homework: thermometer mock (correct)

smart-house/src/bin/thermometer_mock.rs

@@ -1,76 +1,54 @@
 //! Имитатор термометра
 
 use rand::prelude::*;
+use std::io::Read;
 use std::net::SocketAddr;
-use std::sync::{Arc, RwLock};
+use std::str::FromStr;
+use std::sync::Arc;
 use std::time::Duration;
 
-fn parse_args() -> Result<SocketAddr, Box<dyn std::error::Error>> {
-    let mut args = std::env::args();
-    args.next();
-    Ok(args
-        .next()
-        .ok_or(std::io::Error::other("no server address parameter must be specified"))?
-        .parse()?)
+struct Params {
+    addr: SocketAddr,
+    interval: Duration,
+}
+
+const CONFIG_FILE: &str = "thermometer_mock.cfg";
+
+fn read_parameters_from_file() -> Result<Params, std::io::Error> {
+    let mut file = std::fs::File::open(CONFIG_FILE)?;
+    let mut content = String::new();
+    file.read_to_string(&mut content)?;
+    let lines = content.split("\n").collect::<Vec<&str>>();
+    let addr = lines
+        .first()
+        .map(|v| SocketAddr::from_str(v))
+        .ok_or(std::io::Error::other("no address found in config file"))?
+        .map_err(std::io::Error::other)?;
+    let interval = lines
+        .get(1)
+        .map(|v| v.parse::<u64>())
+        .ok_or(std::io::Error::other("no interval found in config file"))?
+        .map(Duration::from_millis)
+        .map_err(std::io::Error::other)?;
+    Ok(Params { addr, interval })
 }
 
 fn generate_temperature() -> f32 {
     rand::rng().random_range(18.0..23.0)
 }
 
-struct RealThermometer {
-    temperature: f32,
-}
-
-const REQUEST: u8 = 0b01010101;
-
-async fn mutate_thermometer(thermometer: Arc<RwLock<RealThermometer>>) -> Result<(), std::io::Error> {
-    let mut interval = tokio::time::interval(Duration::from_secs(1));
-    loop {
-        interval.tick().await;
-        let new_temperature = generate_temperature();
-        thermometer.try_write().map_err(|_| std::io::Error::other("write lock failed"))?.temperature = new_temperature;
-        println!("new temperature: {:02.1}", new_temperature)
-    }
-}
-
-async fn handle_request(
-    request: u8,
-    thermometer: Arc<RwLock<RealThermometer>>,
-    socket: Arc<tokio::net::UdpSocket>,
-    addr: SocketAddr,
-) -> Result<(), std::io::Error> {
-    if request == REQUEST {
-        let data = thermometer
-            .try_read()
-            .map_err(|_| std::io::Error::other("write lock failed"))?
-            .temperature
-            .to_le_bytes();
-        socket.send_to(&data, &addr).await?;
-        println!("temperature was sent to {}", addr);
-    } else {
-        println!("invalid request: {:?}", request);
-    }
-    Ok(())
-}
-
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let real_thermometer = Arc::new(RwLock::new(RealThermometer {
-        temperature: generate_temperature(),
-    }));
+    let params = read_parameters_from_file()?;
     let rt = tokio::runtime::Builder::new_current_thread().enable_all().build()?;
     rt.block_on(async move {
-        let thermometer = real_thermometer.clone();
-        tokio::spawn(async move { mutate_thermometer(thermometer).await });
-
-        let socket = Arc::new(tokio::net::UdpSocket::bind(parse_args()?).await?);
-        let mut buf = [0u8; 4];
+        let socket = Arc::new(tokio::net::UdpSocket::bind(params.addr).await?);
+        let mut interval = tokio::time::interval(params.interval);
         loop {
-            let (_, addr) = socket.recv_from(&mut buf).await?;
-            let request = buf[0];
-            let thermometer = real_thermometer.clone();
-            let socket = socket.clone();
-            tokio::spawn(async move { handle_request(request, thermometer, socket, addr).await });
+            interval.tick().await;
+            let new_temperature = generate_temperature();
+            println!("new temperature: {:02.1}", new_temperature);
+            let data = new_temperature.to_le_bytes();
+            socket.send_to(&data, &params.addr).await?;
         }
     })
 }

smart-house/thermometer_mock.cfg

@@ -0,0 +1,2 @@
+127.0.0.1:10002
+500