wip: implemented hyper-1.0 for http/1.1 and http/2. todo: http/3 and backend handler

rpxy-lib/src/proxy/mod.rs

@@ -10,4 +10,33 @@ mod proxy_quic_s2n;
 mod proxy_tls;
 mod socket;
 
+use crate::error::*;
+use http::{Response, StatusCode};
+use http_body_util::{combinators, BodyExt, Either, Empty};
+use hyper::body::{Bytes, Incoming};
+
 pub use proxy_main::{Proxy, ProxyBuilder, ProxyBuilderError};
+
+/// Type for synthetic boxed body
+type BoxBody = combinators::BoxBody<Bytes, hyper::Error>;
+/// Type for either passthrough body or synthetic body
+type EitherBody = Either<Incoming, BoxBody>;
+
+/// helper function to build http response with passthrough body
+fn passthrough_response(response: Response<Incoming>) -> Result<Response<EitherBody>> {
+  Ok(response.map(EitherBody::Left))
+}
+
+/// build http response with status code of 4xx and 5xx
+fn synthetic_error_response(status_code: StatusCode) -> Result<Response<EitherBody>> {
+  let res = Response::builder()
+    .status(status_code)
+    .body(EitherBody::Right(BoxBody::new(empty())))
+    .unwrap();
+  Ok(res)
+}
+
+/// helper function to build a empty body
+fn empty() -> BoxBody {
+  Empty::<Bytes>::new().map_err(|never| match never {}).boxed()
+}