'message_retry_set' to the Client._" commit that we already merged to master. :)

[xydan83]

I applied the changes, check please:)

[frederikaalund]

I merged your pull request. Thanks for you contribution to asyncio-mqtt. :) 👍

[xydan83]

I merged your pull request. Thanks for you contribution to asyncio-mqtt. :)

Thanks for a great project! ))