Move the examples to the facade crate (#197)

libp2p/examples/echo-dialer.rs

@@ -0,0 +1,138 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+extern crate bytes;
+extern crate env_logger;
+extern crate futures;
+extern crate libp2p;
+extern crate tokio_core;
+extern crate tokio_io;
+
+use futures::sync::oneshot;
+use futures::{Future, Sink, Stream};
+use std::env;
+use libp2p::core::Transport;
+use libp2p::core::upgrade::{self, DeniedConnectionUpgrade, SimpleProtocol};
+use libp2p::tcp::TcpConfig;
+use tokio_core::reactor::Core;
+use tokio_io::AsyncRead;
+use tokio_io::codec::BytesCodec;
+use libp2p::websocket::WsConfig;
+
+fn main() {
+    env_logger::init();
+
+    // Determine which address to dial.
+    let target_addr = env::args()
+        .nth(1)
+        .unwrap_or("/ip4/127.0.0.1/tcp/10333".to_owned());
+
+    // We start by building the tokio engine that will run all the sockets.
+    let mut core = Core::new().unwrap();
+
+    // Now let's build the transport stack.
+    // We start by creating a `TcpConfig` that indicates that we want TCP/IP.
+    let transport = TcpConfig::new(core.handle())
+
+        // In addition to TCP/IP, we also want to support the Websockets protocol on top of TCP/IP.
+        // The parameter passed to `WsConfig::new()` must be an implementation of `Transport` to be
+        // used for the underlying multiaddress.
+        .or_transport(WsConfig::new(TcpConfig::new(core.handle())))
+
+        // On top of TCP/IP, we will use either the plaintext protocol or the secio protocol,
+        // depending on which one the remote supports.
+        .with_upgrade({
+            let plain_text = upgrade::PlainTextConfig;
+
+            let secio = {
+                let private_key = include_bytes!("test-private-key.pk8");
+                let public_key = include_bytes!("test-public-key.der").to_vec();
+                libp2p::secio::SecioConfig {
+                    key: libp2p::secio::SecioKeyPair::rsa_from_pkcs8(private_key, public_key).unwrap(),
+                }
+            };
+
+            upgrade::or(plain_text, upgrade::map(secio, |(socket, _)| socket))
+        })
+
+        // On top of plaintext or secio, we will use the multiplex protocol.
+        .with_upgrade(libp2p::mplex::MultiplexConfig::new())
+        // The object returned by the call to `with_upgrade(MultiplexConfig::new())` can't be used as a
+        // `Transport` because the output of the upgrade is not a stream but a controller for
+        // muxing. We have to explicitly call `into_connection_reuse()` in order to turn this into
+        // a `Transport`.
+        .into_connection_reuse();
+
+    // Let's put this `transport` into a *swarm*. The swarm will handle all the incoming
+    // connections for us. The second parameter we pass is the connection upgrade that is accepted
+    // by the listening part. We don't want to accept anything, so we pass a dummy object that
+    // represents a connection that is always denied.
+    let (swarm_controller, swarm_future) = libp2p::core::swarm(
+        transport.clone().with_upgrade(DeniedConnectionUpgrade),
+        |_socket, _client_addr| -> Result<(), _> {
+            unreachable!("All incoming connections should have been denied")
+        },
+    );
+
+    // Building a struct that represents the protocol that we are going to use for dialing.
+    let proto = SimpleProtocol::new("/echo/1.0.0", |socket| {
+        // This closure is called whenever a stream using the "echo" protocol has been
+        // successfully negotiated. The parameter is the raw socket (implements the AsyncRead
+        // and AsyncWrite traits), and the closure must return an implementation of
+        // `IntoFuture` that can yield any type of object.
+        Ok(AsyncRead::framed(socket, BytesCodec::new()))
+    });
+
+    // We now use the controller to dial to the address.
+    let (finished_tx, finished_rx) = oneshot::channel();
+    swarm_controller
+        .dial_custom_handler(target_addr.parse().expect("invalid multiaddr"), transport.with_upgrade(proto), |echo, _| {
+            // `echo` is what the closure used when initializing `proto` returns.
+            // Consequently, please note that the `send` method is available only because the type
+            // `length_delimited::Framed` has a `send` method.
+            println!("Sending \"hello world\" to listener");
+            echo.send("hello world".into())
+                // Then listening for one message from the remote.
+                .and_then(|echo| {
+                    echo.into_future().map_err(|(e, _)| e).map(|(n,_ )| n)
+                })
+                .and_then(|message| {
+                    println!("Received message from listener: {:?}", message.unwrap());
+                    finished_tx.send(()).unwrap();
+                    Ok(())
+                })
+        })
+        // If the multiaddr protocol exists but is not supported, then we get an error containing
+        // the original multiaddress.
+        .expect("unsupported multiaddr");
+
+    // The address we actually listen on can be different from the address that was passed to
+    // the `listen_on` function. For example if you pass `/ip4/0.0.0.0/tcp/0`, then the port `0`
+    // will be replaced with the actual port.
+
+    // `swarm_future` is a future that contains all the behaviour that we want, but nothing has
+    // actually started yet. Because we created the `TcpConfig` with tokio, we need to run the
+    // future through the tokio core.
+    let final_future = swarm_future
+        .select(finished_rx.map_err(|_| unreachable!()))
+        .map(|_| ())
+        .map_err(|(err, _)| err);
+    core.run(final_future).unwrap();
+}