Re-work I/O

* Auto-register interest whenever we see WouldBlock
* Remove implementations of `Stream<Item=Ready>`, no longer needed
* Add explicit `poll_{read,write}` methods, if needed
* Remove all I/O streams, libstd ones suffice
* Update all I/O futures

src/bin/sink.rs

@@ -9,7 +9,6 @@ extern crate futures_io;
 extern crate futures_mio;
 
 use std::env;
-use std::io::{self, Write};
 use std::net::SocketAddr;
 
 use futures::Future;
@@ -24,7 +23,7 @@ fn main() {
     let server = l.handle().tcp_listen(&addr).and_then(|socket| {
         socket.incoming().and_then(|(socket, addr)| {
             println!("got a socket: {}", addr);
-            write(socket)
+            write(socket).or_else(|_| Ok(()))
         }).for_each(|()| {
             println!("lost the socket");
             Ok(())
@@ -34,20 +33,10 @@ fn main() {
     l.run(server).unwrap();
 }
 
+// TODO: this blows the stack...
 fn write(socket: futures_mio::TcpStream) -> IoFuture<()> {
-    static BUF: &'static [u8] = &[0; 64 * 1024];
-    socket.into_future().map_err(|e| e.0).and_then(move |(ready, mut socket)| {
-        let ready = match ready {
-            Some(ready) => ready,
-            None => return futures::finished(()).boxed(),
-        };
-        while ready.is_write() {
-            match socket.write(&BUF) {
-                Ok(_) => {}
-                Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => break,
-                Err(e) => return futures::failed(e).boxed(),
-            }
-        }
+    static BUF: &'static [u8] = &[0; 1 * 1024 * 1024];
+    futures_io::write_all(socket, BUF).and_then(|(socket, _)| {
         write(socket)
     }).boxed()
 }