Comparison with httptools

[kespindler]

In your readme you say you attempted a cython wrapper around http-parser, which appears to have been done now: https://github.com/MagicStack/httptools

Do you have any points of reference on performance, ease of use, or other points between the two libraries?

[njsmith]

It's not really an apples-to-apples comparison. httptools is substantially lower-level -- it just provides a parser, while h11 implements a complete model of the HTTP request/response cycle. Potentially h11 could be adapted to use httptools internally for parsing, but I don't think it would be very useful. Currently h11 is pure Python, but httptools requires a C compiler, which adds operational complexity. Normally this is offset by C code being faster, but in my benchmarks, h11's parser isn't the bottleneck anyway, so optimizing it wouldn't get you much.

httptools is definitely faster -- but AFAICT that's mostly because it does less. There are a lot of fiddly bits required to correctly implement HTTP, and those have a cost, which h11 pays. If you don't care about handling the edge cases correctly (which is a totally valid situation to be in!) and need Ultimate Speed, then implementing something on top of httptools is probably a better starting point than h11; if you don't want to read RFCs then h11 handles a lot of picky junk for you, and is probably "fast enough".

(For reference, on my laptop, h11 handles the protocol parts of doing a request/response cycle in ~0.2 milliseconds on CPython, and ~0.04 milliseconds on PyPy. So if you're implementing an HTTP server and need, say, 10 ms to actually generate your response -- doing database calls, filling in templates, etc. -- then h11's overhead is very small in relative terms.)

CC: @1st1 in case he has a different perspective he'd like to bring in :-)