feat(error): revamp hyper::Error type

**The `Error` is now an opaque struct**, which allows for more variants to be added freely, and the internal representation to change without being breaking changes. For inspecting an `Error`, there are several `is_*` methods to check for certain classes of errors, such as `Error::is_parse()`. The `cause` can also be inspected, like before. This likely seems like a downgrade, but more inspection can be added as needed! The `Error` now knows about more states, which gives much more context around when a certain error occurs. This is also expressed in the description and `fmt` messages. **Most places where a user would provide an error to hyper can now pass any error type** (`E: Into<Box<std::error::Error>>`). This error is passed back in relevant places, and can be useful for logging. This should make it much clearer about what error a user should provide to hyper: any it feels is relevant! Closes #1128 Closes #1130 Closes #1431 Closes #1338 BREAKING CHANGE: `Error` is no longer an enum to pattern match over, or to construct. Code will need to be updated accordingly. For body streams or `Service`s, inference might be unable to determine what error type you mean to return. Starting in Rust 1.26, you could just label that as `!` if you never return an error.
hyperium · Apr 10, 2018 · 5d3c472 · 5d3c472
1 parent 33874f9
commit 5d3c472
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Showing 22 changed files with 514 additions and 402 deletions.
diff --git a/benches/server.rs b/benches/server.rs
@@ -78,7 +78,7 @@ fn throughput_fixedsize_large_payload(b: &mut test::Bencher) {
 fn throughput_fixedsize_many_chunks(b: &mut test::Bencher) {
     bench_server!(b, ("content-length", "1000000"), || {
         static S: &'static [&'static [u8]] = &[&[b'x'; 1_000] as &[u8]; 1_000] as _;
-        Body::wrap_stream(stream::iter_ok(S.iter()).map(|&s| s))
+        Body::wrap_stream(stream::iter_ok::<_, String>(S.iter()).map(|&s| s))
     })
 }
 
@@ -96,7 +96,7 @@ fn throughput_chunked_large_payload(b: &mut test::Bencher) {
 fn throughput_chunked_many_chunks(b: &mut test::Bencher) {
     bench_server!(b, ("transfer-encoding", "chunked"), || {
         static S: &'static [&'static [u8]] = &[&[b'x'; 1_000] as &[u8]; 1_000] as _;
-        Body::wrap_stream(stream::iter_ok(S.iter()).map(|&s| s))
+        Body::wrap_stream(stream::iter_ok::<_, String>(S.iter()).map(|&s| s))
     })
 }
 

diff --git a/examples/client.rs b/examples/client.rs
@@ -40,8 +40,9 @@ fn main() {
             println!("Response: {}", res.status());
             println!("Headers: {:#?}", res.headers());
 
-            res.into_parts().1.into_stream().for_each(|chunk| {
-                io::stdout().write_all(&chunk).map_err(From::from)
+            res.into_body().into_stream().for_each(|chunk| {
+                io::stdout().write_all(&chunk)
+                    .map_err(|e| panic!("example expects stdout is open, error={}", e))
             })
         }).map(|_| {
             println!("\n\nDone.");

diff --git a/examples/hello.rs b/examples/hello.rs
@@ -17,7 +17,8 @@ fn main() {
     let addr = ([127, 0, 0, 1], 3000).into();
 
     let new_service = const_service(service_fn(|_| {
-        Ok(Response::new(Body::from(PHRASE)))
+        //TODO: when `!` is stable, replace error type
+        Ok::<_, hyper::Error>(Response::new(Body::from(PHRASE)))
     }));
 
     tokio::run(lazy(move || {

diff --git a/examples/send_file.rs b/examples/send_file.rs
@@ -9,7 +9,6 @@ use futures::future::lazy;
 use futures::sync::oneshot;
 
 use hyper::{Body, /*Chunk,*/ Method, Request, Response, StatusCode};
-use hyper::error::Error;
 use hyper::server::{Http, Service};
 
 use std::fs::File;
@@ -19,7 +18,7 @@ use std::thread;
 static NOTFOUND: &[u8] = b"Not Found";
 static INDEX: &str = "examples/send_file_index.html";
 
-fn simple_file_send(f: &str) -> Box<Future<Item = Response<Body>, Error = hyper::Error> + Send> {
+fn simple_file_send(f: &str) -> Box<Future<Item = Response<Body>, Error = io::Error> + Send> {
     // Serve a file by reading it entirely into memory. As a result
     // this is limited to serving small files, but it is somewhat
     // simpler with a little less overhead.
@@ -56,15 +55,15 @@ fn simple_file_send(f: &str) -> Box<Future<Item = Response<Body>, Error = hyper:
         };
     });
 
-    Box::new(rx.map_err(|e| Error::from(io::Error::new(io::ErrorKind::Other, e))))
+    Box::new(rx.map_err(|e| io::Error::new(io::ErrorKind::Other, e)))
 }
 
 struct ResponseExamples;
 
 impl Service for ResponseExamples {
     type Request = Request<Body>;
     type Response = Response<Body>;
-    type Error = hyper::Error;
+    type Error = io::Error;
     type Future = Box<Future<Item = Self::Response, Error = Self::Error> + Send>;
 
     fn call(&self, req: Request<Body>) -> Self::Future {
@@ -119,7 +118,7 @@ impl Service for ResponseExamples {
                     */
                 });
 
-                Box::new(rx.map_err(|e| Error::from(io::Error::new(io::ErrorKind::Other, e))))
+                Box::new(rx.map_err(|e| io::Error::new(io::ErrorKind::Other, e)))
             },
             (&Method::GET, "/no_file.html") => {
                 // Test what happens when file cannot be be found

diff --git a/src/client/conn.rs b/src/client/conn.rs
@@ -45,7 +45,7 @@ pub struct SendRequest<B> {
 pub struct Connection<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     inner: proto::dispatch::Dispatcher<
         proto::dispatch::Client<B>,
@@ -138,7 +138,7 @@ impl<B> SendRequest<B>
 
 impl<B> SendRequest<B>
 where
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     /// Sends a `Request` on the associated connection.
     ///
@@ -262,7 +262,7 @@ impl<B> fmt::Debug for SendRequest<B> {
 impl<T, B> Connection<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     /// Return the inner IO object, and additional information.
     pub fn into_parts(self) -> Parts<T> {
@@ -289,7 +289,7 @@ where
 impl<T, B> Future for Connection<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     type Item = ();
     type Error = ::Error;
@@ -302,7 +302,7 @@ where
 impl<T, B> fmt::Debug for Connection<T, B>
 where
     T: AsyncRead + AsyncWrite + fmt::Debug,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("Connection")
@@ -331,7 +331,7 @@ impl Builder {
     pub fn handshake<T, B>(&self, io: T) -> Handshake<T, B>
     where
         T: AsyncRead + AsyncWrite,
-        B: Entity<Error=::Error> + 'static,
+        B: Entity + 'static,
     {
         Handshake {
             inner: HandshakeInner {
@@ -345,7 +345,7 @@ impl Builder {
     pub(super) fn handshake_no_upgrades<T, B>(&self, io: T) -> HandshakeNoUpgrades<T, B>
     where
         T: AsyncRead + AsyncWrite,
-        B: Entity<Error=::Error> + 'static,
+        B: Entity + 'static,
     {
         HandshakeNoUpgrades {
             inner: HandshakeInner {
@@ -362,7 +362,7 @@ impl Builder {
 impl<T, B> Future for Handshake<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     type Item = (SendRequest<B>, Connection<T, B>);
     type Error = ::Error;
@@ -387,7 +387,7 @@ impl<T, B> fmt::Debug for Handshake<T, B> {
 impl<T, B> Future for HandshakeNoUpgrades<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
 {
     type Item = (SendRequest<B>, proto::dispatch::Dispatcher<
         proto::dispatch::Client<B>,
@@ -406,7 +406,7 @@ where
 impl<T, B, R> Future for HandshakeInner<T, B, R>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
     R: proto::Http1Transaction<
         Incoming=StatusCode,
         Outgoing=proto::RequestLine,
@@ -470,15 +470,15 @@ impl<B: Send> AssertSendSync for SendRequest<B> {}
 impl<T: Send, B: Send> AssertSend for Connection<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
     B::Data: Send + 'static,
 {}
 
 #[doc(hidden)]
 impl<T: Send + Sync, B: Send + Sync> AssertSendSync for Connection<T, B>
 where
     T: AsyncRead + AsyncWrite,
-    B: Entity<Error=::Error> + 'static,
+    B: Entity + 'static,
     B::Data: Send + Sync + 'static,
 {}
 

diff --git a/src/client/connect.rs b/src/client/connect.rs
@@ -36,7 +36,7 @@ pub trait Connect: Send + Sync {
     /// The connected IO Stream.
     type Transport: AsyncRead + AsyncWrite + Send + 'static;
     /// An error occured when trying to connect.
-    type Error;
+    type Error: Into<Box<StdError + Send + Sync>>;
     /// A Future that will resolve to the connected Transport.
     type Future: Future<Item=(Self::Transport, Connected), Error=Self::Error> + Send;
     /// Connect to a destination.

diff --git a/src/client/dispatch.rs b/src/client/dispatch.rs
@@ -39,10 +39,10 @@ impl<T, U> Sender<T, U> {
                 // there's room in the queue, but does the Connection
                 // want a message yet?
                 self.giver.poll_want()
-                    .map_err(|_| ::Error::Closed)
+                    .map_err(|_| ::Error::new_closed())
             },
             Ok(Async::NotReady) => Ok(Async::NotReady),
-            Err(_) => Err(::Error::Closed),
+            Err(_) => Err(::Error::new_closed()),
         }
     }
 
@@ -184,9 +184,12 @@ mod tests {
             drop(rx);
 
             promise.then(|fulfilled| {
-                let res = fulfilled.expect("fulfilled");
-                match res.unwrap_err() {
-                    (::Error::Cancel(_), Some(_)) => (),
+                let err = fulfilled
+                    .expect("fulfilled")
+                    .expect_err("promise should error");
+
+                match (err.0.kind(), err.1) {
+                    (&::error::Kind::Canceled, Some(_)) => (),
                     e => panic!("expected Error::Cancel(_), found {:?}", e),
                 }
 

diff --git a/src/client/mod.rs b/src/client/mod.rs
@@ -96,10 +96,10 @@ impl<C, B> Client<C, B> {
 }
 
 impl<C, B> Client<C, B>
-where C: Connect<Error=io::Error> + Sync + 'static,
+where C: Connect + Sync + 'static,
       C::Transport: 'static,
       C::Future: 'static,
-      B: Entity<Error=::Error> + Send + 'static,
+      B: Entity + Send + 'static,
       B::Data: Send,
 {
 
@@ -139,13 +139,14 @@ where C: Connect<Error=io::Error> + Sync + 'static,
             Version::HTTP_11 => (),
             other => {
                 error!("Request has unsupported version \"{:?}\"", other);
-                return FutureResponse(Box::new(future::err(::Error::Version)));
+                //TODO: replace this with a proper variant
+                return FutureResponse(Box::new(future::err(::Error::new_user_unsupported_version())));
             }
         }
 
         if req.method() == &Method::CONNECT {
             debug!("Client does not support CONNECT requests");
-            return FutureResponse(Box::new(future::err(::Error::Method)));
+            return FutureResponse(Box::new(future::err(::Error::new_user_unsupported_request_method())));
         }
 
         let uri = req.uri().clone();
@@ -154,7 +155,8 @@ where C: Connect<Error=io::Error> + Sync + 'static,
                 format!("{}://{}", scheme, auth)
             }
             _ => {
-                return FutureResponse(Box::new(future::err(::Error::Io(
+                //TODO: replace this with a proper variant
+                return FutureResponse(Box::new(future::err(::Error::new_io(
                     io::Error::new(
                         io::ErrorKind::InvalidInput,
                         "invalid URI for Client Request"
@@ -203,13 +205,13 @@ where C: Connect<Error=io::Error> + Sync + 'static,
             };
             future::lazy(move || {
                 connector.connect(dst)
-                    .from_err()
+                    .map_err(::Error::new_connect)
                     .and_then(move |(io, connected)| {
                         conn::Builder::new()
                             .h1_writev(h1_writev)
                             .handshake_no_upgrades(io)
                             .and_then(move |(tx, conn)| {
-                                executor.execute(conn.map_err(|e| debug!("client connection error: {}", e)))?;
+                                executor.execute(conn.map_err(|e| debug!("client connection error: {}", e)));
                                 Ok(pool.pooled(pool_key, PoolClient {
                                     is_proxied: connected.is_proxied,
                                     tx: tx,
@@ -260,9 +262,7 @@ where C: Connect<Error=io::Error> + Sync + 'static,
                     } else if !res.body().is_empty() {
                         let (delayed_tx, delayed_rx) = oneshot::channel();
                         res.body_mut().delayed_eof(delayed_rx);
-                        // If the executor doesn't have room, oh well. Things will likely
-                        // be blowing up soon, but this specific task isn't required.
-                        let _ = executor.execute(
+                        executor.execute(
                             future::poll_fn(move || {
                                 pooled.tx.poll_ready()
                             })
@@ -277,7 +277,6 @@ where C: Connect<Error=io::Error> + Sync + 'static,
                     Ok(res)
                 });
 
-
             fut
         });
 
@@ -290,9 +289,9 @@ where C: Connect<Error=io::Error> + Sync + 'static,
 }
 
 impl<C, B> Service for Client<C, B>
-where C: Connect<Error=io::Error> + 'static,
+where C: Connect + 'static,
       C::Future: 'static,
-      B: Entity<Error=::Error> + Send + 'static,
+      B: Entity + Send + 'static,
       B::Data: Send,
 {
     type Request = Request<B>;
@@ -353,9 +352,9 @@ struct RetryableSendRequest<C, B> {
 
 impl<C, B> Future for RetryableSendRequest<C, B>
 where
-    C: Connect<Error=io::Error> + 'static,
+    C: Connect + 'static,
     C::Future: 'static,
-    B: Entity<Error=::Error> + Send + 'static,
+    B: Entity + Send + 'static,
     B::Data: Send,
 {
     type Item = Response<Body>;
@@ -564,10 +563,10 @@ impl<C, B> Config<C, B> {
 }
 
 impl<C, B> Config<C, B>
-where C: Connect<Error=io::Error>,
+where C: Connect,
       C::Transport: 'static,
       C::Future: 'static,
-      B: Entity<Error=::Error> + Send,
+      B: Entity + Send,
       B::Data: Send,
 {
     /// Construct the Client with this configuration.
@@ -590,7 +589,7 @@ where C: Connect<Error=io::Error>,
 
 impl<B> Config<UseDefaultConnector, B>
 where
-    B: Entity<Error=::Error> + Send,
+    B: Entity + Send,
     B::Data: Send,
 {
     /// Construct the Client with this configuration.
@@ -640,7 +639,6 @@ impl<C: Clone, B> Clone for Config<C, B> {
     }
 }
 
-
 // ===== impl Exec =====
 
 #[derive(Clone)]
@@ -655,24 +653,19 @@ impl Exec {
         Exec::Executor(Arc::new(executor))
     }
 
-    fn execute<F>(&self, fut: F) -> io::Result<()>
+    fn execute<F>(&self, fut: F)
     where
         F: Future<Item=(), Error=()> + Send + 'static,
     {
         match *self {
             Exec::Default => spawn(fut),
             Exec::Executor(ref e) => {
-                e.execute(bg(Box::new(fut)))
+                let _ = e.execute(bg(Box::new(fut)))
                     .map_err(|err| {
-                        debug!("executor error: {:?}", err.kind());
-                        io::Error::new(
-                            io::ErrorKind::Other,
-                            "executor error",
-                        )
-                    })?
+                        panic!("executor error: {:?}", err.kind());
+                    });
             },
         }
-        Ok(())
     }
 }
 

diff --git a/src/client/pool.rs b/src/client/pool.rs
@@ -245,7 +245,7 @@ impl<T: Closed + Send + 'static> Pool<T> {
             interval: interval,
             pool: Arc::downgrade(&self.inner),
             pool_drop_notifier: rx,
-        }).unwrap();
+        });
     }
 }