Asyncify 'Handler'. Rename 'ErrorHandlerFuture' to 'CatcherFuture'.

contrib/lib/src/serve.rs

@@ -18,7 +18,7 @@ use std::path::{PathBuf, Path};
 
 use rocket::{Request, Data, Route};
 use rocket::http::{Method, uri::Segments, ext::IntoOwned};
-use rocket::handler::{Handler, HandlerFuture, Outcome};
+use rocket::handler::{Handler, Outcome};
 use rocket::response::{NamedFile, Redirect};
 
 /// A bitset representing configurable options for the [`StaticFiles`] handler.
@@ -276,34 +276,34 @@ impl Into<Vec<Route>> for StaticFiles {
     }
 }
 
-async fn handle_dir<'r, P>(opt: Options, req: &'r Request<'_>, data: Data, path: P) -> Outcome<'r>
+async fn handle_dir<'r, P>(opt: Options, r: &'r Request<'_>, d: Data, p: P) -> Outcome<'r>
     where P: AsRef<Path>
 {
-    if opt.contains(Options::NormalizeDirs) && !req.uri().path().ends_with('/') {
-        let new_path = req.uri().map_path(|p| p.to_owned() + "/")
+    if opt.contains(Options::NormalizeDirs) && !r.uri().path().ends_with('/') {
+        let new_path = r.uri().map_path(|p| p.to_owned() + "/")
             .expect("adding a trailing slash to a known good path results in a valid path")
             .into_owned();
 
-        return Outcome::from_or_forward(req, data, Redirect::permanent(new_path));
+        return Outcome::from_or_forward(r, d, Redirect::permanent(new_path));
     }
 
     if !opt.contains(Options::Index) {
-        return Outcome::forward(data);
+        return Outcome::forward(d);
     }
 
-    let file = NamedFile::open(path.as_ref().join("index.html")).await.ok();
-    Outcome::from_or_forward(req, data, file)
+    let file = NamedFile::open(p.as_ref().join("index.html")).await.ok();
+    Outcome::from_or_forward(r, d, file)
 }
 
+#[rocket::async_trait]
 impl Handler for StaticFiles {
-    fn handle<'r, 's: 'r>(&'s self, req: &'r Request<'_>, data: Data) -> HandlerFuture<'r> {
+    async fn handle<'r, 's: 'r>(&'s self, req: &'r Request<'_>, data: Data) -> Outcome<'r> {
         // If this is not the route with segments, handle it only if the user
         // requested a handling of index files.
         let current_route = req.route().expect("route while handling");
         let is_segments_route = current_route.uri.path().ends_with(">");
         if !is_segments_route {
-            let result = handle_dir(self.options, req, data, &self.root);
-            return Box::pin(async move { result.await });
+            return handle_dir(self.options, req, data, &self.root).await;
         }
 
         // Otherwise, we're handling segments. Get the segments as a `PathBuf`,
@@ -314,12 +314,10 @@ impl Handler for StaticFiles {
             .and_then(|segments| segments.into_path_buf(allow_dotfiles).ok())
             .map(|path| self.root.join(path));
 
-        Box::pin(async move {
-            match path {
-                Some(p) if p.is_dir() => handle_dir(self.options, req, data, p).await,
-                Some(p) => Outcome::from_or_forward(req, data, NamedFile::open(p).await.ok()),
-                None => Outcome::forward(data),
-            }
-        })
+        match path {
+            Some(p) if p.is_dir() => handle_dir(self.options, req, data, p).await,
+            Some(p) => Outcome::from_or_forward(req, data, NamedFile::open(p).await.ok()),
+            None => Outcome::forward(data),
+        }
     }
 }

core/codegen/src/attribute/catch.rs

@@ -51,7 +51,7 @@ pub fn _catch(args: TokenStream, input: TokenStream) -> Result<TokenStream> {
     let status_code = status.0.code;
 
     // Variables names we'll use and reuse.
-    define_vars_and_mods!(req, catcher, _Box, Request, Response, ErrorHandlerFuture);
+    define_vars_and_mods!(req, catcher, _Box, Request, Response, CatcherFuture);
 
     // Determine the number of parameters that will be passed in.
     let (_fn_sig, inputs) = match catch.function.sig.inputs.len() {
@@ -96,7 +96,7 @@ pub fn _catch(args: TokenStream, input: TokenStream) -> Result<TokenStream> {
 
         /// Rocket code generated wrapping catch function.
         #[doc(hidden)]
-        #vis fn #generated_fn_name<'_b>(#req: &'_b #Request) -> #ErrorHandlerFuture<'_b> {
+        #vis fn #generated_fn_name<'_b>(#req: &'_b #Request) -> #CatcherFuture<'_b> {
             #_Box::pin(async move {
                 let __response = #catcher_response;
                 #Response::build()

core/codegen/src/lib.rs

@@ -96,7 +96,7 @@ vars_and_mods! {
     StaticRouteInfo => rocket::StaticRouteInfo,
     SmallVec => rocket::http::private::SmallVec,
     HandlerFuture => rocket::handler::HandlerFuture,
-    ErrorHandlerFuture => rocket::handler::ErrorHandlerFuture,
+    CatcherFuture => rocket::handler::CatcherFuture,
     _Option => ::std::option::Option,
     _Result => ::std::result::Result,
     _Some => ::std::option::Option::Some,

core/lib/src/catcher.rs

@@ -77,17 +77,17 @@ impl Catcher {
     /// ```rust
     /// # #![allow(unused_variables)]
     /// use rocket::{Catcher, Request};
-    /// use rocket::handler::ErrorHandlerFuture;
+    /// use rocket::handler::CatcherFuture;
     /// use rocket::response::{Result, Responder};
     /// use rocket::response::status::Custom;
     /// use rocket::http::Status;
     ///
-    /// fn handle_404<'r>(req: &'r Request) -> ErrorHandlerFuture<'r> {
+    /// fn handle_404<'r>(req: &'r Request) -> CatcherFuture<'r> {
     ///    let res = Custom(Status::NotFound, format!("404: {}", req.uri()));
     ///    Box::pin(async move { res.respond_to(req) })
     /// }
     ///
-    /// fn handle_500<'r>(req: &'r Request) -> ErrorHandlerFuture<'r> {
+    /// fn handle_500<'r>(req: &'r Request) -> CatcherFuture<'r> {
     ///     Box::pin(async move{ "Whoops, we messed up!".respond_to(req) })
     /// }
     ///
@@ -153,7 +153,7 @@ macro_rules! default_catchers {
         let mut map = HashMap::new();
 
         $(
-            fn $fn_name<'r>(req: &'r Request<'_>) -> crate::handler::ErrorHandlerFuture<'r> {
+            fn $fn_name<'r>(req: &'r Request<'_>) -> crate::handler::CatcherFuture<'r> {
                 let status = Status::from_code($code).unwrap();
                 let html = content::Html(error_page_template!($code, $name, $description));
                 Box::pin(async move { status::Custom(status, html).respond_to(req) })

core/lib/src/handler.rs

@@ -25,6 +25,11 @@ pub type HandlerFuture<'r> = BoxFuture<'r, Outcome<'r>>;
 /// user provided state to make a request handling decision, you should consider
 /// implementing a custom `Handler`.
 ///
+/// ## Async Trait
+///
+/// [`Handler`] is an _async_ trait. Implementations of `Handler` must be
+/// decorated with an attribute of `#[rocket::async_trait]`.
+///
 /// # Example
 ///
 /// Say you'd like to write a handler that changes its functionality based on an
@@ -44,18 +49,19 @@ pub type HandlerFuture<'r> = BoxFuture<'r, Outcome<'r>>;
 /// ```rust,no_run
 /// # #[derive(Copy, Clone)] enum Kind { Simple, Intermediate, Complex, }
 /// use rocket::{Request, Data, Route, http::Method};
-/// use rocket::handler::{self, Handler, Outcome, HandlerFuture};
+/// use rocket::handler::{self, Handler, Outcome};
 ///
 /// #[derive(Clone)]
 /// struct CustomHandler(Kind);
 ///
+/// #[rocket::async_trait]
 /// impl Handler for CustomHandler {
-///     fn handle<'r>(&self, req: &'r Request, data: Data) -> HandlerFuture<'r> {
+///     async fn handle<'r, 's: 'r>(&'s self, req: &'r Request<'_>, data: Data) -> Outcome<'r> {
 ///         match self.0 {
 ///             Kind::Simple => Outcome::from(req, "simple"),
 ///             Kind::Intermediate => Outcome::from(req, "intermediate"),
 ///             Kind::Complex => Outcome::from(req, "complex"),
-///         }.pin()
+///         }
 ///     }
 /// }
 ///
@@ -131,6 +137,7 @@ pub type HandlerFuture<'r> = BoxFuture<'r, Outcome<'r>>;
 /// Use this alternative when a single configuration is desired and your custom
 /// handler is private to your application. For all other cases, a custom
 /// `Handler` implementation is preferred.
+#[crate::async_trait]
 pub trait Handler: Cloneable + Send + Sync + 'static {
     /// Called by Rocket when a `Request` with its associated `Data` should be
     /// handled by this handler.
@@ -142,7 +149,7 @@ pub trait Handler: Cloneable + Send + Sync + 'static {
     /// generate a response. Otherwise, if the return value is `Forward(Data)`,
     /// the next matching route is attempted. If there are no other matching
     /// routes, the `404` error catcher is invoked.
-    fn handle<'r, 's: 'r>(&'s self, request: &'r Request<'_>, data: Data) -> HandlerFuture<'r>;
+    async fn handle<'r, 's: 'r>(&'s self, request: &'r Request<'_>, data: Data) -> Outcome<'r>;
 }
 
 /// Unfortunate but necessary hack to be able to clone a `Box<Handler>`.
@@ -169,20 +176,21 @@ impl Clone for Box<dyn Handler> {
     }
 }
 
+#[crate::async_trait]
 impl<F: Clone + Sync + Send + 'static> Handler for F
-    where for<'r> F: Fn(&'r Request<'_>, Data) -> HandlerFuture<'r>
+    where for<'x> F: Fn(&'x Request<'_>, Data) -> HandlerFuture<'x>
 {
     #[inline(always)]
-    fn handle<'r, 's: 'r>(&'s self, req: &'r Request<'_>, data: Data) -> HandlerFuture<'r> {
-        self(req, data)
+    async fn handle<'r, 's: 'r>(&'s self, req: &'r Request<'_>, data: Data) -> Outcome<'r> {
+        self(req, data).await
     }
 }
 
 /// The type of an error handler.
-pub type ErrorHandler = for<'r> fn(&'r Request<'_>) -> ErrorHandlerFuture<'r>;
+pub type ErrorHandler = for<'r> fn(&'r Request<'_>) -> CatcherFuture<'r>;
 
 /// Type type of `Future` returned by an error handler.
-pub type ErrorHandlerFuture<'r> = BoxFuture<'r, response::Result<'r>>;
+pub type CatcherFuture<'r> = BoxFuture<'r, response::Result<'r>>;
 
 impl<'r, 'o: 'r> Outcome<'o> {
     /// Return the `Outcome` of response to `req` from `responder`.

core/lib/src/rocket.rs

@@ -674,7 +674,7 @@ impl Rocket {
     /// use rocket::http::Method::*;
     ///
     /// fn hi<'r>(req: &'r Request, _: Data) -> HandlerFuture<'r> {
-    ///     Outcome::from(req, "Hello!")
+    ///     Outcome::from(req, "Hello!").pin()
     /// }
     ///
     /// # let _ = async { // We don't actually want to launch the server in an example.

core/lib/src/router/route.rs

@@ -110,7 +110,7 @@ impl Route {
     /// # use rocket::{Request, Data};
     /// # use rocket::handler::{Outcome, HandlerFuture};
     /// # fn handler<'r>(request: &'r Request, _data: Data) -> HandlerFuture<'r> {
-    /// #     Outcome::from(request, "Hello, world!")
+    /// #     Outcome::from(request, "Hello, world!").pin()
     /// # }
     ///
     /// // this is rank -6 (static path, ~static query)
@@ -160,7 +160,7 @@ impl Route {
     /// # use rocket::{Request, Data};
     /// # use rocket::handler::{Outcome, HandlerFuture};
     /// # fn handler<'r>(request: &'r Request, _data: Data) -> HandlerFuture<'r> {
-    /// #     Outcome::from(request, "Hello, world!")
+    /// #     Outcome::from(request, "Hello, world!").pin()
     /// # }
     ///
     /// // this is a rank 1 route matching requests to `GET /`
@@ -211,7 +211,7 @@ impl Route {
     /// # use rocket::handler::{Outcome, HandlerFuture};
     /// #
     /// # fn handler<'r>(request: &'r Request, _data: Data) -> HandlerFuture<'r> {
-    /// #     Outcome::from(request, "Hello, world!")
+    /// #     Outcome::from(request, "Hello, world!").pin()
     /// # }
     ///
     /// let mut index = Route::new(Method::Get, "/", handler);
@@ -245,7 +245,7 @@ impl Route {
     /// # use rocket::handler::{Outcome, HandlerFuture};
     /// #
     /// # fn handler<'r>(request: &'r Request, _data: Data) -> HandlerFuture<'r> {
-    /// #     Outcome::from(request, "Hello, world!")
+    /// #     Outcome::from(request, "Hello, world!").pin()
     /// # }
     ///
     /// let mut index = Route::new(Method::Get, "/", handler);

examples/manual_routes/src/main.rs

@@ -8,7 +8,7 @@ use std::env;
 use rocket::{Request, Handler, Route, Data, Catcher, try_outcome};
 use rocket::http::{Status, RawStr};
 use rocket::response::{Responder, status::Custom};
-use rocket::handler::{Outcome, HandlerFuture, ErrorHandlerFuture};
+use rocket::handler::{Outcome, HandlerFuture, CatcherFuture};
 use rocket::outcome::IntoOutcome;
 use rocket::http::Method::*;
 use rocket::tokio::fs::File;
@@ -66,7 +66,7 @@ fn get_upload<'r>(req: &'r Request, _: Data) -> HandlerFuture<'r> {
     Outcome::from(req, std::fs::File::open(env::temp_dir().join("upload.txt")).ok()).pin()
 }
 
-fn not_found_handler<'r>(req: &'r Request) -> ErrorHandlerFuture<'r> {
+fn not_found_handler<'r>(req: &'r Request) -> CatcherFuture<'r> {
     let res = Custom(Status::NotFound, format!("Couldn't find: {}", req.uri()));
     Box::pin(async move { res.respond_to(req) })
 }
@@ -82,17 +82,17 @@ impl CustomHandler {
     }
 }
 
+// FIXME: Will this work?
+
+#[rocket::async_trait]
 impl Handler for CustomHandler {
-    fn handle<'r>(&self, req: &'r Request, data: Data) -> HandlerFuture<'r> {
+    async fn handle<'r, 's: 'r>(&'s self, req: &'r Request<'_>, data: Data) -> Outcome<'r> {
         let self_data = self.data;
-        let id_outcome = req.get_param::<&RawStr>(0)
+        let id = req.get_param::<&RawStr>(0)
             .and_then(|res| res.ok())
             .or_forward(data);
 
-        Box::pin(async move {
-            let id = try_outcome!(id_outcome);
-            Outcome::from(req, format!("{} - {}", self_data, id))
-        })
+        Outcome::from(req, format!("{} - {}", self_data, try_outcome!(id)))
     }
 }