refactor(ffi): Add Reason-Phrase API

This adds an internal ability to copy the HTTP/1 reason-phrase and place
it in the `http::Extensions` of a response, if it doesn't match the
canonical reason. This could be exposed in the Rust API later, but for
now it is only used by the C API.

src/ffi/http_types.rs

@@ -23,6 +23,9 @@ pub struct hyper_headers {
 #[derive(Debug, Default)]
 pub(crate) struct HeaderCaseMap(HeaderMap<Bytes>);
 
+#[derive(Debug)]
+pub(crate) struct ReasonPhrase(pub(crate) Bytes);
+
 // ===== impl hyper_request =====
 
 ffi_fn! {
@@ -150,6 +153,30 @@ ffi_fn! {
     }
 }
 
+ffi_fn! {
+    /// Get a pointer to the reason-phrase of this response.
+    ///
+    /// This buffer is not null-terminated.
+    ///
+    /// This buffer is owned by the response, and should not be used after
+    /// the response has been freed.
+    ///
+    /// Use `hyper_response_reason_phrase_len()` to get the length of this
+    /// buffer.
+    fn hyper_response_reason_phrase(resp: *const hyper_response) -> *const u8 {
+        unsafe { &*resp }.reason_phrase().as_ptr()
+    }
+}
+
+ffi_fn! {
+    /// Get the length of the reason-phrase of this response.
+    ///
+    /// Use `hyper_response_reason_phrase()` to get the buffer pointer.
+    fn hyper_response_reason_phrase_len(resp: *const hyper_response) -> size_t {
+        unsafe { &*resp }.reason_phrase().len()
+    }
+}
+
 ffi_fn! {
     /// Get the HTTP version used by this response.
     ///
@@ -205,6 +232,18 @@ impl hyper_response {
 
         hyper_response(resp)
     }
+
+    fn reason_phrase(&self) -> &[u8] {
+        if let Some(reason) = self.0.extensions().get::<ReasonPhrase>() {
+            return &reason.0;
+        }
+
+        if let Some(reason) = self.0.status().canonical_reason() {
+            return reason.as_bytes();
+        }
+
+        &[]
+    }
 }
 
 unsafe impl AsTaskType for hyper_response {

src/ffi/mod.rs

@@ -28,7 +28,7 @@ mod io;
 mod task;
 
 pub(crate) use self::body::UserBody;
-pub(crate) use self::http_types::HeaderCaseMap;
+pub(crate) use self::http_types::{HeaderCaseMap, ReasonPhrase};
 
 pub const HYPER_ITER_CONTINUE: libc::c_int = 0;
 #[allow(unused)]

src/proto/h1/role.rs

@@ -5,6 +5,8 @@
 use std::fmt::{self, Write};
 use std::mem;
 
+#[cfg(feature = "ffi")]
+use bytes::Bytes;
 use bytes::BytesMut;
 use http::header::{self, Entry, HeaderName, HeaderValue};
 use http::{HeaderMap, Method, StatusCode, Version};
@@ -660,7 +662,7 @@ impl Http1Transaction for Client {
         loop {
             // Unsafe: see comment in Server Http1Transaction, above.
             let mut headers_indices: [HeaderIndices; MAX_HEADERS] = unsafe { mem::uninitialized() };
-            let (len, status, version, headers_len) = {
+            let (len, status, reason, version, headers_len) = {
                 let mut headers: [httparse::Header<'_>; MAX_HEADERS] =
                     unsafe { mem::uninitialized() };
                 trace!(
@@ -674,6 +676,20 @@ impl Http1Transaction for Client {
                     httparse::Status::Complete(len) => {
                         trace!("Response.parse Complete({})", len);
                         let status = StatusCode::from_u16(res.code.unwrap())?;
+
+                        #[cfg(not(feature = "ffi"))]
+                        let reason = ();
+                        #[cfg(feature = "ffi")]
+                        let reason = {
+                            let reason = res.reason.unwrap();
+                            // Only save the reason phrase if it isnt the canonical reason
+                            if Some(reason) != status.canonical_reason() {
+                                Some(Bytes::copy_from_slice(reason.as_bytes()))
+                            } else {
+                                None
+                            }
+                        };
+
                         let version = if res.version.unwrap() == 1 {
                             Version::HTTP_11
                         } else {
@@ -681,7 +697,7 @@ impl Http1Transaction for Client {
                         };
                         record_header_indices(bytes, &res.headers, &mut headers_indices)?;
                         let headers_len = res.headers.len();
-                        (len, status, version, headers_len)
+                        (len, status, reason, version, headers_len)
                     }
                     httparse::Status::Partial => return Ok(None),
                 }
@@ -728,6 +744,13 @@ impl Http1Transaction for Client {
                 extensions.insert(header_case_map);
             }
 
+            #[cfg(feature = "ffi")]
+            if let Some(reason) = reason {
+                extensions.insert(crate::ffi::ReasonPhrase(reason));
+            }
+            #[cfg(not(feature = "ffi"))]
+            drop(reason);
+
             let head = MessageHead {
                 version,
                 subject: status,