- Replace `Github` with `GitHub`. - Replace `windows` with `Windows` - Replace `advice` with `advise` where a verb is used. - A few fixes on removing repeated words. - Replace `a HTTP` with `an HTTP` Closes #9802
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Hyper
Hyper is a separate HTTP library written in Rust. curl can be told to use this library as a backend to deal with HTTP.
Experimental!
Hyper support in curl is considered EXPERIMENTAL until further notice. It needs to be explicitly enabled at build-time.
Further development and tweaking of the Hyper backend support in curl will happen in the master branch using pull-requests, just like ordinary changes.
Hyper version
The C API for Hyper is brand new and is still under development.
build curl with hyper
Since March 3 2022, hyper needs the nightly rustc to build, which you may need to install first with:
% rustup toolchain install nightly
Then build hyper and enable its C API like this:
% git clone https://github.com/hyperium/hyper
% cd hyper
% RUSTFLAGS="--cfg hyper_unstable_ffi" cargo +nightly rustc --features client,http1,http2,ffi -Z unstable-options --crate-type cdylib
Build curl to use hyper's C API:
% git clone https://github.com/curl/curl
% cd curl
% autoreconf -fi
% ./configure --with-hyper=<hyper dir>
% make
using Hyper internally
Hyper is a low level HTTP transport library. curl itself provides all HTTP headers and Hyper provides all received headers back to curl.
Therefore, most of the "header logic" in curl as in responding to and acting on specific input and output headers are done the same way in curl code.
The API in Hyper delivers received HTTP headers as (cleaned up) name=value pairs, making it impossible for curl to know the exact byte representation over the wire with Hyper.
Limitations
The hyper backend does not support
CURLOPT_IGNORE_CONTENT_LENGTH
--raw
and disablingCURLOPT_HTTP_TRANSFER_DECODING
- RTSP
- hyper is much stricter about what HTTP header contents it allows
- HTTP/0.9
- HTTP/2 upgrade using HTTP:// URLs. Aka 'h2c'
Remaining issues
This backend is still not feature complete with the native backend. Areas that still need attention and verification include:
- multiplexed HTTP/2
- h2 Upgrade:
- pausing transfers
- receiving HTTP/1 trailers
- sending HTTP/1 trailers