Add websocket support

[gre-42]

Issue or RFC Endorsed by Maintainers

Enable WebSockets #20.

Description of the Change

Added websocket support.

Alternate Designs

Extending the existing http_resource class was considered, but rejected in favor of a new class and multiple inheritance.

Possible Drawbacks

libmicrohttpserver does not yet compile the websocket-support by default. It must be done by building libmicrohttpd/src/microhttpd_ws.

Verification Process

Created and tested an example application hello_world_websocket.cpp under Ubuntu 20.04.

Release Notes

Added support for websockets.

[nawaz1991]

@etr , @gre-42 , Any ETA of merging this PR. PS: I am using libhttpserver in my project for a REST server and planning to consume websocket in as well in next phase.

[etr]

Sorry for the lack on feedback and thanks for the support and for the code contribution.

I think the main reason I cannot go with this change as is currently wired is that it uses a custom version/configuration of libmicrohttpd without making it optional. I think that needs to be solved before we can merge this change - many consumers of the library use libmicrohttpd as installed by their OSes and this would practically break their builds entirely.

[nawaz1991]

Sorry for the lack on feedback and thanks for the support and for the code contribution.

I think the main reason I cannot go with this change as is currently wired is that it uses a custom version/configuration of libmicrohttpd without making it optional. I think that needs to be solved before we can merge this change - many consumers of the library use libmicrohttpd as installed by their OSes and this would practically break their builds entirely.

Thanks for the quick reply.

[jvo203]

Whilst I appreciate concerns for the existing user base, change is inevitable. It is called progress. Existing projects relying on libmicrohttpd would need to update / re-compile their code. Just like all the other open-source projects do when there are API breaks in their codebases and / or dependencies.

I've been a faithful libmicrohttpd user for nearly 10 years. It is just great, the API is ergonomic, the MHD_create_response_from_pipe() function is much appreciated too. But the lack of WebSocket support has always forced me into "clunky" hybrid solutions: for example right now using libmicrohttpd on port 8080 to handle HTTP and a separate thread running the C mongoose library on port 8081 to handle WebSockets. Dealing with two different C APIs as well as frequent changes in the C mongoose API (change is inevitable but hopefully not too frequently!). Not ideal at all.

[jvo203]

Verification Process

Created and tested an example application hello_world_websocket.cpp under Ubuntu 20.04.

Hi are there any plans to provide a C-only WebSocket example? My project uses FORTRAN and pure C with no C++ whatsoever.