feat(body): put Stream impl for Body behind stream feature

BREAKING CHANGE: Using a `Body` as a `Stream`, and constructing one via `Body::wrap_stream`, require enabling the unstable `stream` feature.
hyperium · Sep 5, 2019 · 511ea38 · 511ea38
1 parent b3e5506
commit 511ea38
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Showing 4 changed files with 43 additions and 25 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -57,7 +57,6 @@ tokio-fs = "=0.2.0-alpha.4"
 tokio-test = "=0.2.0-alpha.4"
 url = "1.0"
 
-
 [features]
 default = [
     "__internal_flaky_tests",
@@ -78,6 +77,12 @@ nightly = []
 __internal_flaky_tests = []
 __internal_happy_eyeballs_tests = []
 
+[package.metadata.docs.rs]
+features = [
+    "runtime",
+    "stream",
+]
+
 [profile.release]
 codegen-units = 1
 incremental = false
@@ -94,12 +99,12 @@ required-features = ["runtime"]
 [[example]]
 name = "client_json"
 path = "examples/client_json.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 [[example]]
 name = "echo"
 path = "examples/echo.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 [[example]]
 name = "hello"
@@ -114,7 +119,7 @@ required-features = ["runtime"]
 [[example]]
 name = "params"
 path = "examples/params.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 [[example]]
 name = "proxy"
@@ -155,7 +160,7 @@ required-features = ["runtime"]
 [[example]]
 name = "web_api"
 path = "examples/web_api.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 
 [[bench]]
@@ -171,20 +176,20 @@ required-features = ["runtime"]
 [[bench]]
 name = "server"
 path = "benches/server.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 
 [[test]]
 name = "client"
 path = "tests/client.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 [[test]]
 name = "integration"
 path = "tests/integration.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
 
 [[test]]
 name = "server"
 path = "tests/server.rs"
-required-features = ["runtime"]
+required-features = ["runtime", "stream"]
diff --git a/src/body/body.rs b/src/body/body.rs
@@ -1,10 +1,14 @@
 use std::borrow::Cow;
+#[cfg(feature = "stream")]
 use std::error::Error as StdError;
 use std::fmt;
 
 use bytes::Bytes;
-use futures_core::{Stream, TryStream};
+use futures_core::Stream; // for mpsc::Receiver
+#[cfg(feature = "stream")]
+use futures_core::TryStream;
 use futures_channel::{mpsc, oneshot};
+#[cfg(feature = "stream")]
 use futures_util::TryStreamExt;
 use http_body::{SizeHint, Body as HttpBody};
 use http::HeaderMap;
@@ -18,8 +22,6 @@ type BodySender = mpsc::Sender<Result<Chunk, crate::Error>>;
 /// A stream of `Chunk`s, used when receiving bodies.
 ///
 /// A good default `Payload` to use in many applications.
-///
-/// Also implements `futures::Stream`, so stream combinators may be used.
 #[must_use = "streams do nothing unless polled"]
 pub struct Body {
     kind: Kind,
@@ -43,6 +45,7 @@ enum Kind {
     // while a borrow of a `Request<Body>` exists.
     //
     // See https://github.com/rust-lang/rust/issues/57017
+    #[cfg(feature = "stream")]
     Wrapped(Pin<Box<dyn Stream<Item = Result<Chunk, Box<dyn StdError + Send + Sync>>> + Send + Sync>>),
 }
 
@@ -140,6 +143,12 @@ impl Body {
     /// let body = Body::wrap_stream(stream);
     /// # }
     /// ```
+    ///
+    /// # Unstable
+    ///
+    /// This function requires enabling the unstable `stream` feature in your
+    /// `Cargo.toml`.
+    #[cfg(feature = "stream")]
     pub fn wrap_stream<S>(stream: S) -> Body
     where
         S: TryStream + Send + Sync + 'static,
@@ -277,6 +286,8 @@ impl Body {
                 Some(Err(e)) => Poll::Ready(Some(Err(crate::Error::new_body(e)))),
                 None => Poll::Ready(None),
             },
+
+            #[cfg(feature = "stream")]
             Kind::Wrapped(ref mut s) => {
                 match ready!(s.as_mut().poll_next(cx)) {
                     Some(res) => Poll::Ready(Some(res.map_err(crate::Error::new_body))),
@@ -326,6 +337,7 @@ impl HttpBody for Body {
             Kind::Once(ref val) => val.is_none(),
             Kind::Chan { content_length, .. } => content_length == Some(0),
             Kind::H2 { recv: ref h2, .. } => h2.is_end_stream(),
+            #[cfg(feature = "stream")]
             Kind::Wrapped(..) => false,
         }
     }
@@ -340,6 +352,7 @@ impl HttpBody for Body {
             Kind::Once(None) => {
                 SizeHint::default()
             },
+            #[cfg(feature = "stream")]
             Kind::Wrapped(..) => SizeHint::default(),
             Kind::Chan { content_length, .. } | Kind::H2 { content_length, .. } => {
                 let mut hint = SizeHint::default();
@@ -361,19 +374,20 @@ impl fmt::Debug for Body {
         #[derive(Debug)]
         struct Empty;
         #[derive(Debug)]
-        struct Once<'a>(&'a Chunk);
+        struct Full<'a>(&'a Chunk);
 
         let mut builder = f.debug_tuple("Body");
         match self.kind {
             Kind::Once(None) => builder.field(&Empty),
-            Kind::Once(Some(ref chunk)) => builder.field(&Once(chunk)),
+            Kind::Once(Some(ref chunk)) => builder.field(&Full(chunk)),
             _ => builder.field(&Streaming),
         };
 
         builder.finish()
     }
 }
 
+#[cfg(feature = "stream")]
 impl Stream for Body {
     type Item = crate::Result<Chunk>;
 
@@ -383,6 +397,7 @@ impl Stream for Body {
 }
 
 
+#[cfg(feature = "stream")]
 impl
     From<Box<dyn Stream<Item = Result<Chunk, Box<dyn StdError + Send + Sync>>> + Send + Sync>>
     for Body

diff --git a/src/lib.rs b/src/lib.rs
@@ -18,6 +18,15 @@
 //!
 //! If looking for just a convenient HTTP client, consider the
 //! [reqwest](https://crates.io/crates/reqwest) crate.
+//!
+//! # Optional Features
+//!
+//! The following optional features are available:
+//!
+//! - `runtime` (*enabled by default*): Enables convenient integration with 
+//!   `tokio`, providing connectors and acceptors for TCP, and a default
+//!   executor.
+//! - `stream` (*unstable*): Provides `futures::Stream` capabilities.
 
 #[doc(hidden)] pub use http;
 #[macro_use] extern crate log;

diff --git a/src/server/tcp.rs b/src/server/tcp.rs
@@ -156,17 +156,6 @@ impl AddrIncoming {
     }
 }
 
-/*
-impl Stream for AddrIncoming {
-    type Item = io::Result<AddrStream>;
-
-    fn poll_next(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Option<Self::Item>> {
-        let result = ready!(self.poll_next_(cx));
-        Poll::Ready(Some(result))
-    }
-}
-*/
-
 impl Accept for AddrIncoming {
     type Conn = AddrStream;
     type Error = io::Error;