Make client lifetime and shutdown more explicit in client example

examples/client.rs

@@ -1,59 +1,62 @@
 #![deny(warnings)]
 extern crate hyper;
+extern crate tokio;
+
 extern crate pretty_env_logger;
 
 use std::env;
 use std::io::{self, Write};
 
 use hyper::Client;
-use hyper::rt::{self, Future, Stream};
+use hyper::rt::{Future, Stream};
+use tokio::runtime::Runtime;
 
 fn main() {
     pretty_env_logger::init();
 
-    // Some simple CLI args requirements...
+    // Pass URL as first argument, or use a default
     let url = match env::args().nth(1) {
         Some(url) => url,
-        None => {
-            println!("Usage: client <url>");
-            return;
-        }
+        None => "http://www.columbia.edu/~fdc/sample.html".to_owned()
     };
 
-    // HTTPS requires picking a TLS implementation, so give a better
-    // warning if the user tries to request an 'https' URL.
+    // HTTPS requires picking a TLS implementation, so give a better warning
+    // if the user tries to request an 'https' URL.
     let url = url.parse::<hyper::Uri>().unwrap();
     if url.scheme_part().map(|s| s.as_ref()) != Some("http") {
         println!("This example only works with 'http' URLs.");
         return;
     }
 
-    rt::run(rt::lazy(move || {
-        let client = Client::new();
-
-        client
-            // Fetch the url...
-            .get(url)
-            // And then, if we get a response back...
-            .and_then(|res| {
-                println!("Response: {}", res.status());
-                println!("Headers: {:#?}", res.headers());
-
-                // The body is a stream, and for_each returns a new Future
-                // when the stream is finished, and calls the closure on
-                // each chunk of the body...
-                res.into_body().for_each(|chunk| {
-                    io::stdout().write_all(&chunk)
-                        .map_err(|e| panic!("example expects stdout is open, error={}", e))
-                })
-            })
-            // If all good, just tell the user...
-            .map(|_| {
-                println!("\n\nDone.");
-            })
-            // If there was an error, let the user know...
-            .map_err(|err| {
-                eprintln!("Error {}", err);
+    let mut runtime = Runtime::new().unwrap();
+    let client = Client::new();
+
+    let job = client.get(url) // HTTP GET request on URL
+        .and_then(|res| {     // On successful (non-error) response
+            println!("Response: {}", res.status());
+            println!("Headers: {:#?}", res.headers());
+
+            // The body is a stream, and for_each returns a new Future when
+            // the stream is finished, and calls the closure on each chunk of
+            // the body...
+            res.into_body().for_each(|chunk| {
+                io::stdout()
+                    .write_all(&chunk)
+                    .map_err(|e| {
+                        panic!("example expects stdout is open, error={}", e)
+                    })
             })
-    }));
+        })
+        .map(|_| {           // When done (success)
+            println!("\n\nDone.");
+        })
+        .map_err(|err| {     // When done (error)
+            eprintln!("Error {}", err);
+        });
+    runtime.spawn(job); // non-blocking
+
+    // Wait and shutdown sequence: drop `client` first, in order for "idle"
+    // to occur as soon as `job` completes.
+    drop(client);
+    runtime.shutdown_on_idle().wait().unwrap();
 }