feat(rt): make tokio runtime optional

A Cargo feature `runtime` is added, which is enabled by default, that
includes the following:

- The `client::HttpConnector`, which uses `tokio::net::TcpStream`.
- The `server::AddrStream`, which uses `tokio::net::TcpListener`.
- The `hyper::rt` module, which includes useful utilities to work with
  the runtime without needing to import `futures` or `tokio` explicity.

Disabling the feature removes many of these niceties, but allows people
to use hyper in environments that have an alternative runtime, without
needing to download an unused one.

.travis.yml

@@ -9,13 +9,12 @@ matrix:
         - rust: beta
         - rust: stable
           env: HYPER_DOCS=1
+        - rust: stable
+          env: FEATURES="--no-default-features"
         - rust: 1.21.0
 
 cache:
     apt: true
-    directories:
-        - target/debug/deps
-        - target/debug/build
 
 script:
   - ./.travis/readme.py

Cargo.toml

@@ -22,19 +22,21 @@ include = [
 
 [dependencies]
 bytes = "0.4.4"
-futures = "0.1.17"
-futures-cpupool = "0.1.6"
+futures = "0.1.21"
+futures-cpupool = { version = "0.1.6", optional = true }
 futures-timer = "0.1.0"
 http = "0.1.5"
 httparse = "1.0"
 h2 = "0.1.5"
 iovec = "0.1"
 log = "0.4"
-net2 = "0.2.32"
+net2 = { version = "0.2.32", optional = true }
 time = "0.1"
-tokio = "0.1.5"
-tokio-executor = "0.1.0"
+tokio = { version = "0.1.5", optional = true }
+tokio-executor = { version = "0.1.0", optional = true }
 tokio-io = "0.1"
+tokio-reactor = { version = "0.1", optional = true }
+tokio-tcp = { version = "0.1", optional = true }
 want = "0.0.3"
 
 [dev-dependencies]
@@ -44,4 +46,76 @@ spmc = "0.2"
 url = "1.0"
 
 [features]
+default = ["runtime"]
 nightly = []
+runtime = [
+    "futures-cpupool",
+    "net2",
+    "tokio",
+    "tokio-executor",
+    "tokio-reactor",
+    "tokio-tcp",
+]
+
+[[example]]
+name = "client"
+path = "examples/client.rs"
+required-features = ["runtime"]
+
+[[example]]
+name = "hello"
+path = "examples/hello.rs"
+required-features = ["runtime"]
+
+[[example]]
+name = "multi_server"
+path = "examples/multi_server.rs"
+required-features = ["runtime"]
+
+[[example]]
+name = "params"
+path = "examples/params.rs"
+required-features = ["runtime"]
+
+[[example]]
+name = "send_file"
+path = "examples/send_file.rs"
+required-features = ["runtime"]
+
+[[example]]
+name = "server"
+path = "examples/server.rs"
+required-features = ["runtime"]
+
+[[example]]
+name = "web_api"
+path = "examples/web_api.rs"
+required-features = ["runtime"]
+
+
+[[bench]]
+name = "end_to_end"
+path = "benches/end_to_end.rs"
+required-features = ["runtime"]
+
+[[bench]]
+name = "server"
+path = "benches/server.rs"
+required-features = ["runtime"]
+
+
+[[test]]
+name = "client"
+path = "tests/client.rs"
+required-features = ["runtime"]
+
+[[test]]
+name = "integration"
+path = "tests/integration.rs"
+required-features = ["runtime"]
+
+[[test]]
+name = "server"
+path = "tests/server.rs"
+required-features = ["runtime"]
+

examples/client.rs

@@ -1,17 +1,12 @@
-//#![deny(warnings)]
-extern crate futures;
+#![deny(warnings)]
 extern crate hyper;
-extern crate tokio;
-
 extern crate pretty_env_logger;
 
 use std::env;
 use std::io::{self, Write};
 
-use futures::{Future, Stream};
-use futures::future::lazy;
-
 use hyper::{Body, Client, Request};
+use hyper::rt::{self, Future, Stream};
 
 fn main() {
     pretty_env_logger::init();
@@ -30,7 +25,7 @@ fn main() {
         return;
     }
 
-    tokio::run(lazy(move || {
+    rt::run(rt::lazy(move || {
         let client = Client::new();
 
         let mut req = Request::new(Body::empty());

examples/hello.rs

@@ -1,13 +1,10 @@
 #![deny(warnings)]
 extern crate hyper;
-extern crate futures;
 extern crate pretty_env_logger;
-extern crate tokio;
-
-use futures::Future;
 
 use hyper::{Body, Response, Server};
 use hyper::service::service_fn_ok;
+use hyper::rt::{self, Future};
 
 static PHRASE: &'static [u8] = b"Hello World!";
 
@@ -33,5 +30,5 @@ fn main() {
 
     println!("Listening on http://{}", addr);
 
-    tokio::run(server);
+    rt::run(server);
 }

examples/multi_server.rs

@@ -1,14 +1,10 @@
 #![deny(warnings)]
 extern crate hyper;
-extern crate futures;
 extern crate pretty_env_logger;
-extern crate tokio;
-
-use futures::{Future};
-use futures::future::{lazy};
 
 use hyper::{Body, Response, Server};
 use hyper::service::service_fn_ok;
+use hyper::rt::{self, Future};
 
 static INDEX1: &'static [u8] = b"The 1st service!";
 static INDEX2: &'static [u8] = b"The 2nd service!";
@@ -19,7 +15,7 @@ fn main() {
     let addr1 = ([127, 0, 0, 1], 1337).into();
     let addr2 = ([127, 0, 0, 1], 1338).into();
 
-    tokio::run(lazy(move || {
+    rt::run(rt::lazy(move || {
         let srv1 = Server::bind(&addr1)
             .serve(|| service_fn_ok(|_| Response::new(Body::from(INDEX1))))
             .map_err(|e| eprintln!("server 1 error: {}", e));
@@ -30,8 +26,8 @@ fn main() {
 
         println!("Listening on http://{} and http://{}", addr1, addr2);
 
-        tokio::spawn(srv1);
-        tokio::spawn(srv2);
+        rt::spawn(srv1);
+        rt::spawn(srv2);
 
         Ok(())
     }));

examples/params.rs

@@ -2,7 +2,6 @@
 extern crate futures;
 extern crate hyper;
 extern crate pretty_env_logger;
-extern crate tokio;
 extern crate url;
 
 use futures::{future, Future, Stream};
@@ -93,5 +92,5 @@ fn main() {
         .serve(|| service_fn(param_example))
         .map_err(|e| eprintln!("server error: {}", e));
 
-    tokio::run(server);
+    hyper::rt::run(server);
 }

examples/send_file.rs

@@ -2,7 +2,6 @@
 extern crate futures;
 extern crate hyper;
 extern crate pretty_env_logger;
-extern crate tokio;
 
 use futures::{future, Future};
 use futures::sync::oneshot;
@@ -29,7 +28,7 @@ fn main() {
 
     println!("Listening on http://{}", addr);
 
-    tokio::run(server);
+    hyper::rt::run(server);
 }
 
 type ResponseFuture = Box<Future<Item=Response<Body>, Error=io::Error> + Send>;

examples/server.rs

@@ -1,13 +1,10 @@
 #![deny(warnings)]
-extern crate futures;
 extern crate hyper;
 extern crate pretty_env_logger;
-extern crate tokio;
-
-use futures::Future;
 
 use hyper::{Body, Method, Request, Response, Server, StatusCode};
 use hyper::service::service_fn_ok;
+use hyper::rt::Future;
 
 static INDEX: &'static [u8] = b"Try POST /echo";
 
@@ -40,5 +37,5 @@ fn main() {
 
     println!("Listening on http://{}", addr);
 
-    tokio::run(server);
+    hyper::rt::run(server);
 }

examples/web_api.rs

@@ -2,7 +2,6 @@
 extern crate futures;
 extern crate hyper;
 extern crate pretty_env_logger;
-extern crate tokio;
 
 use futures::{future, Future, Stream};
 
@@ -68,7 +67,7 @@ fn main() {
 
     let addr = "127.0.0.1:1337".parse().unwrap();
 
-    tokio::run(future::lazy(move || {
+    hyper::rt::run(future::lazy(move || {
         // Share a `Client` with all `Service`s
         let client = Client::new();