Switch to non-blocking asynchronous I/O with async_std

* main: add a basic main loop and make the network part async
 * keypair: do not block when writing the generated keyfile
 * keypair: Read the secret file asynchronously

src/keypair.rs

@@ -1,16 +1,21 @@
+
 use ed25519_dalek::{Keypair, PublicKey, SecretKey};
 use json::{object, JsonValue};
 use rand::rngs::OsRng;
 use regex::Regex;
 
-use std::path::PathBuf;
+use async_std::fs;
+use async_std::path::PathBuf;
+use async_trait::async_trait;
 
+#[async_trait]
 pub trait SSBKeypair {
     fn to_json(&self) -> JsonValue;
     fn from_json(obj: JsonValue) -> Self;
-    fn read_or_generate(path: PathBuf) -> Self;
+    async fn read_or_generate(path: PathBuf) -> Self;
 }
 
+#[async_trait]
 impl SSBKeypair for Keypair {
     fn to_json(&self) -> JsonValue {
         let pubstring = base64::encode(self.public.to_bytes());
@@ -50,9 +55,9 @@ impl SSBKeypair for Keypair {
         }
     }
 
-    fn read_or_generate(path: PathBuf) -> Self {
-        if path.exists() {
-            let secret = std::fs::read_to_string(path).unwrap();
+    async fn read_or_generate(path: PathBuf) -> Self {
+        if path.exists().await {
+            let secret = fs::read_to_string(path).await.unwrap();
             let re = Regex::new(r"\s*#[^\n]*").unwrap();
             let secret = re.replace_all(secret.as_str(), "");
             SSBKeypair::from_json(json::parse(&secret).unwrap())
@@ -60,14 +65,14 @@ impl SSBKeypair for Keypair {
             let mut csprng = OsRng {};
             let keypair = Keypair::generate(&mut csprng);
             let keypair_json = keypair.to_json();
-            std::fs::write(
+            fs::write(
                 path,
                 format!(
                     include_str!("warning.txt"),
                     keys = keypair_json.pretty(2),
                     id = keypair_json["id"]
                 ),
-            )
+            ).await
             .unwrap();
             keypair
         }

src/main.rs

@@ -1,8 +1,9 @@
 use clap::{load_yaml, App};
 use ed25519_dalek::Keypair;
 
-use std::net::UdpSocket;
-use std::path::PathBuf;
+use async_std::fs;
+use async_std::net::UdpSocket;
+use async_std::path::PathBuf;
 
 mod keypair;
 
@@ -32,34 +33,39 @@ fn parse_packet(packet: String) -> Host {
     }
 }
 
-fn main() {
+#[async_std::main]
+async fn main() -> std::io::Result<()> {
     let options = load_yaml!("options.yaml");
     let options = App::from(options).get_matches();
 
     let config_file = match options.value_of("config") {
         Some(path) => PathBuf::from(path),
-        None => dirs::config_dir()
+        None => PathBuf::from(dirs::config_dir()
             .unwrap()
             .join("cosmoline")
-            .join("config.toml"),
+            .join("config.toml")),
     };
-    let config = std::fs::read_to_string(config_file).unwrap();
+    let config = fs::read_to_string(config_file).await?;
     let config: Config = toml::from_str(config.as_str()).unwrap();
 
     let path = match options.value_of("path") {
         Some(path) => PathBuf::from(path),
         None => match config.get("path") {
             Some(path) => PathBuf::from(path.as_str().unwrap()),
-            None => dirs::home_dir().unwrap().join(".cosmoline"),
+            None => PathBuf::from(dirs::home_dir().unwrap().join(".cosmoline")),
         },
     };
-    let keypair = Keypair::read_or_generate(path.join("secret"));
+    let keypair = Keypair::read_or_generate(path.join("secret")).await;
     println!("{}", keypair.to_json().pretty(2));
 
-    let socket = UdpSocket::bind("0.0.0.0:8008").unwrap();
-    let mut buf = [0; 1024];
-    let (amt, _) = socket.recv_from(&mut buf).unwrap();
-    let buf = &mut buf[..amt];
-    let packet = String::from_utf8(buf.to_vec()).unwrap();
-    println!("{:?}", parse_packet(packet));
+    let socket = UdpSocket::bind("0.0.0.0:8008").await?;
+    let mut buf = [0u8; 1024];
+
+    loop {
+        let (amt, peer) = socket.recv_from(&mut buf).await?;
+        let buf = &mut buf[..amt];
+        let packet = String::from_utf8(buf.to_vec()).unwrap();
+        println!("{:?}", (peer, parse_packet(packet)));
+    }
+
 }