70 lines
2.1 KiB
Markdown
70 lines
2.1 KiB
Markdown
|
# 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
|
||
|
|
|
||
|
|
Using Rust 1.64.0 or later, build hyper and enable its C API like this:
|
||
|
|
|
||
|
|
% git clone https://github.com/hyperium/hyper
|
||
|
|
% cd hyper
|
||
|
|
% RUSTFLAGS="--cfg hyper_unstable_ffi" cargo rustc --features client,http1,http2,ffi --crate-type cdylib
|
||
|
|
|
||
|
|
Also, `--release` can be added for a release (optimized) build.
|
||
|
|
|
||
|
|
Build curl to use hyper's C API:
|
||
|
|
|
||
|
|
% git clone https://github.com/curl/curl
|
||
|
|
% cd curl
|
||
|
|
% autoreconf -fi
|
||
|
|
% ./configure LDFLAGS="-Wl,-rpath,<hyper-dir>/target/debug -Wl,-rpath,<hyper-dir>/target/release" --with-openssl --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 disabling `CURLOPT_HTTP_TRANSFER_DECODING`
|
||
|
|
- RTSP
|
||
|
|
- hyper is much stricter about what HTTP header contents it allows
|
||
|
|
- leading whitespace in first HTTP/1 response header
|
||
|
|
- 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:
|
||
|
|
- receiving HTTP/1 trailers
|
||
|
|
- sending HTTP/1 trailers
|