Hi,
I was missing some commonly usable HTTP parser on code.dlang.org
and after some research and work I've published httparsed[1].
It's inspired by picohttpparser[2] which is great, but instead of
a binding, I wanted something native to D. Go has it's own
parsers, Rust has it's own parsers, why not D?
I think we're missing other small libraries like this on the
code.dlang.org to be commonly used in larger ones like it's so
common in other languages - while improving the ecosystem. Vibe-d
is just huuuge.
It is nothrow, @nogc and can work with betterC. It just parses
the message header and calls provided callbacks with slices to
the original buffer to be handled as needed by the caller.
Same as picohttpparser it uses SSE4.2 `_mm_cmpestri` instruction
to speedup the invalid characters lookup (when built with ldc2
and target that supports it).
It has pretty thorough test suite.
Can parse incomplete message headers.
Can continue parsing from the last completely parsed line.
Doesn't enforce method or protocol version on itself to be usable
with other internet message like protocols as is for example RTSP.
Performance wise it's pretty on par with picohttpparser [3].
Without SSE4.2 it's a bit faster, with SSE4.2 it's a bit slower
and I can't figure out why :/.
But overall, I'm pretty happy with the outcome.
I've tried to check and compare with two popular libraries and:
* vibe-d - performs nearly the same as http_parser[4] (but that
itself is pretty slow and now obsolete), but as it looks, doesn't
do much in regard of RFC conformance - some test's from [2] won't
pass for sure
* arsd's cgi.d - I haven't expected it to be so much slower than
vibe-d parser, it's almost 3 times slower, but on the other hand
it's super simple idiomatic D (again doesn't check or allow what
RFC says it should and many tests will fail)
* I guess the main problem would be `idup` on every line and
autodecode
* Stripped down minimalistic version of the original [5] is
here [6]
[1] https://code.dlang.org/packages/httparsed
[2] https://github.com/h2o/picohttpparser
[3] https://i.imgur.com/iRCDGVo.png
[4] https://github.com/nodejs/http-parser
[5]
https://github.com/adamdruppe/arsd/blob/402ea062b81197410b05df7f75c299e5e3eef0d8/cgi.d#L1737
[6]
https://github.com/tchaloupka/httparsed/blob/230ba9a4a280ba91267a22e97137be12269b5574/bench/bench.d#L194
