clean up exposed crate features

- Put `TokioExecutor` and `TokioIo` into a single `rt::tokio` module.
- The `rt::tokio` module is behind a `tokio` crate feature.
- Changed `auto` crate feature to `server-auto`.
- Added `client-legacy` crate feature, with `client::legacy` behind it.
- Removed `tcp` and `runtime` features, code now depends on the `tokio`
  feature.

Cargo.toml

@@ -22,9 +22,9 @@ http = "1.0"
 http-body = "1.0.0"
 bytes = "1"
 pin-project-lite = "0.2.4"
-socket2 = "0.5"
+socket2 = { version = "0.5", optional = true }
 tracing = { version = "0.1", default-features = false, features = ["std"] }
-tokio = { version = "1", features = ["net", "rt", "time"] }
+tokio = { version = "1", optional = true, features = ["net", "rt", "time"] }
 tower-service = "0.3"
 tower = { version = "0.4", features = ["make", "util"] }
 
@@ -42,21 +42,30 @@ pnet_datalink = "0.34.0"
 default = []
 
 # Shorthand to enable everything
-full = ["client", "server", "http1", "http2", "tcp", "auto", "runtime"]
+full = [
+    "client",
+    "client-legacy",
+    "server",
+    "server-auto",
+    "http1",
+    "http2",
+    "tokio",
+]
 
 client = ["hyper/client"]
+client-legacy = ["client"]
+
 server = ["hyper/server"]
+server-auto = ["hyper/server", "http1", "http2"]
 
 http1 = ["hyper/http1"]
 http2 = ["hyper/http2"]
 
-tcp = []
-auto = ["hyper/server", "http1", "http2"]
-runtime = []
+tokio = ["dep:tokio", "dep:socket2"]
 
 # internal features used in CI
 __internal_happy_eyeballs_tests = []
 
 [[example]]
 name = "client"
-required-features = ["client", "http1", "tcp", "runtime"]
+required-features = ["client-legacy", "http1", "tokio"]

src/client/legacy/client.rs

@@ -19,7 +19,7 @@ use hyper::{body::Body, Method, Request, Response, Uri, Version};
 use tracing::{debug, trace, warn};
 
 use super::super::pool::{self, Ver};
-#[cfg(feature = "tcp")]
+#[cfg(feature = "tokio")]
 use super::connect::HttpConnector;
 use super::connect::{Alpn, Connect, Connected, Connection};
 use crate::common::{lazy as hyper_lazy, Exec, Lazy, SyncWrapper};
@@ -103,7 +103,7 @@ impl Client<(), ()> {
     /// # Example
     ///
     /// ```
-    /// # #[cfg(feature = "runtime")]
+    /// # #[cfg(feature = "tokio")]
     /// # fn run () {
     /// use std::time::Duration;
     /// use hyper::Client;
@@ -144,7 +144,7 @@ where
     /// # Example
     ///
     /// ```
-    /// # #[cfg(feature = "runtime")]
+    /// # #[cfg(feature = "tokio")]
     /// # fn run () {
     /// use hyper::{Client, Uri};
     ///
@@ -173,7 +173,7 @@ where
     /// # Example
     ///
     /// ```
-    /// # #[cfg(feature = "runtime")]
+    /// # #[cfg(feature = "tokio")]
     /// # fn run () {
     /// use hyper::{Method, Client, Request};
     /// use http_body_util::Full;
@@ -934,7 +934,7 @@ fn is_schema_secure(uri: &Uri) -> bool {
 /// # Example
 ///
 /// ```
-/// # #[cfg(feature = "runtime")]
+/// # #[cfg(feature = "tokio")]
 /// # fn run () {
 /// use std::time::Duration;
 /// use hyper::Client;
@@ -1286,7 +1286,7 @@ impl Builder {
     /// # Cargo Feature
     ///
     /// Requires the `runtime` cargo feature to be enabled.
-    #[cfg(feature = "runtime")]
+    #[cfg(feature = "tokio")]
     #[cfg(feature = "http2")]
     #[cfg_attr(docsrs, doc(cfg(feature = "http2")))]
     pub fn http2_keep_alive_interval(
@@ -1307,7 +1307,7 @@ impl Builder {
     /// # Cargo Feature
     ///
     /// Requires the `runtime` cargo feature to be enabled.
-    #[cfg(feature = "runtime")]
+    #[cfg(feature = "tokio")]
     #[cfg(feature = "http2")]
     #[cfg_attr(docsrs, doc(cfg(feature = "http2")))]
     pub fn http2_keep_alive_timeout(&mut self, timeout: Duration) -> &mut Self {
@@ -1327,7 +1327,7 @@ impl Builder {
     /// # Cargo Feature
     ///
     /// Requires the `runtime` cargo feature to be enabled.
-    #[cfg(feature = "runtime")]
+    #[cfg(feature = "tokio")]
     #[cfg(feature = "http2")]
     #[cfg_attr(docsrs, doc(cfg(feature = "http2")))]
     pub fn http2_keep_alive_while_idle(&mut self, enabled: bool) -> &mut Self {
@@ -1410,7 +1410,7 @@ impl Builder {
     }
 
     /// Builder a client with this configuration and the default `HttpConnector`.
-    #[cfg(feature = "tcp")]
+    #[cfg(feature = "tokio")]
     pub fn build_http<B>(&self) -> Client<HttpConnector, B>
     where
         B: Body + Send,

src/client/mod.rs

@@ -1,6 +1,7 @@
 //! HTTP client utilities
 
 /// Legacy implementations of `connect` module and `Client`
+#[cfg(feature = "client-legacy")]
 pub mod legacy;
 #[doc(hidden)]
 pub mod pool;

src/client/pool.rs

@@ -12,10 +12,7 @@ use std::pin::Pin;
 use std::sync::{Arc, Mutex, Weak};
 use std::task::{self, Poll};
 
-#[cfg(not(feature = "runtime"))]
 use std::time::{Duration, Instant};
-#[cfg(feature = "runtime")]
-use tokio::time::{Duration, Instant, Interval};
 
 use futures_channel::oneshot;
 use tracing::{debug, trace};
@@ -97,9 +94,7 @@ struct PoolInner<T, K: Eq + Hash> {
     waiters: HashMap<K, VecDeque<oneshot::Sender<T>>>,
     // A oneshot channel is used to allow the interval to be notified when
     // the Pool completely drops. That way, the interval can cancel immediately.
-    #[cfg(feature = "runtime")]
     idle_interval_ref: Option<oneshot::Sender<Infallible>>,
-    #[cfg(feature = "runtime")]
     exec: Exec,
     timeout: Option<Duration>,
 }
@@ -130,11 +125,9 @@ impl<T, K: Key> Pool<T, K> {
             Some(Arc::new(Mutex::new(PoolInner {
                 connecting: HashSet::new(),
                 idle: HashMap::new(),
-                #[cfg(feature = "runtime")]
                 idle_interval_ref: None,
                 max_idle_per_host: config.max_idle_per_host,
                 waiters: HashMap::new(),
-                #[cfg(feature = "runtime")]
                 exec,
                 timeout: config.idle_timeout,
             })))
@@ -152,7 +145,6 @@ impl<T, K: Key> Pool<T, K> {
     #[cfg(test)]
     pub(super) fn no_timer(&self) {
         // Prevent an actual interval from being created for this pool...
-        #[cfg(feature = "runtime")]
         {
             let mut inner = self.inner.as_ref().unwrap().lock().unwrap();
             assert!(inner.idle_interval_ref.is_none(), "timer already spawned");
@@ -207,13 +199,11 @@ impl<T: Poolable, K: Key> Pool<T, K> {
     }
 
     /* Used in client/tests.rs...
-    #[cfg(feature = "runtime")]
     #[cfg(test)]
     pub(super) fn h1_key(&self, s: &str) -> Key {
         Arc::new(s.to_string())
     }
 
-    #[cfg(feature = "runtime")]
     #[cfg(test)]
     pub(super) fn idle_count(&self, key: &Key) -> usize {
         self
@@ -403,10 +393,7 @@ impl<T: Poolable, K: Key> PoolInner<T, K> {
                     });
                 }
 
-                #[cfg(feature = "runtime")]
-                {
-                    self.spawn_idle_interval(__pool_ref);
-                }
+                self.spawn_idle_interval(__pool_ref);
             }
             None => trace!("put; found waiter for {:?}", key),
         }
@@ -423,8 +410,9 @@ impl<T: Poolable, K: Key> PoolInner<T, K> {
         self.waiters.remove(key);
     }
 
-    #[cfg(feature = "runtime")]
-    fn spawn_idle_interval(&mut self, pool_ref: &Arc<Mutex<PoolInner<T, K>>>) {
+    fn spawn_idle_interval(&mut self, _pool_ref: &Arc<Mutex<PoolInner<T, K>>>) {
+        // TODO
+        /*
         let (dur, rx) = {
             if self.idle_interval_ref.is_some() {
                 return;
@@ -446,6 +434,7 @@ impl<T: Poolable, K: Key> PoolInner<T, K> {
         };
 
         self.exec.execute(interval);
+        */
     }
 }
 
@@ -466,7 +455,6 @@ impl<T, K: Eq + Hash> PoolInner<T, K> {
     }
 }
 
-#[cfg(feature = "runtime")]
 impl<T: Poolable, K: Key> PoolInner<T, K> {
     /// This should *only* be called by the IdleTask
     fn clear_expired(&mut self) {
@@ -766,7 +754,7 @@ impl Expiration {
     }
 }
 
-#[cfg(feature = "runtime")]
+/*
 pin_project_lite::pin_project! {
     struct IdleTask<T, K: Key> {
         #[pin]
@@ -780,7 +768,6 @@ pin_project_lite::pin_project! {
     }
 }
 
-#[cfg(feature = "runtime")]
 impl<T: Poolable + 'static, K: Key> Future for IdleTask<T, K> {
     type Output = ();
 
@@ -809,6 +796,7 @@ impl<T: Poolable + 'static, K: Key> Future for IdleTask<T, K> {
         }
     }
 }
+*/
 
 impl<T> WeakOpt<T> {
     fn none() -> Self {
@@ -932,7 +920,6 @@ mod tests {
         assert!(is_not_ready);
     }
 
-    #[cfg(feature = "runtime")]
     #[tokio::test]
     async fn test_pool_checkout_removes_expired() {
         let pool = pool_no_timer();
@@ -971,7 +958,6 @@ mod tests {
         );
     }
 
-    #[cfg(feature = "runtime")]
     #[tokio::test]
     async fn test_pool_timer_removes_expired() {
         tokio::time::pause();

src/rt/mod.rs

@@ -1,8 +1,7 @@
 //! Runtime utilities
 
-/// Implementation of [`hyper::rt::Executor`] that utilises [`tokio::spawn`].
-pub mod tokio_executor;
-mod tokio_io;
+#[cfg(feature = "tokio")]
+pub mod tokio;
 
-pub use tokio_executor::TokioExecutor;
-pub use tokio_io::TokioIo;
+#[cfg(feature = "tokio")]
+pub use self::tokio::{TokioExecutor, TokioIo};

src/rt/tokio_io.rs → src/rt/tokio.rs

@@ -1,11 +1,18 @@
 #![allow(dead_code)]
 //! Tokio IO integration for hyper
 use std::{
+    future::Future,
     pin::Pin,
     task::{Context, Poll},
 };
 
 use pin_project_lite::pin_project;
+use hyper::rt::Executor;
+
+/// Future executor that utilises `tokio` threads.
+#[non_exhaustive]
+#[derive(Default, Debug, Clone)]
+pub struct TokioExecutor {}
 
 pin_project! {
     /// A wrapping implementing hyper IO traits for a type that
@@ -17,6 +24,27 @@ pin_project! {
     }
 }
 
+// ===== impl TokioExecutor =====
+
+impl<Fut> Executor<Fut> for TokioExecutor
+where
+    Fut: Future + Send + 'static,
+    Fut::Output: Send + 'static,
+{
+    fn execute(&self, fut: Fut) {
+        tokio::spawn(fut);
+    }
+}
+
+impl TokioExecutor {
+    /// Create new executor that relies on [`tokio::spawn`] to execute futures.
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+// ==== impl TokioIo =====
+
 impl<T> TokioIo<T> {
     /// Wrap a type implementing Tokio's IO traits.
     pub fn new(inner: T) -> Self {
@@ -161,3 +189,22 @@ where
         hyper::rt::Write::poll_write_vectored(self.project().inner, cx, bufs)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::rt::tokio_executor::TokioExecutor;
+    use hyper::rt::Executor;
+    use tokio::sync::oneshot;
+
+    #[cfg(not(miri))]
+    #[tokio::test]
+    async fn simple_execute() -> Result<(), Box<dyn std::error::Error>> {
+        let (tx, rx) = oneshot::channel();
+        let executor = TokioExecutor::new();
+        executor.execute(async move {
+            tx.send(()).unwrap();
+        });
+        rx.await.map_err(Into::into)
+    }
+}
+